[Milsurplus] Re: Question on commercially modified surplus BC 433 gear for marine mkts

[BOEING377 at aol.com]

I am still trying to find out who did the modifications of the SCR 269 (BC 
433) radio compass ADF gear for the commercial marine market. I recall seeing 
these in the 1960s and the conversion was especially well done.  The control 
head was modified with a new freq dial so that band 3 now covered 2-3 MHz. 
instead of previously topping out at 1750 KHz in the mil stock version.  It was so 
well done that it looked 99.9% original.  Jack Antonio generously gave me one 
of these modified BC 433 control heads and it was just as I had remembered it 
as a kid. The rcvr was modified by tweaking the band 3 osc coil and perhaps a 
few other changes such as realignment. Someone went to a lot of trouble to do 
these conversions. My dad (a commercial fisherman) told me that they came out 
of San Diego and someone else thought it was Morrow Bay CA . They were marketed 
primarily to the tuna fleet. I have posted this question before, but perhaps 
some new reader has a clue about who did these conversions. The converted ADFs 
worked beautifully on the marine band and still covered NAV beacons on the 
lower bands. Only part of the BC band was lost in the process. Other commercial 
conversions that I saw in the fishing fleet included gray hammertone painted 
BC 375s with xtal control, ART 13s with xtal control, and even some command 
sets with xtal controlled xmit although these command set conversions looked 
quite crude. There were also some ARC 1's operating as "secret radios" somewhere 
in the VHF region. LOTS of APN 4 and APN 9 Loran A sets, operated stock without 
mods other than perhaps a solid state inverter to give 110VAC @ 400 cps. 
Linear Systems (SBE affiliated?) and Topaz both made 12 VDC and 24 VDC to 110 VAC 
@ 400 cps inverters to replace the noisy brush eating power hungry rotary 
inverters such as the MG 149 (24 VDC) and the very rare PE 109 14 VDC rotary 
inverter.