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Post by Admin on Oct 7, 2019 1:02:23 GMT
My son works for a video production facility. He does both studio and live remote technical directing. The owner is a pack rat like most of us. He throws away nothing, simply adds his old equipment to a store house located on his property. My son occasionally brings me some of the cast offs. A few months ago he brought home an RCA Radiola Model B-52 radio, circa 1942. This is a table radio designed for battery operation, great for rural farm life where batteries were the electric supply for the family. There was also an AC adapter (UC-42). The radio was dead when I got it and it set on the floor of the shop until a couple weeks ago when I decided to check it out. A 5 tube Superhet (2-1N5GT, 1-1A7GT, 1-1H5GT and 1-3Q5GT), all the tube filaments were bad. They run at 1.5 vdc and I figure someone hooked up the wrong size battery since all the filaments were bad. So I ordered a set from Antique Electronics Supply. They arrived two days ago. I cobbled up a 90 vdc B+ supply and a "D" cell for the filaments and checked it out. Not dead but not so good. Had to replace 3 capacitors and give it a tune up. Wha-La, working radio! A little glue up of the case and a little polish and on the shelf it went. The first night I tried it out, among all the locals were also some DX stations. Very appropriate was a station in Rochester, NY playing Old Time Radio programs. It was like being catapulted back to 1942. Here's some Pix of the unit. You'll notice the "D" cell on the left and ten 9 vdc batteries for the B+ on the right. |
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Post by mark on Oct 7, 2019 16:42:47 GMT
Nice! How long do the batteries last with continuous listening?
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Post by Admin on Oct 7, 2019 18:14:45 GMT
I don't know yet as I just started using it a couple days ago.
The B+ current is only about 12 milliamp so I have to think it should run awhile.
I haven't measured the filament current. The "D" cell was old to start with measuring about 1.3 volts. The filaments are parallel so I could look up the data on the tubes to figure it out but quicker to just measure.
Last night I heard a Boston station.
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Post by mark on Oct 7, 2019 20:50:33 GMT
The filaments would use most of the power from the D cell. You can easily see the current drain with a miltimeter on the 10 amp setting and lift the D cell off the contact at one end and use the meter probes to complete the circuit. At least the B+ is very low so those expensive 9V batteries will last a long time!
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Post by Admin on Oct 8, 2019 1:08:13 GMT
Don't think I'll see anything on the 10 amp scale.
These tube filaments are very low current on the order of 50 milliamp. The 3Q5GT is rated 100 milliamp at 1.5 volts.
The 5 tubes would draw about 300 milliamps.
Carbon zinc "D" cells are rated at 4.5 amp hours so that should run the filaments for about 15 hours.
A pack of 12 Rayovac 9 volt batteries was about $20.
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Post by Admin on Oct 8, 2019 1:39:01 GMT
Tonight I'm listening to KYW 1060 in Philadelphia. When I was a kid, KYW 1100 was a Cleveland station from 1956 to 1965. They were a very popular station playing rock. Gerry "G" was the hot jock. en.m.wikipedia.org/wiki/Jerry_G._BishopI taped his farewell show around 1965. Many years later I found him working KPOP and sent him a copy. He was so grateful that he sent me a copy of his show "There's More There Than Hair" from when he toured with the Beatles to produce the program. |
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Post by mark on Oct 8, 2019 4:28:23 GMT
Sure do miss the 60s and great DJs with rock and roll radio. Suggested the 10 amp setting so you wouldn't blow the fuse in the multimeter till you knew the current but the 300mA would show as .300 amps. I listened to Cousin Brucie on WLS Chicago from Toronto at night and Wolfman Jack when he went to WABC New York. Cousin Brucie was, up till awhile ago, still on Satelite radio on the 60s station but I don't know if he is still alive now.....I should look it up. Last I heard on someone's satilite radio was maybe 12, 13, years ago at the cottage but he didn't sound like he did in the 60s.
Just looked it up and he is still there! On Saturday nights on Sirius Satalite radio on the 60s station. He's 83 years old....or young!
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Post by Boomer on Oct 8, 2019 22:44:25 GMT
Great radio, real wood!
I like that radio a lot, and it must have cost a dear sum in its time, to be used on a farm, and it's lasted. I like how it goes all the way to 1700 kilocycles on the dial. People probably wouldn't think that's strange today, because now most radios do tune up that high. In that time, broadcast stations didn't go up that high, but I believe 1700 was added because it was a police band then, so you could hear police calls. I read about that, but it's been a long time, and I recall that the police were 'radio dispatched' to calls, but didn't have a way to talk back by radio to headquarters, and had to find a telephone and call the station house.
I have a radio, I think it's Sentinel brand painted Bakelite table radio, Loctal tubes, that has 1700 on it. I like how yours has the meter band on it, on the small pictures I was thinking it had the longwave band on it too.
I have a battery portable, I forget the name, known manufacturer, I'm sure. All plastic outside, a bit curvy, not a sharp cornered box, metal chassis, miniature tubes, D cell slot, and I think it takes a 67 volt "B" battery with a polarity plug. All that in a small lunch box size case, not bad.
Oh, it has AC power, selenium rectifier and electrolytic cap. The rectifier is the only junction component in it, all the rest is tubes. It was still working last I tried, and it had been constantly used for several decades as a kitchen radio. I need to take the time and do blogs on my different radios!
Most of those old radios sounded good, not good audio response by today's standards, but it was clear, it must have been 5, 6 or 7 kilohertz, so it gave a crisp sound compared to today's radios that are so narrow they sound like someone talking through their nose. They narrow the highs, then lop off the bass to compensate, leading to a monotonic sound that's harder to hear.
I had a Sears aqua and ivory colored plastic case 5 tube radio, probably lower end and for a teen's room, and it could blast with room filling volume, just a few watts from a 50C5.
Boomer
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Post by station8 on Oct 12, 2019 22:11:18 GMT
Hi All: Nothing beat them classic vintages radios. It's to bad a lot of today's company's don't use more of their imagination when building today's radios! If you guy's haven't seen this site check it out! vintage-electronics.comEnjoy and have fun Station 8 |
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Post by Admin on Oct 19, 2019 2:54:29 GMT
Here's another of my old radio collection. This one is the "Country Belle". A 5 tube superhet in an old fashion crank wall phone reproduction. AM only, it has a minor problem. The volume will pop up and down over a period of time. Probably a coupling or bypass cap breaking down, causing an abrupt change in tube bias. As 1950's radios go it's fairly sensitive. The controls on the right side of the box are a "crank" for tuning and two knobs for volume and tone. The on-off switch is the telephone earpiece hook-switch. Pickup the earpiece to turn on the radio.    |
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Post by Admin on Oct 19, 2019 2:59:59 GMT
And here's a little more visual info about the "Country Belle" radio. A drawing from the patent info and a paper detailing the radio.   |
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Post by station8 on Oct 19, 2019 13:13:45 GMT
Hi all:
That's nice your showing history!.
You should have a history page on this site
Then break it down in sections folders
Phones, radios am/fm/sw, test equipment
Transmitters am/fm/sw section, etc
And sort by manufacturers.
Be a nice history museum page site
And well worth the work!.
Station 8
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Post by Boomer on Oct 20, 2019 5:23:28 GMT
The Guiltenna
I'm sure I've raised a Guiltenna or two in my lifetime..
5-tube radios are great, I've heard so much AM radio on one of those, or a transistor. I had a 5-tube table radio in my bedroom real early, because there were plenty of used ones around, you could find them at junk sales for a few dollars.
Once I had one and the outer case was gone, so it was just the steel chassis, with all the tubes, the speaker mounted to it, and the tuning with dial string, loopstick on an insulator card, all in the open and working. I think there was still a pointer and the face for frequency.
There were no knobs, just the metal shafts, and I could feel the electricity on it as I adjusted the controls. It picked up stations well, even like that, and at night it seemed like there was a station on every frequency.
5-tube radios are efficient performers, even with just a one tube IF amplifier, because they use double-tuned IF transformers, meaning both primary and secondary are tuned. Most IF transformers used in transistor radios just have the primary as the tuned tank circuit.
People would have liked the nostalgia of the Country Belle if they were from the era of crank telephones, showing that even in that day people looked back at old technology.
Bob, I think you should open a radio museum, and since you do carrier current Part-15, you have the perfect station to feed the radios and promote the museum.
Boomer
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Post by mark on Oct 20, 2019 6:50:08 GMT
When I was a kid I had a Marconi 6 tube as it had the RF stage and it was a real super radio! All hand wired. No noise from the A/C power back then. Tubes were 12BA6 RF, 35W4 rectifier, 12BE6 mixer/osc. 12BA6 IF amp, 12AV6 pre-amp, and 35L6 amp.
Had it till the mid nineties and then when the power got so dirty and really couldn't listen anymore so it went in a garage sale.
Regretted it later. If I could ever come across another the same model I would get again.
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Post by Boomer on Oct 20, 2019 21:29:01 GMT
That sounds like a premium, or what they'd call a 'long distance' radio. I've seen ads for those, you can hear your favorite sports team or news from a distant city.
Using the 35 volt heater for the power amp instead of 50 volt allows the design to squeeze in another 12 volt tube for the input RF amp, that's clever. You get more sensitivity and selectivity that way, and the tuning capacitor has 3 sections instead of 2.
I haven't had a favorite radio with 6 tubes, but had some to repair or take apart on the bench, including console radios I'd drag home back then.
Maybe you can find your Marconi if you go look at auction sites regularly, they have tons of old table radios.
My radio regret is a Zenith 'Grenadier' model from the late 1960s, solid state AM/FM table radio. My neighbors threw it away, and I found it was just the surge resistor that was blown, so I replaced it with one from a TV, 33 ohm I think, and it worked well.
I didn't use it to DX the AM band or anything, but just seemed to have it around in different rooms with me for a long while. Finally the AM/FM switch broke, and it was a complicated multi section switch I never could find a replacement for. I let the radio just sit in the basement for several years, then got rid of it in a cleanup, but now wish I hadn't. I guess it had a 'Guiltenna'.
Another I'm looking for is my mom's kitchen radio. I'd have to look to see what model it was. I could barely see over the counter to look at it, and remember how 540 was written as a 5 with a smaller 4 on it, like in superscript, and I thought that was funny.
Boomer
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