Radio

Radio equipment and accessories.

Jun 071999
 
The German SEM-25 Transceiver

This page describes the German SEM-25 transceiver. I compiled this information to help other collectors who have (or are thinking of getting) a SEM-25, but cannot find technical information about it; manuals and schematics for this set are very rare in the U.S. at this time.

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May 231999
 
AM-65 Ballast Replacment

This design is a solid-state replacement for ballast tube R-32 in the AM-65/GRC audio amplifier. When the AM-65 is used as a power supply for the RT-70 transceiver, R-32 regulates the RT-70’s tube filament current. The original part is described as follows in the service manual for the AM-65/GRC (TM 11-5039):

 

R-32 RESISTOR, thermal: current through lamp greater than .58 amp w/4.3 v measured across lamp and less than .625 amp w/9.7 v measured across lamp; designed for DC; T-9 bulb, 2 7/8″ lg o/a; intermediate octal base; Amperite type #6-4; Fed Tele & Rad part/dwg #GH-2677-2.

 

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May 231999
 
AM-65 Thermal Relay Replacment

This design is a solid-state replacement for thermal relay K-1 in the AM-65/GRC audio amplifier. When the AM-65 is used as a power supply for the RT-70 transceiver, K-1 protects the filament chain by reducing the filament current if the filament voltage rises too high. This can happen when certain tube filaments burn out, and can cause a chain reaction that burns out many other tube filaments. The original part is described as follows in the service manual for the AM-65/GRC (TM 11-5039):

 

K-1 RELAY, thermal: SPST normally closed; cont rating 2 amp max; silver cont; single wnd heat coil, operates at 6.9 v DC w/ 1 amp cont load, release at 2 to 3.5 v, heater current 250 ma w/6.9v applied, ins; coil and cont leads terminate in octal base; 1.275″ diam x 2 7/8″ lg excluding base cont and locating pin; mts by means of octal base; operates within 10 sec; incl in type T-9 bulb w/std octal base; Raytheon #CK-118; Fed Tele & Rad part /dwg #GH-2392-12.

 

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Feb 161999
 

 


BC-348 FAQ

by Buzz Harrah, KE0MS
February 15, 1999
Originally posted to the MilSurplus Mailing List
Reprinted with permission

 

Calling all MIL-itants,

Recently you all came to my rescue when I needed “Fatherly” advice on a BC-348 I’d found. Thanks to your info, I’ve worked a deal with only pickup yet to take place. Your pricing information especially helped the deal “gel”.

I was asked by several thru direct mail if I could gather together my info and publish it for all the other BC-348 “wannabe owners” out there, kind of as an FAQ or something. I got almost 2-dozen responses over the weekend to send it, so, (not knowing how many are on this list) I decided it’s easier to let you all get it and judge for yourself if you need it. Delete it if you don’t.

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Jan 071999
 
1950's Vehicular Radio Sets

 

This page shows the major components of many of the US military vehicular radio sets in use during the 1950’s. Each link points to a picture which shows the major radio components, mounts, cables, antenna components, etc. that were used in the indicated radio set. These pictures were scanned from a large foldout in the back of TM 11-284: Radio Sets AN/GRC-3, -4, -5, -6, -7, and -8, dated May, 1953.

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