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

[Carl]

>
>
> 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.