[Milsurplus] More Navy radio in China 1944 - 1945

[W7QHO at aol.com]

In a message dated 6/19/05 7:36:12 PM, kargo_cult at msn.com writes:


> A 300
> watt TBX portable transmitter with an Olin 400 cycle rectifier power supply 
> that was
> run by a small engine replaced a 7 megacycle short wave set for 
> communication with
> the fleet and Pacific commands. As one radio operator recalled, "It whined, 
> but what
> a signal! It could pierce anything. The trouble was that it used a lot of 
> gasoline and we
> would run out of it....We finally got diesel generators. Whe had difficulty 
> getting
> diesel fuel too, but the generators were more efficient"
> 

Agree this was probably a TBW but some of the description doesn't fit.   The 
TBW ran off 115 volt, 800 (not 400) cps   primary power provided by one of 
several MG sets, one of which included a gasoline engine.   Others were driven by 
115/230 volt 60 cycle and 115/230 volt 25 cycle single phase motors.   The 
same 115 volt, 800 cycle generator made by Onan (not Olin) was used with all MG 
sets.   These generators howl like a banshee which could be the "whine" 
reported in the reference.   None of the MG sets could be properly called a "
rectifier power supply" but the TBW did include a "Modulator and Rectifier Power 
Supply" unit normally mounted between the HF and MF transmitter sections.   No 
mention of a diesel powered MG set in my 1942 Westinghouse manual, but something 
like that could have been kluged up in the field.

The TBW was officially rated at only 100 watts out on CW/MCW and 25 watts on 
phone, but   this may have been minimum, worst case values.   Can't see 
getting more than 200W CW out of one, though.   Still a lot more than a TBX.   The 
TBW also came with a humongus antenna system which could account for it's 
reported performance advantage over the earlier "7 megacycle" radio.

Dennis D. W7QHO
Glendale, CA




Dennis D. W7QHO
Glendale, CA