ER Article - RCA Radiotron UV200 and 201 Tubes - Well Worth The Read

[W1UJR]

If you are an Electric Radio subscriber, you won't want to miss Bob K7AK's wonderful article on the history and
use of the UV200 ad 201 tubes in the current issue of ER.

If you are thinking about using this tube family in a homebrew regen, or transmitter, its a must read. Bob also gets into detail on the two most common types of regen receivers - one stage and three stages, and deals with many other topics.

It is fitting for an AWA Review article, its that well researched and written.
Not sure if Bob is a member here, but a very hearty "well done" to you old man.

If you don't subscribe, be sure to borrow a friend's copy, its well worth the read.
Or better yet, this provides a real excuse to add yet another radio publication to your mailbox!


-Bruce



Regen set at W1UJR, uses a pair of 201s

[W3GMS]

Bruce,
I just finished reading Bob's excellent article in the latest issue of ER.  Bob obviously did a lot of research in preparing the article and the results of his labor certainly shows.  As you mentioned, it would be very well placed in the AWA review. 
Joe, W3GMS   

[k4kyv]

One item should have been included in the last paragraph.  RCA not only produced a thoriated tungsten version of the UV201, they also produced one for the UV200.  It was named the UX-200A (RCA) and CX-200A (Cunningham), a.k.a. 00-A.  I have one.

I'm pretty sure the UX and CX prefixes indicated the more modern version, which had longer pins and would fit a 4-pin push-in socket as well as the twist lock.  The older UV versions had short pins and required the bayonet socket.

When 5-pin tubes came out, like the 24-A, they had a Y designation, such as UY-224 and UY-227 (24-A and 27).

Actually RCA started out with a series of five "UV2xx" tubes in the early 20's: The UV200 and UV201 as described in the article, then came the UV202 which was an audio power triode/ small transmitting triode, the UV203  "50 watt" transmitting triode and the UV204 which was their largest transmitting triode.  The corresponding thoriated versions are 00-A, 01-A, 203A and 204-A. The latter two are sometimes referred to in the older handbooks and magazine articles as the '03-A and '04-A.  RCA never came out with an 02-A.  Instead they released the type 210 which probably ended up being the most popular amateur transmitting tube until screen grid tubes like the 6L6 and 807 came out.  Some 210's have the thoriated tungsten filament while others have an oxide coated filament.  The thoriated version is said to be the better rf transmitting tube.

The 211 was soon released as a lower-mu version of the 203-A.  There was a whole family of "50  watters", which actually had a plate dissipation rating of 100 watts and were good for about 100 watts rf carrier output in class-C service.  These include the 845 super low-mu triode (recommended by RCA for class-A audio use only), and later on, the 838 high-mu triode capable of zero-bias class-B service.  The 805 was released as a slightly higher power rated 838.  Both tubes have identical internal structures, but the 805 brings its plate connection out to a cap at the top of the glass envelope instead of using a base pin, allowing for higher plate voltage rating and slightly higher plate dissipation rating.

A very good article.  About the only one that aroused much interest for me in this issue.

[W2DU]

I don't have access to a Radio Electric publication, but I'd like to read the history of the UV-200.

The first radio I built used a single UV-200, no regen, in 1925. I still have two or three of them around, plus a few UX-201A's. I still have a few UV-199's. My first tx was a UX-210 Hartley in 1933. Later on I used the 210 to drive a 203A.

Walt

[W1UJR]

Walt, do you have any photos of the 201 sets you built, sure would be interesting to see!

What I found very great about Bob's piece was that he had collated a huge amount of tube lore and history down to just several pages. I could search out vintage RCA tube books, magazines, manuals, and assorted old old publications before I could find even half of what Bob developed, very well done, very pithy.

Even more I appreciate how he got into the old regen designs, something which has become increasingly fascinating for me in my quest for minimalist radio. I love playing with the old regens now, simpler is sometimes cooler!

I think this winter I may acutally build my first wooden radio, I've saved up the parts and pieces to do so, just need a good design. The Doerle two tube regen with a pair of type 30 tubes, has caught my eye. It looks pretty enough, but wonder how it performs? Somewhere I've got the orignal, or is it a reprint, of Hugo Gernsback's publciation on the Doerle sets.