Japanese Tube Radio

[maxm]

I picked this set up over the weekend at a yard sale, we all know of the Japanese transistor radios, but there was also tube radios, mostly smaller AM radios that were sold under various brand names (the nameplate is missing from this set)
This look like an earlier radio, based on the styling and the fact that is still sues a point to point steel chassis, I was expecting a PC board in this little radio.

Some other interesting things that set it apart form its American made counterparts:
- The filter cap looks like a modern one, a metal tube covered in plastic, instead of an uncovered metal tube or a cardboard tube, it is also a clamp mounted cap, something I have only seen in older radios from the 30s.
- There is only one IF transformer on the top of the chassis
- All the resistors look like they are wire wound
- The tuning condenser and output transformer looks smaller than normal to me?
-This radio does use wax capacitors, but they look cheaper made than the American caps, they seem to be leaking much more wax than normal, and the paper is coming off some of them.

Just though I would share some observations on this set, since you don't see these too often, they were probably thrown out when they broke (this set was actually repaired at some time, the rectifier tube was replaced with a RCA)
I haven't powered this set up yet, but will soon, those bad looking wax caps will probably have to go though.

[Charlie]

Hey, I have two of those little sets! One carries a name brand of Invicta (i think) and i don't remember what the second one is. IIRC, they use AA5 tubes. The 35W4 and 35C5 tubes get pretty hot, and have created stress cracks in the cases because they are just barely below the top of the cabinet. I know that one if them actually works, but seems it needs something cause the audio starts to fade after 10 minutes or so.

Yes, the insides do look pretty cheesy, and the tiny chassis are kinda hard to work on. Guess i will have to get them out tomorrow and see if they still play.

[Chad Hauris]

I have one of these, it is a "Hi-Fi Master". Performance is good...the metal electrolytic cans used in Japanese sets still tend to be in good condition.
The IF circuitry cheats somehow...I think it uses an inductive coupled circuit with a single choke and capacitor to replace one of the traditional IF tranformers. There is a tiny schematic on the cabinet of mine that shows how it is wired but cannot remember exactly.

[maxm]

One question I forgot to ask...

In almost all the early electronics I have seen form Japan, the steel parts have this yellowish/goldish/greenish tint to them, as opposed to the regular silver/grey steel we see in American electronics. Is this some coating on the metal, or something form the manufacturing process?

[Sandy G]

Yeah, I've puzzled about that, too ! Must be some kind of chromate covering they use-but you're right-a LOT of the pieces parts have it on 'em. -Sandy G.

[Thatch_Ear]

Looks like the stuff labelled Monarch and Calrad which I think came out of the same plant as Kenwood/Trio/Realistic. That PS cap an Elna? Suzuki wire wounds?

[Sandy G]

Well, Max, have you got 'er goin' yet? I remember my dad brought me back from Louisville a similar set in about '64-I was 7 & all it would pick up was the local station, WRGS. Seems like it would pick it up from about halfway up the dial to the very end. WRGS is 1370 KC & you would start hearing splatter from it about 1100KC, IIRC. Don't remember what happened to the l'il fella, but it was Japanese, & was yellow & white plastic & tubes. Wished I had it now, but being the destructive little shit I was, it might have been lost in some "experiment".-Sandy G.-junior-league budding mad scientist

[merrylander]

Those are carbon resistors, very similar to the way they were made here in the 30s. I think that may be a cadmium plating on the chassis.

Rob

[bgadow]

I've got one, blue cabinet, also missing the nameplate. I've never tried it out. I picture these selling at the corner drug store or something like that, and had to have been real cheap.

I have a Radio Shack (Archer, I think) capacitor substitution box from the early 70s by the looks of it. Stamped made in Japan. I opened it up the other day because the label doesn't list the voltage rating. I expected to see some sort of orange drop clones but instead there are some really cheesy looking paper caps. If I get bored some night maybe I'll recap it.

[Charlie]

I have another Japanese radio that I forgot I had. The brand is National and it's an AM/SW receiver with dual speakers, a colorful face with blue and red numbers and a clear blue dial, and even a tuning eye! There is also inputs for a phonograph. All the righting on the back is in Japanese. The radio works pretty good, although the volume control needs a little spray in it. IIRC, i never did anything to it other than clean it up. Someone in the past made a repair to the bottom of the cabinet using epoxy... aparently there was a crack in it.

The tuning eye is a 12ZE8. I havent' found this number anywhere, and no substitutes. I'd like to get a fresh one as this one is very weak. If someone comes across a listing for this tube, please let me know.

The rest of the tube line-up is 12be6,12ba6,12av6, 30a5, and 19a3.

The front of the dial glass says Wide Sonic All Wave. Wow doesn't that sound fancy!

Sorry, the photo is a little fuzzy due to camera malfunction... damn piece of crap!

How about UM4, UM34 or 1629 for a 12ZE8 sub? Check out this auction for 2 12ZE8 Magic Eye Tubes

[Charlie]

Cool... i will check into that.

I did find a radio very similar to the one I have on this website. It's apparently a japanese site, but the photos show good and the radio is nearly like mine...

http://www.geocities.co.jp/Technopolis/1660/am-380.htm

[maxm]

I brought the set up on the variac last night and it worked!
Not the best sound, but not bad for a cheap set full of leaking wax caps.

The filter cap and resistors were made by "king"...

It is intersting how "American" these sets are, there is no Japanese writing on the set, including the valuses on caps and resistors, the tubes are American numbers...etc.

I will post a PIC soon when I get it put pack together so you can see the case...

[Jeffhs]

Originally Posted by Charlie

I have another Japanese radio that I forgot I had. The brand is National and it's an AM/SW receiver with dual speakers, a colorful face with blue and red numbers and a clear blue dial, and even a tuning eye! There is also inputs for a phonograph. All the righting on the back is in Japanese. The radio works pretty good, although the volume control needs a little spray in it. IIRC, i never did anything to it other than clean it up. Someone in the past made a repair to the bottom of the cabinet using epoxy... aparently there was a crack in it.

The tuning eye is a 12ZE8. I havent' found this number anywhere, and no substitutes. I'd like to get a fresh one as this one is very weak. If someone comes across a listing for this tube, please let me know.

The rest of the tube line-up is 12be6,12ba6,12av6, 30a5, and 19a3.

The front of the dial glass says Wide Sonic All Wave. Wow doesn't that sound fancy!

Sorry, the photo is a little fuzzy due to camera malfunction... damn piece of crap!

That picture isn't bad, Charlie--not from where I sit, anyhow. Looks pretty darn good, as a matter of fact.

Looks to me as if the Japanese were a few years ahead of us when they expanded their AM band to 1650 KHz, as the dial on your set shows, though the FCC went a bit further with the expansion of the U. S. broadcast band (to 1710) when that took effect some years ago. Perhaps, by now, the Japanese AM band has been expanded to at least 1710 KHz as well, if not more.

As to the slogan on your set's dial scale, that was very common in the '60s. Many radios, particularly imported transistor sets, showed fancy high-tech sounding names on their front panels 40 years ago. I once had a 2-transistor radio with the name "Coronet" engraved in fancy script lettering on the front and a crown emblem with a small hole in the center, to show the dial scale as it was engraved on the tuning knob. This radio also had a volume control with a similar scale arrangement to show sound level (and a small red dot at the off position of the switch).

Cute as all get out, but these sets didn't work well, or in some cases at all, unless you were very close to your area's local stations--in fact, these things were lucky if they picked up one station, let alone two or more. IIRC, on a good day, mine didn't get more than one local station about five miles from where I used to live, and wouldn't do much better in the small town I live in today, as the AM radio signals (except the local station in the next town, which only relays [simulcasts] a classical station 50 miles west of here these days) are rather weak out here.

BTW, I often wonder why those little 2-transistor sets had speakers; as I said above, they wouldn't work worth a plugged nickel unless you were close to at least one powerful station. These things may have produced enough volume for earphone listening (and probably did, with a strong local station), but how they could drive a speaker with only 2 transistors is way beyond me.

[maxm]

Originally Posted by Charlie

I have another Japanese radio that I forgot I had. The brand is National and it's an AM/SW receiver with dual speakers, a colorful face with blue and red numbers and a clear blue dial, and even a tuning eye!

Wasn't National the name used on early Panasonic sets? I've seen some that say National-Panasonic...