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

[Dr. Gerald N. Johnson]

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tubes, mostly superseded by 01A improvements.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
>> ______________________________________________________________
>>