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

[Carl]

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.

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.

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

Jerry, you still have time to make that trip before the first blizzard.

Carl
KM1H


------ Original Message ----- 
From: "Dr. Gerald N. Johnson" <geraldj at weather.net>
To: <collins at mailman.qth.net>
Sent: Thursday, September 02, 2010 1:13 AM
Subject: Re: [Collins] Looking for information on the Cunningham C201 and 
C203tubes


> http://www.oldradio.com/archives/hardware/Collins/300.htm is probably
> where the Cunningham stuff comes from. Models 300, 300C, 300D, and 300F.
> From the late thirties. I see it says a station at Washington DC was on
> 1120, that's a clear channel with KMOX in St. Louis entrenched there for
> a very long time.
>
> Based on other historical pages, Cunningham was forced out of the tube
> MAKING business by RCA and allowed to purchase tubes made by RCA (after
> the first 5000 tubes were completed by Cunningham) labeled Cunningham.
> Later on tubes were often labeled Cunningham/RCA. Or RCA/Cunningham. I
> believe I have a tube manual from that era, but I don't know which box
> its in right now. And that agreement between Cunningham and RCA happened
> about 1920, so by 1936, there would have been no unique Cunningham
> tubes. Besides which the C201 I remember would have been what others
> called a 101 or 301, the 01 being the definitive part of the label and
> the first digit often preceeded by a letter or letters such as CX201 for
> Cunningham. Most "01" tubes were interchangeable, but not transmitting
> tubes, mostly superseded by 01A improvements. Still receiving tubes.
>
> http://www.collinsradio.org/Signal08-33.pdf has an article about the
> 300B using 203As. My 1940 Radio Handbook data said 203A were made by
> RCA, Taylor, and GE.
>
> Reading several '33 to '35 Collins Signal, I see some use tubes like 245
> and 203A without prefix and some had a C prefix. And that sequence also
> mentions a 300A which the page up above left out and left out that the
> 300 family of transmitters could be tuned up for short wave as well as
> MF transmission. I suspect 300.htm is not the epitome of accurate
> history. There is a large collection of Collins material in the library
> at Iowa City (University of Iowa) that might possibly have more details
> like drawings and manuals, but its 150 miles for here and I don't need
> to know that bad. There is a folder labeled "Broadcast Transmitters" in
> one of the 39 boxes.
>
> The collection of Signal does show that Collins used standard tubes and
> also their own numbers with the C prefix that didn't quite match
> industry numbers. Yet the ratings of the RCA 203A shows 130 watts
> carrier so a pair would do 250 watts AM.
>
> 73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.
>
> On 9/1/2010 9:00 PM, Carl wrote:
>> The C stands for Collins, not Cunningham although Collins did not make 
>> them.
>>
>> Some were made by Amperex and relabled standard tubes such as the HF-100,
>> HF-125, HF-150, HF-200, 211H.
>>
>> I dont have specific data on the ones you mentioned but there should be a
>> relatively common replacement from Amperex, United Electronics or other
>> small speciality companies.
>>
>> Collins did this to not get around patent issues but control replacements
>> and laid good smoke screens in their ads and literature.. Motorola did 
>> this
>> very well in later years.
>>
>> Do you have specific transmitter models?
>>
>> Carl
>>
>>
>> ----- Original Message -----
>> From: "John Hensley"<w5jv at hotmail.com>
>> To:<collins at mailman.qth.net>
>> Sent: Wednesday, September 01, 2010 2:44 PM
>> Subject: [Collins] Looking for information on the Cunningham C201 and
>> C203tubes
>>
>>
>>>
>>> Some early Collins transmitters (1930's) used Cunningham tubes.  One 
>>> unit
>>> I have been studying used C201 or C203 tubes which I am wildly guessing
>>> weretriodes.  Dunno.
>>> Can anyone show me a diagram with operating voltages, etc. for these
>>> andwhat would have been more modern substitutions?  A pair of the C201
>>> ran100W I believe as compared with the C203 which could do 250 watts.
>>> All I know.  Any input appreciated.  The Cunningham #10 catalog does
>>> notshow them.  The bottom line is I need to figure out the closest RCA
>>> equivalentwhich might be available.
>>> Thank you,
>>> John W5JV
>>> ______________________________________________________________
>>>
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