the stenciled 81 is a small
red "X" which is the
shoot me here mark
one is a spare
FM 24-19 Section IV has info about using the KY-65, 2 ea. BA-1372 HUBs, CX-13168 cable between the RT-1209 upper AUDIO connector and the KY-57 RADIO connector. Z-AKE is an AC/DC power supply for the KY-65. CX-13211 cable between the KY-65 AUDIO connector and the AUDIO connector on the AM-6879 Amplifier-Converter. Handset to AUDIO connector on KY-65.
In a vehicle installation the cable from the J-4885/GRC Junction Box goes to the speaker connector on the Amp-PS. The H-250 handset connects to the J-4885 HANDSET connector. An LS-454 Speaker connects to the Speaker connector on the J-4885
Less than 10.2 volts causes a battery fail condition. This is consistent with a 10 to 15 Volt range for a "12 Volt" supply and the CY-2562 battery box. I wonder if the nomenclature means "25" for the PRC-25 and "62" for the year?
The KY-65 uses the Parkhill algorithm as does the KY-75 (Jerry Proc) aircraft version. The KY-65 and KY-75 may be the only Parkhill machines? If someone talks too fast then the message gets garbled. This is because the output needs to have a narrow (3 kHz) bandwidth to work with HF radios. A fast talking person will exceed 3 kHz bandwidth.
It think this system divides the 300 to 3,000 Hz voice band into 9 sub bands each 300 Hz wide. The signal in any of the 9 bands can be changed to any of the other bands either as is or inverted. So there are 18 things that can be taken 9 at a time or 18!/(18-9)! = 17.6 billion. Note that the key is a fixed permutation of the sub bands and does not change with time like the more modern voice encryption systems, so no date - time input is needed. It may be related to U.S. patents 2183248 & 3012098 assigned to Bell Labs?
KY-65 controls: & IndicatorsINT BAT / AUDIO / EXT BAT works with the analog panel meter, upper scale 0 to 1.50 Vrms, lower scale 0 - 3.0 Vrms and near the center of the scale a green band for the battery check.
OFF / ZEROIZE / STANDBY / ON - standby uses the external DC power for keep alive, saving the HUB batteries. You need to pull up the knob to bet into or out of ZEROIZE.
PLAIN / CIPHER
FILL SELECTOR allows selection of one of three keys
DELAY OUT / DELAY IN / SIG CLEAR - not sure?
HF / NON HF - H.F. has propagation problems that are not present on phone circuits.
Amber Light - "SIG/CIPHR RCV" - filament lamp "JKL 345" - would indicate an encrypted incoming message, but why?
Uses two each BA-4386 batteries, one active and one spare (also active and spare fuses).
HANDSET & FILL - standard U-229 type with 6 pins.
RADIO - 1" O.D. 26 male pin circular connector (the KY-38 also has a 26 male pin RADIO connector) It's likley that the pinouts are the same. There may even be cables that work with either the KY-38 or KY-65 and a radio or phone box.
The KY-99 Miniterm replaces the KY-65 for voice security.
J1 Radio Connector
This speaker was made specifically for the KY-65. It came out 24 Sep 1976, went inactive 2 Oct 1989 and was canceled 29 Mar 1996. It might be fair to assume that the KY-65 came out about the same time and that the KY-65 was replaced about 1986 by the KY-99.
The speaker runs from either "24 Volt" Vehicle power using an internal voltage regulator or from a clean 12.0 +/- 0.7 VDC depending on how the power connector is wired. Schematic on Jerry Proc's web page.
It's composed of an LS-454 with an added amplifier and a relay that prevents clear text from being heard on the speaker. You would not want to be using a PA system to be giving out the clear text. That's probably why the speaker was made.
It's similar to the AM-4979 Speaker that's for use on non encrypted radios.
Front Panel Controls & Indicators
Console rotary Switch (& Indicator lights): Secure (Green) or Normal (Red)
Toggle switch: Remote or Telephone
Amber Indicator: Cipher or Rcv
J2 SMA jack Cipher Indicator
J1 KY-65/75 - 8 sockets (MS3112E 12-8S)
1-1/2 Amp fuse & spare
Mode rotary switch (&amber pilot lamp): Off, AC, Ext DC, Int Batt.
Rear Panel Controls & Indicators
Toggle switch: 230 VAC or 115 VAC
J3 POWER connector 10 male pins (MS3122E 12-10P)
J5 ____?_____ 8 male pins (12-8)
J4 ____ ? ____ 10 female sockets (12-10)
Wire-line push-down jack field
PTT: E & F
Coupler: B & C (2-wire or 4-wire)
Remote Audio I/O, Key Relay (B & C)
Phone System: B & C(2-wire or 4-wire)
Toggle switch: 4-Wire or 2-Wire
Toggle switch: Input Level: 0 to -36 dBm or -9 to -45 dBm
Assy No. 0N288083-1
Serial No. ----
Mfr Code No. 26687
There appears to be an internal battery in it's own metal box.
PCB sockets J6 & J7 are empty, maybe demiled or maybe an option no installed.
It's my understanding that the U.S. military no longer buys products with internal batteries. When the battery goes dead the unit needs to be scrapped since most manuals do not cover battery replacement. This battery measures about 20 mV, I expect it's should be more like 14 VDC.
Fig 1 Front Panel
Fig 2 Label
Fig 3 Rear Panel
Fig 4 Rear Panel
Fig 5 Inside
[an error occurred while processing this directive] page created 15 May 2007.