[TenTec] Corsair II speaker source?

[Dr. Gerald N. Johnson]

At one time FCC rules were clear about spares requirements for BC 
stations. One summer I was chief engineer for a big 250 watt class IV 
station (for two weeks) and thought I could see the up modulator tube 
wasn't quite drawing the peak plate current of the down tube and there 
were no spares on the shelf. I talked the station owner into letting me 
pick up a spare the next morning after class (summer school). When I 
arrived (no radio in the car) the lobby monitor speaker sounded bad and 
I checked the modulation monitor. Upward modulation zilch, downward 
300%, looked at the plate current meters, up tube, not changing from 50 
ma idle, downward banging against the peg. The operator of the morning 
had only been looking at upward modulation and as that tube gave up from 
running out of emission, he kept adding more audio gain. I had him 
announce technical adjustments and shut down, changed the tube, then 
found to set the bias I had to cheat the interlocks but a custom fit 
stick for that was at hand so brought up carrier, set the bias, shut 
down, closed the back door and went back to program. The owner was 
pretty good, he didn't call while I was inside the transmitter asking 
what's wrong, he waiting until it was back on the air and sounding good 
again. But the spare modulator tube was only a spare a few minutes 
inside the station.

Spares are important, and things we know are going to fail, like 
speakers, are good to have, so I'm looking because I do own a Corsair II.

The Jameco 99996 is a round speaker with the mounting holes 75mm 
diagonal, or just over 2" apart in the two rectangular directions. Not 
oval. Might fit two of the four holes.

Far too many on line search engines are not find engines and much 
merchandise can't be found, like replacement radio speakers at radio 
shack. Lots of automotive and marine speakers though. Maybe its because 
the off shore prices are so low they can't make a profit having to buy a 
million units at a time for 69 cents each to have a stock.

I've had first phone, second telegraphy, and ship's radar FCC 
commercials back when they meant something. Passed them all at age 17. 
Same for my extra. Then I went to college almost forever.

73, Jerry, K0CQ

On 2/26/2011 11:54 AM, Mike Hyder -N4NT- wrote:
> When I studied for my commercial telegraph license, I learned of the
> requirements for maintaining spare tubes. When I spent about three years
> in Ethiopia, that lesson was reinforced as to other parts as well. If
> what I have will help Barry, I'll send it on out (even if Jameco denies
> the part number).
>
> 73, Mike
>