Hello-
Manson Labs synthesizer pair { used to operate a pair of R-1247
R-390A's}is available. These synthesizers are very rare and I have heard of
only several others out there.{ serial #'s are low, # 46 and # 71 on this
pair} The system they were part of is the GRC-129, consisted of modified
T-368 for SSB, pair of R-1247's { modified R-390A's by Manson Labs with osc.
switching relays}, SSB receiving converter, and auxiallary items.
This synthesizer provided for the tuning of receiver { substituted for
PTO}and has a mechanical digital counter {as on the receiver}.Other osc.
frequencies are provided by synthesizer { by "MC. CHANGE" switch on it, plus
17 MC. and 455 KC.
Units are in nice cond. and have not been powered up.I cannot locate any
technical data.
Here is a link for pictures of the Manson Labs
synthesizer pair.
http://edebris.com/catalog2/item/1061

I prefer to trade them for a late model 1967 EAC in excellant cond.or
will sell for 750 USD.
Here is some info on the 2 units comprising the
Manson Labs synthesizer pair.They operate together.

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