Fire Bottles

New! Pictures! I'm finally joining the 1990's and adding some pictures to my text. Look for more photos to be added as time allows. (Alas, many of these sets wouldn't fit into my apartment in Oakland so I had to leave them in a storage locker back in Seattle.)

Not so very long ago, radio sets, televisions, and even computers were built and operated using magical glass fire bottles. When in use, a set would get pleasantly warm and give off a reassuring reddish glow from the fire bottles within. All of this died as soulless crystalline entities gradually replaced the magic fire bottles.

Killjoys will at this point remind us that transistors are more efficient and reliable than vacuum tubes, and besides, aside from some high-end audio equipment, you can't buy tube-based electronics any more. But what do they know?

I've always been captivated by the things, perhaps as a result of listening to old radios as a child. (This was already the transistor era, but tube sets weren't all that old, and when it became clear that I liked listening to the radio, parents and grandparents would let me listen to one of the "obsolete" sets from the attic or basement.) Also, it's a refreshing change for someone like me to with something that is so easily repairable at the component level (which surface-mount technology is definitely not!). I also feel the need to do penance for the sins of my youth, in which more than one old radio was taken apart to satisfy my curiosity.

So at least some of my spare time is currently being taken up restoring old radios. What follows is a list of the old radios I currently have, if any of the terms I use confuse you, the rec.antiques.radio+phono FAQ might be able to clear things up:

Arvin 444A

A real "parts set" I bought it for $7 at an estate sale in Portland. Maybe some day I'll run across another one that has good versions of the parts that are bad on this one. This was a real low-price set when it came out; it only has four tubes, including the rectifier: 12SA7, 12SQ7, 50L6-GT, and 35Z5-GT. The 12SK7 IF amplifier stage found in the "All-American Fiver" is not present. Circa 1946.

Arvin 581TFM

A table radio from 1954. It has both the AM and FM broadcast bands, and uses eight tubes: 6CB6, 12AT7, 6BE6, 6BA6 (2), 6T8, 6V6-GT, and 6X4. I bought it for $10 at this year's Multnomah Swap Meet in Portland. I've replaced all the old wax-paper capacitors in it, more than half the tubes, the electrolytic filter capacitor, and about 25% of the resistors. Both the band switch and the volume control were very noisy and had to be cleaned. I've gone through the entire AM section and aligned it and have also tweaked one or two of the FM alignment trimmers.

The old filter capacitor had degraded to the point where it was essentially a dead short; this had caused the 6X4 rectifier to partially melt down and had burnt open a power resistor in the filter section. A surprising number of the other tubes were either very weak, shorted, leaky, or had intermittent connections in them (thankfully, I had spares for all on hand, scrounged from numerous flea markets). FM plays very well now (as should be expected, given that the FM section has an RF amplifier and two stages of IF amplification). AM suddenly got better after I sprayed an IF transformer with WD-40 in an attempt to unfreeze a slug. I use it in my bedroom for late night and early morning listening; someday I'll go in and rebuild the offending IF can and fix it permanently.

Capehart R-390A/URR

Purchased in January, 1997 for $270 in Tacoma. This is a military (the seller said it was used by the Navy on board the USS California) shortwave receiver designed by Collins Radio, has more tubes than I can easily count, and has a mechanical digital display that is fascinating to watch the innards of as I work the tuning knobs. It is at the opposite end of the spectrum from my Hallicrafters S-38C. It needs a good thorough inspection and cleaning, which it will get as soon as I get a service manual for it. I plan on mounting it in the rack in my radio room and using it as an audio source for an old tube PA amplifier I use to drive a set of speakers throughout the house.

Delco R-1410

I purchased this set for $5.00 at a flea market in July, 1995. This set dates from around 1946 and can be operated on 110 volts AC or DC from a wall socket, or from battery power (9 volts "A", 90 volts "B"). It has five tubes -- 1U4(2), 1R5, 1U5, and 3V4 -- and a selenium rectifier. It tunes the standard medium wave broadcast band (540 to 1610 kHz). I replaced all the wax-paper capacitors (around 20 total!), about half the carbon resistors, the dead 4-section electrolytic, and the selenium rectifier. It now works very well on both batteries and AC; the tuned RF amplifier ahead of the 1R5 converter makes it both sensitive and selective. I've modified the battery connections so that it works with modern batteries (10 9v transistor batteries and six C cells), and plan to show it off at several picnics this summer.

Drake 2B

This is the radio responsible for my current obsession. I had bought it used for $100 about 10 years ago, used it a little, then basically forgot about it as I moved from one place to another in the course of getting through college and my first several jobs. Then one day I opened a storage closet to get something and noticed the 2B looking back at me. I had been toying with the idea of moving one of my digital shortwave receivers into the bedroom for late-night listening, and all of a sudden I thought "why not put the 2B in there".

The magic began as I first turned it on -- no sound, then a little hum, then a little static noise building in the background, then a rapid crescendo as the last of the tubes warmed up and the set came to life. What memories, reliving how an old radio gradually warms up! And that wonderful smell of hot glass and singed dust the tubes make, just like they did 20 years ago when I was a kid! I had become hooked.

The radio itself is a dual-conversion shortwave communications receiver, with 10 tubes -- 6BZ6, 6U8, 6BE6 (3), 6BA6, 8BN8, 6AQ5, and 6BF6. It used to have a 6X4 rectifier but someone replaced it with silicon rectifiers and dropping resistors. replaced the rectifier tube with solid state rectifiers). It is intended for use as an amateur radio receiver, but you can purchase additional crystals to cover any 600 kHz part of the shortwave spectrum that you choose. Modern hams and SWL's use passband tuning as a bragging point when describing their receivers, and act like this is the latest new invention. Not so -- the 2B had this feature over 30 years ago! Its performance rivals that of all but the very best receivers made today.

GE 577

This is a clock radio that I bought together with the Zenith C724W at an estate sale in September 1995 ($10 for both radios). The electronics in it is a very normal 1955 All-American Five: 12BA6, 12BE6, 12AV5, 50C5, and 35W4. The clock has the unusual feature of displaying the day of the week and the day of the month in addition to the time. It has a brown Bakelite case in good condition, but the three little knobs used to set the alarm and snooze features and turn the set on and off are missing.

Grundig SO2U1

A small console Hi-Fi circa 1960. It has three bands: MW (530 - 1620) SW (5.7 - 17) and FM (88-108, so obviously made for the US market). It has a phonograph built into the cabinet below the radio, which has eight tubes: ECC85, ECH81, EM84, EF89, EABC80, ECC83, EL95(2), and a selenium rectifier. It can play stereo records with an external speaker, but is not going to be plugged in at least until the mouse nest gets cleaned out of it. I got it for free in August, 1997 from rec.antiques.radio+phono poster Don Boroski, who got it for the effort of helping to clean out a co-worker's storage shed. It came with the original owner's manual and an (incorrect) schematic.

Hallicrafters S-38C

The classic entry-level communications receiver of the tube era. Essentially an "All American Five" with bandspread and the ability to tune the shortwave bands, it has five tubes: 12SG7, 12SA7, 12SQ7, 50L6GT, and 35Z5. I bought it for $17.50 at the Radio Club of Tacoma Flea Market in August, 1997. After replacing all the dried-out electrolytic capacitors, leaky old wax-paper condensers, out of tolerance resistors, it still didn't work, but sprang to life after the three remaining circuit faults -- two bad tubes (one intermittently so), and a broken wire -- were corrected. It will never beat a fancy communications receiver, but it's surprising what one can hear with such a minimalist set. It sits on my nightstand and gets used for late-night shortwave listening.

One can get an idea of how much "dollar engineering" (in some cases rather clever engineering at that) went into it's design by looking at a picture of the tuning capacitor. Note how the bandspread feature was implemented.

Knight-Kit Star-Roamer

This set showed up on my doorstep one day. A friend of my mother's had found it lying around in her basement and had boxed it up and had UPS send it to me because she had heard I might be able to give it a good home. From the looks of it, it had been assembled by a very sloppy first-time kit builder, didn't work (not surprising, given the number of faults I found in it), was passed on to the friend's late husband, and ended up sitting on his "to-do" pile for several decades. The case, however, was cosmetically in very good shape.

I ordered a reprint of the construction manual for it and went through it step by step, checking all the existing work. After replacing the selenium rectifier and the old electrolytics, correcting the atrocious soldering work, numerous miswirings, and very shoddy construction (just one sample of the latter to give you an idea: the tuning capacitor had been mounted with two pieces of Scotch tape!), it powered up and worked like a champ.

Lafayette HA-52A

This is a VHF/FM communications receiver that uses eight tubes (6CW4, 6AQ8, 6BA6(2), 6AU6, 6AL5, 12AX7, and 6AR5) and tunes from 152 to 174 MHz. I bought it in November, 1996 for $25 in Portland, complete with owner's manual. I've recapped it and it works, but the audio is a little weak (this may be because the set seems to be designed for wider-band FM than most services in its tuning range currently use). I now have something other than a soul-less, computerized scanner to do VHF monitoring with.

Nordmende Elektra C

A very attractive-looking German radio from 1965. I bought it in April, 1995 at a swap meet in Vancouver, BC for $120 Canadian (about $85 US at the time), having decided to for once spend a little more for something that looks nice instead of looking for low price sets (which are often ugly). It has five tubes (ECC85, ECH81, EBF89, ECL86, and EM84), two OA79 germanium diodes, a silicon bridge rectifier, and covers four bands: BC (515 - 1650), SW1 (1.6 - 5.2), SW2 (5.9 - 18.5), and FM (88 - 108). It was obviously made for export to the North American market, because the FM band goes all the way to 108 MHz and the power cord fits domestic electric outlets. Its construction is a real mixed bag, with a solid state ratio detector and power rectifier, and a mix of printed-circuit and point-to-point chassis construction.

Packard-Bell 100A

An "All-American Fiver", circa 1950: 12SA7, 12SK7, 12SQ7, 50L6, and 35Z5. I bought it for $20 (or was it $25?) at the Tacoma Ham Radio Flea Market. I was itching to get my hands on another old radio at the time; had I known what I do now I would have probably attempted to bid the price down more. The set worked when I got it, but there was more hum that I liked and the audio was not very loud. It's since had all its capacitors, two of its tubes, and the volume control replaced; it works much better than when I bought it. The volume control in particular was an annoyance, as it worked just fine until I got done with replacing the last wax-paper capacitor, then it quit on me!

Philco 42-PT-94

This is a transformerless five-tube mediumwave ("AM band") receiver circa 1941. It came out of the attic in my aunt's house in Portland, OR. I've replaced the old, failing components in it; in particular, the noise filter capacitor across the AC line looked roasted and had leaked most of its wax -- scary! I'm not the first person to have worked on it -- some time in the last 30 or 40 years someone replaced the electrolytic capacitor in it. Tubes in it are: 35Z3, 50L6-GT, 7B7, 7A8, and 7C6. Aesthetically, it looks very pretty: inside the loktal tubes have lots of getter which shines and sparkles, outside it has a handsome wood cabinet and marbled phenolic speaker grille. Electronically it is pretty as well, providing surprisingly good performance for a 5-tube set. I currently having it in the living room sitting atop its big brother (see next entry).

Philco 42-365

This is a console radio of the sort that used to be in everyone's living room. Philco used model numbers that started with the year (and just like automobile manufacturers the model year always was ahead of the calendar year), so this set comes from late 1941 or early to mid 1942. Like the 42-PT-94, it came from the attic of my aunt's house. It has 7 tubes (84, 42, 7C6, 7B7 (2), and XXL (2)) and three bands ("Broadcast" (530 - 1800 kHz), "Police" (2.3 - 6.6 MHz), and "Shortwave" (8.9 - 15.5 MHz)). Those are Philco's labels for the bands, not mine, so no flames about there never being police as high as 6.6 MHz. In Seattle, I'd often use it to listen to radio dramas on weekend nights on KIRO. In the Bay Area, it's often finding itself playing the Big Band music on KABL.

You can see a picture of this set, with the previous one sitting atop it (and yours truly sitting nest to both) here. Unfortunately, the lamp I was using to get rid of unwanted shadows also got into the picture.

Philips P145

This is a tabletop I bought at a flea market in August, 1995 for $28. It receives the MW broadcast band and two SW bands (1.8 - 5 MHz and 6 - 16 MHz); or rather it will receive these bands when fixed. It is full of old leaky wax-paper capacitors and most of the microfarads have leaked out of the electrolytic capacitor, which refused to re-form after two days. It has 7 tubes: 6X4, 6AQ5, 6AT6, 6BA6 (2), 6BE6, and a subminiature tuning eye whose type number I can't make out.

Although the set has a European brand name on it and looks very European, it was made in Canada by Rogers after Rogers was taken over by Philips. All the tubes in it are Rogers tubes (including the interesting tuning eye, which I've heard is a Rogers design).

RCA RFA-11V

The Sams Photofact I have on this set dates from 1965, making this about the last of the "All American Fivers". It has a printed circuit board (yes, tubes on a PC board!) instead of a metal chassis; tubes in it are 12BE6, 12BA6, 12AV6, 35W4, and 50C5. I bought it for $1 at an old radio swap meet, replaced the bad filter capacitor, and it works like a champ! It had two wax-paper capacitors, which have since been replaced with mylars on general principles.

RCA 75ZU

I bought it for about $17 at an estate sale (the same one the 444A came from). This is a radio-phonograph (not working, and on the "fix list"). The main reason I bought it was that the case is in absolutely beautiful condition (almost new), and the electronics on the inside aren't that bad either. Electronically, it is an "All-American Fiver" just like the Packard-Bell 100A, with a phonograph added on (the 50L6 tube is also used as the phono amplifier).

Surplus Special FM Receiver

This consists of a circa-1960 monaural Monarch FM-100 tuner (purchased for $10 at a surplus electronic store in Bellevue), currently paired with an amplifier out of an old RCA console stereo that I found at a flea market for $7. The FM-100 was in near mint shape; apparently it came from the back room of a failed Hi-Fi shop and had never been sold or used. After re-forming the electrolytics, I powered it up and it works (I've since replaced the one paper capacitor because I don't trust it). It has seven tubes: 6AQ8 (2), 6X4, 6BA6 (3), and 6AL5. The amplifier has five tubes -- 6AV6, 6CG7, 6V6 (2), and 5Y3GT. It worked when I bought it, but had a hum and was full of wax-paper capacitors, which I quickly replaced (first with the infamous late-model paper caps, one of which quickly developed a leak that made the plate on one 6V6 glow red, then with known-good "orange drop" mylars). The hum was caused by a short between heater and cathode in the 6AV6.

Currently, this radio resides in my office and I use it with '50s era RCA studio monitor speaker. In fact, it is playing as I type this.

Zenith C724W

I purchased this together with the GE577 for $10 at an estate sale. It is an AM/FM tabletop radio built in 1960, with a white plastic case that looks more like a TV than a radio from the back. The case is very well designed and served to keep most of the dust and dirt out of the set (which looks almost new inside, despite the case being very grimy and dusty when I bought it). The case cleaned up very nicely with Windex and looks almost new now (alas, there is a small chip on the right front corner of the set, and the knobs are on the worn side).

Electronically, it is a transformerless AC/DC set with a selenium rectifier (which had to be replaced because it had too much internal resistance and was robbing the set of B+ volts). Tubes in it are 12AT7, 6BJ6, 12BA6 (2), 12AU6, 19T8, and 35C5. That adds up to only 108 volts, so Zenith installed a 39-ohm power resistor to take it up to around 114v. That's still too low for my liking, so I've replaced the 35C5 with a 50C5. FM was totally dead when I got it but was revived by rebuilding the discriminator transformer and replacing a bad 12AU6 limiter tube.

True to Zenith's reputation, it is well built with a sturdy chassis, good quality tube sockets, and only three paper capacitors (two wax, one black molded plastic, all three of which have been replaced with mylars; all the other caps. are ceramic). It has the unusual feature of using the same tube (the 12AT7) as both an AM and FM converter.

Blaupunkt Derby 660

Technically, this set does not belong here, since it is solid state. But (a) I don't have a separate section for solid-state radios, and (b) it is over 30 years old and interesting in its own right. This is a radio designed for both automotive and portable use (this seems to have been popular with many German manufacturers in the 1960s). It dates from about 1965 and has 17 semiconductors (transistors: AF106, AF135, AF122, OC45, AF136, AF137, AF138, AC122(2), and AC117(2); diodes: AA112, BA109/II, E20C30, and AF112(3)). It tunes four bands: AM (500-1615 kHz), SW1 (5-7.5 MHz), SW2 (2-5 MHz), and FM (87.5 - 108 MHz).

I had always wanted to have a shortwave radio in my car, yet I don't drive enough to justify spending $500 or more for a new automotive SWL receiver. When I saw this set for sale for $5 at a flea market in August, 1996, it was too good a deal to pass up. It works well both in and out of the car, but it is fussy about the kind of antenna it has when in a car. If it's not connected to a vertical whip suspended just above a metal surface and fed with the special coax used for automotive receiving antennas, forget it!

Spare Parts for Old Electronics

(This section is currently incomplete.)

Junk boxes.

Tubes.

Capacitors.

High voltage electrolytics are also still available, but in my experience they tend to be pricey. So I've learned to keep an eye out at swap meets and surplus houses. One thing to be aware of is that most old radios use electrolytic capacitors rated in the hundreds of volts and the tens of microfarads; it is easier to find hundreds of microfarads at the required voltage in surplus bins than it is to find the ones in the tens of microfarads. I've left out mica and ceramic capacitors in this discussion because they typically don't require replacing.

It is worth mentioning that old electrolytics can sometimes be rejuvenated; see the FAQ (below) for more information on how to do this.

Links to Related Information

• Rec.antiques.radio+phono FAQ
• Gerard Tel's Radio Gallery (Zeist, The Netherlands)
• Bellingham Antique Radio Museum (Bellingham, WA)

Last changed: 25-NOV-1999 12:52:29