Hello All-
I have some pictures to send if you are interested.
Here is some more details of the two units comprising synthesizer and
frequency sources for GRC-129 system : Remember the GRC-129 used 2 of R-1247
receivers and a separate SSB receiving converter.

Regarding the Synthesizer, Electrical Freq. serial #71
O-1203 / GRC129 Manson Labs { Rack mount, about 4" tall}

Front Panel has : Power Switch
KC. Change crank knob and 1 KC. Change
smaller knob, mech. coupled in set. { Turning 1 KC. change smaller knob will
step KC change large knob in 1 KC. steps}
4 digit mech counter, about 1-1/3 size
of R-390A
10 KC. Test push button and zero adj.
pot knob
Synth. Level pot knob
Meter Selector 8 position knob
Test meter is " 0-5-0 " scale, round
about 1-3/8" OD
Rear Panel has : 2.455 to 3.455 MC. Output pair of BNC conn.
100 KC. Input BNC conn.
115 VAC 60 CPS power input Amphenol 3
pin conn.
Terminal strip with 4 term. labeled "
GND- FIL.- FIL.- B+"
Stamped " Unit 9" in white lettering

Regarding the Converter,Frequency,Electronic serial # 46
CV-1693 / GRC129 { Rack mount, about 5" tall}

Front panel has : MC. Change knob 0-31
3 Loop Warning lights
Test Meter " 5- 0 -5"
Meter Selecror switch
Power Switch
Has fan grill / filter in
front center

Rear Panel has : Power Input 115VAC 60 CPS Amphenol
Qty. of 8 BNC conn. as
follows -
2 are" 9 to 17 MC.
Output"
2 are " 17 MC.
Output"
1 is " 455 KC.
Output "
1 is " 100 KC.
Output"
1 is "100 KC. Input
"
1 is " 100 KC. To
Synth. "
Stamped " Unit 10"
in white lettering

Please accept my apologies for no pricing. In all fairness, as I believe
that this is probably a pretty rare set and I doubt I will run across
another in my lifetime, I would like to accept a trade on this :
EAC R-390A late model cherry set, original meters, no water or restored
pieced together types, etc.I believe that would be a fair trade and would
keep money out of it. Thanks,Byron.