[Groundhog74]

Went to an antique/craft fair with the wife, mainly because there was nothing else to do. Anyway, found a Transoceanic H500 in really good physical condition (although very dirty and smelly) but needs some electronics work. It just buzzes. The power cord is bare on both conductors immediately as it enters the chassis, and the seller had been plugging it in to "show that it works". All tubes are good except one of the 1U4's. I'm usually not too in to the later radios from the 50's/60's, but these are just cool.

[Image: http://i1319.photobucket.com/albums/t679...6c0264.jpg]

[Image: http://i1319.photobucket.com/albums/t679...2e0c47.jpg]

[Image: http://i1319.photobucket.com/albums/t679...b330c9.jpg]

According to a member on "another radio forum"...it is a Revision E. I have no clue. Just kinda wanted a Transoceanic.

[BrendaAnnD]

Not sure how it can even buzz... it's missing it's ballast tube.

[codefox1]

Saw that. You can ultimately get around this. Not sure you even need it if you can recap properly and tame your line voltage to work the filament and B+ properly. Those sets were designed to work all over the world with much different mains supplies.

Fisst conservatory measure to see if delicate filaments of the tubes are OK, next step deal with all the filter and other paper capacitors, look for crispy or out of range resistors, then come back. Do not atempt to power up again until then.

Many things might have happened over the decades. Take a look and make a few snaps to see what has gone on in the set, and please post them.

[Groundhog74]

In reading up on the H500's on the web, I understood the ballast tube was only necessary if you were in an area where power might vary higher or lower than you would encounter in the states where power was pretty uniform. Perhaps I mis-interpreted the situation.

[BrendaAnnD]

There is some mis-information here. The 50A1 ballast tube is DEFINATELY needed. It performs at least three functions:

1) it acts as a voltage dropping resistor

2) it acts as a current "valve" to keep inrush current from killing the tube filaments and

3) it acts as a fuse

Some sell a large power resistor that can be plugged into the socket, but this only does one of the jobs of the 50A1. Without the tube in the socket, there is no filament current at all, so no operation.

[codefox1]

No argument, of course pointless, but you can can work around it if you have a string of good tubes and a suitable fuse and no other issures.

[37silverstreak]

Nice find, I just finished rebuilding the same model for a friend. I'm not into postwar radios either but it was an interesting experience. the biggest thing was getting the filament voltage to run at about 1.4 volts to protect the tube filaments, had to try several different resistors to get it right. It turned out to be a great playing set, enough so that I bought one for myself, although I got the 47/48 8G005YT version. There is a guy on the barking dog forum who has a great thread about restoring this same model. I used it quite a bit for reference when working on my friends radio. it was a big help. Good luck with yours!
Kevin

[Groundhog74]

Had some time to investigate under the chassis. I had replaced the shorted power cord. The first thing I saw was a .047 cap basically split wide open (c31). I replaced it and since I currently don't have a variac or a dim bulb tester, all I can do is power it up, so I Tried it again and it still just buzzes.
So, I decided to try it with battery power. Using some of the batteries from my 1925 Liberty 5 set up, I immediately got good reception. I imagine the selenium rectifier and electrolytic s are shot. I think I'll order one of the reproduction battery boxes and run it that way for now. I'll spend 90% of it's time on display anyway until I can dig deeper. I have several ahead of it on my priority list. Nice to know it works if even only on batteries. Sounds good.