The mode switch has the following positions:
Serial numbers of 635 and higher have a different RF cable & ANT adapter than on earlier sets and have an output every 5 MHz from 30 through 80 MHz. Spectrum of modulated 30 MHz output from PRM-34.
The original primary battery was the BA-5847 (NSN 6135-01-090-5364)
The Lithium Ion secondary battery BB-2847 (NSN 6140-01-419-8194) is the newer rechargeable version.
This battery is used in some thermal sights, AN/PRS-7 Mine Detector and other equipment.
Home made BA-5847 battery pack:
RS 270-391 4 AA battery holder with wires RS 274-154 Big (positive) female connector RS 274-234 Small (negative) female connector 4 AA batteries
The BA-5347 NSN 6135-01-455-7946 also has the same two sockets as the BA-5847 and will work in the PRM-34.
- The small PCB that is the plug for the battery has room to fit on the rubber pad that's there for the real battery. A small piece of bubble wrap placed over this battery adapter and the plug holds them in place.
Self Test showing 1.000. Note higher battery voltages would cause different displays.
Brentronics - BB-2847 - nominal voltage 7.2, about 4 or 5 AH
Hawker Eternacell - BA-5847/U with fuel guage.
Manual & Links
TM 11-6625-3015-14 is restricted at ETM but -24P (054912.pdf) and -14-H ( 055792.pdf ) are on line.
TM 11-6625-3015-14 Radio Test Set AN/PRM-34, 14 Oct. 1983
PRC-68 Alignment Procedures with PRM-34 - GTA 11-3-21 - instead of the 75 MHz frequency for testing the squelch of the PRC-68, any frequency in 5 MHz steps can be used. Except for those that are unusable because of spurs.
Radios that can be tested
Theory of Operation
There is a comb generator with outputs of 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, and 80 MHz at -97 dBm with a 900 Hz FM modulation for receiver testing.
There is a Watt meter with a 1 to 50 Watt range along with a digital frequency counter for transmitter testing and a reverse power test for antenna VSWR testing. What is the frequency coverage?
There is a field strength meter to align the L1 ANT adjustment on the PRC-68 in transmit mode.
PRM-34 NSN 6625-01-094-5646
Test Cable 2249-C-24 or 393707
Antenna Adapter NSN 5985-01-097-7337 (could also use my 68AA Antenna Adapter)
Transit Case (80045) 384858 or (80045) 393662-1
Return to Products made by Brooke, Squad Radio, Battery, PRC-68 Family, Electronics or Home page
This is for testing the Steerable Null Processor Group OL-275/VRC. The SNAP-1 system is for use with SINCGARS radios when operated in the single channel mode. SNAP-2 is for SINCGARS radios in the hopping mode. The OL-275/VRC consists of:
CP-1380/VRC Steerable Null Antenna Processor (SNAP)
CX-13179/U 3' Cable
J-3792/VRC Interconnecting Box for the second antenna.
The top BNC connector is to send a signal to/from the PRM-34.
It uses the same BA-5847 battery as the PRM-34 and so can be powered by the same battery adapter.
ManualsFM 24-18: Tactical Single-Channel Radio Communications Techniques, Appendix E, Steerable Null Processing Group OL-275( )/VRC
TM 11-6625-3155-13, Operator's Unit, and Intermediate Direct Support Maintenance Manual, Test Set, Processing Group, TS-3991/VRC (NSN: 6625-01-126-3105)
page created 30 Nov. 2000.