[Jayce]

I have a Zenith H725Z (could be a H725Z1, hard to read that part of the stamp) that I bought off a friend roughly 7 years ago in an already recapped condition. This radio became my semi-daily player when I had it in my rotation, but it did have times when the dial cord would slip. I was going to possibly have it restrung when it started acting like it had the dreaded SMD and I just gave up and shelved it for the last three of four years.
After the 35c5 issue on my 60's Zenith K725 was caught on my 'new' Sencore checker, I decided to dig this radio out and check the tubes in it and also clean the sockets. Well, turned out it had a bad 6BJ6 and luckily I had a good one in a parts radio. I put the radio back together and it played great... for ten minutes then went almost totally blind on both FM and AM. This was on Tuesday and I just gave up and put it away. Yesterday I got it back out and went through the tubes again. Even my tube checker was acting odd and I figured out the issue was most of the sockets on this radio were really filthy! The first cleaning must have brought the gunk loose, but it stuck to the tube pins. After cleaning the sockets again, including the ones I used on my tester the radio came back to life and is working great on both AM and FM. It is even easier to tune on FM than it originally was. The dial cord stays fine as long as I don't tune it all the at to the very bottom of the dial. Now this is the only bakelite and also the oldest working Zenith AM-FM in my collection.

On a side note, I got away with one mistake. I forgot this model uses two 6BJ6 tubes and accidentally put it on the checker after setting it up for a 12BA6! I wondered why the filament was so bright and why it was testing strange and then quickly pulled it off the tester. Luckily, the tube survived as I have no more spares of those.

[klondike98]

It’s always fun to figure out what is troubling a radio and get it sorted!

[Jayce]

Thanks, Bob. So far I am batting 500. Tinkered with four radios, got two figured out. One might be getting passed on down the the line while the other head scratcher will get one more chance before it becomes a shelf queen.

[Jayce]

Just a quick update: The radio is still playing fine, though I am hoping the line capacitor got replaced in this one. It was done at the same time my friend and I were just trying to get the essentials done of these radios and the old guy doing the work missed the line capacitor in my C845. I can't recall if I bought this already redone or had it redone right after purchase. One thing this radio does is it kind of forces you to use it daily at least for a short bit. It's like an old Jukebox, if you leave it sit, it gets fussy! At least on FM. Nothing fatal, but it makes you pay for leaving it sit idle more than a couple days. It was like that when I first got it going, though it is now easier to get out of its fussy state.