I aquired 3 "new" sets free today. One immaculate Magnavox 21" console, one Magnavox 21" table set (should have legs) and one 17" Motorola table set.

I'm REALLY proud of the Magnavox console, what do you guys think? I havent plugged it in, cleaned it, or done anything else to it. I can tell this set was used constantly, as all of the tubes, inluding the picture tube. The picture tube was replaced in January of 1970 with a dumont tube *woo hoo, its new!* I'm getting a variac very soon, and wondered what the process is for "bringing up" a set after its been retired for about 20 years? I also wondered what the steps are to check the set if its ready to even be turned on for a diagnosis

Here are some pics of the three sets...
Tell me what you guys think!

(ps, that white sopt on the front of the magnavox set doesnt exist, i dont know why the camera chose to slip up :p: )

heres a shot of the top

shot of the chassis

heres a shot of the moto, the front is somewhat scratchy :(

chassis shot

And heres the other magnavox, which i may just use as a parts set; its pretty scratched up, not too attractive (its missing its legs), and seems like a rather cheap set. If anyone wants to pic it up, they're welcome to; it'd give me a nice feeling if i knew it were going to a loving home ;)

A note about the moto: it has aal the original tubes including the picture tube :)

the chassis, however, is on very good condition

I'm SO jealous of you guys in New England, & the northeast..we didn't have TV down here til 1954-55, & as such its hard to find earlier than then sets, if you find any at all. Great score!! Wanna see pics when you get 'em running !! -Sandy G.

Believe me, its pretty hard to find sets around here too. The last score before this was the Admiral in early march, and then then my color Zenith roundie in July of last summer. Take it from me, its slow!

I've got one of those Magnavoxes with the lifting lid over the controls...it has an automatic power switch that turns on when the lid is lifted and off when the lid is lowered.

Great sets!

There is a Magnavox here near me in Beaumont that is very similar to the one you have pictured. only major differences is that the controls are below the crt, and the cabinet has doors. i have been considering going to get it, but right now do not have the room for it.

I kind of like the Maggie with the lift up lid!
If the CRT is good it might be worth fixing. Some suitable legs can probably be found at Home Depot or similar.

Eric

I think that the lifting lid Mag. may be made to set on a cabinet rather than legs. There are no fittings for legs on the bottom on my set, and at the estate sale where I bought mine I saw a cabinet with doors of similar wood style and size to the TV...so that when you put the TV on top of the cabinet it would be the typical height of a 50's console TV. It was $35 extra from the TV so I didn't get it.

Hey all! Thanks for the responces!

I was most interested in the magnavox with the vertical controls. Ive never seen a cabinet in such great condition, and the chassis is great as well. If you noticed, the warranty card for the DuMont CRT is still inside; never filled out. I'd like to know more about this set, like what year, if anyone has any ads, and what a tv in this condition might get in the market.

The irony is, I was least interested in the magnavox with the under-the-lid controls, as it has many scratches on it, and just seemed somewhat cheap looking, although the chassis is in pretty nice condition.

Chad: My set also has that little switch; at first iwasnt too sure what it was for, and assumed it was some sort of protective spring to keep the lid from slamming down.

I havent powered any of the sets up yet (although Im biting my nails like crazy wanting to) because I dont have a variac *yet*. Its arriving on friday (purchased it online sunday night). I know that theres some sort of order you need to follow when you power up a set for the first time in about 20 years, and I'm wondering what that is.

I love that little Motorola set, mostly because of its size and the fact that im 90% sure it has all of its original tubes, including the CRT. I dont really know how to tell if they really are all original, except from the fact that every tube says motorola on it in the exact same red font.

One confusing thing I noticed about that set is that i cant find a flyback transformer, nor can I find an HV rect. There isnt any sign of canibalisim, because nothing appears to be missing from the chassis (there isnt even any space in there for one anyway). I did find the HV wire coming out of the CRT bell, and if you look closely at the chassis picture, you'll notice its going down inside the chassis. Why is this? I'd also like to know if anyone knows the year of this set, along with any ads they might have (I'd love to see them).

I havent been able to do any looking around inside the sets, as I damaged my wrist in the process of lifting all three sets (putting them in car, taking them out, bringing them inside, ect). So when my wrist is all better, I'll bring down the moto and flip top, and get a good look inside.

Any other questions?

Originally posted by H2s04

One confusing thing I noticed about that set is that i cant find a flyback transformer, nor can I find an HV rect. There isnt any sign of canibalisim, because nothing appears to be missing from the chassis (there isnt even any space in there for one anyway). I did find the HV wire coming out of the CRT bell, and if you look closely at the chassis picture, you'll notice its going down inside the chassis. Why is this? I'd also like to know if anyone knows the year of this set, along with any ads they might have (I'd love to see them).


I just looked your Motorola's chassis number printed there in your photo... TS-418... and found it in Sam's 269-9. The date is March 1955, so I would guess that the set is from 1954.

Sams' photos show FOUR tubes mounted under the chassis... the 1B3 HV rectifier you were in search of, the OSC and RF tubes for the VHF tuner, and also the RF tube for the UHF tuner... and your set doesn't have UHF. Your flyback is shown being mounted under there as well.

It seems they were making good use of all the empty space under that chassis. Even with the tuners and HV components being under the chassis, it looks like there is still plenty of room for you to get your fingers in there!

Originally posted by H2s04
I havent powered any of the sets up yet (although Im biting my nails like crazy wanting to) because I dont have a variac *yet*. Its arriving on friday (purchased it online sunday night). I know that theres some sort of order you need to follow when you power up a set for the first time in about 20 years, and I'm wondering what that is.


As far as bringing it up slow, we probably all have our different procedures. But, the most important thing to remember that applies in any set is to remove your horz output tube before starting.

Myself, I start out on 20 volts, wait 10 or 15 minutes, then go up to 30, wait another 10 or 15 minutes, up to 40... so on and so forth. I feel the electrolytic cans as I continue up to make sure they aren't getting hot. They should be relatively cool, but if one seems to be getting hot, there is likely a short and it needs replacing before coninuing further. A little bit of warmth may be okay, but monitor it well. Also keep an eye out for any other signs of trouble.

Some guys take more time during this process... usually to give the lytics a better chance to re-form. In most cases, I plan on replacing them all anyway.

This Sams shows plenty of paper/wax and black-beauty caps under your chassis. It may be in your best interest to go ahead and change them out while you're waiting on your variac. The same goes for the main lytics. Being 50 years old, it would probably be better than trying to bring up the old ones slowly. Besides, it'll give ya something to do while you wait on the variac to arrive.

If you need the Sams for it, send me your address in a PM and i'll get it out to you. I have two copies for this chassis, so you're welcomed to one of them. See if you can get some numbers for the Maggies and I'll look to see if I can find those as well.

Wow! thanks for all that info chuck, i had a feeling some tubes were missing up on top :p:

One quick question: why is removing the horizontal out tube a good idea? isnt there some sort of HV going/coming out of the cap that goes on top of it; wouldnt that lead to arching if left unplugged? is there ever a time when i can put it back in and try to get a picture while im powering it up? And whats the deal with black beauties? theres some buzz about them, and I dont know what its about. Yeah, im a tv n00b :rolleyes: sorry.

Jeff,

You want to pull the HO tube out because it would end up running too hot. Since you are only giving the set partial power, the horz osc tube won't be reach the correct frequency to drive the output tube. The plate of the output tube will get hot enough to glow... not good. :no:

You only want the HO tube in there once you can give the chassis the full line voltage.

Black beauty and paper/wax caps are always prone to failure. It's best to simply get them out of there. I've been changing alot of BB caps in my Zenith, and in doing so, I've corrected a lot of problems. Many of the BB's i've changed actually checked good out of the set... but in the set and under a load, they simply couldn't hack it.

In any case, they're 50 years old and need to go. :yes:

My motorola 12VT13 from 1949 also has the flyback and the HV rect. tube under the chassis.

Thanks for the info Chuck,

What do I replace the BB's with? paper caps instead? I'm also wondering how one reads the BB's color bars; what values they make.

I just finished cleaning the Moto chassis tonight, and have included some pics

Right after removing the unit from the cabinet:

Seconds after cleaning the whole chasis; shines nicely doesn't it? :yippy:

I am working on a Hoffman with the high voltage rectifier and flyback under the chassis. This Hoffman has a removable bottom to allow you to change this and the tuner tubes. It also has several black beauties which I am changing. I have removed a couple with nice cracks down the sides.


Another interesting feature of the Hoffman is that it has a transformer for the filiments but uses a selenium rectifier voltage doubler for the DC power supply. This supply is not isolated so the entire metal chassis could be 120 volts. All except one of the controls, front and back have insulators between them and the chassis and the chassis mounts on plastic insulators. I am guessing that the one control is not original.

Of course I am using an isolated variac to work on this set.

You would replace the black beauty caps with mylar caps of the correct value and voltage.The link below has a table for calculating bb's values.It is a very good idea to use at least an isolation transformer when working on a non isolated chassis set.

http://antiqueradio.org/recap.htm

Man that chassis looks awesome! Looks good enough to display out of the set! Although that wouldn't be very safe being a series string chassis. Still looks good, though. Very impressive!

Would you like to have the Photofact folder for the set? As i said, I have multiples of this particular one and would be happy to send it to you.

I've never seen a chassis that nice looking! Looks like a production line shot. Great job my man & great find!

H20 did you spray engine detailer on that chassis. Hey! That may be a good idea fellows. I'm talkin about the stuff car dealers spray under the hood after degreasing. Makes everything look shiny and well kept. You can buy the stuff at your local Auto (Twilight)Zone or Advance (retard)auto.

The reason for the parts/toy store comments is a whole other long topic. :puke:

Being that this set has heaters in a series, jerking the HO tube would knock out most of the other tubes. If it used a 6BQ6, ya could just put a jumper across the filament line at the socket for bringing the set up slowly with no major issues. But, I just noticed that Sam says this set uses a 25BQ5 for the HO tube. Would it be unsafe to jump the filament line where a 25 volt tube should be?

What do ya'll think?

Would it be unsafe to jump the filament line where a 25 volt tube should be?


Don't do it. If you have to, take another 25 volt tube and jump those heaters in or use a suitable resistor. Jumping a 25 volt tube without suitable resistance will cook the rest of the heater string. On my RCA metal portable, I substituted a 6 volt tube for the CRT for the soft start. It didn't light up, but the rest of the string lit up normally and I was able to finish the soft start. Also, I disconnected the top cap for the hor out, but left the tube in. No problems.

WOW! This is the largest forum post I've ever had!!

You know, there must be somthing about this town; somthing magical in the air :p: . Like, every set I've ever brought home has had a fantastic chassis, regardless of the condition of the cabinet. I cleaned off a similar looking Admiral 19G1 (for sale, mind you) that came out the exact same way. I'll fill you guys in on how the other two sets come out (yet ot be cleaned) but they look pretty good even now!

I swear, all I used was some generic distilled water and some paper towels, nothing else. I considdered using some noxon 7, but was worried about how the ammonia would affect the lytic cans.

I'm still pretty confused about the HO tube discussion, remember, I've onl been doing this for about 2 years, and I've never actually powered up a 50's set. I've only done actual work on 60's b&w sets that didnt need much work.

So how does the whole HO thing play out again, im sorry

Here are some more pics of the moto, and i'll take a smaller format pic of the admiral soon

another

and yet another :D

One worry: so you're saying my chassis isnt isolated?

That's correct. Your set does not have a power transformer, and your filaments in the tubes are wired in series. Take a look at where your A/C line comes into the set. One side of the line goes to the switch, and the other side of the line goes to a chassis ground. This is why you want to use an isolation transformer.

Also, something else I was noticing looking at the Sams... the speaker in your set uses an electro-magnet, not a permanent magnet. Because of this, you'll need to make sure that all speaker connections are made while powering up this set. If the speaker isn't plugged in, you won't get any B+ voltages.

hmmmm........120V running through the chassis............MOTOROLA TABLE SET FOR SALE

As mentioned previously, I have a Hoffman made the same way. I also have a Motorola built similarly.

There were some AM radios built in the 1940s that if a knob was missing, 120 volts could be yours if you turned the affected control. Very dangerous. These same radios usually had metal screws attached to the potentially hot chassis sticking out of the bottom of the case. If course the line cord was not polarized.

While quite well insulated when all put together, most 1950s-1960s series string TVs can be a shock hazard when opened up. This is why I always use an isolated variac as a power supply when working on TVs and radios.

What do you mean by isolated, grounded? Like clipping a ground to the chassis and the other end to the ground port on a variac? my first ever variac is arriving in the mail soon, so i dont really know anything about them; i thought they were all grounded

A variac allows you to slowly apply power, in steps, and also allows you to monitor the ammount of current the device draws as you slowly increase the voltage.I always use a variac when I power up a tv for the first time,this prevents damaging the set in the case that something is shorted.By watching how much current the chassis is pulling you can tell if there are problems.You should hear something from the speaker at around 90 volts.
BTW- Many older televisions did NOT have an isolated chassis.

The isolated variacs that I use are from Heathkit. I built one myself and bought the other. They consist of a 1 to 1 isolation transformer followed by a variac autotransformer. The 1 to 1 isolation takes 120 volts in and outputs 120 volts. The output of the transformer is isolated from the main power lines, greatly reducing the risk of you being shocked by the voltage applied to what you are working on. It also protects your test equipment.

The variac autotransformer allows you to apply power to the TV/radio that you are working on slowly, checking for shorts before any damage is done.

If you buy a variac, be careful, as many of them are not isolated and will not protect you from shock. It that is the case, you will need to purchase a seperate isolation transformer.

I completely know about the whole variac thing. it being an autoformer and such, but I still dont understand how just adding a 1 to 1 transformer before the variac will significantly reduce my chances of getting shocked? Wont the chassis still be running at 120V? :confused:

Without the 1:1 isolation transformer, if you touch the chassis (which could be at 120 volts on your TV) and also touch any other grounded point, you will have 120 volts AC across a portion of your body. Other grounded points include the case of your oscilliscope, the ground of your multimeter (if not battery operated), the case, if metal, of the lighting you may be using, etc. Anything with a ground/neutral connection to the power line.

Even if you do get a shock yourself, connecting a scope ground to the chassis which is at 120 volts will cause a direct short across the 120 volt line, possibly damaging the scope and your shop wiring.

With the 1:1 isolation transformer, a hazard would occur only if you touched both sides of the isolated supply. As one side of this is used to generate your TVs DC power supply , it is usually contained in the TV and an accident is much less likely.

With the 1:1 isolation transformer, touching terminals and surfaces of your test equipment, lighting, etc will not cause an electric shock or damage test equipment.

When working on un-isolated equipment, it is very important to have this transformer. In fact, I believe that it is much more important than the variac.

If I had this set I would just make an isolation transformer and install it in the bottom of the cabinet. I think it would be unsafe to use without it. I did this with a Magnavox hot-chassis phono console...found a large Heathkit power supply transformer whose secondaries added up to 110 v. when put in series. Also I have taken old computer monitor transformers from the 70's and connected the secondaries together to make an iso. trans. This motorola looks like it does not have the later safety features used on hot chassis sets such as plastic control shafts.

...

Andy, you are correct when the item is assembled. However if you are restoring or repairing this type of set(and have it taken apart) it is very important to have the isolation transformer as the chassis (with its possible 120 volts) is fully exposed. In the case of the Hoffman and Motorola that I am working on, the entire metal chass can be hot-the line cord is not polarized.

Of course, when these sets are completely assembled with the correct knobs, etc, they are safe, unlike the 1940's radios that I have seen.