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1951 Zenith Super Trans-Oceanic H500 Short Wave Radio

Started by HobieSport, December 08, 2008, 06:52:49 PM

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PSGreg


[/quote]

If that don't do it, send it to me.

D/P


[/quote]

This sounds easiest  :D

When I plug the radio in it does absloutely nothing.  No tubes light up.  Nothing hums.  It's as though I hadn't plugged it in.
Best,
         Greg

BDM

Here are some pics to show you the very basics of these sets. This is my bench test set. It's a perfectly good 500 series that I like fiddling with on the bench every so often. It came to me with very low B+ due to well worn selenium rectifier.

Here is the all famous selenium rectifier in these sets.


Next, I connected a diode, anode is fed the AC, cathode emits the DC. Remember, these in effect are half wave rectifiers, 60/hz ripple.


Next, the DC dropping resistors. I generally start off with about 150/ohm 5 watts power resistors. From that value you can tweak it to achieve about 8.2 - 8.4 DCV at the condom resistor. Look at the next two pics to see what I mean.



Next, I confirm voltage at the tubes. You must check across pins 1 & 7 of each tube to see what voltage it is seeing. In this next pic, I'm checking the all powerful, desired, famous, and expensive 1L6 osc tube. I like to see the 1.4v tubes right around 1.3 to 1.4 volts, no more no less. Some run the 1L6 tube as far down as 1.2 volts. I find they don't oscillate reliably at the higher freqs around that voltage. Also, some tubes will oscillate fine, while others that may have greater mileage will not oscillate at all. Personal preference here.


Here is the main electrolytic filter can. I prefer to cut these open and stuff the new caps inside. Remember, these aren't standard by-pass caps, but electrolytic capacitors with a negative/positive connection. They also are "floating ground", meaning they don't directly connect to the chassis ground.


I keep the removable antenna from a 600 series T/O handy for bench work. Makes things easy during alignments. Remember, the T/O antenna is part of a tuned circuit. Operating these sets without one causes not only weak reception, but hum, degraded/distorted audio also. I've read post from folks in the past that actually tore their T/Os apart thinking something was wrong, when it was nothing more than a poor antenna connection. The antenna connections in the lids of the G500 & H500 sets are famous for poor and intermittent contact issues. WATCH OUT FOR THAT! A good sign is distorted audio and weak reception.


Last. These are "hot" chassis sets. Meaning they chassis is hot, not isolated like on a transformer operated set. If you're touching the chassis, and somehow touch something that is grounded to an AC outlet, you'll regret it!! I like to use isolation transformers when working on AC/DC sets with hot chassis. I also try and use the "one arm" rule. Meaning one arm is kept off all thing electrical whenever possible. Having suffered a 300/dcv ZAP that knocked me on my butt, and caused a severe burn to my fingers. I can't say enough about electrical safety!! I'm serious, had I had a weak heart in any way, I probably would have been a statistic.
--Brian--

St Clair Shores, MI

McHeath

QuoteHaving suffered a 300/dcv ZAP that knocked me on my butt, and caused a severe burn to my fingers. I can't say enough about electrical safety!! I'm serious, had I had a weak heart in any way, I probably would have been a statistic.

Yikes!! :o


Steve


I don't know anything about radios, but I see your ready for anything. 12 ga, switchblades, and brass knuckles. hands off my T/O bad guys!
If you're a long way from home,
Can't sleep at night.
Grab your telephone,
Something just ain't right.

HobieSport

#49
Quote from: Dan/Panther
Matt; I have what is called an SSTRAN 3000 am transmitter. I hook it to my computer and broadcast Old Time Radio shows to my AM radios. You can buy a kit, for about $100.00 from the internet. At least you used to be able to.  D/P

That's perfect for what I want to do and with my, er, "modest" skill level.  Thanks D/P. Here's the link to the product and the company for anyone interested:  http://www.sstran.com/index.html

Quote from: Steve...12 ga, switchblades, and brass knuckles. hands off my T/O bad guys! 

Hmm.  Yes.  Interesting set of tools you use there. ;)

BDM

Quote from: Steve on January 12, 2009, 03:14:35 PM

I don't know anything about radios, but I see your ready for anything. 12 ga, switchblades, and brass knuckles. hands off my T/O bad guys!

LOL...Didn't even consider that until I posted the pics. Now, believe it or not, I have a good excuse ;D The switch blade belonged to my great uncle who was a Detroit police officer back in the bad old days. He took that off someone many moons ago. I would imaging in the 50s or 60s. It's an American made blade of all things(imaging that). It is without a doubt, one of the best letter/box openers I've ever owned. The blade is actually quite dull from years of opening boxes with it.

The knuckles I recently found at my mothers home. I honestly can't remember were they came from. She recently passed away and I've been going through stuff, and that was one of many things I've found. The lighters get used for wire stripping ;D

My brother needed shells recently for trap shooting. I'm loaded with years of shells I've collected. I used to be a big trap shooter myself. Anyhow, he needed bird shot of course. Not #4 shot high power shells. So I pulled'em out, and threw them on the desk.
--Brian--

St Clair Shores, MI

McHeath

Sure, sure, good stories all but we know the real story is that you are not about to let anyone take that Trans-Oceanic baby without a stiff fight!
;D


Steve

Quote from: BDM on January 13, 2009, 09:04:04 AM
Quote from: Steve on January 12, 2009, 03:14:35 PM

I don't know anything about radios, but I see your ready for anything. 12 ga, switchblades, and brass knuckles. hands off my T/O bad guys!

LOL...Didn't even consider that until I posted the pics. Now, believe it or not, I have a good excuse ;D The switch blade belonged to my great uncle who was a Detroit police officer back in the bad old days. He took that off someone many moons ago. I would imaging in the 50s or 60s. It's an American made blade of all things(imaging that). It is without a doubt, one of the best letter/box openers I've ever owned. The blade is actually quite dull from years of opening boxes with it.

The knuckles I recently found at my mothers home. I honestly can't remember were they came from. She recently passed away and I've been going through stuff, and that was one of many things I've found. The lighters get used for wire stripping ;D

My brother needed shells recently for trap shooting. I'm loaded with years of shells I've collected. I used to be a big trap shooter myself. Anyhow, he needed bird shot of course. Not #4 shot high power shells. So I pulled'em out, and threw them on the desk.


Good stuff.

I work in construction, and it's funny that we have a similar tool kit :)

Detroit P.D. you say? they used the nickel plated S & W model 10's. there's a bit of a cult following for those. does he still have it?
If you're a long way from home,
Can't sleep at night.
Grab your telephone,
Something just ain't right.

BDM

Quote from: Steve on January 15, 2009, 09:12:41 PM
Quote from: BDM on January 13, 2009, 09:04:04 AM
Quote from: Steve on January 12, 2009, 03:14:35 PM

I don't know anything about radios, but I see your ready for anything. 12 ga, switchblades, and brass knuckles. hands off my T/O bad guys!

LOL...Didn't even consider that until I posted the pics. Now, believe it or not, I have a good excuse ;D The switch blade belonged to my great uncle who was a Detroit police officer back in the bad old days. He took that off someone many moons ago. I would imaging in the 50s or 60s. It's an American made blade of all things(imaging that). It is without a doubt, one of the best letter/box openers I've ever owned. The blade is actually quite dull from years of opening boxes with it.

The knuckles I recently found at my mothers home. I honestly can't remember were they came from. She recently passed away and I've been going through stuff, and that was one of many things I've found. The lighters get used for wire stripping ;D

My brother needed shells recently for trap shooting. I'm loaded with years of shells I've collected. I used to be a big trap shooter myself. Anyhow, he needed bird shot of course. Not #4 shot high power shells. So I pulled'em out, and threw them on the desk.


Good stuff.

I work in construction, and it's funny that we have a similar tool kit :)

Detroit P.D. you say? they used the nickel plated S & W model 10's. there's a bit of a cult following for those. does he still have it?

Don't know as he died many years ago. My cousins received much of what he owned. But, I seem to remember his revolver and it was nothing more than a blue .38... I can remember it in the closet. If he had another gun, I wasn't aware of it.
--Brian--

St Clair Shores, MI