[Milsurplus] Help needed with RT-70/AM-65

Mike [email protected]
Tue, 26 Mar 2002 12:44:15 -0600


Alan Tasker wrote:

> A friend of mine has asked for help in using his newly acquired, incomplete
> RT-70/AM-65 rig. I am unfamiliar with this equipment, so I ask the following.
> 
> 1.- What are all the hardware mounts he is going to need to mount this in
> his vehicle?

He's interested then, in putting together the components for the set
known as the "AN/VRC-7."  This provides a half-watt FM set and
interphone amplifier.  The other components needed are:

1.  MT-300/GR  Vehicle mount with cables (3) going to AM-65/GRC and
cable (1) going to vehicle DC supply.  Fair Radio Sales (FRS) has been
carrying these for $85.

2.  CX-1213/U  Dogbone between RT-70 and AM-85.  These are hard to find,
but Fair Radio has used connectors that can wired up to duplicate.  It
is connected just pin A to pin A, pin B to pin B, etc. hookup, BUT THERE
IS ALSO AN INTERNAL JUMPER THAT MUST CONNECT PIN D TO PIN E on at least
one of the connectors.

3.  Internal vibrator power supply for AM-65 (also supplies RT-70): 
PP-281/GRC (12v) or PP-282/GRC (24 volt).  These can be hard to find. 
FRS had the PP-282 a while back.

3.  CG-530/U  RF cable to antenna base, with BNC connectors.  This is
***93 ohm*** RG-62/U coax!  (FRS has it...but you have to ask.)

4.  AB-15/GR  Antenna base  (FRS has it)

5.  Mast sections AB-22/GR and AB-24/GR.  (FRS has them)

6.  Right-angle BNC connector UG-306/U (used at RT-70) and PL-259/U-BNC
adapter UG-273/U (used at AB-15).  (FRS has them)

7.  Remote control box C-375/VRC and cable WM-46 for each station using
the interphone (Optional item).  (FRS has them)

8.  LS-166/U loudspeaker and H-33/U handset.  (FRS has them)

> 2.- If he restricts the use of the AM-65 to just the RT-70, I assume he can
> get along with just an H-33 handset on the RT-70. But if he wanted a
> speaker, what type would he need and which type of plug would it use?

The speaker would be a LS-166/U, which comes with the appropriate U-77/U
(or U-161/U) connector.
The speaker will have to be plugged into the AM-65 to take advantage of
the AM-65 output.

> 3.- Is the RT-70 to AM-65 dog bone unobtanium at this point?

Pretty much so unless it came with the purchase of the RT-70 and AM-65. 
I bought a pair on eBay JUST to get the CX-1213/U!

> 4.- What cable does he need to run 24V power to the AM-65? He says he has a
> 24V PSU.

So he has the PP-282/GRC.  The junction box that is part of the
MT-300/GR provides the cable and connections for 24 volts to the set.

> 5.- Are we forgetting anything?

Manuals:  TM 11-285  for the AN/VRC-7
          TM 11-290  for the RT-70/GRC
          TM 11-5039 for the AM-65/GRC
          TM 11-5050 for the PP-282/GRC
         
These Korean War sets are, to me, more interesting than the later
AN/VRC-12 series of radios.  I've got a complete AN/GRC-7, which
includes the RT-68, RT-70, R-110, PP-112, PP-282 (2), AM-65, MT-297,
C-435, C-375 units all on the same rack.  Hard-core neat-looking in the
extreme!

73,
Mike / KK5F