Anybody own or repaired one of these...
 

A Zenith Transoceanic Model H-500 (1951). Nice cosmetics, but nothing but a loud hum...no stations...suspect the PS cap. I have the Sam's schematic but could use some step by step help with the diagnostics.

Thanks.

These are fairly easy to restore, if you've done tube radios before. I did one such set, and it still hummed-until I replaced the Selenium rectifier.

Also, that set uses a very expensive tube-the 1L6. While the rest of the tubes in your set sell for about $3-$5 each, the 1L6 sells for about $35. Maybe more, now, since I haven't checked in awhile. Use a 1R5 (if you have one) in place of the 1L6 until you you get it working properly.

These are good performing radios when completed. I use one for a bedside radio.

C25 is the first place to go. C26, C27, C28 next if they are all in one can. But C25 will get rid of the hum. Jump it out with another one.

Username1,

This is a four section cap isolated from the chassis. It looks to me like they used the (metal cap can) twist tabs, which are isolated too, as a common connection point for lots of other components that needed to be insulated from the chassis...maybe the B-,...it's very confusing to me. :scratch2:.

I've pulled the can and am going to replace with individual caps--perhaps going with a bit larger values than the original. What do you think?

Thanks.



Leadlike,

My, quite a big and fancy bedside... :D

Yep, first thing I did was replace the SL with a diode and hum is still there. Thanks for the info on the tubes, I looked on that auction site and the 1L6's are outrageous, some are asking $100. I'll look for the 1R5 as you suggest to use during testing. BTW, is this a direct sub for the 1L6?

Thanks.

I have this guys older brother (8G005) on my bench right now waiting for me to re-align it. On mine, both can caps are insulated from the chassis, as is the tuning condensor. I replaced all the electrolytics and paper caps, which for two or three of them involved temporarily removing other components in order to get to them. There was a bad mica in the tuning assembly getting to which required partially disassembling the tuning assembly itself. All in all, one of the less fun recaps I've done, but its a nice radio, will be nicer when I get the alignment touched up.

There is some documentation of your set here:http://www.transoceanic.nostalgiaair.org/
though you may already have all you need.

Another alternative for preserving the expensive 1L6, someone sells an adapter that allows you to use the 1LA6 Loktal tube. Some information here:
http://bellsouthpwp.net/p/a/padgett46/bilh1la6.htm

Here's an ebay site selling the adapter (no affiliation).http://cgi.ebay.com/1L6-to-1LA6-Adap...94716360272430

FWIW, there have been cases where that 4 section filter develops a short from one of the B+ sections to the low voltage 200mf section that's across the filament string. Bill(oc)

Hey, i actually own one of these! Though im near useless with electronics..thats why im here, to start to get a grasp on them. Its its not an obviously bad cap, bad wiring or a tube that tests bad..im useless. Im a very "monkey see, monkey FIX" kinda guy right now.

Though at least mine still works great after all these years.

The 1R5 is a direct plug-in substitute. It just doesn't oscillate high enough to do much when you change to the shortwave bands. But, just to check that the radio is working on the AM band, it works just fine. Not all 1R5s were created equal-some will do several of the shortwave bands, and on the set I just worked on, the 1R5 couldn't do anything above the AM band-just a terrible howl coming from the speaker.

On my set, I put in a locktal tube. I didn't buy or make a conversion socket, I just soldered flying leads onto the tube pins with thick wire, and plugged it in.

I have one. The only tube Trans-oceanic I have right now. Not as nice cosmetically as yours, but never had a problem with it-still works! Should by-pass that selenium eventually, though... Good luck and keep us posted!

My grateful thanks to everybody for your suggestions and comments...

I spent some time with the radio today and added discrete caps (larger values too) to replace the multi-section...and viola, we have lots of stations and absolutely no hum! Isn't that just the "bees knees". I'll probably put the multi-section cap back in just for looks.

BTW, what do you guys use to blacken up the vinyl on your radios if you have any covered with this?

It's not really vinyl, believe it's called Tolex or whatever Tolex was back in the day. Clean the covering first. I use Goop non-pumice orange "flavored" hand cleaner. Then you can shine it up with black shoe polish. If it's really discolored, use black shoe dye instead. That will bring it back.

Be very careful with those 1-volt filament tubes. Don't pull a tube while the set is powered and then plug it back in. The filter cap will build up a charge in between and zap at least one tube with overvoltage on reinsertion.

http://www.antiqueradios.com/forums/...t=transoceanic

It wouldn't be fair to not show you this guy's restoration of his set-everything he does is completely correct, and very thorough.

Boy!! that's quite a thread--thanks for the link. BTW, lost a 1U4 :sigh: yesterday so I'm out of business until I replace it. Decided to check the other tubes on my TV7 and all except the 3V4 are borderline at best--oh well, at least I didn't pay much for the radio.

Thanks again.

Speaking of the 1l6, I'm using one of these in my h500.
(no affiliation) http://cgi.ebay.com/1L6-Solid-State-...item19c26ed27b

Congrats on getting it running!
Now if politicians could communicate like this...