Background
Frequency Hopping
Communications Security
(COMSEC)
Data Modes
Batteries
Scanning
Operation
Self Test
Adjustable Output Power
Leaving Turned On
Squelch
Fill & Joining Net
Displays
Versions & Configurations
Versions
Configurations
Components
RT-1439 Receiver Transmitter
Modules
System Conn
Antennas
Antenna
Connector
AS-3683()
Short MP Antenna
AS-3916
Low Profile (SLPA) Ant Vehicular
AS-4266
Long MP Ant
AS-3900
Vehicular Ant
AS-3916
OE-254
Dual Discone
Audio
H-250
Handset
HRCRD
Handset - Remote
2-Wire Adapter
LS-671
Speaker, Remote Handset & Master DC on-off
CX-13292
Speaker
Cable
Series
5200 Padlock
LS-688 Speaker
LS-454
Speaker (be itself)
LS-454 with Special Amplifier
Battery Boxes & Trays
CY-8523
Battery Box
CY-8523A
Battery Box
CY-8523B
Battery Box
CY-8523C
Battery Box
CY-8664
Battery Tray
PP-8249
Battery Charging Tray
Cables
External
Inside Radio
Carry Case
Mounts
MT-6352
Dual Radio PS/A Mount (A13)
MT-6353
RF Amp Mount
MT-6576
Single Radio PS/A Mount
Adapters
AM-7239()
Dual Radio Power Supply/Adapter
MX-10862
Single Radio Power Supply/Adapter Tray
RF Amp AM-7238
Remotes
HRCRD
(Handheld Remote Control Radio Device) Handset C-12493/U
C-11291
Control-Monitor (C-M)
C-11561
Remote Control Unit (RCU)
Fill Devices
MX-18290
MX-10579
CV-4228
SNAP
Manuals
What Goes Wrong
PS Magazine
Related Equipment
Links
Background
After Vietnam there were a
number of lessons learned regarding the
PRC-25,
PRC-77 (and their vehicular
versions) and the
VRC-12 Series
radios which led to the
Single
Channel
Ground
and
Airborne
Radio
System (SINCGARS)
concept for the next generation squad radio.
This web page is newer than the
SINCGARS
web page and eventually they will be different, but for now
there may be some duplication.
Comparison with PRC-77 (with battery box & battery)
|
PRC-77
|
RT-1439
|
H"
x W" x D"
|
4 x
11 x 11.25
|
3.5
x 9 x 14.75
|
weight
lbs
|
|
17
lbs*
|
* with battery, but without handset and antenna.
Frequency Hopping (FH)
A major new capability is the ability of the SINCGARS radios
to frequency hop covering the 30 to 87.975 MHz band in 2,320
channels. This is not done as a Transmission Encryption
security measure, like is provided by the
KY-57, but to prevent jamming and
direction finding. The PRC-25 & PRC-77 are
susceptible to
squelch capture
jamming since they are single frequency at a
radios. The 225 to 400 MHz aircraft band
radios now use Have Quick which is a similar frequency hopping
scheme for the same reason.
MIL-STD-200 - System Design and Engineering Standards For
Tactical Communications
MIL-STD-188-242
Interoperability & Performance Standards For Tactical
Single Channel Very High Frequency (Vhf) Radio Equipment
contains specific performance requirements for both
voice frequency and wideband (digital) channels.
In my opinion,
older DF sets that use a conventional receiver channel will
have trouble DFing a frequency hopping radio, but DF sets
that use what amounts to a spectrum analyzer can DF a
frequency hopping radio, and probably can de-interleave a
number of them, so the anti DF part of the reason for
frequency hopping is not too strong. Note that
SINCGARS uses about 100 hops per second, which is considered
a slow hop. It is not a direct sequence spread
spectrum system like is used by GPS.
Once a FH radio has been located by DFing then it's possible
to jam it. Not by knowing the hop sequence, but
by listening for each new transmission (like using a very
fast spectrum analyzer) and then jamming that transmission,
then the next, and so on. So the advantage of
Frequency Hopping against a sophisticated enemy has a short
life. The next generation radios will probably be
either fast hoppers or direct sequence spread spectrum
types.
GPS is designed so that all the satellites transmit in the
same frequency band and the receivers separate them by using
different pseudo random codes that are designed to all be
mutually orthogonal. Meaning that they have minimal
interference with each other (minimal cross
correlation). The SINCGARS radios don't have that
capability and so when a number of them are co-located there
are times when two nets will use the same frequency at the
same time causing a collision. This can become a
problem. Note that if the hopping bandwidth is
narrowed the anti jam resistance is lowered in direct
proportion to the bandwidth reduction, so that's not a good
thing to do. It's more probable that interleaved hop
sets are used.
Although it's theoretically possible to have an analog voice
signal on top of a slow hopping carrier it's not as good as
using a digitized voice (or data) signal on top of the slow
hopper. This way there can be some overlapping and
redundancy in the digital data, similar to what's done on a
music CD that can tolerate a small scratch. In the
SINCGARS it's called forward error correction.
The ECCM module works in two ways. One relates to
choosing which RF frequency is to be used and the other
related to converting from analog voice to digital and back
from digital to analog.
In order for frequency hopping to work each radio in a network
must be setup with the parameters that allow all of them to
work together. The channel hop set determines what
frequencies will be used and is selected in positions 1
through 13 of the
MX-18290 Fill
Device. The Transmission Security Key (TSK), T1, T2 or
T3 on the
MX-18290, provides the
key to be used by the pseudo random generator to determine in
what order the hop set will be used. There is also
a provision to have a list of excluded or protected
frequencies that will not be part of the hop set.
The Date and Time must also be set to within about a second in
order synchronize the hopping. This can be done using
the
PLGR GPS receiver or can be done
manually if the time is accurately know. In a practical
net the Net Control Station (NCS) sets the date + time in the
channel used by the net stations. Each of the 6 channels
can have a different "net time". The channel "ID" number
is an offset into the period of the hop set. So there
can be a number of different nets all using the same hop set
and TSK and set to the same date & time.
The various keys are loaded using the AUDIO/FILL connector and
can also be loaded over the air if a higher level Key
Encryption Key (KEK) has already been loaded into the radio.
Communications Security (COMSEC)
COMSEC is handled on the RT-1439 using the same
KY-57 that was used with the
PRC-77 and/or
VRC-12 Series radios. And
when the RT-1439 is used in the single channel mode it can
inter operate with a PRC-77 in either plain text or secure
modes. Later models of the SINCGARS radios have internal
COMSEC (KY-57) capability (ICOM). Note that the MX-18290
can not load the KY-57 key so a separate
Fill Device is needed for that or
the key can be loaded over the air.
Data Modes
Although the PRC-77 can handle 16 k bits per second digital
data it can not accept any of the common digital data
connections that a PC can use. The SINCGARS radios have
a
AUDIO/DATA connector that
directly supports a number of synchronous and asynchronous
data modes. These data modes can be audio tone based
like a fax or modem or can be digital signal levels like from
a teletype machine or a computer serial data port. The
System Improvement (SIP) and Advanced SIP (ASIP) radios
support RS-232 data and Internet Protocol (IP) data packets.
Batteries
Main
The PRC-25 and PRC-77 used the BA-4386 style battery (or my
257477BA Battery Adapter).
But as part of a U.S. military battery standardization program
the SINCGARS radios (and many many other military electronics
devices) use the
BA-5590 (or my
5590BA
Battery Adapter), or any of the rechargeable versions
(BB-390, BB-590, BB-2590, etc.). Note that the CY-8523()
Battery Box connects the battery as a "12 Volt" battery rather
than as a "24 Volt" battery. This means that a SINCGARS
radio can be powered from a civilian "12 Volt" motor vehicle,
but not when in a Mount that needs military vehicle "24 Volt"
power.
The RT-1523A and RT-1523D (EGTN version)
will
not properly work with the Li-Ion BA-2590/U
battery. It's 16.5 volts is too much for these radios.
Hold Up Battery (HUB)
The BA-5372/U (NSN
6135-01-214-6441) is installed on the bottom of the RT-1439
and the front of an RT-1523(nc/A/B/C/D). There are two
(-) screws holding the cover which has a white area where the
BATT INSTL date can be written. Note that inside the
cover there's a insulating washer. If the HUB is
installed correctly with the tit contacting the cover it will
work, but if installed upside down the flat part of the
battery will contact the insulating washer and so will NOT
make electrical contact.
The HUB maintains the CMOS memory and clock in the radio when
the main battery pack is removed or vehicle power is
lost. It also keeps the memory and clock alive when the
radio is switched to OFF. But when the FCTN switch is
set to Stow (STW) the HUB is turned off and all memory is
lost. This is good in that is does not run down the HUB
battery when it's not needed.
Unfortunately the labeling of the Function switch is backwards
between the RT-1439 and the RT-1523() radios. On both
radios when the FCTN switch is fully CCW (called OFF on the
RT-1439 and STBY on the RT-1523) the HUB battery is
maintaining the clock and all the channel fill data. On
both radios when the FCTN switch is turned full CW (called STW
on the RT-1439 and OFF on the RT-1523) the HUB battery is
disconnected saving the battery but erasing all the memory and
stopping the clock. So the instructions in the Aug. 1998
PS mag article on pg 48 apply only to the RT-1523 radios.
Note the HUB battery has a negative tit unlike most common
batteries. It's a 6 Volt battery so trying to
substitutive a 3 Volt BA-5123/U or some other battery just
will not work.
For the RT-1439 used in a vehicle mount it's a good idea to
add a label to the front panel with the HUB battery
install date. This avoids taking apart the system just
to see the date and rebuilding the system if a battery change
is not needed. The correct interval is every 6
months. Ref June 1998 PS mag pg 48. Mar '94 & PS mag
496 pg 36.
The RT-1523E can use Battery holder NSN 6130-01-462-4442 and
four common AA batteries for the HUB function.
Scanning
The RT-1439 has a channel scan
function. That's to say that it can be made to scan
each of the programmed SC channels. It can not do a
frequency scan like is done with scanner radios where
there's a start and stop frequency and a channel
spacing. For more on this and the half dozen or so
options see TM 11-5820-890-10-3 Chapter 4 Other Operating
Procedures, Section V Additional Operating Procedures,
Scanning. (page 4-24 in the no change version).
Operation
Once a Man Pack or Vehicle
system is configured and prepared the radio is ready for
operation.
Self Test (TST)
Preparation
Before running the self test the Antenna and Hand set should
be removed. (
PS
Mag
March
2001
issue
580
pg 46) either one may cause signals to be present that
the self test does not allow for. (Might cause a
FAIL 1)
The Data Rate knob should be set to OFF. (some positions
will cause a
FAIL
2). This happened when I first got the radio
and now after using it this no longer happens. Not
sure what's going on.
Normal
Whenever the Function (FCTN)
switch is put into the TST position the radio performs a
self test. This includes not only the internal systems
but also stimulates and reads test results on externally
connected equipment. If the test passes the display
will show
GOOd
otherwise one or more
FAIL # messages will appear.
Results
Fail
#
|
Meaning
|
1
|
Receive
Path Test
|
2
|
Data
Rate Adapter
|
3
|
ECCM
Module
|
4
|
Rem
& wire line
|
5
|
COMSEC
(not in CT)
|
6
|
System
conn (SNAP/FHMUX)
|
7
|
Routing
Module
|
8
|
Routing
Module
|
Diagnostic
If a FAIL-Number message
appears and the FCTN switch is moved to any other position
and any keyboard button is held down while turning the FCTN
switch back to TST a new self test is started, but now
instead of a FAIL-# message the message is a preamble number
some dashes and a detail number. For example the
Normal Self Test shows FAIL 2 and the Diagnostic test shows 2--01.
TM 11-5820-890-30-5 Chapter 2 has some information on how to
interpret the self test results, but seems to be missing the
diagnostic 2--nn
and higher number messages. If you have that manual
please let me know. In general all the 890 series
manuals are very poor regarding explaining what the FAIL # messages
mean, especially ones where the operator could correct the
failure.
Adjustable Output Power
Using the front panel RF
switch allows adjusting the Man Pack RF output power to LO,
M or HI (the PA switch position only works when an external
RF Power Amplifier is connected). Using the 1 meter
whip antenna on the radio and an outdoor
OE-254 feeding the
HP 4395A Spectrum Analyzer input
the output signal (dBm) was measured.
Freq
MHz
|
LO
0.5 mw
|
M
160 mw
|
HI
4W
|
30
|
-65
|
-39
|
-26
|
40
|
-69
|
-45
|
-32
|
51
|
-58
|
-32 |
-21
|
60
|
-74
|
-47
|
-34
|
70
|
-67
|
-43
|
-32
|
80
|
-62
|
-36
|
-23
|
There appears to be about a 20
dB change between LO and M and a 10 dB change between M and
HI, an overall change of 1,000 times in power. This is
the same amount of change that occurs between using a 1
meter whip and a rubber duck antenna on a
PRC-68 series radio.
The signal is not a single carrier when no audio input is
fed to the mike since the radio is sending a 150 Hz
tone. Deviation is about 7.5 kHz without any audio
input. The channel frequency is right on at 51 MHz.
The current draw for the "HI" power position is more than 3
Amps (it trips the over current limit on the BK Precision
1786 P.S.).
Leaving Turned On
The LED SIG and frequency
displays turn off after a short time to conserve battery
power, but then the radio is dark and it's easy to leave it
turned on thus draining the battery. It might be
better if one of the LEDs were to flash every so often to
remind you that the radio is powered and that the main
battery is OK. The LED to flash is the battery gauge
reading on the SIG display.
When Powered from a Vehicular mount the display time out is
disabled and the display stays lit. Brightness can be
controlled by the DIM knob.
Squelch
The RT-1439 requires a 150 Hz
tone with about 7.5 kHz deviation to open the squelch
Fill & Joining a
FH Net

No Fills are needed for Single Channel
operation. In order to Frequency Hop there are different
amounts of fill required depending on the circumstances.
The simplest case is that you are a member of a net (and not
the Net Control Station). Then all that's required is to
load the CUE and MAN single channel frequencies as well as the
net's Transmission Security Key and request an Electronic
Remote Fill (ERF) from the NCS. The NCS can load the hop
set (with lockout set if needed) and the correct net time
remotely. These can then be stored into one of the
channels (typically chan 1 for your local net). This is
the same procedure that's used for a normal net opening.
If your radio already has the TSK and hopset for the net
and the clock for the net channel is reasonably accurate, then
you can do a late net entry by setting the radio just like
when it's part of the net and pressing "3-L.E." (Late
Entry). This causes your radio to search in time to
exactly match the net time and when in sync the frequency
display will change from
LFnnn (Late Frequency hop set nnn) to
just
Fnnn
(Frequency hop set nnn) and if there's net traffic you will
hear it. This will not work if your radio's clock is too
far off or if the net ID number or any of the fills is not
correct.
Fills
Prior to filling load the MAN and CUE single channel
frequencies.
Fill TSK
FCTN = LD-V Load the
Transmission Security Key Variable
Mode = FH
Connect fill device, select T1 or T2, power on
Connect Fill cable, note display shows FILLE
Press "0 H*Ld", note display shows LOAD
If there's a problem the display shows bad, or if the
fill was OK the display shows GOOd
Fill Hop Set or Lockout Set
FCTN = LD Load either a Hop
Set or Lockout Set
Mode = FH
Connect fill device, select 1 through 13, power on
Connect Fill cable, note display shows FILLE
Press "0 H*Ld", note display shows LOAD
If there's a problem the display shows bad, or if the
fill was OK the display shows GOOd
Time & Date
Manual Set Time & Date Set
FCTN = LD
Press "TIME" and enter the Julian day number (1 to 99) based
on the table in the back of the manual (note there are two
tables, one for normal years and another for leap years),
press "Sto Ent", enter the 2 hours digits, press "Sto
Ent", (This last press sets the seconds to 00).
1 Jan is always 01, 28 Feb is always 59, Feb 29 is 60, 1
March is 60 in a regular year and is 61 in a leap year, and
all the rest of the days follow. 27 Oct in a
regular year is day 00, and in a leap day 00 is Oct 26.
PLGR AN/PSN-11 GPS
Time & Date Set
TM 11-5820-890-10-7 which includes the PRC-119A (RT-1523)
has a Task 3 "Load PLGR Data and Zulu Time into SINCGARS
RT". There's no mention that the RT-1439 does not
support this fill, but when I try, it does not work.
(error in PLGR says radio not responding).
FM 11-1 says PLGR only works with RT-1523A and higher letter
radios and the ARC-201A.
MX-10579 can only load FH
data into the RT-1439 and the ARC-201 (not any of the
RT-1523 series radios and not the ARC-201A).
TM 11-5820-890-10-3 which applies to the PRC-119(no letter),
i.e. to the RT-1439, describes how the NCS is to either
manually set the time and date or use Electronic Remote Fill
from another network, no mention of using a PLGR.
This procedure worked on the RT-1523C to load date and time
from PLGR:
Set the radio to SC and set to CT.
Select SINCGARS under the MENU key of the PLGR, select ACTIVATE on the PLGR,
then LOAD on the RADIO.
LOAD displays on the radio, and PLGR displays SUCCESSFUL TIME FILL.
Sure enough had the correct julian day on the radio and UTC time.
Displays
The 5 digit LED display is of
the 7-segment type which can display the digits 0 - 9 as
well as some stick type letters.
Frequency
As the CHAN switch is moved from MAN through 1 - 6 to CUE in
SC mode (FCTN any pos) if there are no frequencies
loaded the display will show: 30000 (default
MAN freq), FILL 1
through FILL 6
and FILL 7.
But if the HRCRD is used to scan those same channels the
display will show FILLE
on all but the CUE channel which shows FILL 7.
Below the display between the second and third digit from
the left is printed a decimal point that separates the MHz
part of a single channel frequency from the lessor
digits. The smallest frequency step is 5 kHz, so you
can load 30.125, but not 30.123. The SINCGARS are much
more restricted than the PRC-126 in that the offset between
Tx and Rx frequencies is limited to +/- 5 or 10 kHz in the
SINCGARS but the PRC-126 has no restrictions. This
limits the flexibility of how the radio is used, for example
with the PRC-126 you could program the Tx frequency to be
the input to a repeater and the Rx frequency to the the
repeater output.
TSK
If the Transmission Security Key has been loaded but neither
a hop set nor a lockout set has been loaded the display will
show cold.
Hop Set
As the CHAN switch is moved from MAN through 1-6 to CUE in
FH mode (FCTN any pos) if there are no hop sets loaded
the display will show: FILLE on all channels. If there's
a Hop Set loaded the display will show Fnnn (Hop
Frequency net ID number nnn). If the Lockout set has
been loaded but the hop set has not yet been loaded the
display will show HLncc.
With a Hop Set loaded the display will show Fncc where the
first letter is always F the second letter is the hop set ID
and the cc is the net ID between 0 and 99. The set
starting time can be changed by the NCS when in FH-M mode.
Just after a hop set is loaded the display shows HFncc if the
set was a Hop Set or HLncc if it was a Lockout set.
Z-A
A few seconds after switching to Zero-All the display shows
good.
Meaning that all memories have been erased. Note you
need to go through this switch position to get to STW on the
RT-1439 (OFF on the RT-1523x) where power including backup
battery is disconnected.
CUE
Cue allows a radio that is not
part of a FH net to get the attention of the NCS when the
net is idle even through the NCS is in a FH net. This
probably works like a police scanner priority channel, i.e.
the radio checks the Cue frequency when in FH or FH-M mode
and when the channel is idle.
The NCS (and alternate NCS) would hear any SC radio sending
on the Cue frequency. Another feature of Cue is that
if the channel is changed to Cue, then to MAN and back to
the net channel, it can passively rejoin the net probably
without the wait associated with a passive net entry.
I think that only one station in a net may be set in FH-M
mode. This is because the Master station is sending
the net time to keep all the net stations in time
sync. If two stations tried to do this the times would
not match and there would be a problem. The alternate
NCS would switch into FH-M mode if something happened to the
NCS. If this is the case then all the stations in a
net (with that Cue frequency set into their radios) would be
aware that a Cue call was in progress, but typically only
the alternate NCS would switch to the Cue channel and talk
to the calling station, which might be a VRC-12 Series or
PRC-77 radio.
The instructions for how to make a CUE call are very
consistent in that the calling station needs to turn off
voice encryption. and just press PTT (no voice call is being
made). Since the calling station does not know when
the net is idle the process may need to be repeated several
times until an idle time is used for the call. The
SINCGARS radio probably detects that there's a carrier on
the CUE frequency and alerts the radio operator.
Note that although a SINCGARS radio can store 6 separate
channels (6 nets) there is only one CUE frequency CHAN
position and so the CUE frequency needs to be manually
programmed for each of the 6 channels as does the MAN
frequency.
Versions & Configurations
Radio & System Versions
TM 11-5820-890-20P-1 Figure 1
(23 pages) has drawings of the components of each of the PRC
and VRC configurations including the RT-1439, RT-1523A and
RT-1523D radios and the correct letter versions of the
related equipment. The 20P-2 manual covers the
RT-1523E.
There are a number of letter
suffixes to the nomenclature like PRC-119/A/B/C/D/E where
the system letter is the same as the RT suffix letter.
The Power Supply/Adapter (aka VAA) also changes to be
compatible with the radio.
The early SINCGARS radios were developed by
ITT
Aerospace/Communications Division (31550) around 1988
and second sourced to
General
Dynamics Land Systems (0HGX3).
The radio version progression has been:
RT-1439
- Non ICOM made by ITT (31550) needs external KY-57
- FM operation in the VHF band (30 to 87.975 MHz)
- 25 kHz channel spacing for 2,320 operating
frequencies
- Interoperable with VRC-12 series and NATO
requirements
- Single Channel (SC) or Frequency Hopping (FH) mode
- 6 preset channels for FH and 8 for SC (SC can use
the MAN and CUE channels)
- Scan of single channel presets
- Offset tuning of single channel frequencies (+ 5, +
10 kHz)
- Single channel access to hopping nets (CUE’ing)
- 3 RF power settings (500uW, 160mW, 4W)
- Provides control for external 50W RF power amplifier
(AM-7238)
- Built-In-Test (BIT)
- ECCM Remote Fill (ERF) of
hopping information
- Data Rates: 75, 150, 300, 600, 1200, 2400, 4800,
16000 bps, AD1, AD2 (TACFIRE)
- Majority Logic Forward Error Correction
- Mode 1 Fill
- Volume control/Whisper mode select
- Retransmit (with second SINCGARS radio) (a single
ASIP radio can act as a packet repeater)
- Remote Control capable (via the Securable Remote
Control Unit (SRCU)) (most manuals call this RCU)
- Nuclear survivable (EMP not blast)
- 7 different configurations from Manpack (PRC-119) to
Vehicular Dual Long Range (VRC-92)
- Size: 9.3"w x 3.3"h x 14.6"d (includes battery)
- Weight: 18.3 lbs (includes battery)
TM 11-5820-890-20P-1 Figure 203, 204
RT-1523 - Internal
ICOM ( KY-57 built in) increased the run time from 16 to 25
hours per battery. probably made by ITT
TM 11-5820-890-10-8 Fig 2-2
RT-1523 Features
TM 11-5820-890-30-4 Chapter 2
RT-1523(C)/U
NSN 5820 01 2348 093
RT-1523A- Internal
ICOM ( KY-57 built in) increased the run time from 16 to 25
hours per battery. TM 11-5820-890-20P-1 Figure 203, 204
made by GD Land Systems
(0HGX3)
TM 11-5820-890-10-8 Fig 2-3
RT-1523A Features
RT-1523A(C)/U
NSN 5820 01 3187 990
RT-1523B TM
11-5820-890-20P-1 Figure 166 Not much mention in the TMs, so
maybe made by GDLS
TM 11-5820-890-10-8 Fig 2-4 RT-1523B Features
RT-1523B(C)/U
NSN 5820 01 3652 725
RT-1523C/D - Special
Improvement Program (SIP) adds more data modes including
RS-232 and IP packets to support easy computer interfacing
for the Tactical Internet. Also an interface to an
external GPS receiver to allow automatic position reporting.
This requires an additional connector on the Vehicle Power
Supply/Adapters. see FM 6-02.72 Tactical Radios
1523C = TM 11-5820-890-20P-1 Figure 166 probably made by
GDLS
TM 11-5820-890-10-8 Fig 2-5 RT-1523C Features
RT-1523C(C)U NSN
5820 01 3636 929
1523D = TM 11-5820-890-20P-1 Figure 205 internal
layout very similar to the RT-1439 so probably made by ITT.
TM 11-5820-890-10-8 Fig 2-6 RT-1523D Features
RT-1523D(C)U NSN 5820
01 4108 981
RT-1523E - half size
Advanced Special Improvement Program (ASIP) also a single
radio can act as a packet repeater (sort of a digital
version of a
simplex repeater).
Uses DSP technology that can be upgraded. The tactical
communication system (TCS) handset replaces the HRCRD that
displays the operators Lon-Lat and the received stations
Lon-Lat. The radio really is a dual channel radio with
both voice and digital coms at the same time. Really a
new radio. The GPS key controls how the radio transmits GPS
data. GPS is set to OFF, voice only (AUTO), periodic (PER),
or movement (MOV), and can only be modified in CT. Periodic
and movement modes automatically generate short
GPS-data-only transmissions.
RT-1523E and Radio sets that use it = TM
11-5820-890-20P-2 all ASIP made by ITT.
RT-1523E(C)/U NSN 5820 01 4441 219
RT-1523F
Improved version of the E
RT-1523F(C)/U
NSN 5820 0 15353 667
ITT vs GDLS
I've heard that although the ITT and GDLS radios are
functionally equivalent the internal construction is
completely different and non interchangeable. This
means that extra care is needed to correlate the exact model
number with the manual when trying to understand the inner
workings of a radio. Module layouts. The 1439
and 1523 have the modules both left to right and front to
back(LRFB). The 1523A and 1523D have the modules all
lined up like books front to back(Book).
It maybe like this:
ITT: 1439-LRFB, 1523-LRFB, 1523D-Book, 1523E-half size
new radio
GDLS: 1523A-Book, 1523B-Book, 1523C-Book
7 June 2005 - ITT says they made all versions except for the
1523D. Have not yet heard back from GDLS.
PRC-119 Man Pack
- PRC-119 uses RT-1439
- PRC-119A uses RT-1523
- PRC-119D uses RT-1523D
Wheeled
The plain version uses the
RT-1439, A version uses RT-1523 and D version uses RT-1523D.
VRC-87 Short Range
VRC-88 Short Range optional man pack
VRC-89 Long Range - Short Range
VRC-90 Long Range
VRC-91 Long Range - Short Range optional man pack
VRC-92 Long Range - Long Range

The stack of equipment for SINCGARS is very similar to that
for a
VRC-64 (
PRC-77 in a vehicle).
In comparison photo you can see that the VRC-87 is about as
wide as a PRC-77. The SINCGARS radios are narrower,
shorter and heavier than the PRC-77(VRC-64).
VRC-64
|
SINCGARS
|
SINCGARS |
SINCGARS |
Function
|
PRC-77 |
RT-1439
or
RT-1523()
|
RT-1439
or
RT-1523() |
-
|
Receiver Transmitter
Low Power
|
AM-2060
|
MX-10862
PS/Adapt
|
AM-7239()
PS/Audio Amp
|
AM-7238()
RF Amp |
DC power conditioning
|
MT-1029
|
MT-6576 |
MT-6352 |
MT-6353
|
DC power cabling
& /or
VIC/TSEC interface
|
Steel
mounting
shelf |
Steel
mounting
shelf
NSN 5340-01-215-1044
for HMMWV
|
Steel
mounting
shelf
NSN
5975-01-413-1547
for M998
|
Steel
mounting
shelf |
Mechanical attachment
to vehicle sheet metal
|
Tracked
Tracked vehicles can cause the
DC supply to drop when the hydraulic pump is pulling down
the engine RPM. To counteract this the
MX-10862 routs either
vehicle DC or BA-5590 DC to the radio.
SR = Short Range
LR = Long Range
-D = Dismount kit for man pack (the -D is different from the
D suffix that indicates which radio is used)
Item
|
PRC-119
MP
|
VRC-87
SR
|
VRC-88
SR-D
|
VRC-89
LR-SR
|
VRC-90
LR
|
VRC-91
LR/SR-D
|
VRC-92
LR-LR
|
RT-1439
Radio
|
1
|
1
|
1
|
2
|
1
|
1
|
2
|
CY-8523()
Battery Box
|
1
|
|
1
|
|
|
1
|
|
Carry
Case
|
1
|
|
1
|
|
|
1
|
|
AS-3683()
Antenna
|
1
|
|
1
|
|
|
1
|
|
H-250
Handset
|
1
|
|
1
|
|
|
1
|
|
AM-7239()
Dual Radio
PS/A
|
|
1
|
1
|
1
|
1
|
1
|
2
|
W-4
Audio/Data/Fill
Cable
|
|
1
|
1
|
2
|
1
|
2
|
2
|
MX-10862
Single Radio
PS-Adpt
|
|
opt
|
opt
|
|
opt
|
|
|
CX-13314
Cable
|
|
|
|
|
|
|
|
AM-7238()
RF Amp
|
|
|
|
1
|
1
|
1
|
|
W-2
RF Cable
|
|
|
|
|
1
|
1
|
|
CX-13291
Cable
|
|
|
|
|
|
|
1
|
CG-3856
Cable
|
|
|
|
|
|
|
1
|
CX-13303
Cable
|
|
|
|
|
|
|
1
|
MT-6353
RF Amp Mount
|
|
|
|
|
|
|
|
Components
RT-1439 Receiver Transmitter (A1)
Modules
No.
|
Description
|
p/n
|
#
pins
|
Ltr
Num
|
#
coax
|
1
|
Antenna
Tuner
BPF
|
|
17
|
L
|
1
Bot
1 side
|
2
|
Remote
I/O
|
|
41
|
L
|
0
|
3
|
Main
Power Supply
|
|
14
|
L
|
0
|
4
|
Control
|
|
61
|
N
|
0
|
5
|
ECCM
|
|
33
|
L
|
0
|
6
|
2-wire
Interface
|
|
33
|
L
|
0
|
7
|
Switch
|
|
77
|
N
|
0
|
8
|
IF
Demodulator
|
|
17
|
L
|
1
|
9
|
Rx
Tuner Mixer
|
|
9
|
L
|
3
|
10
|
Synthesizer
|
|
17
|
L
|
2
|
11
|
Tx
Excit & P.A. Rx LPF
|
|
25
|
L
|
3
|
12
|
Audio
P.S.
|
|
77
|
N
|
0
|
13
|
Audio
Control
|
|
77
|
N
|
0
|
14
|
Audio
I/O
|
|
41
|
L
|
0
|
15
|
Data
Rate Adapter
|
|
33
|
L
|
0
|
System Connector
Pin
|
DC
Func
|
Audio
Func
|
PA Ctrl
Func
|
SNAP
- FHMUX
Func
|
A
|
|
|
|
Test
|
B
|
?
|
|
|
|
C
|
|
|
|
Serial Data
|
D
|
|
Fixed Level
|
|
|
E
|
|
Tx voice
|
|
|
F
|
Batt
+15
|
|
|
|
G
|
|
|
|
Tune Clock |
H
|
|
|
Hi Power (amp on)
|
|
J
|
|
|
Pwr Level
|
|
K
|
|
PT/CT select
|
|
|
L
|
|
|
Filter B (43 - 61.5)
|
|
M
|
|
|
Filter A (30 - 43)
|
|
N
|
|
|
|
Tx/Rx
|
P
|
|
|
|
Disable
|
Q
|
|
|
|
FH
|
R
|
|
|
|
Fault 6 1 |
S
|
|
PTT
|
|
|
T
|
|
|
|
/Tune Gate
|
U
|
BA-x90/BB-x90
Batt used by Tray
|
|
|
|
V
|
|
|
Filter C (61.5 -88)
|
|
W
|
?
|
|
|
|
X
|
|
|
sidetone disable
|
|
Y
|
|
wire line rem
|
|
|
Z
|
Gnd
(Batt)
|
|
|
|
a
|
|
wire line rem
|
|
|
b
|
?
|
|
|
|
c
|
?
|
|
|
|
d
|
Batt/Adapter
sense
|
|
|
|
Note
1 Fail 6 is an
input for other equipment to report their self test failure
during an RT self test.
TM 11-5820-890-20P-1 Figure 57
Alignment plate NSN 5935-01-316-8720 helps the KY-57 cable
connect to the RT-1439. Ref Sep 1995 PS mag 514
pg 47.
Antennas
SINCGARS Antenna Connector

The antenna connector is a BNC Jack (female) with a
surrounding shroud that has external threads. A BNC
nut is about 0.570" diameter and the I.D. of the shroud is a
little larger. The shroud OD is about 0.8" and 20
TPI. This may be the same antenna connector used on
the PRC-117 and PRC-138?
Do not use a knife to clean twigs out of a vehicle antenna
spring since doing so may cut the coax cable inside the
spring. Ref Mar 94 PS mag 496 pg 36.
On the early model RT-1439 that had the solid front panel
protectors or the ones with a small hole it was almost
impossible to connect a straight BNC cable. The fix is
to use a right angle BNC connector (UG-306B/U NSN
5935-01-032-5404) Ref: July 93 PS mag 488 pg 44.
AS-3683() Short MP Antenna

31" for
the tape whip part that has a male 5/16-24 thread like most
military antennas.
The 11 3/4" long flex base
(A3140084-2) accepts the threaded tape whip antenna and
has a combined 1&3/16"-20 female thread and a BNC-m
connector. But instead of using a BNC nut the flex
base has two slots for the lugs on the radio BNC-f
jack. This BNC connector also has an extra long male
pin (or you can say that the dielectric is recessed more
than a normal BNC connector. This is so that when
the flex base is installed it will NOT press on the radio
BNC dielectric (switch).

The SINCGARS radios have an
antenna switch that's similar to the one on the
PRC-25 and
PRC-77
radios. But instead of using panel space for both a
whip antenna and for a BNC connector for a 50 Ohm antenna
the SINCGARS radios combine these into one connector.
When the A3140084-2 is installed the switch is NOT
activated and when a standard BNC-m connector is installed
the switch activates and the radio switches into 50 Ohm
mode.
A3140084-2 shown at left.
TM 11-5820-890-20P-1 Figure 2
The A3140084-1 that was made by Unicor had a breakage
problem. It has a visible spring at the base end.
AS-3916 Low Profile (SLPA) Ant
Vehicular
AS-4266 Long MP Ant
TM 11-5820-890-20P-1 Figure
104A
Connects to radio using the 50 Ohm mode and has it's own
matching circuit.
Replace the stock attaching sleeve with NSN
5935-01-468-5485 which is smaller in diameter allowing
easier attachment. Use Loctite on the mounting
screws. (Ref: PS mag Mar. 2001 580 pg 47). TM 11-5820-914-40P
AS-3900 Vehicular Ant
This antenna needs to
present the radio a reasonable match while the radio is in
frequency hopping mode. The
AS-1729
(part of
VRC-12 Series
vehicle radios) that used mechanical switches to adjust
the match is way too slow for a frequency hopping radio
and so this antenna uses a matching circuit that also has
loss. TM 11-5820-890-20P-1 Figure 107
Built in protection up to 20,000 Volts A.C.
Lock washers needed both above and below each attachment
bolt and on the ground strap for good electrical
grounding. Ref Oct '96 PS mag pg 38.
Tip Cap NSN 5820-00-437-2352 will stay on without
tape. Ref 1999 PS mag 564 pg 61
Do NOT paint the AS-3900 plastic antenna base. The
paint will breakdown the plastic. Ref Feb '96 PS mag
pg 35.
AS-3916
TM 11-5820-890-20P-1 Figure
108A
The collet (NSN 3460-01-435-8079) that holds the top
antenna section is too long. File 1/16" off the
bottom to fix it. (Ref: PS mag Sep 2002 598 pg 42).
Nut for connecting the antenna to the base NSN
1560-01-435-8079. Ref Jul '97 PS mag pg 61
This antenna is
inherently a broad band type without using lossy matching
networks. Note that the
RC-292
will not work for SINCGARS FH mode, but is OK for SC mode
if the RC-292 has the correct element lengths.
Audio
In vehicle installations
connecting to the LS-671 is closer to the driver than the
power supply/adapter so the cord will not be pulled as
much. Ref Aug '97 PS mag pg 36. & May '94 498 pg
48.
Stepping out of a HMMWV and pulling the H-250 handset cord
can break connections. A safety measure is to cut a
3 foot length of nylon cord and tie one end to the LS-671
and tie the other end around the handset just above the
mike. This will limit the cord extension to a safe
amount. Also a closeline made from the same cord and
tied to the front canvas bow and hang the H-250 up and out
of the way of damage. Ref July 995 PS mag 512 pg 44.
Another way to keep the H-250 handset up and out of harms
way is to use Velcro to attach it the Mount. Ref Mar
'95 PS mag 508 pg 42.
The problem is the clip designed for the H-250 puts it in
the way of belt worn equipment (m-17, M-40) when the
driver sits down.
HRCRD (Handheld Remote Control
Radio Device) Handset C-12493/U
The main purpose is to allow the radio in a man pack
configuration to be controlled by the operator without
removing the pack to get access to the front panel.
Can also be used with vehicle configurations for more
convenient access to the most frequently used controls.

After setting front panel FCTN switch
to REM allows control of:
Channel: C, M, 1, 2, 3,
4, 5, 6
RF Power: L, M, H, PA
Mode: SC, FH, FHM
COMSEC: PT, CT
Volume: analog
Back light on/off
Note that unlike the
C-11291 that can turn the RT off, the
HRCRD can NOT turn the radio off.
Uses the 6-wire protocol with 2880 Hz FSK data and straight
through audio.
This will work with the RT-1439 since it's related to the
revision of the battery box and the only connection is the
wire line remote control, the HRCRD uses the same
audio signaling system as the CTRL-MON.
Manpack: connect cables to RT-AUDIO and CY-8523C
Vehicle: connect one cable to RT-AUDIO and for
RT-1523E use AUX or with
AM-7239
use J9 CTRL-MON.
This also means that a PC could do this function with
software/hardware that emulated the tone functions.
There is no separate label, but molded into the plastic
near where the cable leaves the handset is:
handheld Remote Control
C-12493/U
DAAB07-96-C-C008
NSN 5895-01-432-8370
and overstanped in white paint: 9806-C
The 6 pin AUDIO connector is marked: PCI-2298, OCS66
The 6 pin Radio Remote connector is marked PCI-106PM
Since the HRCRD can be used on J9 (CTRL-MON) then the
signals are the same as for the
C-11291 small Control
Monitor. From TM 11-5820-890-30-4 Chapter 6:
"A 2880-Hz FSK carrier is
used with ones and zeros at 2560 and 3200 Hz. Normal
output level is 600 mV p-p." This is most likely
also the wire line control signaling method.
The HRCRD can be connected
to either the
MX-10862-J3
(Cont Mon) or to the
AM-7239()-J9
(Cont Mon) or a CY-8523C. This means the the HRCRD
can run from either "12 Volts" from the battery box or
from "24 Volts" from the Amplifier/Power Supply.
I received an email that also had the Assembly number
A3249865-1 for the HRCRD.
Manuals
TM 11-5820-890-10-6 ANCD,
PLGR & HRCRD
Section V PLGR
Section VI HRCRD
TM 11-5820-890-20-2 Unit Maint Man
Chapter 10 HRCRD
TM 11-5820-890-10-7 Pocket Guide to SINCGARS ICOM ground
radios
Section 8 HRCRD
TM 11-5820-890-20P-1 Figure 3
LS-671 Loudspeaker (A15)

This is an amplified speaker
that interfaces using the standard VIC-1 cable (
CX-13292).
The LS-671 can be connected to a handset (or microphone)
and used for receive and transmit operations. It can
turn the main DC power to the Mount & RT on and
off. It can be located up to 100 feet from the RT
providing a limited remote control capability. Note
that if the LS-671 is left on and the Mount is turned off
the LS-671 stays on and drains the vehicle battery.
Best to leave the Mount turned on and just switch the
speaker. (Ref: PS Mag April '04 Vol 616 pg 43)
Also be sure to fully unscrew the
CX-13292 cable wing-nut
BEFORE trying to remove the connector. Otherwise the
struggle to get it off probably will break something
inside the speaker. (Ref: PS mag 2003 621-44)
Also do NOT twist the connector assembly for the same
reason (PS mag Sep 2002 598 pg 43).
The Volume control on the LS-671 can be used to control
the connected handset when in the normal position and when
pulled out controls the speaker volume. Don't forget
to pull it out. Ref Jan '97 PS mag pg 50.
J1 on the LS-671 is the standard
VIC-1
18 terminal type connector and mates with the
CX-13292 "VIC"
cables. You should be able to use the LS-671 in any
system that has the VIC-1 connector, like the
VRC-12 series radios that use
the
MT-1029 mount which has
the connector.

When the LS-671 is connected using a
VRC-12 series radio (VIC-1)
CX-4723
cable to the
MT-6576 it works as a
speaker and audio feed to a handset connected to it, but
does
not
allow keying the transmitter.
The reason is that the proper
CX-13292 cable is not
symmetrical and has the PTT line on different pin for the
speaker end and the mount end, unlike the
CX-4723 that is a
symmetrical (1:1) cable. See TM 11-5820-890-20-01
Chapter 4 Cables, p4.2
CX-13292
Speaker Cable schematic.
There may be a need for the CX-13314 cable (
MX-10862-J1(TEST) and
the RT AUDIO/DATA connector with only 1 wire for PTT.
The combined LS-671 +
CX-13292
may work with VRC-12 series mounts.
The On-Off switch on the LS-671 turns the speaker on or
off, but not the mount. This is because the
screwdriver switch that's between the radio and the mount
was set to LOCAL, changing it to REM allows the LS-671 to
control mount power, which is the recommended way to use
the LS-671 so that both the speaker and mount are turned
off (so as to not drain the vehicles battery when the
radio is not in use).

On the front of the LS-671 is a clip
for holding the H-250 handset.
On the back is a mounting bracket that allows the LS-671
to be removed by loosening the two large knurled
screws. Why is this done? ans: the LS-166,
LS-454 have wing nuts that allow you to remove them so
that they can be used away from a vehicle, like in a tent.
The LS-671 can be connected to the Mount J3 or J4.
Manuals:
TB 11-5820-890-10-14 LS-671
TM 11-5820-890-30-4 Ch 16, FO-30 schematic
TM 11-5820-890-20P-1 Figure 119
LS671 block wiring diagram.pdf
Submitted by
rusty56@attglobal.net
Series 5200 padlock
In order to use the LS-671
you need the
CX-13292
cable. I finally got one from eBay and it came
with an American Lock
Series
5200 padlock attached and

a bracket marked:
80063-A3256667-2
MFR-31550

My local locksmith will
rekey the padlock for about $8 (he says it will take 10
minutes and the lock is worth about $20.
This series of locks can have the 5 pin tumbler
cylinder
replaced for rekeying.
One locksmith in town could not rekey the padlock
because I did not have a key. Note that when the
hasp is open you can see a philips head screw down in
one of the holes, which when unscrewed frees up the
tumbler. The other locksmith in town had no
problem grinding off the rivet and taking the lock
apart, but when it came time to pick (using a shim) the
tumbler in order to fit a key, he was delayed for some
time since each pin has grooves that making using a shim
very difficult. But in the end I now have the same
lock and a coupe of keys.
The keys have a 5 digit number (one for each pin) that
would allow duplicate keys to be ordered. Note
that these numbers can be punched out of the key.
If left in the key and someone gets them then the key is
comprised.
In the Series 5200 padlock photo you can see that at the
back of each key there's a "fish hook". This holds
onto the key when the lock is open. The only way
you can remove the key is after it's locked.
Lock installed between left bracket that's part of the
MT-6576 and the left front panel
grab handle on the RT-1439 trapping the
MX-10862.
CX-13292 Speaker Cable

The military vehicle connector has a metal part added
that puts a bend into the cable. Note that the
CX-13292 cable has
two different ends, one for the speaker and one for the
radio and will not work if installed reversed.

There are labels on the cable, but on the very used
cable I got the sun has bleached out the labels so that
they are very hard to read. But I notice that on
the connector body of the SPEAKER metal connector there
is a number 2 just above the nut and on the RADIO end
there is a number 1.
LS-688/VRC, NSN
5965-01-382-3222 Manpack Speaker
This is the speaker that hooks up to the MCS in
the VIS-3 intercom system. 6" Loudspeaker cable,
NSN 5995-01-393-7694 (the connections on the cable are
just like a handset, they connect right to the radio, no
modifications needed)
LS-454
The LS-454 can be connected
to Adapter AM-7329-J6.
see: TB 11-5820-890-10-14 Fig 1
LS-454 Audio
Amplifier

It's
an
audio
amplifier
intended
for
use with SINCGARS radios, but there's some strange things
about it.
The label says:
Amplifier, Audio - LS-454/U, MFR 31550 (that's ITT),
8143815-1
with the ports labeled:
To
MX-10862/VRC
LS-454 Speaker
P1 To Receiver-Transmitter
but there's no nomenclature and no NSN.
The 5 sheet manual that came with it is marked TB
11-5820-890-20-82 and is titled:
Installation and Unit Maintenance Instructions for
Amplifier, Audio - LS-454/U to Permit Operation of
Loudspeaker LS-454/U with Receiver-Transmitter, Radio
RT-1439/VRC and Power Supply Adapter, Vehicular
MX-10862/VRC
but there is already a manual with that TB number and it's
titled:
Installation Instructions for Installation Kit Electronic
Equipment MK-2616 /VRC to Permit Installation of Radio Sets
AN/VRC-87/88/90 Series in a M915A2 Truck, Tractor (NSN
5895-01-361-7606) (EIC: N/A).
To use this amplifier a DC power cable
CX-13290
is used between the amplifier and J3 on the back of the
MX-10862. J3 is the
connector used for either the
HRCRD
handset and/or the
C-11291
Control-Monitor. But in this case the cable is only
being used for 24 volt DC power and the 6-wire remote
signals are not being used. The Amplifier has an
attached coiled audio cable that needs to be connected to
one of the AUDIO connectors on the front of the radio.
The cable attached to the LS-454 is attached to a connector
on the amplifier.
This may be a simpler way to get a loudspeaker then using
the normal LS-671 but you don't get neither the remote power
on-off capability not the remote handset capability with
this amplifier. It probably was priced much below the
LS-671.
"
The
LS-454 amp was designed to accommodate the LS-454
speaker for use with the single radio mount (MX-10862/VRC) until the LS-671 was
fielded. The mount was available before the
speaker and needed this special amplifier to have a
speaker capability."
M.C. design engineer. 8 May 2008 email
Battery Boxes & Trays
CY-8523()
Battery Box
When the PRC-25 radio was
designed the only thought was to keep water out. Then
there were problems with hydrogen gas buildup that resulted
in the box being propelled at the operator when the latches
were released and also maybe some explosions. This
resulted in a MWO to retrofit a vent on the battery box to
let the hydrogen out.
The battery box on the KY-57 and HYX-57 are designed very
similar to the PRC-25 battery box with the vent although
they hold the BA-559/U.
But the CY-8523() battery box was designed to withstand the
explosion of a single "D" size LiSO
2 cell in the
BA-5590/U battery without allowing any stuff to be
expelled. Note that a PRC-25 type vent can not get
enough gas out fast enough to be of use. But it is not
designed to contain an explosion of more than one cell like
might happen if you tried to charge a BA-5590/U and the
batteries internal protection diodes failed (like might
happen after long term hot storage and when hot). This
may have been related to why the Battery Tray has had the
charging function deactivated, but that does not make sense
since the Battery Tray uses pin 3 for charging and that pin
is only active on rechargeable batteries (There's not even
any metal in the pin 3 position on a BA-5590). If you
know about this
let
me know.
CY-8523A

The
CY-8523A has two
telephone type wire terminals to support the tone based
remote control of the radio. The CY-8523C replaces
these with a circular connector that mates to the HRCRD for
tone control.
TM 11-5820-890-20P-1 Figure 12 Metal die cast body.
CY-8523B
TM 11-5820-890-20P-1 Figure 208 Plastic with a pair of
telephone push terminals.
CY-8523C NSN
6160-01-424-8514

The CY-8523C replaces the two wire line terminals with a
circular connector to support the HRCRD handset. This
makes operating the radio while it's on your back much
easier.
The HRCRD connector on the battery box is the same as the
connector on the CY-8664 Battery Tray and the PP-8249
Battery Charger.
The CX-13290 cable mates to all of these. The cable
plug is a MS3116F10-6P. This is also the same cable
used with the
C-11291
Control-Monitor.
TM 11-5820-890-20P-1 Figure 12A
CY-8664
Battery Tray (A12)
The original design supported
charging the battery but this was later discontinued.
The design does take into account the function of pin 3
which is connected to pin 1 only in rechargeable BB-series
batteries. So it's a mystery why the charging function
was removed. One possible reason may be that it
correctly charged the BB-590 Ni-Cad but it would over charge
a BB-390 Ni-MH. Note that a Ni-MH tends to get very
hot at the end of charge whereas the Ni-Cad does not, that's
why the BB-390 has the temperature sensors that are not part
of the BB-590. Note that the mechanical keying
difference between primary and secondary can NOT be used
since the radio needs to work with either kind.
TM 11-5820-890-20P-1 Figure 13
PP-8249 Battery Charging Tray

This is
identical to the CY-8664 with the exception that the
internal wire allowing battery charging has been
connected. Given new name so they will not be mixed
up.
Cabling Battery Box/Tray
The
CX-13290
cable can be used to connect the Battery Box/Tray directly
to either the
MX-10862-J3
(Cont Mon) or to the
AM-7239()-J9
(Cont Mon). If there is one
C-11291 Control Monitor
already connected to the Amplifier/Power Supply (using
C-M-J1) then the Battery Box/Tray can be connected to
C-M-J3. Note that pins "A" and "F" of the CX-13290
cable are not crossed end-to-end and they carry ground and
+27 VDC.
Cables
External
These are cables used to
interconnect equipment outside a radio.
There are more cables that
have part numbers rather than being nomenclatured.
Note* - Many of the above cables come in different
lengths. I haven't yet figured out which come in what
lengths.
Note
1 -
The CX-13488 is wired 1:1 which is consistent with being able
to connect to either a VRC-12 series radio or a SINCGARS
radio. That's to say the "data" carried by this cable
probably is in the form of audio tones, not digital
bits. I think the TCIM is being replaced with routers
for the Tactical Internet. This cable could be used as
an extension cable for any AUDIO type application, except both
ends are plugs, so it's probably only good for connecting two
boxes with an AUDIO cable.
Cable Manuals
TM 11-5820-890-20-1
Chapter 4 has cable schematics
TM 11-5820-890-20-3
Section 4 has cable drawings
Internal Cabling
Since there are now at least 7
different versions of the SINCGARS radios and the currently
manuals are sometimes not as helpful as you might want I
started looking at the internal coax connections to get an
idea of what the front end modules were doing. Note
that coax is used when the frequency gets high enough where
it's not practical or economical to route the signals on the
printed circuit board. Also in the case of SINCGARS
there's probably some EMP related considerations.
Based on the RT-1439 the coax cables are carrying the RF
input frequency range and the Rx and Tx LO frequencies which
are no more than 20 MHz higher than the basic RF range (30
to 88 MHz) and also a 12.5 MHz IF signal.
It's reasonable to expect that the other versions would use
coax for signals in these frequency ranges (but maybe
putting the IF on a trace), but for sure keeping the VHF
signals on coax. But, so far, it's not clear what the
different version number modules are doing. For
example the first module that connects to the front panel
antenna jack must contain the antenna matching
circuit. In the case of the 1439 this module then has
a coax to the module that contains both the transmit exciter
power amplifier and the receiver low pass filter. The
1439 synthesizer has two outputs, one to drive the receiving
mixer and the other to drive the exciter power amplifier.
Manuals:
RT-1523D = TM 11-5820-890-20P-1 Fig 205 It may be that the
The 1439 is very similar to the 1523 in most respects, it
just has the added ICOM module. These have the modules
both front to back and side to side.
The coax paths in the RT-1523A (GDLS) are completely
different from the RT-1523 (ITT). At first glance
these appear similar since all the modules are lined up like
books and are numbered left to right. But in the
RT-1523A there are 8 boxed modules but in the RT1523D only 6
boxed modules.
Carry Case, Manpack
NSN 5820-01-322-3477
This is the same camouflage
ALICE medium pack as used with
the
PRC-104. It's not clear if
this NSN is for just the special pack with a Velcro closure
for the antenna or if it includes the pack frame, cargo
shelf and/or cargo straps.
Mounts
Mounts have the female and
male MW20 type 4 contact vehicle 22 to 32 Volt connectors
for DC power and some have the VIC-1 type connectors.
They are secured to a strong metal support, not to the
vehicle sheet metal. The mounts pass the DC on to the
Power Supply Adapters after filtering it for EMI and EMP.
If there's an LS-671 connected to a mount then use the
switch on the LS-671 as the main radio power switch.
But if there's no LS-671 then the mount circuit breaker
needs to be turned off, not just the RT FCTN switch.
If the FCTN switch is turned fully CCW but CB1 on the mount
is left on the mount will drain the vehicle battery.
Ref Sep '96 PS mag pg 37.
MT-6352 Dual Radio PS/A Mount
(A13)
 |
 |
Left
rear
has oblong connector that mates with rear of AM-7239 Dual Radio
Power Supply/Adapter. Note there are two sets
of clamps on the front. The outer set holds
the AM-7239 and
the inner set of clamps holds the RT on the lower
shelf. |
Do
not understand why the bottom of the Mount is
so wide.
Maybe it's on a mounting shelf?
|
Very similar to the
MT-1029 used
with the
AM-2060 and
PRC-25 or
PRC-77.
Connectors:
Function
|
MT-1029 |
MT-6352
|
DC
in
|
J21
|
J1
|
DC
Out
|
J23
|
J2
|
VIC
or TSEC
|
J22
|
J3
|
VIC
or TSEC
|
n.a.
|
J4
|
to
Amp-PS
|
J24
|
J5
|
Note the SINCGARS mount has two VIC type jacks and the
radios have a built-in connector (J5) for the
KY-57 and so don't need the
J-3513/J-3514 interface boxes like the VRC-12 radios.
TM 11-5820-890-20P-1 Figure 109, 110, 111, 206
Note the four corner mounting holes accept a 5/6-32x1"
mounting bolt. These holes are in the same location
for the
MT-1029,
MT-6234 and this MT-6352.
An approximate hole pattern is:
Front mounting holes are 13.375" apart left to right.
Left rear hole is 8.09375" behind left front hole.
Right Rear hole is 10.9375" behind right front hole.
If you know the design dimensions please
let me know.
MT-6353 RF Amp Mount
This mount holds the AM-7238 RF Amplifier. Fed using a
CX-13291 Cable from either a single radio Power
Supply/Adapter
MX-10862-J5
or a Dual Radio Power Supply/Adapter
AM-7239-J11. On-Off
Breaker/Switch on front and dimable pilot lamp. On the
bottom rear are three connectors: DC In, DC Out and 14 pin
control. The same 14 pin control connector is used to
mate with the AM-7238 Amplifier.
There is an electronics box as part of the mount and it's
job is to generate the 200 Volts needed by the amplifier PIN
diodes for band switching.

|

|
MT-6353
Top w/o Amp
|
MT-6353
Bottom
Connectors
|
Has it's own 4 pin vehicle DC input and 4 socket DC output
connectors and so would be connected downstream from the
RT. Note that no RF goes to or from the mount.
Jack
|
#
pins
|
Function
|
J1
|
4
|
Vehicle
DC In
|
J2
|
4
|
Vehicle
DC Out
|
J3
|
14*
|
CX-13291
to PS/A
|
J4
|
14*
|
Direct
Connect
to RF Amp
|
* This is the same 14 pin
Jack as used on the
PRC-25 and
PRC-77 for the POWER connector.
I sell a
Power
Connector
Kit that includes this connector, 2 would be
required to make the CX-13291 PA control cable described
in TM 11-5820-890-20-1. It should be made from 9
conductor shielded cable.
TM 11-5820-890-20P-1 Figure 112 to 118
MT-6576 Single Radio PS/A Mount
(manual says A9 ? marked A4)

Used with the
MX-10862 Single Radio
Mount (SRM) Power supply Adapter PS/A.
Looks very similar to the
MT-6352,
why is it different?
Ans: It's narrower since there is no need for mounting an
AM-7238 RF Amp.
This mount is an optional component of the VRC-87 (SR),
VRC-88 (SR-D) or VRC-90 (LR) vehicular radio systems.
The metal plate on the left side allows a padlock to
attach the radio directly to the mount and since the guide
pins and rear connectors are engaged also traps the
MX-10862 between the
radio and mount.
What Goes Wrong
As delivered there were some problems. The DC power
input connector J1 had a pin B (+27V) broken off and
someone had started to make a repair but quit after
removing all the wires from the connector and not marking
them. It was easy to figure out that all the red
wires went to B, Black to A, Brown to C and white to
D. Note there are only two ways the connector can be
installed in the box and it's best done with the alignment
ridge toward the front of the mount to allow easy cable
connection. But even then the CX-4720 connector
needed to be turned one notch.
One the the thumbscrews on the front had been hit hard
damaging it's threads and the threads in the mount.
The M8 threads are 8 mm x 1.25 mm and a tap for the mount
and a die for the thumbscrew chased the threads
clean. The mount hole was at an angle and after
installing the thumbscrew all the way in a small hammer
blow got the threads aligned.
The (-) screws go all the way through the box and hold it
to the mount. The (+) screws hold the lid onto the
box.
Adapters
Have an oblong connector on
the back side that interfaces to the mount. Take in
raw vehicle 20 to 30 Volts DC and convert it into "12 Volts"
for the SINCGARS radio. The radio interface is the
circular "System connector" on the front of the mount that
mates with the connector on the back of the radio.
AM-7239()
Dual Radio Power Supply/Adapter (A5)
Interpretability
The 7239, 7239A and 7239B all work fully with the RT-1439.
The 7239C, 7239D and 7239E support data packets which the
RT-1439 & RT-1523 do not support. A RT-1523 C/D/E
is needed for this. The RT-1523A will not mechanically
fit. They are probably the ones that also have the GPS
connector.
Locking bar NSN 5340-01-352-3053 and A-200 padlock
NSN
5340-00-158-3807 with 5/16" hardened steel
shank. Ref 1995 PS mag 514 pg 46.
The Dial Light can be mechanically dimmed all the way to
being blacked out. Then it's easy to forget to turn
off the Mount circuit breaker thus draining the vehicle
battery. (Ref : PS mag for Dec '98 pg 52)
Left rear has oblong connector
that mates with Mount
MT-6352.
Tray side has two system connectors that mates to back of
radios A and B.
Jack
|
Function
|
J1
|
Direct
to RF Amp
|
J2
|
Audio/Data
|
J3
|
Audio/Data
|
J4
|
Data
|
J5
|
Data
|
J6
|
Speaker
|
J7
|
RT-B
(top)
|
J8
|
RT-A
(bottom)
|
J9
|
CX-13290
to Ctrl-Mon
|
J10
|
CX-13179
to CP-1380 (SNAP)
|
J11
|
CX-13291
to RF Amp B
|
E1/2/A/B
|
Wireline
remote
control
|
P1
|
Interface
to Mount
|

|

|
Tray
Side
|
Mount
Side
|
Version
|
NSN
|
Manual
|
AM-7239 |
5895-01-188-8819
|
TM 11-5820-890-20P-1
Figure 86 |
AM-7239A
|
5895-01-323-6265
|
TM 11-5820-890-20P-1 |
AM-7239B |
5895-01-334-3164 |
TM 11-5820-890-20P-1
Figure 146, 151, 153 |
AM-7239C |
5895-01-421-0093 |
TM 11-5820-890-20P-1
Figure 211, 212, 213 |
AM-7239D |
5895-01-422-8781 |
TM 11-5820-890-20P-1
Figure 214, 214 |
AM-7239E |
5895-01-444-1218 |
TM 11-5820-890-20P-1 |
There does not seem to be an AM-739X that is designed to
hold the smaller RT-1523E and higher radios. The newer
radios fit the
AM-7239E
and that PS/A supports all the radio features, BUT it wasts
a lot of space.
Note that the radio in the lower shelf is the Long Range
radio that uses the
AM-7238 RF power amp.
MX-10862 Single Radio Power
Supply/Adapter Tray (A8)
Left rear has oblong connector
that mates with Mount
MT-6576.
Tray side has system connector that mates to back of radio.
10 7/8" wide x 12"+/- Deep x 5 1/4" high.
TM 11-5820-890-20-2 Chapter 5
The
MT-6576 Single Radio
Mount draws 0.32 amps with only the MX-10862 installed and
no current draw when the MX-10862 is off.
|

|
Tray
Side
J2 (RT)
Power sw, Lamp, wire line terminals, J1 Test Con
Add-on left thumb screw has big lock hole
|
Mount
Side
J3 (CTRL-MON), J5 (RF Amp), J4 (Batt), P1 (Mount)
|

|
 |
RT-1439
+ MX-10862 Front
Qtr View
Stock left & right thumb screws have 2 small
safety wire holes
|
RT-1439
+ MX-10862 Rear
Qtr View |
Jack
|
#
pins
|
Function
|
J5
|
14
|
CX-13291
to RF Pwr Amp
|
J2
|
28
|
to
RT
|
J1
|
14
|
Test
or PTT*
|
J3
|
6
|
CX-13290
to Ctrl-Mon
|
J4
|
6
|
CX-13290
to Battery Tray
|
P1
|
|
Interface
to Mount
|
E1
& E2
|
1+1
|
wire
line remote
|
* J1 is used for testing or to accept an external PTT signal
by means of a CX-13314 to an LS-671.
Both 14 pin jacks are the same as the POWER connector on the
PRC-25 and
PRC-77
as the POWER connector.
Note that J5 is to support an external RF Amp, and is an
optional configuration of the VRC-90.
This Power Supply/Adapter has a BATT connector for use with
the CY-8664 Battery Tray or the PP-8249 Battery Charging
Tray to provide DC prime power even when the vehicle DC
power sags(but not when it's zero), like in an armored
vehicle when the hydraulic pumps are working hard. But
the
AM-7239 does not
have the BATT connector, so is it not used in armored
vehicles.
I wonder if having the external battery takes a load off the
radio's internal HUB.
TM 11-5820-890-20P-1 Figure
147
AM-7238() RF Amp (A6)
One can be mounted to the left
side of the
AM-7239() or
on the
MT-6353 Mount that's just for
it. The control and power are fed through the mount
connector and the RF is fed through separate coax cables.
The amplifier has it's frequency coverage split into three
bands as described in TM 11-5820-890-30-4 Paragraph 5-3 on
pdf page 577.
Filter/Band
|
Frequency MHz
|
A
|
30 43
|
B
|
43 - 61.5
|
C
|
61.5 - 88
|
Note this is a different band plan than that used on the
PRC-25 and
PRC-77
where the band split is: 30 - 52 and 53 - 75 MHz.
So even if you could jury rig a band signal out of the
PRC-25 or PRC-77 it would not match the band plan of the
AM-7238 amplifier.
So the only way you could use the AM-7238 with the PRC-25 or
PRC-77 would be to use a manual band switch to control the
amp which would be set prior to keying the radio. If
the manual switch was set improperly it might let some smoke
out of either the amplifier and/or radio. So this is
probably not a good idea. Another option that would
work would be to build a "smart interface" that would use a
counter to determine the frequency coming out of the radio
and select the appropriate amp band. But even this
would need some safety precautions to prevent a frequency
change going unnoticed.

|

|
BNC
RF Connectors end
|
P1
14-pin connector end
|
Remotes
There are a couple of hardware interface methods allowing
remote operation. 6-Wire non secure and 2-Wire secure.
6-Wire
There is the non secure 6-wire protocol like used with the
HRCRD, C-11291 Control-Monitor.
HRCRD
C-11291 Control-Monitor (C-M) (A7)

6-wire
protocol has the same functions as the HRCRD plus it can
turn the RT off.
This is the small non secure remote that works using the
same in band audio protocol as the HRCRD. Typically
used in vehicular installations. Two are used inside
the M60 tank.
The upper right display has two functions in one
window. COMSEC: PT or CT and CONTROL Main or Standby.
J3 is used to connect a second C-M and has a 650 Hz data
stream that's different from the 2880 Hz data stream used
for radio coms. This means that only 2 C-M can be
connected in tandem, they can not be daisy chained.
Although the name for J3-E is C-M out and for J3-F is C-M
In. on the functional schematic, they probably should be
called J3-E data and J3-F Clock, or some other names that
don't imply a cross connect cable is needed since a standard
CX-13290 cable can be used between the two J3 connectors of
a pair of C-Ms. Ref: TB 11-5820-20-49 Fig 5-8(1) Cabling
M60A1/A3 with VRC-89/91/92.
The CX-13290 cable is also used with the CY-8664 Battery
Tray and the PP-8249 Battery Charger. In TM
11-5820-30-5 FO-21 Battery Tray Schematic dia it shows the
CX-13290 with pins A and F wired straight through and pins D
& E crosses (i.e. D-E and E-D) and B & C are crossed
(i.e. B-C, C-B) But those are not the correct pins to
cross to get E & F crossed which is implied by the
names of the C-11291 pins??? It may be that C-M Out
and C-M in are on pins D&E which are crossed in the
cable and the C-M presence is sensed on C or F?
Note the C-M is the same size as and has mounting provisions
to attach to a
VIC-1
control box also has rear ears so can be mounted on a wall.
Note the display is red to match the display color of the
RT-1439. (thanks Kurt).
6 pin connectors:
Pin
|
J1
VAA J9
Radio 1 & 2
|
J2
radio 3
|
J3
2nd C-M-J3
|
A
|
Gnd
|
Gnd
|
Gnd
|
B
|
RT1a
|
RT3a
|
27.5
vdc in/out
|
C
|
RT1b
|
RT3b
|
Gnd
|
D
|
RT2a
|
|
C-M
Pres
|
E
|
RT2b
|
|
C-M
Out
|
F
|
27.5vdc
in
|
|
C-M
In
|
TM
11-5820-890-20P-1 Figure 4
TM 11-5820-890-10-1 Chapter 4 sec II operation
2-Wire
The 2-Wire protocol is secure when the radio is keyed.
CY-8523A
or CY-8523B Battery Box
These have regular telephone type push down terminals (E1
& E2) for remote operation.

|
Note the E1 & E2 2-Wire terminals on the battery
box.
|
This battery box has a 6-pin circular connector for the
HRCRD remote control microphone, but that can be used by
the above 6-wire remote controls or the below 2-Wire
adapter that interfaces between the 6-wire and 2-wire
protocols.
AM-7239() Dual
Radio Power Supply - Adapter
These have the E1 & E2 remote terminals as well as J9
for a 6-Wire Control-Monitor.
MX-10862 Single Radio Power
Supply/Adapter Tray
Has both the E1 & E2 2-wire terminals as well as J3
for a 6-Wire Control-Monitor.
2-Wire Adapter
This is an adapter that goes between the 6-wire remote
protocol and the 2-wire remote protocol.
The main use probably is by connecting to J6 on the new
1/2 size SINCGARS radios (RT-1523E & RT-1523F) and
WD-1 field wire.
But it also could be used
These showed up on eBay atticstocksurplus
August 2016 new in the sealed bag.
The bag is marked:
NSN: 5935-01-463-8290
CAGE PRIME 92837
SINCGARS 2-Wire Adapters
One Each
MIPR9IFFPI9C811
A/C
It uses the same PCI-106 PM connector as the HRCRD and so
can be connected in the same places.
Pin-A to E2 & to E1 is 4 nf compared to 0.5 nF for the
other pins.
E1 to E2 = 11 Ohms.
The box seems very light in weight and there is no provision
for a battery. So it's not clear what function it
serves.
C-11561 Remote Control Unit
(RCU)
This unit is the same size as the RT-1439.
This remote was designed to
work with the RT-1523 series radios that have ICOM
capability. This means that the C-11561 also has
ICOM capability. Used the 2-wire protocol.
This uses a 40 kHz digital data stream for both voice and
data. Instead of the limited control capability of
the 6-wire protocol this one has full front panel control
including setting the FCTN switch to OFF. (Ref: -30-5 para
2-19 pg 45.)
Looks almost identical to the RT-1439. The wireline
connection between the RCU and radio is secure unlike the
C-11291.
TM 11-5820-890-20P-1 Figure 84, 207
It's not clear if the RT-1439 supports this level of
remote control. It may be there in an undocumented
way or there may be some other test mode that allows
digital control of the RT-1439 designed for testing.
Most probably on J5 since only a few of those pins are
used for crypto and the others might be for remote
control.
Test equipment has gone through a evolutionary development
where the first test instruments were all analog and
manually controlled, then simple remote control based on
one wire per switch contact, then to a buss where multiple
instruments could all be controlled from one computer to
the current buss where the instruments share a common
control language. But radios have not progressed to
anywhere near this level of automation.
Note the display is green to match the display color of
the RT-1523. (thanks Kurt).
The only speaker that can be used with the C-11561 is the
LS-685 that uses a crystal
speaker element. That may be because it uses a very
small amount of power and/or to minimize
TEMPSET emissions that could break
security.
Since the RCU comes with the speaker and either the
CY-8523A or CY-8523B battery box
the battery box 2-wire telephone line terminals would
be used for the remote function.
Fill Devices
Always use the W4 cable when
filling. Do not make a direct connection between the
fill device and the radio. This warning shows up in
the manuals and numerous PS magazine articles like June 1994
issue 499 pages 2 and 3. Also put a small amount of
silicon grease on your finger then lube the O-ring inside
all AUDIO connectors. Then when mating them to the RT
or other equipment start with the flat or bump up, press in
turn clockwise until the stop then release. Check by
lightly pulling out on the connector (not the cable).
Can be used to fill the
RT-1439 or later radios with hop sets and their keys, but
not the KY-57.
TM 11-5820-890-20P-1 Figure 16
MX-10579 Fill Device
This unit looks very similar
to the MX-18290. Don't know why there's two devices
unless it relates to being made by two manufacturers, like
the early radios were made by two different
companies. Can be used to fill the RT-1439 or later
radios with hop sets and their keys, but not the
KY-57. TM 11-5820-890-20P-1 Figure 17
Can be used to load all
needed fill data when connected to a PC running the proper
software.
SNAP
- Steerable Null Antenna Processor
FAS - SNAP -
FM 24-33 -
Ch
2 2-3. Transmission Protection Use
Steerable
Null
Antenna
Processors. The
Steerable Null Antenna Processor (SNAP-1) Group OL-257()/VRC
is designed for use with the AN/VRC-12 family of radios and
in the nonhopping (SC) mode of the Single-Channel Ground and
Airborne Radio System (SINCGARS). It provides ECCM
protection for the single-channel combat net radios in the
VHF range (30-88 MHz). It will operate efficiently when the
operator has no prior knowledge of the direction of either
the unwanted or desired signal. It has a bypass or override
feature that can be used in a jam-free environment or when
equipment fails. The SNAP-1 will process the desired signal
to its attached receiver even if the sending transmitter is
not equipped with the SNAP-1. The SNAP-1 will be doctrinally
employed on essential command and control and fire support
single-channel radio nets from platoon to division level in
forward areas.
FM
24-18 (Tactical Single Channel Radio Communications
Techniques) contains a more detailed explanation of
steerable null antenna processors.
Steerable Null Antenna Processor CP-1380/VRC
Interconnecting Box J-3792/VRC uses 3 ea. CX-4722 cables,
two to the two antennas and one to the radio antenna control
jack.
Special Purpose Electrical Cable Assembly CX-13179/U.
(Included in Group.)
Two AS-1729 or two AS-2731 antennas.
Two antenna cables CG-1773.
Two control cables CX-4722
Mount MT-1898 to hold CP-1380
COMSEC equipment, TSEC/KY-8, TSEC/KY-38, or TSEC/KY-57.
AN/VRC-12 family of radios and AN/GRC-160 and AN/VRC-164
& SINCGARS in non frequency hopping mode.
Documents
Manuals
FM 11-1 Talk SINCGARS,
Multiservice Communications Procedures for the Single-Channel
Ground and Airborne Radio System, May 1966. A joint Army,
Navy, Air Force & Marines document. Good overview of
SINCGARS, but has dated radios listed, no SIP or ASIP radios.
There are a number of overall manual sorting methods.
ICOM vs. Non-ICOM
Operator vs. Net Control Station (NCS)
TM vs. TB
TB sub categories are
890-10-nn for auxiliary equipment
890-20-nn for Install Kits (about 100 as of
June 2005) a couple are for base stations but most are for
wheeled, tracked or water vehicles.
More install kit info in PS mag 2000 issue
566 pg 57.
TM 11-5820-890-10-3 Non-ICOM
Operator's Manual
TM 11-5820-890-10-4 Non-ICOM RT Pocket Guide
TM 11-5820-890-30-5 DS Maint Manual Chapter 2 is for the
RT-1439
TM 11-5820-890-30-4 DS Maint Manual (says it's for the RT-1523
(no letter) but it looks like it may be for the RT-1439?
If you have a no letter 1523 please
contact
me.
TM 11-5820-890-30P-3 for the RT-1523E ASIP RT
TM 11-5820-890-10-6 ICOM Pocket Guide for ANCD (AN/CYZ-10),
PLGR (PSN-11) & HRCRD (C-12493/U)
TM 11-5820-890-10-8 ICOM Operator's Technical Manual SINCGARS
Ground Combat Net Radio ICOM - good overview & details
TM 11-5820-890-10-HR Basic Issue & Additional Issue Items
for RT-1439 & RT-1523() based configurations.
SB 11-131-2 Vehicular Sets and Authorized Installations Volume
II, SINCGARS, FHMUX & EPLRS (note that SB 11-131-1 is for
Non SINCGARS radio installations) Searching on 6576
finds hits only on tracked vehicle install kits.
TM 11-5820-914-40P Gen Sup Maint Repair Parts w/ RT-1439
& RT-1523(no letter), RT-1523B
TM 11-5821-333-12 Operator's and Aviation Unit Maintenance
Manual, SINCGARS Airborne Combat Net Radio, ICOM &
Non-ICOM, Non-ICOM AN/ARC-201(V) and ICOM AN/ARC-201A(V)
1 Sep 1992
TM 11-5821-333-30 Aviation Intermediate Maint. Manual Non-ICOM
AN/ARC-201(V) and ICOM AN/ARC-201A(V) 1 Aug 1992
Training Videos
PS mag issue Jan 1994 issue
494 pg 54 for both ICOM and Non-ICOM radios
Computer Based Training
What Goes Wrong
The Function (FCTN) knob on the RT-1439 is a poor
design. When used it's necessary to pull the knob out to
get to some positions.
This one is of plastic
construction with a metal insert. and uses a 1/16" Allen screw
that goes through a clearance hole in the plastic knob.
The location of the screw clearance hole is in line with the
notch in the knob skirt (i.e. the weakest part of the
knob), so it no surprise that the knob failed in this area,
NOT when being forced, but just due to normal use. The
joining of the two parts depends only on friction which is not
good enough to handle temperature variations and the combined
in-out and rotational forces. The set screw works as a
wedge to break the plastic when the two parts move relative to
one another.
The repair is to use a very small amount of J-B Weld to epoxy
the metal insert into the knob.
Marking on the bottom edge of the skirt:
MFR-31550 (ITT Ft. Wayne, IN) 80053 ASSY A3147839-1
PS Magazine
2001 #579
This
"V"
Ain't for Victory - Cracked LCD -> Use Carrying Strap
NSN 5340-01-461-4741.
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May 2005.