Author Topic: Another orphan followed me home  (Read 32129 times)

TC Chris

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Re: Another orphan followed me home
« Reply #30 on: May 21, 2019, 10:26:38 PM »
That second link shows the original pincushion frame but would be an upgrade--larger magnets!

I just looked at Parts Express.  They have a 6-1/2" woofer with rubber surround (I resist anything with foam).  Check it here:
https://www.parts-express.com/dayton-audio-dc160-8-6-1-2-classic-woofer--295-305#lblProductDetails

That one would probably give a bit more robust bass.  I have a couple Dayton tweeters that I bought for the Heathkit console.  In fact, I bought them twice, which is why I have extras.  Maybe the meory does go when you get old....

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #31 on: May 21, 2019, 11:08:47 PM »
I was excited when I found those 6" Quams.  Anything would be better than what is there now.   ::)
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #32 on: May 23, 2019, 12:36:56 AM »
I'll see if the electronics are functioning this next weekend.  The little device is now situated so it's easier to get to, after the big garage-reorganization project last Sunday.  Of course, better news still is that the Chevy can just be started and driven out without moving the Subaru, two old lawn mowers, and a garden cart of of the way first.  And because of the oxidized rear window, I needed another person as a lookout to back it in to its former space.  Last night I located the recent plastic-window article from Practical Sailor magazine, figuring that clear vinyl is clear vinyl, whether it's in a car or boat.  I also found articles suggesting the in '61, GM was using brake fluid in the convertible top hydraulics.  I had been convinced that I had screwed up when I topped it off with brake fluid 35 years back.  Turns out I used the right stuff.  But there are also suggestions that some people purge the brake fluid and replace with ATF or hydraulic fluid, which are probably better choices than moisture-absorbing brake fluid.

But back to the console.  If the electronics work, I'll decide what to do about speakers--go original with Quams, or upgrade with Daytons.  I don't expect to mistake the bass for an earthquake with 6" infinite-baffle speakers....

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #33 on: May 23, 2019, 10:03:10 AM »
Sometimes performance is not the key issue.  The key issue with that little stereo is that it is cute and unusual.  And you saved it.  Who has another one?  It probably will make as much bass as a Magnavox bi-amp!   ::) ::) :) :)
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #34 on: May 25, 2019, 11:19:52 AM »
@#*&%$!!!  I brought some small speakers to connect to the console via its speaker-out jacks.  Plugged 'em in, dragged an extension cord over, plugged in, turned on, waited for warm-up....and nothing.  I took the back off--about 8 little hex-head screws, @#(&!!!--and the tubes aren't lighting.  I had put the little AC tester that came with it in my traveling mechanical tool box, and there's power at the interlock.  And when I was wiggling tubes,  got poked slightly by something (kneeling on damp concrete floor).  Last time I tried, it functioned enough for the FM stereo light to come on. So it WAS working then.  All I've done since s move it (lifting, not dragging).  Next I looked at my early chassis photo and then at the eBay console photo and verified that the tubes are in the right location even though it looks as though they aren't (one 50C5 is between IF cans).  Maybe I'll walk away and drive the Chevy out to get some vinyl rear-window polish.  Sometimes things work better after leaving them alone.  By the way, the V-M changer doesn't power up either--never has.

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #35 on: May 25, 2019, 12:21:27 PM »
Sounds like you will be working in the power supply as a first step.  Good luck and keep us posted.   :) :)
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #36 on: June 01, 2019, 09:34:00 PM »
Since the tube heaters weren't lighting up, I brought a tube tester this weekend, expecting to find a bad one in the series string.  There are two 50 volt tubes and six 12 volt ones--122 volts if we ignore the ".6" on the 12 volt filaments' specs.  But no, they all test OK.  I'm not sure where the two 6 volt tubes on the multiplex converter come in.  Thy test OK too.  There's power at the console side of the interlock.  Maybe a power switch failure?  Not easily removed for service so I did other projects today.

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #37 on: June 02, 2019, 11:37:15 PM »
Could there be a circuit breaker or a fuse somewhere that you may have overlooked?
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #38 on: June 03, 2019, 08:43:11 PM »
I didn't see anything fuse-like and certainly no breaker (way above this device's pay grade).  The only other easy explanation would be a bad power switch--it's a push-pull method on the volume control that activates a slide switch.  So I worked it back and forth and yanked a bit with pliers and then worked it back and forth some more, to no avail.  And then there's the classic tube-socket issue, so I wiggled all the tubes after I had pulled each one to put it in the tester.  One thing I didn't check was what buffaloed me on the little Zenith 6-tube radio--a 12-volt tube that's center-tapped, with only 1/2 of the heater connected in the tube tester so it tests OK when it's not.  But then, it seems like the multi-section 12-volters had different heater connection on the tube tester for each section.  When we have a bad-weather day on a weekend and no other pressing chores, I'll pull the chassis and poke around with volt and ohmmeter.

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #39 on: June 03, 2019, 09:41:07 PM »
If there was a fuse, it likely would be under the chassis anyway.
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #40 on: June 03, 2019, 11:21:41 PM »
I'll be able to figure things out when I get the chassis out.  It's not simple--kinda like the Stereo Theater experience, I bet.   You have to pull the knobs, unscrew the faceplate, then pull the chassis-mounting screws that are under the faceplate, and then extract the chassis far enough to examine it or cut the speaker and AC supply wires.  There are not speaker connectors.  Just in case there's no simple explanation, I've asked about a schematic over on ARF.  I mentioned the Madison-Fielding provenance and the Home-Mark model no.  We'll see if there are specialists in low-end phonos over there.  I haven;t quite figured out why a device with such modest speakers was built with such nice veneers.

Chris Campbell

TC Chris

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Re: Another orphan followed me home
« Reply #41 on: June 07, 2019, 08:50:45 PM »
I had a conference to attend in Ann Arbor today so I drove down last night to my mother's home, where the Home-Mark is in the garage.  I was home early in the evening and decided to remove the chassis.  Then I pulled the bottom plate (one screw and one tab of solder that I just broke).  There are no connectors so I couldn't un-hitch it from the cabinet so it remained tethered.  Inside I found a wire-wound with the sand covering flaked off.  Aha! I thought, burned resistor and probably a short downstream somewhere.  I dug my little analog meter out of the traveling mechanical tools box and found that the resistor asn't open; it measured about 400 ohms.  Then I checked the power switch.  It's a DPST on-off switch.  No continuity on either side.  All I had was WD-40, and after a big squirt of that it was working.  While the chassis was out I made a tube diagram while I could still see the pin orientation to replace them. 

But then came the problem of re-installing the chassis.  It hangs from 4 screws turned from above, but it's impossible to hold the chassis in place with one hand and reach the screws with the other.  There was a lot of bad language.  At one point the chassis fell, and it broke the twinlead at the FM RF front end.  Aaargh!!!  At that point I gave up.  I'll fix it tomorrow when I'm in a better mood.  And then I'll tro to fnd some way to hold the chassis up from underneath while I drive the screws from above and in front.  WHO DESIGNS THESE THINGS????

Chris Campbell

TC Chris

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Re: Another orphan followed me home
« Reply #42 on: June 09, 2019, 12:51:45 PM »
It's working!  Today I re-soldered the twinlead FM antenna stub that had broken off.  That took longer than usual because I was working on a garage floor with the chassis still connected by too-short wires. #$*^@!!!  Next I recruited another set of hands to run the screw driver from top/front while I held the chassis up from the bottom/back.  But then it was done and, oops, what's this loose blue wire?  One wire had pulled out of the changer's Molex connector so I had to pull the changer to see which blank spot it went to. More %*&^#@!!!  But I plugged it in, on it came, and it works on FM, FM stereo, AM, and passes the "needle scratch" test on phono.  At first it sounded grainy but I left it playing a while to see if caps reformed.  The filters on this one are modern, plastic-covered devices, not the paper and wax versions shown in the eBay ad photo.  I figured it was safe to go with them.  Eventually it sounded louder and better over to little Radio Shack speakers plugged in to it.  I'll bet the originals were more efficient.  Now that it works I'll buy some to fit--Quams to match originals, or Daytons for better sound??

I'm not anxious to do another chassis extraction, at least until I get a schematic so I can make sense of what I'm seeing.  Right now the face plate is in the basement with the dial glass (plastic) being glued back on at the loose end. 

Chris Campbell

electra225

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Re: Another orphan followed me home
« Reply #43 on: June 09, 2019, 11:43:26 PM »
Was that a model 360?  I thought I posted the Sams for that, but maybe not.  I found it in my Sams index, if I remember right.  The tuners in Magnavox stereos are HORRIBLE to get back in.  Surprising how heavy they get when you try to hold them up and get the screws started.  By the way, Chris, that's why %$*&@!! was invented.   ;) ;) :) :)
I don't need Google.  My wife says she knows everything.

TC Chris

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Re: Another orphan followed me home
« Reply #44 on: June 10, 2019, 06:37:20 PM »
The Madison-Fielding model no. for the similar device was 360, I think, but they also used that for a real hi-fi integrated  amp or preamp, which is what usually shows up on a search.

I think I'll order some speakers.  The choice is between the eBay Quams, 2 for $16, or going up to 6-1/2", where there are a lot more options at Parts Express.  They have this nice-looking device for $6 each:
https://www.parts-express.com/6-1-2-poly-cone-midbass-woofer-4-ohm--299-609

I'm thinking that the P. Express device is probably more efficient and wider-range.  It wouldn't look original but would probably sound a lot better (less like two table radios playing).

Any thoughts from other about this choice?

Chris Campbell