[Milsurplus] AN/VRC-7 Questions etc etc

[Morrow, Michael A.]

Scott / KB9VNQ wrote:

> I recently got what I think is a AN/VRC-7.  It has
> the RT-70, AM-65, a MT-791/U mount and the C-375.

The AN/VRC-7 uses the MT-300/GR.  The MT-791/U is the
mount for the AN/GSA-7.  The MT-300/GR has the three
short cables and connectors that mate to the three
sockets on the bottom front of the AM-65/GRC.  The
MT-791 does not.  You also need the CX-1213/U dogbone
between the RT-70 and the AM-65.  If you make your own,
make sure pins D and E are connected to each other in
the dogbone.  Also note that the coax used for the
AN/VRC-7 is RG-62/U, which is 93 ohm, IIRC.  CG-530/U
is the proper cable between the RT and the AB-15 antenna
base.

> The mount/power suppy has a cable coming out that I
> think is the power cable.  One connection has the
> metal braid and the other is the center conductor
> like coax)  Which is pos and which is neg?

The MT-300/GR battery cable has two heavy conductors
within a heavy jacket (cable CO-212).  The dark one is
negative.  I don't know about the MT-791 cable arrangement.

> Also, what manual should I get for this setup.

You need four:
TM 11-285  AN/VRC-7
TM 11-290  RT-70(*)/GRC
TM 11-5039 AM-65/GRC
TM 11-5040 PP-281, -282, or -448/GR 12, 24, or 6 vdc supply.
  
> BTW  Anyone that knows about these types of
> sets(GRC-7, VRQ-3)  please let me know.

I have all components for the AN/VRC-7 to 11, 13 to 18,
20 to 22, and AN/GRC-3 to 8.  I only lack AN/VRQ-1 to 3
components.

I like these 1950's sets.  Not many other BA collectors do,
though.  I'm **not** an expert on them.  My favorite is
the AN/GRC-7 (all 225 pounds of it).

73,
Mike / KK5F