1960s Magnavox set info

[Garrard201]

Well dudes, it's been a year and a half, but I brought the set into a tech here at work for when he had some spare time. A little electrical tape on the cord, some black magic(?) and IT'S WORKING!!!!!! Here in Chicago I can get 2, 7, 9 & 11 pretty clearly. Picture is pretty decent, too with my rabbit ears. I found the warranty card inside as well from the delivery shop (Dave's TV Service / Fox Radio Parts Co, Inc.). I assume this is for a warranty repair, since it's dated May 7, 1966, and the set has no UHF knob (meaning it's pre-'64, right?). Tube type is 17DKP4- (17DS) GF. Wow. Now to the problem I'm having (see next post)....

[Garrard201]

In the back are 2 screws for VHF, and a space for 2 screws for UHF. Looks like the UHF "board" was never installed, though. This makes sense, as the set was used in a Cleveland suburb, and they didn't have any commercial UHF till 1968.

Their main stations in Cleveland were 3, 8 & 5, only the latter of which is in use here in Chicago. SO, I hooked my digital converter (which only works on 3) to the VHF screws and get nothing. I know the terminals are working, because I hooked rabbit ears straight into the VHF screws and it made a huge difference.

I know the box is working because I have a small portable I plugged it into (also using RF).

I'm thinking 3, 5 & 8 may be non working on this set due to overuse when it was in Cleveland. I get no picture on channel 5 in Chicago, and Channel 3 is displaying a much coarser-looking static than 2 (which comes in great) or 4 (which has no signal in this area).

Thoughts? I wanted to hook in my digital box because I have the TV in my cubicle. And I work for a UHF station!!! AND WE HAVE 4 DIGITAL SUBCHANNELS! So I'd like to watch those. : )

[Garrard201]

OH, and there's a switch on the back marked "L-S-D." Do I dare??????


Seriously, what is it for?

[nasadowsk]

Ok.

Looks like you're gonna need to do a bit of repair.

How good are you with a soldering iron?

You say it's got a picture. Is it a good one? Clear? Take a screen shot with a camera.

I don't think you've got a 'burnt out' channel - they generally don't do that. Does the set have fine tuning? Have you tried that?

I'm not sure what the LSD switch does - might be a range adjustment. TVs of this vintage did'nt have the modern AGC setups we take for granted today, and they need a bit of adjustment. You might see an 'agc' control in the back - that often needs to be set right, or you won't get a picture, or you'll get an overloaded one (the picture won't lock and be stable at all).

if you're getting ANY channels, then the problem's in the tuner, which is mostly working anyway. You might want to pop it out and look at it. Turret types can be cleaned up. Be careful - bending the wires or such <b>will</b> affect the adjustment!

[Jeffhs]

That "L-S-D" switch probably is a range switch, for Local, Suburban, Distant. The switch probably selects one of three different AGC networks.

I've never heard of TV tuner channel strips going bad from overuse. However, as another poster said, maybe the reason you are not getting channel 5 is that the fine tuning could be off. I'd check that before doing anything drastic, including adjusting the oscillator slugs in the channel strips. These ordinarily do not need readjustment, as the set's own fine tuning control generally has enough range to go either side of the channel you are watching; that is, with the fine tuning all the way to one end of its range, you should be able to get a fuzzy picture on channel 3 if you are watching channel 2, or, if you are watching channel 3, the fine tuning should go from the edge of channel 2 to the edge of channel 4. The clearest picture and sound should appear with the fine tuning control at or near the middle of its range. If you can get a clear picture or sound only with the fine tuning at one end of its travel, the oscillator slug for that channel strip is probably out of adjustment and should be reset. To do that, set the fine tuning at the middle of its range, then adjust the slug in the channel strip until the picture and sound are clear. As a matter of fact, this is a good way to set the local channels in your area so you won't have to adjust the fine tuning when going from one channel to the next; just set the fine tuner to midrange and adjust the oscillator slug in each strip for the best reception. One other thing you can do if you don't use the vacant channels on a turret tuner is to remove the strips entirely for the unused channels. That way, you can go from one local station directly to another, without flipping through vacant channels.

All-channel tuning was not mandated for US television sets by the FCC until April 30, 1964, so your Magnavox TV was manufactured prior to that date if it has only a VHF tuner. The open holes in the antenna terminal board suggest to me that there may have been other models of this TV that did have UHF; that or else the same basic terminal board was used in a number of different sets, with the UHF side being left open in VHF-only receivers.

[Tubejunke]

Many sets from "back in the day" were smoked around. After all these years I would not be at all surprised if the tuner contacts were not loaded with smoke tar and carbon which eventually forms on contacts in nearly everything that has a contact such as: the tuner; volume control; LSD switch; and all other potentiometers or rheostats that control adjustable settings.

I recommend a good can of electrical contact cleaner, or actual tuner cleaner (if you can still find it). I just use plain, cheap, contact cleaner. The "tuner cleaner" was about the same thing with some type of lubricant added. With this I recommend soaking ALL of the controls and switches. Each one you spray must be rotated completely through its range repeatedly. I recommend somehow marking the exact position of anything that is not user friendly and meant for everyday adjustment. Mainly this would be the picture size (horizontal, vertical) adjustments. Watch out for the AGC control as well.

While you are at it you can go ahead and pull each tube from its socket, spray the socket, work the tube in and out of the socket several times. Take an old pocket knife and scrape the pins of the tube so the metal shines. This may sound like a lot of work but cleanliness is a prime factor in the proper operation of any old set, really electronics in general as for my personal rule of thumb.

To me this set looks well kept and likely not over used. There should be plenty of life left in it with some care and maintenance. Oh, when you are trying the DIG-a CROCK on channel 3 try slightly turning the channel changer to both sides. The picture may suddenly pop in crystal clear if you hit the sweet spot. Another indication of needed cleaning.

Tube out....

[Robert Grant]

Channel 3 has a DTV transmitter Chicago (WBBM-DT - they hope to change to channel 12 soon).

Have you tried using channel 4 for the converter box instead of 3?

BTW, my emerson 1224 is also dead on channel 3, I think part of the coil on that turret section broke, so I have to use channel 4 for VCR or converter box.

You might try tuner cleaner to see if that restores your tuner to all of it's channels.

I don't think a tuner can lose the use of any channel due to "overuse". The parts exclusive to each channel are passive, the same tubes are shared with every VHF channel.

[Garrard201]

OK, everyone, good info from all! I haven't done any cleaning... yet, that's phase 2 of my evil plan.

The digital box does not seem to have a ch. 3-4 selector, either in the menus or on the back, so I'm gonna get a VCR and see if I get anything on 4. By the way, I have the Magnavox box w/o analog pass thru (brand unity!).

I tried the fine tuning for Ch. 3 with no luck. I also tried moving the tuning knob a bit in each direction to see if the picture "popped on" (which is what it did for 7). Ch. 5 does come in weakly even after adjusting the fine tuning. 9 is probably strongest, followed by 7, 2 & 11. I'm wondering if in our building (Ch. 26) the dishes on the roof aren't interfering with 5? Oh well, no biggie, I just need 3 or 4 so I can get the box right now. Will keep you posted...

[Garrard201]

Well, our collective head scratch can end. The problem was... DIRTY CONTACTS IN THE VHF SCREW TERMINALS! They were a little loose, too. I popped the back of the set open, sprayed the terminals, reattached the clips snugly, put the back on and plugged in my antenna. PRESTO-crystal clear picture from the digital box on ch. 4. AWESOME! I'll take some pics tomorrow.

[Garrard201]

Finally got a pic! The set fits perfectly under my desk, and the image is actually much better balanced than this photo looks.

[nasadowsk]

Now I'll say pardner...that there is one two faced cowboy...

[AUdubon5425]

Nice - gives me motivation to get back to work on my old Maggie!