[Milsurplus] National R-1230 countermeasures receiver
zbyte at comcast.net
Sat Dec 10 00:16:22 EST 2011
Many, many thanks to those in the Milsurplus group who responded with recommendations and to Francesco Ledda with some critical PDF pages.
Progress report: With the help of a partial schematic, I traced all wires of the ten-pin power connector and then carefully applied voltages to confirm each traced connection. Everything worked; all tubes lit up; and the receiver came to life. However, sensitivity was quite low, so, now every stage will have to be checked--a slow process to begin early next year --IF I can find a complete readable schematic. Meanwhile, for anyone who might own this remarkable receiver, here are the Amphenol (Type 18-1) pin IDs with voltage/current measurements. Note that other versions of this receiver may have different pin allocations.
Pin A 115VAC (for the rear fan if installed)
Pin B 115VAC (for the rear fan if installed)
Pin C 175VDC (B+ at 250mA)
Pin D 7.3VAC 5.5A (reduced by internal resistor to 6.3VAC)
Pin E 7.3VAC 5.5A (reduced by internal resistor to 6.3VAC)
Pin F no connection
Pin G no connection
Pin H Ground
Pin I 5VAC 330mA (for receiver lamps, other side grounded)
Pin J 18VAC 730mA (reduced to regulated 6.3VAC for V301 filament, other side grounded)
Again, if anyone has any readable schematic pages for either the R-1125/FLR or the R1230/FLR, please let me know. I am desperate!
73 Hal KK6HY
Website for receiver: http://online.sfsu.edu/~hl/R-1230FLR.html
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