View Full Version : I'm getting a Magnavox!


TUD1
08-25-2017, 06:33 PM
I'm getting up extra early tomorrow and heading to the rich people part of town to snag this beautiful Magnavox. Anybody have any info about these? This is my first Magnavox TV ever, and my knowledge on them is very limited. I'm guessing 1967? I'm super excited to be getting this thing. Especially since it's a remote set.

Findm-Keepm
08-25-2017, 08:49 PM
My guess? Heavy.

I hated them combos - I was the kid on the lighter end, but still, they made them like tanks. Never dropped one, never necked one, but I did knee a knob once. The knob was ok, I needed a bandage - through corduroy pants, that Maggie "Mediterranean" got my knee good.

Ever carry a jonboat with some water in it? Lift up your end, and the other end gets heavy for the other guy? :D That's my analogy for carrying one of these B****rds down a set of stairs. Suddenly, everyone has water in their end of the boat. to make matters worse, all the homes here were built in the early part of the century, with little thought as to how narrow one could design a set of stairs.

Congrats on the find....:thmbsp:

Ed in Tx
08-25-2017, 08:58 PM
The mask around the tube reminds me of my old Star System Magnavox, but that was about 1979 vintage. It was one of the first with a comb filter Y-C separator and man did it have a clean detailed picture.

old_tv_nut
08-25-2017, 09:42 PM
You may have read around here that Maggies had something of a reputation for eating flybacks. Good idea to check the horizontal current, I think.

Congrats on the furniture find!

mr_rye89
08-26-2017, 12:32 AM
That's similar to the Magnavox I had (gave to a coworker) mine was a solid state table top unit and it was heavy as hell, it had A/V inputs and the fly was still good.

consoleguy67
08-26-2017, 06:25 AM
With the design of the speaker grilles, I would say early 70's.

davet753
08-26-2017, 12:14 PM
Yep, I'd guess early 70's, too.

TUD1
08-26-2017, 12:50 PM
Score. NOT a remote set. Original CRT.

TUD1
08-26-2017, 07:38 PM
Here's the picture it makes after having done no work on it at all. In fact, I have not even removed the back cover yet. Tomorrow, I'll check the tubes, clean it out, set it up, the whole shmagoigle

Findm-Keepm
08-26-2017, 10:00 PM
T9 _ _? Chassis?

holmesuser01
08-26-2017, 10:49 PM
I'd leave the tubes alone at this point. No need to disturb parts that have been in one position for 40 years.

I think it's a 73-74 model

I think it used an odd tube for the vertical output. Didn't see it in many other sets. It looks pretty good, except for the little vertical linearity problem it has, and that can easily be the output tube.

sampson159
08-27-2017, 01:32 PM
is this the hybrid chassis?crt looks really sharp.those maggies of that vintage were real fine performers with excellent crts and solid wood cabinetry.these were very high end customers didnt mind spending some real money to keep them going.great score and post more pictures of it

Jeffhs
08-27-2017, 01:37 PM
Your set makes a good picture right now, but it could be better. Those '70s Maggies were great sets when new, and can be just as good today if they are properly restored. It looks like the CRT is still in excellent shape. The set must have had very little use by its former owner(s) (perhaps the stereo components were used more than the TV) before you got it; I wouldn't expect a 40-year-old CRT to be this strong unless the set was seldom used.

BTW, I am always amazed whenever you get a new TV, especially a large console like your Maggie, as to where you find room for them. Where do you put them all? :scratch2: I think you mentioned awhile ago that you have, or have access to, another building where you can store your TVs.

Also, I wonder how you are getting any TV reception at all without a cable box or OTA converter and antenna (I don't see either on top of your set), since, as everyone knows (or should know) by now, some years after the DTV transition, it is all but impossible to get any kind of OTA TV reception without the use of, at a minimum, an OTA converter box with an antenna. Are you hiding the box behind the TV? :scratch2: Your set shows a picture from the local CBS affiliate in Birmingham, which, again, is all but impossible to get without at least a converter box--unless the station has an analog SD (standard definition) feed in addition to its main HD signal.

TUD1
08-27-2017, 05:16 PM
I thought the set was a hybrid at first, but it is actually all tube. I checked all the tubes, and amazingly, they all checked good. There were only three non original ones, 2 6GH8's, and a 6KE8. After completely setting up the TV, here is the picture it makes. I adjusted the dynamic convergence to fix the blue on the left side.

Jeff, there are no analog stations here. I am using a DTV converter.

Tony V
08-27-2017, 06:31 PM
Hows the stereo portion in this combo? Is it in working order? Any pictures? I've had a couple of the slightly older Magnavox combo's and they were nice. I now own a 1963 Magnavox color roundie combo and it's the prize of my collection. I'm glad this one fell into good hands! Nice find!

TUD1
08-27-2017, 06:57 PM
Oh my, yes. The stereo will blow you away. 15" woofers and exponential horns. Unfortunately, the color on the set just went out. I watched it for about 30 minutes, and it just instantly went to black and white. I'm thinking the problem is in one of these tubes.

consoleguy67
08-27-2017, 10:31 PM
Also, check the tuner.

old_coot88
08-27-2017, 11:35 PM
While watching the screen in a mirror, give the suspect tubes a gentle tapping and wiggle 'em in their sockets.

TUD1
08-27-2017, 11:55 PM
I'll do that tomorrow.

Jon A.
08-28-2017, 02:07 AM
If it's a 70s set it's most likely to be VERY early 70s with a T940 chassis. If late 60s, probably T933.

I guess we'll never know. I'm out of here.

Ed in Tx
08-28-2017, 09:44 AM
While watching the screen in a mirror, give the suspect tubes a gentle tapping and wiggle 'em in their sockets.Reminds me of the Zenith I grew up with like in my avatar. When it would go off-channel or vertical/horizontal would lose lock my father would stomp his foot on the floor to straighten it out for a while.

TUD1
08-28-2017, 03:00 PM
Got the color back, but I expect it to fail again soon. This set is being extremely temperamental.

magnasonic66
08-28-2017, 06:33 PM
Can you show shots of the control panel and the record changer? Nice save, I hope you enjoy it as much as I would.

Bill R
08-28-2017, 07:05 PM
Buy a box of those 6GH8A tubes. They will come in handy.

TUD1
08-28-2017, 07:36 PM
This sucks. I reflowed a bunch of cold solder joints, got the color back, and I *think* it's here to stay now. However, in order to get the chassis out, I had to cut a shielded wire (I now realize) and just soldering it back together isn't good enough. Now I've got a whole bunch of horrible 60 Hz hum in the audio. :dammit: :dammit: :dammit:

Electronic M
08-28-2017, 08:11 PM
This sucks. I reflowed a bunch of cold solder joints, got the color back, and I *think* it's here to stay now. However, in order to get the chassis out, I had to cut a shielded wire (I now realize) and just soldering it back together isn't good enough. Now I've got a whole bunch of horrible 60 Hz hum in the audio. :dammit: :dammit: :dammit:

The moral of the story: unplug wires, instead of cutting, and if there is no plug unsolder the wire and add one....If you can't reach the solder joints it probably means the makers wanted the stuff on both ends to be removed as a pair, or your missing something important.

I'm guessing it was an audio cable you cut? Try to see circuit wise what is on both ends and how it connects. Perhaps it can be replaced easily with some modern cable you have on hand.

TUD1
08-28-2017, 10:35 PM
Now I feel extremely stupid. Turns out the wireS did plug in, and if I had realized that, I could have saved myself about two hours. HOWEVER! The color is STILL intermittent! I'm at my wit's end with this thing. I cleaned every tube socket, checked every tube, and reflowed every solder joint in the color circuit. I'm at a loss.

Update. The color is working again, but I'm scared to watch the set for fear of it breaking again.

old_coot88
08-29-2017, 01:02 AM
Have you tried turning the color killer control? If it's set just 'under the threshold', it could be cutting the chroma on and off.

Electronic M
08-29-2017, 09:54 AM
If you can get the intermittent to hard fail or better yet to be predictable troubleshooting becomes easier. Run it with the back off. Look for tube heaters that are glowing dimmer when color goes out (I've seen tube heaters be intermittent in the socket and other wired things). If that don't work try to monitor voltages and waveforms/amplitudes in the color stages and see what changes and where it originates.

It is easiest to do signal tracing when you have a working set to compare to....This situation allows you to do that without a needing a second set.

TUD1
08-29-2017, 10:51 AM
Have you tried turning the color killer control? If it's set just 'under the threshold', it could be cutting the chroma on and off.

I found that if I turn the color killer all the way up and down a few times, sometimes, the color will come back.

TUD1
08-29-2017, 11:37 AM
This is interesting. I found that the color is much more likely to fail when the digital converter box is outputting a garbled, digitized signal than when it is outputting a clean signal. That's not saying it's guaranteed, but that is a phenomenon I have noticed with this set.

dieseljeep
08-29-2017, 12:00 PM
This is interesting. I found that the color is much more likely to fail when the digital converter box is outputting a garbled, digitized signal than when it is outputting a clean signal. That's not saying it's guaranteed, but that is a phenomenon I have noticed with this set.
What make of a Digital converter are using? Some are better receivers than others. I find, the Zenith, Insignia units work the best with earlier sets.

TUD1
08-29-2017, 12:08 PM
It's a Magnavox from 2009 I found at at estate sale. I really don't like it, because I can only pick up one or two channels clearly, no matter which antenna I use.

Update - I swapped out the Magnavox converter box with the Zenith converter box in the other room. Now, the color does not fail, and I can get all the channels very clearly. If anybody remembers back last December, when I got DirecTV, a few of my TV's at that location did not take kindly to to the new source. A few of them had color problems very similar to this where the color would vanish completely, or they would start barberpoling. I think this TV's chroma circuit is just extremely sensitive to fluctuation from the video source.

jr_tech
08-29-2017, 12:38 PM
Buy a box of those 6GH8A tubes. They will come in handy.

And this might be a good time to swap out the 6GH8s for known good NOS tubes. :scratch2:

jr

TUD1
08-29-2017, 01:29 PM
I wonder what would happen if I put a 6KE8 in the color oscillator circuit, instead of a 6GH8, if that would help keep it from having these issues?

old_tv_nut
08-29-2017, 02:10 PM
I wonder what would happen if I put a 6KE8 in the color oscillator circuit, instead of a 6GH8, if that would help keep it from having these issues?

If changing the source fixed it, it's not likely a color oscillator problem, but a color phase lock or color killer issue. (Just my 2 cents worth. Anything is possible.) Note, in some sets, if the color oscillator dies, the screen gets a greenish color balance. You didn't mention anything like that. You can try pulling the oscillator tube to see what the symptoms are for future reference.

zeno
08-29-2017, 02:58 PM
There were a few mylar? caps in these Maggies in either
the burst or 3.58 osc that went BUT IIRC it gave bad tint range or
barber pole color.
For now turn the color killer off & be sure the tuner isnt drifting.
Also sometimes there are 2 AFT switches. One often part of the auto
color AKA brownilator & a separate one. Both have to be OFF to properly
fine tune the station.
To test for drift turn all AFT OFF then FT the set so you still get the
channel but it starts to just get wormy & bendy. Watch it like that
for a few hrs & see if it changes. You can also get AFT drift but its rare.
Just leave the aft OFF to fix that.

For a source IF YOU DARE:nono: get a low power (10W) translator for a blank channel. If you are high up it will cover your town & much father
LOS.

73 Zeno:smoke:
LFOD !

TUD1
08-29-2017, 04:52 PM
I've sat and watched it with the DVD player for about 2 hours now, and I haven't had any problems.

centralradio
08-29-2017, 05:31 PM
Here's the picture it makes after having done no work on it at all. In fact, I have not even removed the back cover yet. Tomorrow, I'll check the tubes, clean it out, set it up, the whole shmagoigle

Nice screen cap of the hurricane. Crisp and clear.

I've sat and watched it with the DVD player for about 2 hours now, and I haven't had any problems.

What a gem .Great color pix too.It looks like not many hour on the CRT in this set.Its stunning to see this today on older sets.

I would pull up a chair and put on a classic TV show from the 1970's and watch it for hours .

TUD1
08-29-2017, 06:17 PM
I would pull up a chair and put on a classic TV show from the 1970's and watch it for hours .

Try again...

LADR
08-29-2017, 06:27 PM
I've sat and watched it with the DVD player for about 2 hours now, and I haven't had any problems.


Thats great!

Bill R
08-29-2017, 06:31 PM
Resolder ALL the ground stakes for the chroma board. ALL of them. They can cause all kinds of intermittent problems.

TUD1
08-29-2017, 06:50 PM
Resolder ALL the ground stakes for the chroma board. ALL of them. They can cause all kinds of intermittent problems.

I did.

TUD1
09-01-2017, 02:27 PM
Color's still working perfectly as of last night. Knock on wood. I think switching the converter box to the Zenith kind really helped.

Jeffhs
09-01-2017, 02:44 PM
Color's still working perfectly as of last night. Knock on wood. I think switching the converter box to the Zenith kind really helped.

The picture looks better as well. :thmbsp: The Zenith converter boxes have received good reviews compared to other converters, so I would agree with you -- the Zenith box you are now using is probably much better than the box you had before.

TUD1
09-01-2017, 05:40 PM
The audio amplifier is acting stupid now though. Ocassionally, it will start humming and popping regardless of which function it's on. TV, radio, or tape. It's extremely annoying, especially since it happens randomly.

Findm-Keepm
09-01-2017, 07:29 PM
If it's a 70s set it's most likely to be VERY early 70s with a T940 chassis. If late 60s, probably T933.

I guess we'll never know. I'm out of here.

Dave - all these problems, and still no chassis number posted. :scratch2:

With one post, you could have folks looking at their Sams Photofact folders, seeing markups on the Sams for various problems/cures for the color, sound, etc, and possibly have had the set working 100%. Is there no chassis number to this set?

Tons of resources are available. Heck, even American Radio History has all those PF Reporters, Electronic Servicing, and Electronic Technician Dealer magazines with lots of "SYMCURE" problem/solution help, but the search engine wants........a chassis number.

Exhibit one: http://www.americanradiohistory.com/hd2/IDX-Service-&-Sales-IDX/Archive-Radio-Retailing-IDX/IDX/60s/Electronic-Technician-1967-01-OCR-Page-0022.pdf#search=%22technical%20digest%22

TUD1
09-01-2017, 09:54 PM
T951

TUD1
09-05-2017, 06:01 PM
Color went out again. It worked perfectly a whole 6 days.

TVTim
09-06-2017, 09:11 PM
Looks sweet.

I have always wanted a console but have not had the room for one.

Enjoy it!!

dieseljeep
09-07-2017, 11:43 AM
Color went out again. It worked perfectly a whole 6 days.

Did you hit the color killer control and a few others with contact cleaner?
Those controls were never touched in normal operation! It seems like that chassis was the last all tube model Magnavox made. That chassis, almost changed my attitude toward Magnavox, they were rock-solid. They must've got all the bugs out, in that late production. :thmbsp:

TUD1
09-07-2017, 12:51 PM
Since the color comes and goes at the drop of a hat, I've decided to just stop caring when it breaks or fixes itself. It popped back in yesterday. Yes, I hit the color killer control with cleaner. Whenever I get a new set, every control and every tube socket get DeOxit.

Findm-Keepm
09-07-2017, 01:44 PM
I pulled my Dad's Sams 1180-1 folder - man that schematic is huge. C760 is circled with "no chroma". Looking at the pix of the main video/chroma board, the cap is a polystyrene cap - silver foil with clear body. My guess is heat kills the cap, which is right after the last Chroma Amp, before the demods. If you decide to replace it, it appears to be the only polystyrene cap on the board, and is on the right side (looking at it from the back of the set), halfway between the 6MK8 Z-X demod tube and the 6GH8A Oscillator, and is next to a stand-up adjustable coil. Replace it with a dipped silver mica - 220pF, 300V or more.

Bill R
09-07-2017, 07:03 PM
I have seen problems with the tube sockets as well. Not necessarily oxidation, but loose connections to the tube pins, and broken connection in the socket. It might be worth changing the tube sockets on the chroma board. At least the color killer and bandpass amp sockets.

Findm-Keepm
09-07-2017, 09:06 PM
I have seen problems with the tube sockets as well. Not necessarily oxidation, but loose connections to the tube pins, and broken connection in the socket. It might be worth changing the tube sockets on the chroma board. At least the color killer and bandpass amp sockets.

If you do - be forewarned - the phenolic boards are super brittle and heat+torque can easily break a board. My tactic has always been to minimize any mass before desoldering the socket by clipping out as much of the socket as possible from above, and removing the individual pins, letting the board cool before desoldering the next pin. This places less stress on an already stressed board.

Likewise, when soldering in the new socket, go slow and allow the board to cool before plugging in the tube - the socket will be tight, and any flex may break or crack the board. Been there - done that, and finding a donor set was a pain.

Any Predicta owner knows the brittle board syndrome well - all that heat and age equals problems.