[Collins] Looking for information on the Cunningham C201 and C203tubes

[Dr. Gerald N. Johnson]

On 9/2/2010 2:27 PM, Carl wrote:
> Very interesting reading Jerry and thanks. It confirms my earlier
> statements.
>
> I see that the 300B is rated at "in excess" of 200W which means they
> were pushing the 203A's.

And they may not have been aiming for CCS service or 20,000 hours tube 
life. In ham applications they probably figured it took years to 
accumulate 1000 transmit hours so the tubes could have several years of 
lifetime while pushing the RF ammeter a bit harder (though the 
difference didn't make much difference in the DX worked, still doesn't).
>
> In the 45A the C-830B is an Amperex 830 or 830B and the C-211D is a UE
> 211D. Both were later made by others.
>
> In the 202A the C-200 is obviously a HF-200 or a UE HV-18. I also note
> that the 202A also offered the new Eimac companies 150T as an option for
> the C-200.

Might had to have changed the base socket to fit in the 150T, almost 
sure to have needed different grid and plate leads and maybe caps. So 
long as they kept the upper frequency limit to 15 MHz, lead length 
wasn't a problem. Though in the advertisements I linked a few minutes 
ago, one of the ham transmitters was rated to have a 5 meter option 
along side the 10m option.
>
> The 600A continues the Amperex relationship with the C100 which was a
> rather unique tube with a C100D also used. Both apparently can be
> replaced with a 2A5 for circuit functionality. The HF200 or HF-300 were
> the output tubes.
>
> After WW2 the 300G switched from Amperex to the RCA "developed" 810
> which is the same as a HF-200. Was this because thousands of 810's wound
> up surplus in 1945?

I'm sure of that. My boss in the BC and High power transmitter 
department was Lloyd Winter, badge number 5, lower than Art's badge 
number. He told me they used much surplus in the post WW2 BC transmitter 
designs that eventually became very costly to get parts like new vernier 
drives made to the WW2 specs when the makers had gone out of business. 
Many WW2 makers went out of business post war because of the huge 
stockpiles of surplus product sold at a price they couldn't match. Like 
10 cent 807s and 810s. Eventually Collins had to redesign all the 
broadcast line to get rid of the no longer available surplus parts. 
Heathkit did the same thing. Bought train car loads of surplus tubes and 
then figured out how to use 6SN7s for a VTVM and gain stages for a scope 
using 5BP1 radar display tubes. The early kits shipped with military 
surplus tubes.

I used a pair as modulators for surplus 250TH's when
> I was still in HS in 57; and found NIB surplus ones a few years ago for
> a current modulator for HK-354's.
>
> Carl
> KM1H
>
73, Jerry, Technical Adviser to the Collins Radio Association.