Greetings Gang -

I was traveling to Atlanta, and saw a D7000Y for $50 on FB marketplace, and made a detour to pick it up. In retrospect I should have bargained!

Pics are below.

It's filthy. Does the top part come off/disassemble so I can clean without ruining the UTC time display?

I was going to bring it up on my dim bulb tester. At first, it was dead, but someone had left the voltage switch in the "230" position. When i switched to 115V, it powered up with a mechanical hum. AM worked, but nothing else. I discovered the spade that connects the whip antenna to it's post was missing. When I jumpered it in, FM and weather band worked, SW still dead. I stopped experimenting at this point. Here are some pics and questions.



Can this be disassembled and cleaned?


A previous owner stuffed wadding here to minimize some sort of vibration


Is this glue, or did one of these caps spill it's guts?



Missing the D cell spring contact for the Map lights. Any suggestions?



I guess these won't come out for cleaning



Thanks for any suggestions or feedback. Looking forward to the journey. I think i'll be learning a lot.

D

I'd start by replacing all those electrolytic capacitors. The power supply cap 500uF? would probably cure most of that hum. Running it off batteries will definitely reduce any hum too.
The volume and other pots are probably dirty.

This set uses around eleven (more or less) electrolytic caps in PS filtering and inter-stage signal coupling roles. Replace them all, then stand in awe at the radio's restored audio performance!

There are "how to" guides on the web that will help walk you through the cap replacement process. Other suggestions that may be helpful: (1) "J-hooking" the replacement caps is a quick and effective method of cap replacement; (2) to reach the three caps that are more or less under the tuning-indicator drum, it's safest to dismount and slightly move the drum. This is easy to do and fairly self-evident as far as how to do it. Trying to replace the caps with the drum in place will probably lead to a melt hole in the drum scale.

You also have to unbolt the pot carrier bracket to reach a couple of the caps; but this is obvious as well. (Just be aware that you need to do it, and don't try to cheat and skate under the bracket.)

The non-electrolytic caps in the set are all high-grade ceramics and should not need preventative replacement, since they aren't prone to age-deterioration. I've e-recapped several of these sets and it isn't that much of a challenge... and the results will pay back the time investment many times over.

The overall parts and build quality of this radio is fine... except for the electrolytic caps. Even when the sets were near new, they had a fairly high failure rate due to crappy electrolytic caps. Any cap that is marked "CALLINS" is immediately indicted.

Maybe my old project thread will help with yours ??? https://www.antiqueradios.com/forums/vi ... 4&t=352968

Mine still works well with original electrolytics but do wonder if replacement might improve sound quality a bit. Volume level is fine, but audio quality just not as "clean" as I'd like. What specific improvements did you notice lorenz200w ?

Good luck and will be watching !

John

If my memory serves me well today, I am pretty sure that this radio has a reputation of the occasional "bad" ceramic capacitor(s).
Of course, 99.9% of the time ceramic capacitors are known to be very reliable. But there were issues with them in this production period
and from the supplier used.

When I learned of this, I decided to send my radio to a well-known Zenith D7000Y T/O specialist for recapping and alignment (about 7 years ago). He was aware of the ceramics in question and would replace if needed. I am not saying every Zenith D7000Y radio had this problem, just to be aware of it.

I also remember that attempting to replace the electrolytic capacitors near the rotating translucent frequency "band tube" WITHOUT removing the assembly could easily result in a hot solder tip melting the super-thin plastic from a momentary touch. Too risky. Don't take short-cuts!

Great radios! Be aware that the map light is mostly useless IMO. It is very dim and uses a momentary switch. Which would leave you with one hand on your chart and the other pushing a light switch while in the salon of a sea going vessel in "sporty" seas. Been there, done that.

Jeff

<<You also have to unbolt the pot carrier bracket to reach a couple of the caps; but this is obvious as well. (Just be aware that you need to do it, and don't try to cheat and skate under the bracket.)>>

Also you'll want to unsolder the black wire routed to one of the lugs at the bottom of it, that will allow you to lift and prop up the whole bracket a LOT farther for access to the small electrolytics that are buried under there.

As for replacing the caps located near the dial plastic, following another restoration page I stuck a curved piece of card paper in front of the dial to protect it from any slip of my soldering iron.

If you are resting the chassis rear side down, make sure that if you've removed the long screw that sticks way out on the upper right, put it back or else the chassis will be resting on the end of the ferrite AM antenna. I goofed with that and it broke the antenna's mount on that end, I was able to repair it with cement and luckily I didn't break the antenna itself.

Thanks to everyone for the encouragement and advice. Also, Thanks John for that thread link! Seeing how far the radio breaks down will definitely help in the cleaning process. This thing is filthy, and much of the chrome has something sticky on it. The inside (fortunately) looks better than the outside.

David

You've gotten some good advice. I have a 3000-1; is a great performer and pleasing to use.

As for the "goop," I'm pretty sure that was some glue used during assembly. I'd leave those caps alone and focus on the others as recommended above.

Hey,

Would these types of caps from Just radios, at the appropriate uf and voltage, be fine for this radio?

I would make a list of all electrolytic caps in the radio and make note of uf & voltage. They should all be visible on the chassis. Or, look at the parts list.

Then exceed the voltage rating a bit for good measure. I think the voltage ratings are varied with this radio. I always
replaced with same value if possible and exceed voltage by 25-50% - not much difference in size or cost to do that.

Jeff

For the Zenith 500MDR70 chassis:

1uf - 25v (2)
5uf - 12v (2)
10uf - 6v
20uf - 3v
100uf - 6v
220 -15v
300 - 15v
500uf - 12v
500uf - 20v
1000uf - 15v

I don't think those low voltage ratings (< 15v) are found anymore. Most small electrolytic caps start around 25v and they are no larger than the originals.I would get 25v rating and maybe 35-50v on the 1uf's.

I found a note in my service manual that the ceramic capacitors that "may" be an issue are the .05uf - 25v discs.

Jeff

Greetings Gang -

Thought I'd provide a brief update on my progress. I'm glad this radio was beat up and filthy. Makes me feel a little better about the damage I'm inflicting.

I'm waiting on the electrolytics, but I've fired up the radio on a dim bulb/AC and on batteries, and here's what I've found.

• On AC (after contact cleaning) , the radio works (poorly) on VHF, FM, AM, and LW. Some SW bands are silent, others can pick up a hint of signal.
• On AC, there's a bad hum that resolves on DC.
• On DC radio weakly picks up VHF, FM AM, LW (with volume at max). SW is dead.
• AFC and bandwidth don't appear to be working.

I've managed to break a few things during the cleaning.

Broke one of the tabs when removing the dial cover.

The compass had grit underneath, and when cleaning with a pipe cleaner, managed to break the post.


There was a stuck screw in the bottom that I had to use a rotary tool to cut a slot in after mangling it.


When cleaning the time calculator knobs, my cleaner stripped the finish off.


Anyone got any suggestions for cleaning the grill? Mine is stained with a reddish substance.

David