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  #1  
Old 04-07-2017, 01:29 AM
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Jeffhs Jeffhs is offline
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Zenith TO 3000-1 - SW/FM works, AM dead

I have a Zenith TO-3000-1 radio which I won in an eBay auction a couple days ago. The seller said, in his item description, that the radio "works (but has) no cord". I won the auction and received the radio via FedEx a few days later. The set works very well on FM, but not so well on SW (I can receive a few stations on SW, however, such as WRMI in Miami and a few others) and is completely dead on the AM standard broadcast band; the dial calibration is way off on all bands as well. I am extremely reluctant to do anything with any of the alignment adjustments on the chassis, for fear I will mess up this set the same way I messed up my first TO-3000-1.

What could silence the AM broadcast band (but not the others) in a solid-state T-O? I had no reception at all on any band except FM when the radio arrived here, but I was able to get the SW bands working (albeit with extremely weak reception) by jiggling the band switch. I'm thinking the switch is badly in need of a good cleaning. The radio has a 1965 date stamp on the chassis, which of course means the set was built over fifty years ago. I bet that switch hasn't been cleaned since the radio was new.

Note: I said the seller's item description for this radio stated the radio "works" but there was no cord. I knew he meant no batteries or AC wall wart; fortunately, I had an exact replacement wall wart that worked perfectly. However, I do not believe he was being entirely honest regarding the condition of the radio when he said it "works". That is, the set does in fact work very well on FM and picks up a few stations on shortwave, as I mentioned, but the AM band is completely dead.

I would not consider any radio with these problems a 100-percent "working" set. I do wish the seller had been more honest regarding the radio's condition; if he had, I would have looked a bit longer on eBay to find a TO 3000 that worked, and well, on all bands.

I am tempted to give this seller negative feedback due to the inaccurate description; however, I will not return the radio, as I believe it can be made to work again as it once did. Since I get stations on shortwave, after all, the set must be working for the most part. I'm tempted to think the only problem is the alignment is off, especially since the dial calibration is off by about 1 MHz on FM (and probably on AM/SW as well). I don't want to fiddle with the alignment adjustments myself, since I do not have a signal generator; that is exactly how I silenced my first T/O 3000 a year or so ago. I don't want to make the same mistake with my "new" TO 3000.
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  #2  
Old 04-07-2017, 04:27 AM
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Tubejunke Tubejunke is offline
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I have several of the older tube type Transoceanics, thus I have nothing with an FM band, but I can say a couple of potentially valuable things here. FIRST, most often than not, alignment isn't going to be the cause of a complete loss of signal. That is unless someone else suspected the same or for some other reason got into the chassis and randomly started turning the alignment adjusters to god knows where. So, I wouldn't touch any of that.

The FM band is a separate and fairly unique process that almost has nothing to do with the AM and shortwave bands. So if you lost all AM, sound then you would get a schematic and systematically trace the AM circuit (via a signal tracer) to find where the loss occurs. Then you are at least in the vicinity of where the component is that is causing the signal loss. I'm no expert by any means, so I'm going to hope that some of the more seasoned vets pop in and elaborate on what I am saying. My experience has been to have a set with AM and lack FM more than vice versa.

As for Ebay, I could write a book on the dirty tricks and deception that occurs there, particularly with electronics. It's really crazy what people get away with there. I mean some would say IT WORKS or POWERS UP because a pilot light comes on. Of course it's often best that nobody has applied wall current to something at all and run a serious risk of frying a power transformer (if applicable) or some other expensive component. Good luck with this. Let us know what you find.
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  #3  
Old 04-07-2017, 06:58 AM
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Electronic M Electronic M is offline
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If I was in your shoes I'd have spent my money on a small working alignment generator and schematic for the first one rather than buy a second, but to each his own. If you suspect the contacts are dirty you should carefully clean them as a first step.
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Old 04-07-2017, 09:02 AM
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init4fun init4fun is offline
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It is my belief that many (most) of the folks selling antique radios on Ebay and etsy and other sites of the like have no clue about what it means for a radio to be "working" . Most I'll bet will plug it in (or in this case put a bunch of batteries in) and if they get any reception at all they think all is A OK and that it's "working" . This seller likely did just that , put batteries in , got reception on the FM band , and said "well , it works" , which it does . Now , since the seller didn't say "works perfectly on all bands" I really don't think there was any attempt at deliberate deception and for you to ding him/her with a negative feedback would be mean spirited indeed . Antique radios WILL need work , just as all antique electronic technology will , and the fact that it didn't show up totally dead means you got just that , a working radio that needs a bit of service to be what your demanding it to be , "perfectly working on all bands" , which I don't believe the seller stated .

PS , I have no relation to either the seller or the buyer , I've just seen enough of the "chip on the shoulder" posts to know when someone's being overly picky , which seems like the case here . Your supposed to be some kind of radio expert with the HAM callsign you so proudly display in your sig line , now why not put some of that radio knowledge to work and polish this into the "perfectly working" radio you expect it to be ....
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  #5  
Old 04-07-2017, 09:47 AM
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maxhifi maxhifi is offline
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Quote:
Originally Posted by Jeffhs View Post
I have a Zenith TO-3000-1 radio which I won in an eBay auction a couple days ago. The seller said, in his item description, that the radio "works (but has) no cord". I won the auction and received the radio via FedEx a few days later. The set works very well on FM, but not so well on SW (I can receive a few stations on SW, however, such as WRMI in Miami and a few others) and is completely dead on the AM standard broadcast band; the dial calibration is way off on all bands as well. I am extremely reluctant to do anything with any of the alignment adjustments on the chassis, for fear I will mess up this set the same way I messed up my first TO-3000-1.

What could silence the AM broadcast band (but not the others) in a solid-state T-O? I had no reception at all on any band except FM when the radio arrived here, but I was able to get the SW bands working (albeit with extremely weak reception) by jiggling the band switch. I'm thinking the switch is badly in need of a good cleaning. The radio has a 1965 date stamp on the chassis, which of course means the set was built over fifty years ago. I bet that switch hasn't been cleaned since the radio was new.

Note: I said the seller's item description for this radio stated the radio "works" but there was no cord. I knew he meant no batteries or AC wall wart; fortunately, I had an exact replacement wall wart that worked perfectly. However, I do not believe he was being entirely honest regarding the condition of the radio when he said it "works". That is, the set does in fact work very well on FM and picks up a few stations on shortwave, as I mentioned, but the AM band is completely dead.

I would not consider any radio with these problems a 100-percent "working" set. I do wish the seller had been more honest regarding the radio's condition; if he had, I would have looked a bit longer on eBay to find a TO 3000 that worked, and well, on all bands.

I am tempted to give this seller negative feedback due to the inaccurate description; however, I will not return the radio, as I believe it can be made to work again as it once did. Since I get stations on shortwave, after all, the set must be working for the most part. I'm tempted to think the only problem is the alignment is off, especially since the dial calibration is off by about 1 MHz on FM (and probably on AM/SW as well). I don't want to fiddle with the alignment adjustments myself, since I do not have a signal generator; that is exactly how I silenced my first T/O 3000 a year or so ago. I don't want to make the same mistake with my "new" TO 3000.
If it took a lot of jiggling of the band switch to get SW to work, begin by cleaning it and inspecting solder joints on and around it. Get SW to work positively before proceeding to diagnose AM. Reception being dead could be a bad transistor, open coil, bad electrolytic cap, dirty contacts, etc. A bad local oscillator would definitely kill reception completely too, you could try the trick of running another radio beside this one to verify if the local oscillator works. If it works on SW it more or less rules out the parts common to SW and AM, and leaves you with coils and switches.

The fact that dial calibration is off tells some someone else has already messed with alignment too. An RF signal generator is small and can be had cheaply. Don't be put off by past failures with alignment, if you use a working signal generator and follow the alignment instructions exactly you can't really make it worse.

Last edited by maxhifi; 04-07-2017 at 10:03 AM.
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  #6  
Old 04-07-2017, 10:59 AM
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jr_tech jr_tech is offline
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The set has "plug in" transistors, poor connections there could be the problem... might need to deoxit the sockets.
The "Wavemagnet" antenna plugs in through a 7 pin socket, which may also need cleaning.
Yes, the bandswitch is likely in need of cleaning.
If you are tempted to align (assuming a proper signal generator) DO NOT!!! use a metal tipped screwdriver... get some proper nylon tools for alignment, if you don't already have them.

73,
jr
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  #7  
Old 04-07-2017, 11:26 AM
broadcaster broadcaster is offline
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Your problem is a shorted transistor. It is the one with four leads. I am traveling, will be home on Sunday. I have a replacement that will work fine. I can send one to you. Just PM your address to me. Charles broadcaster
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  #8  
Old 04-07-2017, 02:06 PM
old_coot88 old_coot88 is offline
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Here's the complete service manual and schemo...
https://www.manualslib.com/manual/69...al-3000-1.html
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  #9  
Old 04-08-2017, 11:23 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by jr_tech View Post
The set has "plug in" transistors, poor connections there could be the problem... might need to deoxit the sockets.
The "Wavemagnet" antenna plugs in through a 7 pin socket, which may also need cleaning.
Yes, the bandswitch is likely in need of cleaning.
If you are tempted to align (assuming a proper signal generator) DO NOT!!! use a metal tipped screwdriver... get some proper nylon tools for alignment, if you don't already have them.

73,
jr
Proper operation of that set is highly dependant on selector switch contacts making properly.
I worked on one of those several years ago and couldn't seem to get the selector switch to work properly. The contacts had some kind of corrosion, that the contact cleaners of the day, would only help a little.
The radio was well kept and was stored properly.
When I returned it, the AM and FM worked OK.
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