Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Other Topics => Topic started by: Frankenamp on June 12, 2010, 11:11:47 pm
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The other evening I took two hours to compose a nice email to a not quite so nice Freecycle.org moderator after attempting to post "wanted: old tube equipment" the individual sent me a snippy reply that accused me of posting a list... :evil5: I Bcc'd the response to the offensive moderator (citing examples & chapter and verse...) to the War Office... well, to make a long boring story short... My better half happened to be looking for garage sales to cruise (and drop off the odd AVON flyer) and saw an ad for a garage sale locally that mentioned "tube radios" in the blurb <perk> well, ya nevvah know... So this morning I dragged my tired keester off to the address mentioned- and managed to hit a small jackpot. I made off with three before I had to go in to work to crack the whip on my day off <love being on salary at times like this> on the way out of work I mentioned to SWMBO that I had snagged three radios, a couple of engineering rulers, and a (free) microclip test lead set for about $15 or so... her reply was to :huh: go back and get a few more if the price was so good! :angel: I wasn't sure there would be many more left, but no guts- no glory... The second time I went over there there were still a respectable pile of radios to paw through and I left there with another four plus a Wavetech 27XT DVM for another $25 (and another radio added to the pile- because it was going to a good home) Needless to say I was happy with the outcome... (no old Tweeds, but what the hey) There are enough toys to feed my Frankenstein, and I might learn something in the deal. As it is, The meter was more than worth it! Now I have to find some radio repair resources... Anyone have a good site?
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All AM: some with clocks. Most with the all-American miniature 5 lineup:12BE6, 12BA6, 12AV6, 50C5, 35W4. The only two variants were the Heathkit (transistor- skunked me) and the Zenith M505 AC/DC portable job which was most unusual:1U5 (diode/pentode) 2- 1U4's (sharp pentodes) a 1R5 (pentagrid converter) and a mighty 3V4 (power pentode) which my RCA book says takes a whopping 90 volts on the grid & plate and kicks out a thunderous .24 watt! Lots of neat features- battery (missing) cord on a reel, removable antenna with (hardened) suction cups to attach the 'wave magnet' to a handy window or something... nice case minimal dings no cracks. The other Zenith was a model A 512 Y with twin speakers and the tube layout seems to suggest that the 12AV6 can be interchanged with a 12AT6. A cursory examination reveals that someone tried to recap with two skinny wires sticking out of the top of the chassis attached to one section of a multi-cap which was rolling around freely inside. the outstanding features are twin 4" speakers and a phono input Black & gold trimmed plastic cabinet that looks like it may be able to be buffed out nicely. Two run of the mill GE radios: one clock, one plain. The plain one looks to be mostly intact, the clock one has the odd wire sticking out from inside the chassis :shocked: (one for the bench). A fairly nice looking Emerson clock radio (with accessory timer socket) revealed tubes on a circuit board (looks late 60's early 70's) cost cutting to the extreme. The peice de restance was a black and gold Bulova clock radio that looked better built than average (there's a worse looking one on fleabay with a $30 tag. (wife liked it) The other interesting piece was a little turquoise blue Japanese radio marked "Londala" which was a marvel of miniaturization. the tube lineup has scarcely 1/8 inch between the tubes! (wife likes that one too)
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Now I have to find some radio repair resources... Anyone have a good site?
Of course.... Antique Radio Forum (http://www.antiqueradios.com/forums/).
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Thanks! :grin:
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> most unusual: 1U5 (diode/pentode) 2- 1U4's (sharp pentodes) a 1R5 (pentagrid converter) and a mighty 3V4 (power pentode) ... a thunderous .24 watt!
Very standard Battery Beach Radio. Anything more than 0.1W-0.25W eats expensive batteries too fast. The speaker will be fairly efficient, but unless large, won't have bass.
You can battery-up with 5 to 10 9V batteries. Plus D-cell(s) for filament power.
Power that is "a lot" for a battery is trivial from the wall. The hard part is dropping the filament power. You may find some messy switching.
With a proper -isolated- power source, this would be a fine micro guitar amp. Go in at the top of the volume pot. You may need more gain; a booster pedal is simplest. If you franken-hack, take the IF tube as a preamp.
> The other Zenith was a model A 512 Y with twin speakers
Many high-end Zeniths were very nice machines.
> the tube layout seems to suggest that the 12AV6 can be interchanged with a 12AT6.
No real difference. In fact they were often sold interchangably. On paper the AT has less gain but for AM radio use that's a teeny change of Volume knob.... you never "dime" an AM radio.
Some Bulova radios were fine, others were the cheapest commodity contract junk with a Bulova badge. Bulova was pretty good at making nice-looking boxes.
I think you know, just saying for the lurkers: these are Hot-Chassis radios and dangerous to power-up while the case is open.
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Thanks for the info- seems like I'm always learning something from y'all.
If I can get the 'beach radio' up and running, I'll keep it as is, it's in pretty good condition. There's a GE 'speedometer radio' that has a couple wires hanging out that shouldn't be, and a phono input- but no visible switch... The dual speaker Zenith also has a phono in and a switch... and has a big clunky multicap hanging by a couple strands of what looks like kynar wrapping wire rolling around inside. Fortunatly it has a tube chatr with model #s but no schem. the Japanese mini radio has a schem but it's microsize and may not have the exact same values... How pervasive is "silver-mica disease"?
Oh Yeah, Ditto on the hot-chassis safety! wasn't it a standard murder-mystery device to drop a radio in the bathtub (before blow dryers were invented)?
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I'll third on the hot-chassis warning. unless you get it plugged in the right way for its power cord and your outlet, you will have line voltage on whatever body part touches it.
Now, I'd like to say nice find and capture, Franken. Most people around here where I live seem to all too keenly *THINK* top dollar collectible even if condition won't support that price.
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If you need any 1V "beach radio" tubes, let me know, I have a zillion of them NIB and you can have them for free; eg, what it costs to ship them.
That was MY last garage sale find. *#*(#$*&^ I bought a load of tubes circa 1942-1958 and I must have hallucinated two full sleeves of RCA 6V6 brand stinking new. There were a fair no of 6V6 in there--motley brands...but NOS, and metal 6L6 for days plus some transmitting tubes, prob 3 dozen NOS 5Y3, and whole load of crap.