The Mississippi Historical Radio and Broadcasting Society
| Vol 2 #6 | November 30, 1992 |
News Letter
Our regular monthly meeting was held November 8th, 1992 at the usual place and time. A review of the Mall show was covered - the show has netted at least 4 new members so far - and all and all was considered to be a large success. Last month's newsletter was distributed to members at the Mall show. Those that didn't attend will find their copy in with this edition -- Ya should've come by -- it was a lot of fun! The discussion moved to the next show - which is our BIG one of the year. The date and location have both been firmed up - February 27th, 1993 at theÊJ.C.'s building on Hwy 39 north. With the new memberships, and a couple of T's sold, we now have enough (barely) for the building rent. We still could use some working capitol, though -- any suggestions -- donations -- are greatfully anticipated!
Our next regular meeting will be Sunday, December 13 - 2PM at 2412 C St. Meridian. The Zenith console that is currently under full restoration will again be the central subject of our "hands-on" workshop. Last meeting, various stripping techniques, and methods for repairing loose and "bucking" veneers were covered. This time, various refinishing options (staining, final finish, etc.) will be covered. For those of you who haven't seen this project, it is a 1941 console Zenith, that had been "antiqued" using one of those white & gold paint kits that were so popular in the 60's. Underneath that horrible white globbed mess hid a gorgeous walnut / walnut burl cabinet. Why anyone would do that to any furniture - much less something with wood this beautiful -- is beyond explanation. This particular radio is an excellent example of what can and often does lurk beneath some terrible refinishing and/or paint jobs -- and what it takes to restore them.
Radio Collecting Today
This column will be a continuing feature here. It will cover various aspects of collecting, restoration techniques, repairs, and other related topics. This issue's topic is the first part of "Dating a find". It covers some easy to remember "mile stones" to help you put a date on a radio or similar item. While there are always exceptions, these general guidelines can help you date items within reasonable time frames.
Wow!, neat! What is it? How old is it???
You've run across an interesting radio at a flea market, and you like it's looks. The price seems a bit high, but the seller keeps assuring you that this is a real antique! So how old is this thing? There are four major methods of dating a radio:
1)If you are a real "nut" you'll have your Riders and SAMs indexes, both of Johnson's books, both of Bunis' books and a couple of other reference books with you. If you're also lucky, the manufacturers name and model number will all be intact. Then 9 times out of 10 you can date the radio by looking it up. This is a simple and accurate way, but again, works only if everything above is true.
2)If it is a Philco, and built between 1937 and 1953; and the model number is intact, then dating it is real easy. The first two numbers in a model number is the date. I. E. 37-640 is a console built in 1937.
3)If you are a worse fanatic, you will be an expert in the particular brand of radio you found, and will know from memory the exact date (and probably the number of units produced, etc.). Ya, sure...
But if you're like most of us, a little help is in order. And that brings us to method 4.
4)Deducing the approximate date based on clues given by the radio itself. There are three major areas of "clues".
1)It's tubes, etc.
2)Type of set / how the set was constructed.
3)Markings on passive components, patent notice stickers, etc.
This month, we'll look at clue #1. In following installments, we'll look at the remaining clues, and how they can help.
The tube compliment is my favorite method of "quick dating" a radio, because at a glance I can usually place the age of a radio to within a couple of years. Three things about tubes really help in dating:
1)shape and size of the glass envelope,
2) the number and configuration of the pins; and
3) the tube's designation or type.
The "Three digit" tubes - '00, '01, '01A, '02 etc. (1917-1925). These were the first "practical" consumer tubes. The ' in the number is because the manufacturer of the tube was indicated by the first digit, and had nothing to do with the characteristics of the tube - 101's & 201's were made by GE/RCA, 301's were made by RCA but distributed by Cunningham, 401's were made by Kellog, and so on. Designed for use in battery sets, these 5 Volt filament tubes were the mainstay of the early "practical" sets throughout the early to mid 1920's. These tubes usually have 4 - 5 pins, and have "pear" or large "ST" glass envelopes.
WD11, WD12 & 199's (1922-30)
These tubes, with their 1.1 volt filament/cathode, were strictly battery tubes. A tube commonly used with these was the 3.0V filament tube 199 also known as the X99 and the V99. They have tubular envelopes and 4 pins.
The "two-digit" tubes - 24, 27, 40, 45, 80 etc. (1928 - 1936-7) . These are really just new kids on the three digit block - but by now the manufacturers have given up that "first" digit. All of the tubes, even the early ones, are now known by their two digit number. One of the main improvements in this series of tubes is that the filaments are now designed for AC (2.5 Volts, except for the big rectifier 80, which has a filament of 5VAC). These then, become the workhorses of the industry until replaced by octals, in roughly 1935. There are some early "modern numbered" tubes in this generation of tubes, as well - such as the 2A7. Four, five, six and seven pin sockets, grid connections on the top, are all indications of the late 20's to mid 1930's
The Octals and metals (1935 - 1950). Several problems with tubes were solved in 1935 when GE introduced two major advances in tubes - a standardized 8 pin auto-keying base - and a series with metal envelopes for shielding. One of the most well known tubes of this era is the "Green-eye" tuning indicator tube. RCA developed and introduced this familiar item in the years 1934 - 35. It is probably one of the most recognized symbols of radio from that era. 8 pins with a center locating "keyed" pin and 6 volt filaments are common in the tubes of 1935 - 1950
Loctal (1946 - 1955). The metal-based wonder. Introduced during WWII, and because of the fact that civilian radios weren't produced during the war, they were first used in consumer radios beginning in 1946, and are very common in sets from 1948 - 1950. The loctal was very similar to the octal, except for the center locating pin. In these tubes, the pin is metal, for grounding, plus it has a locking mechanism -- making removal of the tube from the socket (whether intentional or accidental) difficult.
Miniatures (1950-1975+). The miniature and subminiature tubes. 1950's - on; sort of! Though around since the early 1940's, (RCA had a portable radio that used them in 1941), these tubes did not come into popular use until the early 1950's. War was the reason for both ends of this time table. Miniatures weren't accepted by the military for use in WWII for the most part (with the notable exception of proximity fuses!), so development and production wasn't pursued with much gusto in the early to mid 40's. However, by the time the "Korean conflict" got underway with earnest, miniatures were a proven item, and were well on their way to replacing almost everything else. One interesting bit of irony here, the tube shields that the manufacturers had worked so hard to get rid of were back. The miniatures have no shielding of their own to speak of, plus, their tiny thin pins aren't real good at holding onto the socket. They come out all too easy. But they reduce the size of equipment by a factor of 4, so a solution had to be found! Sockets, with built-in sleeves to hold shields were developed, and the shields had a spring installed in the top, that both hold the shield in a "locked detente", and press the tube firmly into it's socket at the same time. Problem solved. Shortly after miniatures got a good hold on the market, the next advancement quietly took place. At first, no one dreamed that this tiny device would make virtually all tubes obsolete, but that's just what the transistor did, and in short order.
Next time we'll look at the next clue: type of set and construction notes.
Until next time: Happy Collecting!
The Mississippi Historical Radio and Broadcasting Society Newsletter is published monthly by:
The Mississippi Historical Radio and Broadcasting Society
2412 C Street
Meridian, MS 39301
601 693-5958
© 1992, The Mississippi Historical Radio and Broadcasting Society.
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