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

[Dr. Gerald N. Johnson]

There is some real original history at:
http://www.collinsradio.org/archives/Collins_Radio_Signals_From_1930s.aspx
Original documents from the time, no garbled memories. Makes for 
interesting reading about this topic. Several featured the 300 family of 
radios in ham service.

On 9/2/2010 1:12 PM, Carl wrote:
>
>
>>
>>
>> On 9/2/2010 8:11 AM, Carl wrote:
>>> I seriously doubt if Collins used the RCA 203A for long, if at all, as
>>> it was a 1923 introduced tube of fairly low reliability and obsolete by
>>> the time Collins got into the BC market. The 203A was simply a higher mu
>>> 211 and was rated at 100W output in Class C AM service (1934 RCA
>>> Transmitting Tube Manual) so a pair wouldnt make the 250W of the Collins
>>> TX.
>> The 211 went on to be the VT4C of BC191 and BC375 fame (or
> infamy).
>
>
> And one of the audiophools most sought after tubes. I understand the
> Chinese version is quite good.
> My earliest vintage rig is PP VT4C's in a classic yooper circuit except
> it doesnt yoop. Its on 80M, feeds coax fed antennas and runs regulated
> DC on filaments and B+. I should have DXCC with it soon. Then I'll
> rebuild to a multistage 160-20M rig with PP VT4C modulators.
>
>
>>
>> The 1933 Collins Signal articles show tubes like the 203A while the
>> 1935 Collins Signal articles show common receiving tube numbers, like
>> 245 or the common 866 rectifier with mostly C prefixed numbers for the
>> power tubes.
>
>
> In 1933 I would have expected the 203A to be used, serious competition
> didnt come until a 1-2 years later; I wasnt aware that Collins was into
> BC rigs that early. Somewhere I have an interesting history on Amperex
> and it is amazing how many different areas of tube applications they
> were deeply involved in and also how far back they went.
>
>
>>>
>>> There was almost no order to industrial tube numbering back then and
>>> companies simply used whatever they wanted. So a RCA 203A was quite
>>> different from a C203, and CE203 (MV rectifier)
>>>
>>> If any Collins documentation exists I feel rather certain that Amperex
>>> would be at the top of the supplier list as they were very active at the
>>> time and despised RCA. Personally I believe they made better tubes which
>>> certainly would have attracted Art Collins.
>>
>> I don't know what documentation Collins kept in the 30s. I know in the
>> 60s that every bit of every product had to be covered by a component
>> specification. Nothing could reach production without a complete set,
>> preferably from a list of preferred parts. Everything had a part
>> number down to the least bit of hardware.
>>
>> These component specifications described the part, who was acceptable
>> to make it (like carbon comp resistors excluded IRC), and how to test
>> it. Samples had to pass test by the components spec department at
>> intervals to stay in use. A significant fraction of the surplus bought
>> by McKercher and then by Surplus Sales of Nebraska were parts that had
>> survived or failed those component qualifications tests, or incoming
>> inspection.
>>
>> In the 60s, I know Art showed a definite dislike of RCA. Someone
>> proposed using RCA 8122 instead of 4CX350 for 300 or so watt linear
>> stages and broad band driver stages. Their data sheets show the same
>> characteristics, but the 8122 cost half the price of a 4CX350 and fit
>> in a 98 cent socket versis the $10 socket for the Eimac tube.
>
>
> And were they lucky they didnt. The initial NCL-2000 prototype had
> 4CX350's (its still in existence) and National was convinced to switch
> to the RCA 8122 which caused them serious financial and reputation harm.
> RCA's eventual redesign was slow in delivery.
>
>
> < This went
>> into a working paper which Art dutifully read and responded, saying,
>> "I've known Bill Eitel since 1936, we'll use Eimac tubes." Could have
>> been he was soured by rotten performance of the RCA 203A.
>
> RCA was years behind in new designs for service up to a 1000W and didnt
> have a new power tube until the 833 in 1937, the 813 in 1938 and the
> 811/812 in 39. By that time Eimac, H&K, Amperex, Taylor, Raytheon and
> others were feeding the demand.
>
>
>
> I wasn't all
>> that pleased with the Eimac 4CV100,000C that had great plate
>> dissipation but the innards of a 4CX35,000 and they were worked to
>> glowing to get 125KW carrier. We had to melt down many tubes to get
>> Eimac to make tubes that would actually meet the data sheet claims. I
>> spent days one time with their graphic tube calculator coming up with
>> 123 or 124 KW output before figuring in losses. We certainly yanked
>> their chain wanting new data or better performing tubes, which VOA may
>> have actually gotten from Machlett.
>
>
> I never got into RF much beyond 10KW but spent awhile with industrial PS
> in the 100-500KV range, that was interesting!
>
>
>>>
>>> Cunningham receiving tubes would not have used the 201 label as that was
>>> RCA as in UX-201, and UX-201A which became the ubiqitous 01A of battery
>>> radio fame. The Cunningham version was imprinted C-301A and also
>>> CX-301A. Other competitors used varying prefixes and numbering for the
>>> same tube such as 401A, 501A, etc with a lettered prefix somewhat
>>> indicating the manufacturer, NU, SY, etc
>>
>> OK.
>>>
>>> Jerry, you still have time to make that trip before the first blizzard.
>>
>> Only if I don't get finished moved before that first blizzard.
>
> After this summer you are probably waiting for it. Im not thinking
> beyond Earl for the moment.
>
> Carl
> KM1H
>
>>>
>>>
73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.
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