[Milsurplus] National R-1230 countermeasures receiver

[Glenn Little WB4UIV]

The red wire to each module should be B+.
Disconnect the wires from one module, pull the tubes and check for 
continuity from the filament pins to the feed through capacitors on the module.
This will identify the filament leads.
Check continuity from the filament leads to the power plug.
You now have the filament pins.
The filament leads are probably the white wire with the (what looks 
like) brown tracer.
Where is the transformer located?
It looks like one cover has been removed, is the transformer behind this cover?

73
Glenn
WB4UIV


At 08:29 PM 12/1/2011, HL wrote:

>Peter:
>
>Many thanks.  I have travelled down that road to some extent.  The 
>power plug is an Amphenol 18-1 with ten pins, A through J.  "H" is 
>probably ground. "A" and "B" are probably 115VAC. "F" and "G" are 
>tied together and not used --unless as a bridge.  The other pins go 
>through fuses to hidden areas in silver module boxes as seen in the 
>photo I took of the bottom interior:
>
>http://online.sfsu.edu/~hl/R-1230FLR.html
>
>The receiver has 28 tubes and assorted lamps that receive ACV from 
>four taps on the separate power transformer: 6.3V at 0.5A,
>18V at 4.0A, 5VAC at 5.0A, and 7.3VAC at 30.0A. Note from my photo 
>that the tube bottoms are hidden in these modules, so if I don't 
>find the schematic,
>I will have to use Vector 9-pin and 7-pin tube extenders to trace 
>the filament connections of each tube individually to determine how 
>they are grouped.
>
>I enjoy this kind of mystery solving, but, alas, this receiver 
>weighs 65 pounds.
>
>Regards, Hal KK6HY
>
>On Dec 1, 2011, at 4:36 PM, Peter Gottlieb wrote:
>
> > You should be able to figure out several pretty easily.  Start 
> with ground, then use an ohmmeter to track back from a 6 volt tube 
> to the 6.3 VAC pins, same for a 5 volt tube.  Find a plate of some 
> output tube and that should lead you to B+ input (175 VDC?  or is 
> there a separate supply run by 115 VAC inside?).  Either way you 
> will know, and presumably there is some 115 VAC transformer in 
> there from which you can ohm out those input pins.  That kind of 
> technique should get you pretty far.
> >
> > On 12/1/2011 6:44 PM, HL wrote:
> >>
> >>
> >> Wanted: manual, schematics for National Radio Company's 1963 
> countermeasures receiver, Models R-1230 (aka: R-1125 or AN/FLR-11 
> or AN/FRA-54). (Manual ID: NAVSHIPS 94581) I think I can deal with 
> its 65kHz IF output, and I can provide the needed power voltages, 
> but am stymied without a schematic by the power connector with its 
> ten unidentified pins (A through J) for 175VDC, 6.3VAC, 18VAC, 
> 5VAC, 115VAC, etc. Would love to get this wonderfully built, 
> complex beast operating! Any info will be appreciated. Holiday 
> greetings, Hal KK6HY
> >> _
>
>______________________________________________________________
>Milsurplus mailing list
>Home: http://mailman.qth.net/mailman/listinfo/milsurplus
>Help: http://mailman.qth.net/mmfaq.htm
>Post: mailto:Milsurplus at mailman.qth.net
>
>This list hosted by: http://www.qsl.net
>Please help support this email list: http://www.qsl.net/donate.html