Collecting 201A Radio Tubes
by Hal Kravig
In the early 1950’s I was fascinated by electronics and radio. I remember that on my shortwave radio I heard that Joseph Stalin had died the day before the local newspapers had the story and in 1953 I got my amateur radio license WNOQCD. I thought it was marvelous that one could communicate around the world. I lived in the Black Hills of South Dakota on the northern side of a mountain. On the radio I could make contacts around the world on 40 and 20 meters, and 10 meters when the band was open, but couldn’t work the southern United States because of the mountain between us. I even contacted the King of Jordan once. My QSL card had a pick and shovel crossed behind a gold pan to symbolize my local Homestake Gold Mine roots. For the King I actually glued a gold nugget to the card to make it worthy of who I was sending it to. When other parents were whining about where there children were at night my mother said she always know where I was, in the basement calling CQDX into the night.
After school, college, two years drafted in the army and many years of work into the mid 70’s I saw an old RCA AR1300 crystal set in a coal company’s sales office where I bought charcoal for my BBQ and more than a year later they agreed to sell it to me. In back they had the RCA AA1400 amplifier that went with it that had three beautiful brass based, clear, tipped UV201 tubes in it. One tube had an open filament and so I looked for a replacement. I looked at the ham fests and for a period of time I didn’t find another UV201 that had good filaments either. I was a novice who didn’t really know about early tubes but I did acquire a few more old radios with various 201A and 301A tubes in them. I decided to learn something about the 201 tube as they seemed to be using the 201A and 301A interchangeably.
With the formation of RCA there was a standardization movement in tubes to populate the earliest commercially reproduced radios. Tubes were to be numbered 00, 01, etc. to 99 with the prefix number to mean the manufacturer of the tube, e.g., 101 was Arcturus, National Union or Ken-Rad, 201 was RCA, 301 was Cunningham and 401 was DeForest. Some manufacturers used their own, different numbering system. De Forest who had used DV2, DV3, etc. converted to 401A and so did CeCo who had used type A, K, etc. tubes converted to 201A tubes. It must have been thought that 100 tube numbers (00 through 99) would cover every conceivable tube at that time. The early US tubes, 5 volt filaments tubes had one ampere filaments and until the mid 1920’s all the sets were battery sets so the early tubes were energy hogs that would run down a battery in no time at all.
The early tubes also had four small short pins (UV based) each with uniform thickness and relied on a locating key on the side of the base to insert the tube correctly into the socket to align the filaments with the correct pins. Contact was usually made to the bottom of the pin but some complicated sockets could grasp the sides of the pin and the base key would hold the tube in place in the socket. The early tubes also had the vacuum evacuation tip at the top of the tennis ball, tubular or globe shaped glass envelope that was very prone to breakage and to lose the vacuum in the tube. Tubes were expensive and radios were sold without tubes with tubes extra. Early tubes were all clear as there was no getter in them.
The early tubes went from brass based to porcelain or Bakelite based for electrical and production cost reasons and went from tipped to tipless by evacuating the remaining air and contaminants in the air from the bottom of the glass envelop and hiding the evacuation point inside the Bakelite base. The base was also changed to have two, longer large pins for the filaments and two, longer small pins for the grid and plate elements in the tubes thereby simplifying the tube socketing and orientation problem. This became known as the UX base and the tubes were simply pushed into the socket. The UV and UX based tubes were interchangeable with an adapter to mate the tube to the socket and to align the proper elements to the pins.
Battery drain was still a big problem and tubes that drew less current had less durable filaments that would become weak as contaminants remaining inside the vacuum tube formed oxides on the filaments reducing their emissions and effectiveness.
There were a group of tube tester manufacturers that made tube rejuvenators to restore correct operation of these tubes. The principal they used was to raise the filament voltage above the 5 volts normal for operation for a short time to burn off the oxides that had attached and coated the filaments thereby reducing the tube performance. The elevated voltage and the duration was a function of the filament material. As the tubes were clear and had no getter the tube going through the rejuvenation process lit up like a light bulb and was a scary encounter.
The tube manufacturers standardized on the suffix A to denote the lower 1/4 ampere version of the 01 tube so a UV201A is the same as a UX201A or a UX301A except for the basing and the manufacturer. Research was conducted by different groups to improve the filament material and the vacuum in the tubes and thereby allow the 1/4 ampere tubes to work longer. The technique developed was to place a small photo-flash type pan inside the tube and when the vacuum was drawn down and the tube sealed the flash material would be ignited and would burn using up the remaining oxygen inside the glass envelope leaving a more perfect vacuum. This also coated the inside of the glass with the getter material that made a shiny coating of the glass to appear from the deposits on the inside of the glass.
Various types of material were used for this flash getter that caused some tubes to have silver coatings, some gold and some to have rainbow coatings. The amount of getter was a function of how much air was left in the tube, a poor vacuum had more air and more resultant getter and a good vacuum had little air and little getter visible in the finished tube. I have heard tube sellers at swap meets say that there is a lot of getter left so this signifies that there is still has a lot of life left in a particular tube. A small getter probably means the tube was better to begin with.
Later tube manufacturers made shoulder tubes (ST shape) and tubes with lower current draw for the filaments with UX201AA, B, BB or C suffixes to denote even lower current draw. The current draw was not so critical with the advent of AC sets in the mid to late 20’s and with rural electrification of the 30’s (REA). And in 1934 the new tube numbering system was developed where the first digit(s) signified the filament voltage, the next alpha letter the function of the tube and the final number the number of elements in the tube. The 2A3 is the same triode as the 5A3 and 12A3 except with different filament voltages. With better manufacturing processes and better filament materials and the vacuum could be drawn down to near perfect conditions, and the getter was less needed.
In the early 1920’s there were but a few tube manufacturers and some other licensed tube manufacturers that used the prefix 101, 201, 301, 401 etc. according to their license and maybe another prefix e.g. GX201A to denote the manufacturer. Tube manufacturers licensed by RCA used the 201 number and licensees of Cunningham used 301 and the tube manufacturers and licensee’s proliferated. Soon there were hundreds of tube manufacturers, some legitimate and some knock off versions of popular brands. The prefix was dropped and the tubes became know as the 01A for the generic version of the 201 with a 1/4 ampere filament. In Minneapolis I saw a collection of different brands of 201A’s at the Pavek Museum that was built into a glass front bookcase built into the wall between the studs. This makes a beautiful display collection in a relatively small space and really shows the 201 that popularized radio in the 1920’s and made radio a commercial reality.
With my growing collection of battery sets I needed 201A’s and so I traded my common RCA and Cunningham 201A’s for uncommon brands so I had a collection of different brands of 201A’s within a collection of battery sets. In a glass cased battery set or an exposed tube Colin Kennedy set a compliment of five gold Super Airline GX201A’s is a beautiful combination. In an AK breadboard a set of rainbow and tipped 201A’s is awesome even though the rainbow, tipped tubes were not from the same identical period. 01A’s come in many different shapes and sizes. I know of about 30 blue tube brands, six gold brands and tubes also came with amber glass, green glass and pink glass.
At one of the national AWA swap meets I met with Ed Bell who had a collection of different brands of 01A’s larger than mine and he showed me a list made by Brother Patrick Dowd, editor of “The Vacuum Tube” column that had appeared with several updates in the AWA Old Timer’s Bulletin. Brother Pat is the curator of the Manhattan College Vacuum Tube Museum in New York City. The most current list at the time was published in the Old Timer’s Bulletin of about 400 different brands to which Ed had added about 15 more that were not listed from his own collection. The list has been updated and republished several times in the OTB over the years. I reviewed my collection against the list and found many additions to bring the total up some more. In May 1995 the Bro. Patrick Dowd list published in OTB listed 513 different brands including the additions Ed and I had found. George Fathauer published a book, Radio Tubes and Boxes of the 1920’s, July 1999, with a list of 547 different brands that he had obtained from Bro. Patrick Dowd for his book. When I was at the AWA meet in Rochester a few years ago I showed Bro. Pat my list of over 600 known brands which now also includes Ed Bell’s collection. Bro. Pat in turn called over Ludwell Sibley, author of Tube Lore, to show him our list. The chuckles followed and the list still grows.
As we find tubes on the list it confirms that the tube listed was real. We also add names to the list as we find out about them at swap meets, auctions, and from comparing notes with other collectors. Bro. Patrick’s latest list that I am aware of, listing 628 brands, was published as a booklet put out by the Tube Collector’s association 12/2/99. At present the list I update contains about 750 known brands. Some tube manufacturers from the 20’s era may not have made their own branded 201A tube, and I am sure a tube known as a Tipless Rytone is the same as a Ry-Tone and a Wasco Tipless is the same as a Wasco, but rebranded to highlight their innovation, so there may be some duplication of the same brands on the list but from a different vintage.
It is obvious that there was much appeal, and knock-offs, for some names, e.g. Clarion, Claritone, Claritron, Clearatone, Cleartone, Cleartron, Keen Tone, Kleen Tone, Kleer Tone, Kleertone to cite a few. Some of the names on the list seem implausible until you find one of the tubes, e.g. “By Heck”. Come on is that real? Who would name a tube that name? At an AWA Charlotte meet I saw a By Heck tube box in a contest display a few years ago The picture on the box was a hillbilly with straw hat, bib overalls, thumbs hooked in his suspenders, back arched and saying “By Heck ’nuther tube if this don’t work”. Later I found a By Heck tube NIB, with the same slogan but unfortunately not quite as good graphics. Other tubes are not marked on the base nor is there a paper label, just the designation DX-201A, etc. Other tubes you may never find unless you find NOS. I ran across a person who had about eight Essex tubes NIB and carefully opened each box and none of the tubes had any marking on the tube even though the boxes were perfect and the packing undisturbed.
Not all tubes that have the X01 designation are 01A’s. The Kellogg 401 and Sparton 401 and other 401 numbered tubes are often AC tubes, with 15 volt filaments that connect via a plug for the filaments at the top of the tube, used in the Kellogg and Sparton and a few other sets. Even so these are the same vintage triodes as the 201A.
Except for the very early 1 ampere 201 tubes the 01A is very resilient over time. If the filament is good there is a high probability that the tube is also good. Of course there will be the occasional shorted and gassy tubes but they aren’t too common. I have a handful of known shorted and/or gassy tubes that I use to check tube testers to see if they read the same and detect gas and shorts. Be careful handling radio tubes as they will brake easily if dropped and the tipped versions are still prone to breakage and of losing the vacuum. I have a Livingston brand 201A that I dropped and had to tape the decal label back together just to show that there really was that brand.
Ed Bell asked me how I display my tubes, I don’t, and instead I keep them in Antique Electronic Supply boxes with 64 honeycomb dividers. The NIB tubes that won’t fit in the AES honeycomb boxes I keep in other boxes. Ed didn’t have a display set up either. Along with a lot of 01A’s I have a number of other old tubes that I bought because there was an odd brand 201A included in the lot. I also have hundreds of duplicates of 01A’s to trade since I bought Ed’s collection. I am not an ebay seller though I do buy on ebay and at other auctions, but won’t chase a tube price out of sight just because I don’t have it. I have set up an ebay ID, radiohcn, to sell duplicate tubes when I retire in early 2008. Long ago I decided that no matter how many 01A tubes I found the list would still grow and I would not collect all of them. My advice to collectors is find what is available and unless you have a lot of money to invest don’t try to obtain every last 01A. Tube box art from the ‘20s is an attractive complement to the tube collection as are very early tube testers.
For any who would like the latest 201A list email me and I’ll send you an up-datable list in an Excel spreadsheet with columns to write in your own inventory list. Just let me know what brands you find that I have not yet listed.
I collect early tube literature, tube advertising, and tube testers to display with my 01A collection and collect battery sets, particularly exposed tube, glass panel and glass cased battery sets that display the venerable 01A.If you ever run across any odd brand 01As let me know.
Regards,
Hal Kravig, PO Box 341361, Memphis TN 38184 or call toll free (866)
237-7940 nights and weekends or (800) 859-4436 weekdays. Hal Kravig, W4OZL, PO Box 341361, Memphis, TN 38184. Email hkravig@bellsouth.net (home); radiohcn@netscape.net (for eBay).
