Vietnam Era Radio

[WarrenD]

I'm looking for the appropriate radio model for use in a Vietnam M37 guntruck. Time period would be summer of 69-71.

Also, there was someone (in the DC area?) that had CD's of the AFRN Vietnam programs. I tried a search and couldn't locate, anyone have a link?

 

[maddawg308]

The RT-524 or RT-246 would be the appropriate radio. I have a pile of the AFVN radio programs, I'll bring them to Gilbert for ya on a thumb drive.

 

[maddawg308]

Forgot to mention, it would also be appropriate to have a PRC-25 or PRC-77 in a AM-2060 mount, instead of the RT-524/246.

 

[WarrenD]

Thanks Mike. Looks like I'll go for a RT-524 in a MT-1029

 

[bones1]

Would an AS-3900 antenna be the correct one for these sets?.
Found this info
http://digitalcartography.com/n0eq/AS3900.htm
and this
http://www.valcom-guelph.com/products/AS-3900A_VRC.html

 

[maddawg308]

Would an AS-3900 antenna be the correct one for these sets?.
Found this info
n0eq Tests the AS3900 Antenna Temporary Base

No. The AS-3900 is for the SINCGARS radio sets.

The correct antenna base for the RT-524/246 radio sets would be the MX-6707. They are always on eBay....

 

[vtdeucedriver]

No. The AS-3900 is for the SINCGARS radio sets.

The correct antenna base for the RT-524/246 radio sets would be the MX-6707. They are always on eBay....

Actually the mx-2799 would be more correct. I have only seen one 6707 on a GT and it was not a M-37.

 

[maddawg308]

Actually the mx-2799 would be more correct. I have only seen one 6707 on a GT and it was not a M-37.

+1, the MX-2799 was the original one to that series, but it was quickly replaced by the 6707, can't remember the reason but it was discussed previously. HOWEVER, finding a 2799 is sometimes difficult, when I bought one for my GT project two years back, they were 2x as much as the 6707s, and that's IF you can find one. Bernie M. in Delaware told me that a lot ended up in the UK after the 1970s. Not sure why, but I trust his input.

 

[bones1]

Thanks. I have a AS3900 on my Deuce,1970 year and now need to find a working radio set that this antenna will work with .

 

[Pakfront]

The problem with the MX-6707 is finding one that works, I've got 4 sitting in the basement that don't work.....and I'm trying to get a working radio vehicle together.

 

[Pakfront]

Thanks. I have a AS3900 on my Deuce,1970 year and now need to find a working radio set that this antenna will work with .

If you have
Valcom Manufacturing Group Inc - Guelph - AS-3900A/VRC Broadband Vehicular Whip Antenna <--this antenna

its for a SINCGARS radio which is still current (but FUBAR to operate) so good luck. I think you'd do better with an RT-524/246 based system, esp with the date of the vehicle.

 

[maddawg308]

The problem with the MX-6707 is finding one that works, I've got 4 sitting in the basement that don't work.....and I'm trying to get a working radio vehicle together.

Get one from this guy - sells them for $45 plus shipping in tested working condition:

MX6707 Antenna Base For Sale

 

[Storm 51]

In '69 you still might have found a fair amount of the old family radios in country too (not everyone got the newest, hottest, slick stuff). So GRC series stuff would work for your truck too. It might not be what all the cool kids have, but there was still a lot of it in VN in the late 60's and early 70's. It's also a lot cheaper and is definitely correct for an M-37.

Just something to keep in mind..........

Storm 51

 

[papakb]

The 2799 was probably the best of the antenna matching units for the VRC-12 family of radios but it was expensive to produce because it had gold contacts in the switching assembly and didn't have an external way to switch frequencies when the stepper solenoid inside died. The 6707 solved that problem but was suceptable to the plastic top piece cracking in the heat and that let water into the unit and ruined them pretty quickly. The plastic bushing around the switch shaft was also prone to breaking. The 3900s are a similar looking unit and don't require the extra frequency control cable and match the entire 30 - 75 Mhz freq range. 9 out of 10 people looking at one probably wouldn't notice the difference.

The upper mast sections from the 2799, 6707, and 3900 will interchange but all 3 matching units use different lower mast sections that won't.

Kurt
KG6KMJ

 

[bones1]

Thanks for the good info, that helps a lot. Now to find a working radio for the AS3900 and the Deuce

 

[Wile E. Coyote]

The AS-3900/3900A will work as the RT-524 and RT-246 will take a VSWR of 4.0 where I think the worst match on a 3900 is something like 2.3-2.8 max. Using one would cut out all the trouble with the CX-4722 and the matching motor/assy in the MX-6707 which - as previously mentioned - fails a lot. Most of the problem is water ingression which either prevents the motor turning (which blows the circuit breaker in the RT-524/246 which often won't reset) and/or provides a horrible match to the freqs you're feeding it which in turn cooks your radio's output stage(s).

The MX-2799 is the better ATU, but as I think someone mentioned, the bottom element is different than the commonly-available one for the MX-6707 and very, very hard to find. The Canadians kept the MX-2799 in service right through 1986 or thereabouts and sometimes list them for sale on Epay. Seen lots of MX-2799s and have yet to see one with water contamination -- where I've lost count of how many soggy MX-6707s I've had to deal with.