View Full Version : Just got this magnavox


DaveWM
07-07-2009, 06:17 PM
should make for an interesting 1st TV resto. SS astrosonic radio, I have not been able to get it out of the back of the explorer for a week (back still hurtz from getting it in).

Anybody have one of these? what should I be on the look for?

My plan is to recap the stereo 1st then the TV (will be careful, read up on HV and stored charges in the CRT).

It looks like it has some kind of crude remote, not sure about that.

Its pretty ruff....

radiotvnut
07-07-2009, 06:25 PM
That looks like a B&W set. The first thing I'd do is make sure the CRT is good, if you have access to a CRT tester. The next thing I'd do would be to replace all electrolytic and paper caps. That will probably get it going again.

DaveWM
07-07-2009, 06:35 PM
unfortunitly I have no way of checking the CRT... oh well I will do the recap, check the other tubes, and go from there.

DaveWM
07-07-2009, 08:25 PM
tried the tuner, rec signals strong on am and fm , plays but volume is down, and there is a constant rushing sound of white noise. I don't know anything about SS so I will pull the tuner and start checking caps/resistors. Now I need to find a schematic for an astro sonic tuner.

DaveWM
07-07-2009, 08:37 PM
oh yea one more thing the TV chassis looks like it will be easy to work on, very low parts count. I don't really like PCB's but I need the practice so at least it is not super complex.

AUdubon5425
07-07-2009, 10:36 PM
That set may use the same chassis as mine (U44.) Post a picture of the chassis - if it is the same I'll scan the Sams for you.

DaveWM
07-07-2009, 10:58 PM
roger will do in the am.

more progress, checked all the tv tubes, all good except for 2 on the IF board, on had a short, one had grid leakage. I need to rummage around my box o tubes and see if I have any. One was a 6BZ6 and a 6GH8

There are only 3 can caps, two look to be part of the power supply, one on the far side of the chassis.

I have not pulled the chassis out yet, but unless there are some electrolyitics stuck on the bottom of the PCB's then that is all there is. No wax papers at all.

The chassis sit up vertically, with the tubes pointing out straight back. Has a metal chassis with about 5 pcb's screwed on to it. Very clean.

I will get a pic tomorrow.

radiotvnut
07-07-2009, 11:03 PM
Unless the other caps are ceramic disc, I would replace them. Even in the '60's, there were still "paper" caps in use; but, they usually weren't housed in a wax tube. They were either in a white ceramic casing or in a colored plastic case. I've found that many of these "later" plastic & ceramic cased paper caps are in worse shape than some of the "wax" caps of the '30's and '40's.

rcanewvista
07-08-2009, 01:07 PM
is the remote the one that uses the bellows, and is called the Magnavox Phantom? I have a similar remote for an astrosonic stereo, but it doesnt work anymore.

DaveWM
07-08-2009, 03:30 PM
pics

DaveWM
07-08-2009, 08:24 PM
WTH, I pluged in into the variac brought it up, picture tube is dim but full raster, I hooked up an analog signal to channel 3 nothing, checked tuner has a bad tube (grid leak), so that will get replaced. I am not looking forward to recaping this thing, as I do not like the idea of unhooking in from all the wires in the console. Its like a critical patient in ER with all the hookups...

I did peak behind the TV chassis, has a few what I presume to be paper caps (big white tubular 1000v jobs). I may just recap it in place but that will not be fun.

DaveWM
07-08-2009, 08:30 PM
dark garage this is what I get

DaveWM
07-09-2009, 09:02 PM
tried it again, I had forgotten to hook up wire from the tuner that I had disconnected. put the converter box on it, turned it on, adj the horz, bam, i see the main menu woo hoo.... cooking with gas now.... :D

I forgot to attach a antenna to the converter box to get some live action, but looks like I might have a keeper.

DaveWM
07-19-2009, 09:38 PM
TV pic is workign great, rejuvenated the tube, brightness and contract fine for daytime viewing. replaced one doubler cap, the others tested fine.

Messed with the height and linearity trim pots, which are bad and need to be replaced, made adj a mega hassle. but finally got it worked out except for the pic height not quite good enough, the pot would come up just short then bam start getting smaller (even though I would turn the same direction so it has more adj just not working right). It was about 1" short on the bottom and top. I left it on for an hour and came back and it was full screen. I am guessing the caps while testing fine must have still some forming to do.

next up will be the astrosonic radio tuner and amp so I can get some good sound (the audio is working but the SS amp needs some help).

DaveWM
07-19-2009, 10:39 PM
geez finding a 600 ohm trim pot is like looking for the holy grail....

DaveWM
07-22-2009, 09:00 AM
still checking it over, seems the voltages are all wrong but it works fine.

one really odd thing is the current reading on the B+ out of the doubler, only reading 24ma not 280ma per the schematic. No way the 24ma can be right its got a dozen tubes!

I am going to have to triple check my meter settiing on that. I have scoped a few of the check points in the problem area (vert sweep) scope patters look ok but low peak to peak. But then again the pictrue is fine so I am about ready to call it a day and leave it alone before I break something.

DaveWM
07-22-2009, 08:31 PM
what a dope, the DMM range was wrong, changed it to amps, got .250 so current is right.

Still need a new linearity trim pot (super critical adj, its all junked up, way beyond deoxit). The problem is its 600 ohm and I think hi wattage (maybe a wire wound pot).

I am hitting the local surplus store to see what they have, then my vintage radio guy this weekend.

Pictrue is fine, just very very sensitive to adj (or vibration as in moving it around), which is why I want a more reliable pot.

Still need to pull the am/fm tuner amp and check it out.

DaveWM
07-30-2009, 09:00 PM
got the pic working fine now, a new linearity pot and all it working well now. I had to fugde the series resistor value since the only trim pot I could find was a 300 ohm, so I upped the series resistor value and wattage, and got it right in the middle of the adj, bonus is with the lower value trim pot the adj is less critical (just hope the range does not shift too much).

I recapped the astro sonic tuner amp that goes with the TV for sound. had a persistant rushing sound that was still in one channel after the recap.

Turned out to be a leaky transistor in the preamp circuit. replaced it with a generic silcon transistor, sounds great now.

Still have the filter cans to do on both the astro sonic amp, and the TV chassis, and still have to pull the TV tuner and clean it up (dirty contacts).

but getting close now.

zenithfan1
07-30-2009, 09:15 PM
Sounds like she's going well, lets see some pics of 'er running.

DaveWM
07-30-2009, 09:30 PM
looks like a battlefield right now, parts all over the place :)

hope to pull it all back together soon. I don't want to reinstall that darn tuner till I know it is ok.

I am going to put the two FM stereo to the test, put a 400hz sine wave to it thru a stereo transmitter.

something still odd going on.. one channel distorts when the adj trim pot is turned up much more than 1/4 the other channel is fine all the way up, just louder like it is supposed to be.

The scope will prove out where the distortion is happening. I can live with it as is (just adj the two trim pot to no more the 1/4 and all is fine, lisening level is correct as well), but I want to know why it is doing this.

After this experience I hope to tackle more TV's smaller TV's this thing is HUGE...

zenithfan1
07-30-2009, 10:21 PM
I had a Maggie stereo do that to me once, never tried to fix it, just dropped it back off at GW. I wish I had it back sort of. Good luck and I hope you get everything back together with no bad issues. (there's always little ones :) )

DaveWM
08-01-2009, 10:14 AM
if anyone cares about the SS amp used in this TV I have a thread going on in the vintage solid state detailing the issues I am having with the astrosonic unit used for the audio of this set.

Charlie
08-02-2009, 06:56 PM
I have the same set, but with slightly different sliding doors. This one is non-remote. I haven't done anything to it yet. It plays, but recently the filters took a dump. Made a really good picture before that happened.

The stereo amp needs work... one channel is out and the other has a lot of static.

DaveWM
08-02-2009, 08:36 PM
well on mine it was the preamp driver transistors, both were bad on one channel causing a lound hiss or rushing sound (I have since been told that transistor can get "noisy". I also replace every single one of the small electros, left the filter alone but may go back and to them too (I only replace the single double cap on the TV as well, the others tested ok, but will prob do them now, sooner rather than later). I picked up some cheap germainum transistor at a suplus store (45cents each) which so far are working fine. I have been trying to get a schematic so I can have some test point for later service, just is case...

Hope your power output transistors are ok, they are expensive. I would recommend you just do a compete recap, with a desoldering gun you can fly..

DaveWM
08-03-2009, 10:11 PM
adventures in refinishing...

I hate this part.....

ok got the old cracked disgusting mangled burned difigured etc.. etc.. etc..

off the top trim (not the sliding top just the thick solid wood trim.

did this with a chem stripper and steel wool and sand paper. got a nice blonde wood, very smooth. Used a sealer (the lowes guy said too) then applied a dark walnut stain (the color on the can top looked right). Oil base, messy uck. Well it just sat there did not hardly stain anything. I tried leaving it on, applying heavy, applying light lotsa coats. Maybe 1/2 as dark as it should be. I tried light sanding in between coats, one time I left it on heavy and for a long time, barely got it off, had to resort to aggessive sanding and steel wool to get it off...

the best results were light coats barely enough to have to wipe off.

I am going to get some darker stain and try again.

If the rest of the finish was messed up I would not mind the color, but it is no where near a match I and don't want to have to strip the whole thing.

DaveWM
08-03-2009, 10:22 PM
I'll post a pic tomorrow with it working and the top with the PITA finish...

Trying to locate one of these "phantom" remotes, I will keep an eye on praybay.

I have not even looked at the remotes chassis, I dont see any tubes so I am guess it is solid state to operate the relays.

Got a lead on another maggie console tv, I may just have to get another.

DaveWM
08-04-2009, 11:19 AM
pics, WIP on the finish.

The TV pic is better than shown in the picture, the camera seems to pick up bars that are not there.

If anybody has a tuner face plate they want to get rid of cheap let me know. The one I have is pretty worn. I am hoping to find one that shows the TV position.

the Black plug to the tuner goes into the newly installed RCA jack, right next to the orig mono input. I can put the two together with a Y connector to run the original audio out from the TV chassis, or do like I have here, direct to the L and R from the DVD.

Reece
08-05-2009, 08:03 AM
Dave, you'll probably find it gets better as you use it and the moisture bakes out of the coils and all. You could even put a couple of light bulbs inside 24 hours to add some heat when the set is turned off. Final tweaking to come after the long bake-off.

Reece

DaveWM
08-06-2009, 07:58 PM
indeed i have noticed it is getting better, even the vert height has improved with use.

Refinishing

I got another stain, this one seem a little darker and thinner (minwax oil based dark walnut). I think I will get what I want with a few more applications. This is on the top trim.

the sliding top doors are another story. I put on the chem stripper to get the old finish off, this time though its not a toned finish, the wood remains dark after stripping.

I then hit it with some 120 grit in an orbital sander to get the deep scratches out. Finished up sanding with some 320 grit. The tops are solid, about 3/8 thick.

They clean up very very well. I put some sanding sealer on it and the grain really pops and has a beautiful rich color. No staining needed here.

I will just use an oil finish and later a paste wax.

I can then final stain the trim to get as good a match as possible to the finished sliding top doors.

Its really coming along nicely. I figure it will take up residence in the house in about a week. I will get some pics when it is all done. I am feeling pretty good about it.

DaveWM
08-08-2009, 09:04 PM
got a NOS picture tube off praybay, hope it gets here in one piece. Figured I should have a spare.

DaveWM
08-08-2009, 09:41 PM
here is the new one, all good. I threw in some other pics of recent magnavox's

the two TV's were freebee's, the small console was 15$

That pictrue of Margo is actually very clear, I must have moved when I took it.