AN/VRC-7

Radio Telephone and Telegraph Transmitting and Receiving Equipment
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Richard
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AN/VRC-7

Post by Richard » Sat Aug 23, 2008 4:16 pm

Hello all, I have a rt-70, AM-65 but I do not know if is necesary a PP 109 to AM 65
Somebody has a squeme of this set or some photos ?
Thanks in advance

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willy
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RT 70

Post by willy » Sat Aug 23, 2008 4:20 pm

The RT70 and AM-65 are a stand alone radio set VRC-7
The am-65 is also used as amp for intercome in some conficarations
AN/GRC 3 t0 8
No need for more the power supply is inside the AM-65 or should be
6, 12, or 24 volts.
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Post by wa5cab » Sat Aug 23, 2008 9:35 pm

Richard,

To add to what Willy said, inside the AM-65 should be a small plug-in vibrator power supply. There were three types, PP-282/GRC (24 volt), PP-281/GRC (12 volt) and PP-448/GRC (6 volt). The PP-281 and PP-282 were also used in the R-108, R-109 and R-110/GRC receivers. For an AN/VRC-7, you also need one MT-300/GR Mount plus antenna and audio components depending upon vehicle.

AM-65 by itself was used as part of Interphone System AN/UIC-1. RT-70 by itself was part of AN/PRC-16, with Generator G-8/GRC and Battery Box CY-590/GRC.

In the AN/VRC-7 and the AN/GRC-3, 5 and 7 (and a few other sets), the AM-65 is attached to the mount and cables from the mount plug into it. The RT-70 attaches to the top of the AM-65 and they are connected by the small dog-bone cable CX-1213/U.
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Richard
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Post by Richard » Sun Aug 24, 2008 2:03 pm

Thanks Willy and wa5cab for your answers.
I do not have the MT-300 yet, but I want to check the AM-65 & RT-70.
Could I connect 24 Volts in "power in" (AM-65)? and where, because "power in" has 4 pins.
Thanks for your support

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Korea family radios

Post by Gerry42 » Sun Aug 24, 2008 5:24 pm

the TM 11-184 is on the VRC3 thru 8 but it covers all the radios in that family really well it tell what all the parts do and how they are hooked together
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wa5cab
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Post by wa5cab » Mon Aug 25, 2008 10:34 pm

I believe that is TM 11-284 on AN/GRC-3...8.

Ref TM 11-285 on AN/VRC-7, the 4-pin DC power input connector on the AM-65 is J-6. Pins A & B are +, Pins C & D are -. Check which power supply is plugged into the AM-65 before you apply LV DC to J-6. Odds are about 10:1 that it's a PP-282 but it might not be. And if it isn't and you power the set up with 24 VDC, you won't love the results.

Second, odds are worse than 3:1 that the vibrator in whichever supply you have won't start. If this proves to be the case, don't throw the vibrator away. And don't go looking for an NOS replacement on eBay as it will have the same problem for the same reason (see earlier posts having to do with vibrators in PE-237's or PE-97's, 117's and 120's). I offer a cheap service to fix most vintage vibrators. $5.00 plus shipping if the easy fix works. $10.00 if I have to do surgery and open it up to physically burnish the contacts. Or if you qualify as an ET or an EE over 55 I can tell you how to do it.

Third, as with the recent discussion about operating an RT-66/7/8 off of the mount, you will need to jumper pins J and H in Connector J-4 (the one marked REC-TR CONT). Else there will be no B+ to the 2nd Audio tube in the RT-70.
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Re: AN/VRC-7

Post by ktm25089 » Wed May 15, 2019 4:11 pm

i have one set complete in working condition. Please, anyone can tell me what elements i have to use in the AB-15 mast base for antenna? and what combination?

thanks
George

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Re: AN/VRC-7

Post by pacho » Wed May 15, 2019 6:14 pm

hi George, could you attach photos?

Tks

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wa5cab
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Re: AN/VRC-7

Post by wa5cab » Thu May 16, 2019 2:48 pm

Besides one AB-15/GR, the antenna for the AN/VRC-7 consists of one AB-22/GR screwed into the AB-15 and one AB-24/GR screwed into the AB-22. Coax between the RT-70 and the AB-15 is CG-530/U which in this case is made up of 50" of RG-62/U and two UG-260/U (BNC Male) or equivalent.

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