Mighty Monarch of The Air
 

I wanted to start a thread to show my Majestic 1600 restoration. I am a little late on posting progress but I'll get you up to speed. I found the unit in an antique store and fell for it pretty hard. It had a price tag on it for $125. I worked the owner down to $75 and tax and took it home that night. I thought it would just make a nice decoration in the apartment but then something started eating away at me to find out the history of the unit. Some Google searches later I found my way to this site and made the decision that I would restore it. The first thing I did was clean the insides as much as I could. It wasn't extremely dirty but it did have a fine layer of black dirt on it. It cleaned up very nicely with some elbow grease and electronics cleaner.
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After cleaning the interior I replaced the missing tube you can see on the right hand side. I work with some one who is a wealth of electronic parts and he gave me one for free. With all the tubes in place it was time to fire it up and see what we've got. I brought the voltage up slowly with a variac and got raster :-). Unfortunately there was no vertical deflection, just a solid horizontal white line in the middle of the screen.
My next step was to pull the chassis from the cabinet and put it on a tabletop to get ready for recapping. I got a copy of the photofact and ordered my capacitors from www.wjoe.com, 17 of the them to be exact. Today I think I'll begin the recapping process.
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Underestimated the difficulty of replacing capacitors. I removed the first cap and I don't know where the markings are for polarity. I've read in another post
"The symbols are little cutouts in the phenolic material right next to the terminals."
I can't seem to find any markings though.
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that's on the bottom of electroylic multistage cans. With most new caps (except electrolytics), polarity is not an issue, like resistors. The old ones had the terminal with the outside foil on it marked, not usually the ground. Be careful though, small electrolytics will have the negative marked and that must be followed. They usually have a paper or cardboard covering and are pretty easy to read. Electroytics are usually 1-2 mfd (microfarad) or higher. You usually won't see one lower than a 10 or 8 mfd. That .1 mfd you have in your hand is not an electrolytic. Some capacitors are rated in mmfd (micro micro farad), or pf (picofarad, same thing), which is even lower. Mmfd or pf caps are usually mica or ceramic.

Is this your first attempt at electronic repair? If so, I would suggest letting the TV sit for a while and buy a cheap AA5 tube radio. This will help you to identify parts and repair something that is a lot more simple than a TV. Also if you totally screw it up, like I did the first couple of times, you haven't wrecked anything important. I hope I'm not out of line. Just a friendly suggestion.

I think I'll forge ahead and break something important the first time. You have however made my evening a lot shorter. There are very few larger mfd capacitors in the set, and they are all very easy to read polarity.
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What kind of capacitor did I have in my first picture?

Wax paper. Guaranteed to be bad. Nonpolarized. Replace with "Orange Drops" or similar mylar and foil cap. Use the same capacitance (or within 10%) and same or higher voltage rating. More at http://www.wa2ise.com/radios/repair.htm

I meant to say you usually won't see one lower than a 10 or 4 mfd. :banana:

Good luck, ask for help if you need it.

Here are more articles that may be helpful. The first one covers recapping:

http://antiqueradio.org/recap.htm

http://antiqueradio.org/restoration.htm

Regards,

Phil Nelson
http://antiqueradio.org/index.html

Thanks for the articles. I read both of them before actually. I did run into one more thing. I actually ran into it when ordered my caps. There is one cap that on the photofact says 600v but the one that is installed is 800v. I ordered a 630v trusting that the photofact is correct but now I'm second guessing myself into thinking I need something over 800v.

Which cap is it (Sams part number)?

Phil Nelson

I'm not sure to which part number you are referring. The parts list has an item number, which is C40. There is also replacement part numbers from-
Majestic- D03.100-12
Aerovox- P688-022
Centralab- DF-203
Cornell Dubilier- PTE6S2
Sprague- 6TM-622
The schematics state that it's used for audio coupling. Sams states .022mf capacitance and 600v voltage rating. The cap in the set is .02mf 800v.

I mean the part number given in the Sams manual (C40). 630V should be fine there.

Phil Nelson

Why do you think there is an 800v in there? Could it have been repaired in the past possibly?

Just about every old radio or TV that I've owned had at least a few repairs.

Or, perhaps the manufacturer was using up parts that they happened to have in abundance, even though the voltage rating exceeded the specified minimum. They might have gotten a great deal on a boxcar full of 800v-rated caps.

Phil Nelson

Progress!!!
Well if progress means moving backwards. I finished with the caps that I had ordered, but after spending some intimate time with the under side of the set I realized that I missed 7 electrolytics hiding under two metal cans. So they are on order and I await their arrival. I decided to fire the set up again to see what, if any, progress I have made. I fired the set up and... no raster. Moving backwards! I also thought that the flyback transformer was quieter than it was before, although that could be in my imagination. The tubes did light up pretty like a Christmas though.
http://farm6.static.flickr.com/5021/...7c41bf7832.jpg
I didn't spend much time trying to figure out where I went wrong. I figure I'll have some time in the next few days before the new caps get here.

BTW thanks so much for all of your help Phil.

Steady as she goes, Grasshopper...It ALMOST worked before, that is a VERY good sign...Somethin' THAT purty HAS to work well.

The flyback might be quieter because it's not putting out any voltage. Check your work. Believe me, I'm not doubting your ability, but I still hook up stuff wrong sometimes and I've been doing this for years. Just did it on the last one I did. Also check the tubes in the HV cage, 1B3, etc. Make sure nothing is shorting and trace the schematic on each cap you changed to make sure it went to the same spot the old one went to. Have fun, this is what it's all about.

All good things come to those who wait!!!

Spent some time looking over my work, going from solder point to solder point and making sure nothing was shorted, not soldered, etc. I also refered to my photographs to check polarity on the three electrolytics that I replaced. All of my checks turned up nothing, all looked good. What could it possibly be? I decided to give it power again and have a good look around and visibly check the tubes. I fired the set up and confirmed that all the tubes lit up. They lit up like a warm fire on a cold night. All of a sudden what do I see?

http://farm6.static.flickr.com/5182/...e3db0f9e1b.jpg

Wait for the set to warm up of course!
I forgot watching television as a child required turning the set on, going to the kitchen to get a bowl of cereal, and then returning to your Saturday morning cartoons.

Now I wait for my next batch of caps with a feeling of satisfaction that, lack of visible progress not withstanding, at least I'm not moving backwards.

A raster, yay. The bright horizontal line is the classic sign of issues in the vertical circuits. It may be cured after you finish replacing capacitors.

Don't play it long in this condition, lest it make a permanent line in the picture tube.

Phil Nelson

I set to task today and replaced the multi-stage can capacitors with new individual axial lead capacitors.

Cans I replaced.
http://farm6.static.flickr.com/5023/...3e605a3520.jpg

It was a bugger trying to find room for all of the new leads, but I got all of them in without any shorts.

After picture with the 7 new individual caps.
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I have not yet plugged it in because I do not have a variac here at the moment. I don't know if that makes a difference now that I have replaced the capacitors but I wanted to ask all of you. Should I wait until I have a variac to fire it up, or should I fire her up all at once? I await the councils decision. :scratch2:

On a related note does any one have advice on procuring a variac? Specs, things to look for, price range, etc...?

I would use the variac. If you hit the caps with full B+, you risk damage. I had that happen once, the caps all hot really hot even though they were 'new'.

They can be quite expensive depending on the amperage etc. If you anticipate doing more work on tube sets in the future, it's certainly a worthwhile investment, but for a single set, the cost:gain ratio isn't that pleasing.

You can do without one, a lot of people use what's called the "dim bulb" (no sense repeating what's in a lot of other threads/sites - a quick search will net you the details) method to protect their sets when they fire them up; it gives a nice visual indication very quickly if there is a short, and is essentially a lightbulb-based voltage divider/current limiter.

Or, you can try borrowing one... there are plenty in many university physics labs and if you're friendly with the staff they might let you borrow one for a bit. I borrowed mine when I did my Fleetwood set.

Edit: Note that I meant you can use other protections instead of a variac, not that you can just fire it up without any safety!!

"If you anticipate doing more work on tube sets in the future, it's certainly a worthwhile investment"

Hehe, I think that ship is sailed. I'm in pretty deep already. I have a set in my basement ready for round two, and I'm constantly on the lookout for rounds 3-26.

That is pretty much a moot point indeed for anyone who has the space/skills. Once you do one, you have an itch to do more. Everyone here's been bitten, I think. :D However, I do imagine there must be people that do "Just One™" because it was their grandfathers or whatever and has particularly special value to them, but they have no interest in other sets.

(sadly, I have neither a lot of space, nor does anything overly interesting ever pop up in my area. I only got my fleetwood because the previous owners left it in the hayloft of our barn.) Sure, there's the odd AA5 that some idiot wants $200 for, but given my limited space (look at my nickname and if you need a better hint, my website, then take a guess with what it's filled...) and already having a tube radio, I _really_ want to do a tube-based TV set.

It helps avoid shorts if you place stripped off wire insulation on the bare cap leads. "Spaghetti" they call it. You can make your own from scrap wire of large enough gauge (old house wire or power cord) or even use coffee stirrers (very small straws).
http://farm6.static.flickr.com/5230/...4bc06bb603.jpg http://pw2.netcom.com/~wa2ise/radios/spplug.gif The "dim bulb"
For a quick substitute for a variac, wire up two outlets in series. One outlet plug in a lamp that has say a 100W light bulb, and the other plug is for the TV under repair.

No gratification tonight it is. I'll bring a variac home tomorrow, and look to purchase one soon. I had thought about using shrink tubing on the leads on the caps, thanks for the tip wa2ise. I hear you on the no space VintagePC, I live in a sub 900sq foot one room loft with my wife. She has been really suportive of my new obsession, there is no hiding anything when you have no walls.

I don't think it's a big priority to rush out and spend a bunch on a variac for your first restoration project. If your main concern is not frying your TV, a cheap dim bulb tester actually provides more protection. If your TV has a dead short, the bulb simply lights up, and no harm is done. With an un-metered variac, you can still burn up a power transformer while gradually increasing the voltage, a fact that I learned to my dismay some years ago. A metered variac lets you monitor current use while you increase voltage, of course.

Phil Nelson

http://www.audiokarma.org/forums/images/icons/icon3.gif Why not make a wall of vintage TVs? Two birds with one stone :D

I didn't know there was such a thing as an un-metered variac. Then again what I don't know could fill a ocean :).

Update.
Brought home a variac and fired her up... No vertical deflection. I've now replaced all of the paper, multi stage cans, and electrolytics in the chassis (as far as I know). Time to move on to other trouble shooting. Any suggestions on where to start/where not to start?

The easiest place to start is with the vertical deflection coils (the ones on the neck of the CRT) - check them for continuity with a multimeter. If they're good, then I'd start looking for open or shorted resistors. A complete lack of deflection means a total failure somewhere...

Someone with a service manual might be able to point you in a more specific direction, but this is usually a good start for anything of this age. The carbon resistors tend to go high when exposed to a lot of moisture and cause all sorts of problems.

After you check the deflection coil, check R3, the vertical linearity control and R4 the vertical size control.

I assume you've already checked V13 the 6C4 and V14 the 6V6.

The way they've drawn the alternate circuits is confusing to me and I'm not sure where this section is getting it's B+.

I might have to pull my chassis and see what they really did.

John

"The easiest place to start is with the vertical deflection coils (the ones on the neck of the CRT) - check them for continuity with a multimeter."

Forgive my new guy ignorance but I don't know how to do that. I know how to check continuity with a meter but I'm not sure where you're suggesting I check. Could you elaborate on that some more for me?

"After you check the deflection coil, check R3, the vertical linearity control and R4 the vertical size control.

I assume you've already checked V13 the 6C4 and V14 the 6V6."

I've tested V13 and V14, they both check good. I've also adjusted R3 and R4 to no avail.

"I might have to pull my chassis and see what they really did."

Wow! You guys are so helpful here it's hard to believe. Please don't go that overboard for me yet. Let me do some due diligence of my own before we get to that point.

Certainly - I had to start somewhere too, so I know how it feels :) But, we're always happy to explain if you don't understand. I suspect the terminology we throw around doesn't help either...

If you look at the back end of the picture tube itself, you have the end that is wired up to the rest of the set, where the guns are. Moving forward towards the wider [bell] area of the CRT, you may encounter some rings with a bunch of tabs on them [purity magnets]. You won't need to touch those at this point. Further towards the bell, around the part where the tube begins to widen, will be a cone-shaped form [the deflection assembly, AKA the yoke]. This contains the coils of wire that the set uses to move the beam of electrons within the tube. One pair of coils is for the horizontal deflection of the beam, the other pair is for the vertical deflection.

(from the picture in the first post, yours appears to be boxed in in that metal cage that rises up from the main chassis).

Essentially what you want to do is find where those are wired to the rest of the set, and use those points to test each of the vertical coils in the deflection assembly for continuity. If it's closed in, you can't tell which leads go to which coils, so you'll have to go by the schematic. I don't have one on hand, so perhaps another member can tell you exactly where they are. You should be able to locate them by wires running to the vicinity of the vertical components just mentioned (R3, R4, V13, V14).

If you get an open reading on one of them, then there's a break in that coil, and you've found your problem. If not, then the problem is somewhere else... and hopefully it is, because coils aren't exactly easy or fun to repair.

Apologies for the wall of text, but it'll have been worth it if you learned something, and my job will be complete for today :)

It's what we do here. Everyone was really helpful while I was restoring my Fleetwood console, and some people go above and beyond to help you. I guess we are dedicated to preserving these sets too much...

From what I can tell there is continuity across the coils. I looked at the schematic and I think the areas I pointed to in yellow is where to test.

http://farm3.static.flickr.com/2363/...82ab4c205c.jpg

I pointed to those leads in yellow below and there is continuity across those two leads. For some reason the wire on the output side of the transformer is soldered on a "landing strip"(I'm not sure if that is what you really call it but that is what I came up with). Maybe it's so you can test things easily, it certainly did make it easier for me.

http://farm4.static.flickr.com/3641/...d0c8f076c8.jpg

Could the next step be firing the set up and testing voltage out of the vertical output transformer(T4)?

Terminal strip.

Anyway, be careful with the vertical output tube plate, when it's working normally it has pulses about 1 to 2KV tall.

Before firing up the set, check that you have continuity on the primary of the vertical output transformer. Likely a few hundred ohms. Oh, on the yoke, getting continuity across the secondary either tells you the yoke has no opens or the secondary has no opens. Or both have no opens. You'll have to disconnect a lead on one of these to tell for sure.

Besides T4, you should also check for continuity on both the primary and secondary of T2 in the vertical oscillator. That one will be easy because you won't need to disconnect anything.

R3 is in the cathode of the vertical output and sees quite a bit of power which is hard on it. You should check to see that it has the correct resistance.

R4 supplies the plate of the oscillator and could be bad too, but it doesn't see as much power.

You might need to try substituting the 6C4 also even though it tests good. It might have too much grid leakage which might not show up on your tester.

John

T4's secondary reads spot on at 7.5 ohm. T4's primary which is supposed to read 700 ohm is reading twice that 1.4 k ohm.
T2's secondary which is supposed to read 1.3 k ohm is reading 1.4 k ohm. I'm assuming that is well within accepted tolerance levels. T2's primary is supposed to read 160 ohm. It is reading wide open.
R3 is good to go at 5 k ohm and adjusts as I turn the control.
The tester that was used to test the 6C4 had a leakage detector and it tested good there to.

So it looks like my problem is T4 and T2? Are those parts that one can find?

Sometimes the open happens at the spot where the enamel magnet wire is soldered to the lead wire. The old rosin sometimes corrodes the wire, causing the break. You could dig into the outer paper tape wrap to see if that might be the case. At this point the transformer would be trash if that's not the cause anyway, so nothing lost.

As for the output primary showing twice the resistance listed, well sometimes the schematic services have errors. Or the manufacturer made a production change. But T2's primary being open would kill the vertical. So pay that more attention.

Vertical transformers are somewhat similar to audio transformers, and also power transformers. Getting the turns ratio close enough would be trial and error, also getting the phasing correct is important. I don't know what turns ratio and impedances would be correct, or what would be close enough, so it would look like black magic... :scratch2:

It's a blocking oscillator. I wonder if they rely on the core saturating? Sams only gives a Majestic part number for it so it might be difficult to find a replacement.

I think your point about the connection at the lead is a good one. I've seen that a couple of times. Refresh my memory. The primary is usually the inside winding isn't it?

I cut through the transformer in haste and cut too deep totally screwing up the winding so I don't know if it was the leads or not. I did pick up a new vertical block oscillating transformer to replace it though. The impedance on the primary and secondary are lower than the original but I put it in and I'm going to hope it'll oscillate. I may have to tweak the circuit with resistors inline with the new transformer to make it linear but I'm crossing my fingers it'll be ok as is.

http://farm3.static.flickr.com/2138/...14683bfbf5.jpg

Again I don't have a variac at home so I'll have to wait until tomorrow to fire it up and see what how I did.