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 Post subject: 1950's Viking Television Questions
PostPosted: Mar Mon 11, 2019 5:44 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
There is a guy semi-local to me selling a vintage (I assume) 1950's B&W, Viking brand television.

The model is a TCD-255 and it was purchased by the person before the person selling it from Eaton's, used, in 1960.

I have searched online and have not been able to find any information on it thus far. I'm wondering if anyone here has heard of such a model before. I'd like to get some opinions on value and service information if I can.

I'll post some pics when I get off work.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 11, 2019 7:16 pm 
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Location: Waxahachie Texas
Here is a mention of a Viking TV. Seems that it might be Canadian?

http://www.ushistory.org/us/53c.asp

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 11, 2019 7:17 pm 
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Joined: Jan Sun 18, 2015 5:01 am
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Location: Waxahachie Texas
Here's another.
https://www.kijiji.ca/v-general-electro ... 1271835677

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 11, 2019 8:43 pm 
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Joined: Jan Thu 01, 1970 1:00 am
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Location: 13 Critchley Avenue, PO Box 36, Monteith Ont, P0K 1P0
Crist Rigotti wrote:
Here is a mention of a Viking TV. Seems that it might be Canadian?

http://www.ushistory.org/us/53c.asp" -="window.open(this.href);return false;
.

Viking was the store brand of the Eatons company. Their radios were typically Dominion Electrohome (aka : Grimes / Phonola)


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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 11, 2019 9:09 pm 
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Joined: Apr Sat 06, 2013 2:18 pm
Posts: 459
Location: New Hampshire
All the Vikings I saw were built by Admiral. A photo of the
guts will ID it. If an Admiral you can often find a close
schematic for it. Look up any inked on chassis numbers or
sometimes its on the model tag.

73 Zeno 8)
LFOD !


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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 11, 2019 11:31 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
Here are some pictures of the set.

Image

Image

Image

I have never worked on a TV nearly this old, so I really don't know much. Since it was bought used in 1960, I would assume it's mid to late 50's? And, yes, it is Canadian, or at least, I would assume so since I'm in Canada! :P

I have not seen it in person yet. Hopefully this weekend.

The current owner said he has never attempted to power it up, maybe for the best. I don't own a CRT tester, so testing the tube as a first step is out of the question. I do have a variac though, and I plan to take it with me and try powering it up slowly. Assuming there are no filter cap shorts or the like, I'd like to see if I can get something on the screen as a confirmation before buying it. The seller is asking $150 CAD for it.

Any other hints or tips I should follow when I inspect it? I feel a little out of my element here, but I've always wanted to try my hand at restoring a vintage TV like this.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Thu 14, 2019 4:48 am 
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Posts: 550
Location: Belrose, NSW, Australia
Great news it hasn't been powered up. Sometimes using a dim bulb tester (google it) you can reform the electrolytics. Much safer and kinder than a variac and you can let it run unattended confident you won't let the smoke out if something breaks down.

Test the CRT? Try this:

viewtopic.php?f=3&t=331576&hilit=How+to+test+a+CRT+if+you+don%27t

If you've done a radio that's a good start....

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Thu 14, 2019 5:34 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
Yeah, I'm happy that the current owner has not attempted to power it up. I was hoping to get a schematic and perhaps some other info before I go to see it, but it's not looking like that will be the case. I have no idea what the CRT is and hence the pinout. I'm not even sure if CRTs follow a standardised pinout, but I assume they do.

At this point, I think I'm just going to go there with the variac and power it up slowly, just monitoring the current as I power it up to make sure it's not shorted somewhere. I can't say I've ever been fond of reforming electrolytics anyway. Who knows?! Maybe they'll be alright! I'm hoping that I can get it up to working voltage and get some sort of raster. I think my luck in that scenario will determine what I pay for the unit. Although, by now, I've gone from "sure, why not" to "I really want it!". I was not a huge fan of the look of the unit, but it's grown on me quite a bit. If I'm making the hour trip there and back, I gotta make it worth while. :P I'm optimistically hoping that since it's in such a good physical condition, that maybe the electrical condition will match. I'll cross my fingers that it's a low hour set!

And yeah, I've done my fair share of radios for sure! Radios, turntables, amplifiers, power supplies, signal generators, volt meters, even the odd oscilloscope. Just about everything but a TV! It's about time I think!

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Fri 15, 2019 4:07 am 
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Joined: May Sun 07, 2017 11:35 am
Posts: 550
Location: Belrose, NSW, Australia
The CRT looks like it'll be a 21" 90 degree. There are more of them still about than most.

Apart from some rare exceptions, as I said in the post all B&W CRTs have the same pinout, at least as far as the heater, cathode and grid 1 connections go. Even though the numbers of pins are different on 90 degree and 110 degree tubes, the ones you are interested in are the same either side of the CRT's base indexing spline.

If the CRT turns out to be a goer, there are a few paper caps you should change before powering up, even via dim bulb. Places like coupling caps to grids of power tubes, you know the ones. Oh, and the B+Boost cap.

You may find that some of these caps have already been changed to more modern polyester caps in service. There is no point in replacing these.

I don't believe in shotgunning a chassis, i.e. replacing all the paper caps at once. Get the set running then change them a few at a time, checking in between. Take lots of pictures. This advice comes from many years of experience restoring old TVs, both recent and in the 1960s. I was a senior tech at a large TV service company before I got my engineering qualifications.

There has been some posts on this site offering Canadian TV circuits. Search it.

Enjoy!

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Fri 15, 2019 12:36 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
Ah, I see. Well that's handy! I suppose I will try that testing method then.

And, yeah, I always recap in sections and test other components as well while I'm in there.

And I'll look around some more for some info like a schematic.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sat 16, 2019 7:08 am 
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Joined: May Sun 07, 2017 11:35 am
Posts: 550
Location: Belrose, NSW, Australia
Try this for circuits:

viewtopic.php?f=3&t=292378&hilit=Canadian+TV+circuits

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 1:05 am 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
Thanks for the link! I might send him a note and see if he has any more info on this particular set, for now though, it came with a user manual that has the schematic. I'm likely going to need it, the set doesn't work. I attempted the "poor man's emission test" and got no voltage at all on the meter. I attempted the same test on a small CRT here and got results, so I'm not sure what I did wrong. The connector on the base of the CRT is loose though, so I fear that perhaps the grid or cathode wire has broken off inside. I will have to take a closer look at things.

Here are some pics of the set.

Image

Image

Image

I powered up the set while in the seller's shop and got audio from the speaker. All the tubes lit up, including the CRT, and I could hear the cliche high pitch whine, so the horizontal is trying to work I think, but there's no HV out of the flyback. Also, the CRT had a brightener on it when I took the back off, so hopefully it's not too cooked. I'll look into things again tonight and post updates here. I'll also scan the schematic and post it here as well.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 2:08 am 
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Posts: 257
Location: Durham, NC
Interesting to see the "naked" flyback on that chassis, without the usual protective cage. I haven't seen many sets like that.

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A collector of TV signal boosters and UHF converters -- God help me!
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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 2:21 am 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
I just have the protective cage off actually. I took it off at the shop to dig a little deeper into the lack of HV.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 5:40 am 
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Joined: Dec Mon 31, 2012 11:09 pm
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Location: Portage le Prairie, Manitoba
As I said, the TV came with the original operator's manual as well as the schematics but what's really neat is that it comes with the receipt from 1960 when it was bought used from Eaton's. Below you can see the receipt and the schematics.

Image

Image

Image

Image

I've scanned the whole manual, schematics, and receipt and will print some copies of the manual and schematics for when I work on the set. Tomorrow I will take a closer look at the CRT and see if I can get the "poor mans CRT analyser" circuit to work for me.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 10:52 am 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
The CRT in this TV is a 21ATP4. After using the data sheet to double check my connections, I tried testing the tube again with the poor man's method and same results. I then desoldered and removed the CRT connector entirely to try again. The good news is that none of the wires have broken off at the tube base, the bad news is that after testing the tube again, I got .04 volts on the grid with 21 volts input. This CRT is looking deader than dead.

Anybody have a spare 21ATP4 lying around?

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 3:25 pm 
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Joined: Jan Sun 18, 2015 5:01 am
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Location: Waxahachie Texas
towble wrote:
The CRT in this TV is a 21ATP4. After using the data sheet to double check my connections, I tried testing the tube again with the poor man's method and same results. I then desoldered and removed the CRT connector entirely to try again. The good news is that none of the wires have broken off at the tube base, the bad news is that after testing the tube again, I got .04 volts on the grid with 21 volts input. This CRT is looking deader than dead.

Anybody have a spare 21ATP4 lying around?

The Early Television Foundation has 3 of them.
https://docs.google.com/spreadsheets/d/ ... edit#gid=0

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Sun 17, 2019 7:36 pm 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
Thanks for the info, Craig! I also found another place that has one of them, but they don't ship tubes of that size. Not sure if anybody does actually. Especially since I live in Canada.

I feel I need more than my own opinion here. Is it actually worth it? I paid $80 for the TV. Probably more than I should have. And I'm not opposed to the fact of pouring money into it to get it working, in fact, I'm used to that. I just don't want to do that to have it fail again a short time later. Maybe I should sort out the HV problem and make sure that the flyback is good before trying to get a CRT.

I'm thinking that this tube may have lost its vacuum. Perhaps I could apply an external HV source or try the flyback if I get it working then test to see if the tube stores a charge. There is no visible getter that I am used to checking to see if a tube has lost vacuum. I can't think of anything else that would cause such low emissions other than loss of vacuum.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 18, 2019 4:15 am 
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Joined: Dec Mon 31, 2012 11:09 pm
Posts: 295
Location: Portage le Prairie, Manitoba
Well surprising progress has been made today, and I didn't really do anything to achieve it. I had the set powered up and was poking around near the flyback testing voltages and trying to find out what was missing. While looking under the chassis at a capacitor that appeared to be melting the wax on it, the high pitch whine changed. It sounded like I suddenly had high voltage. So I poked output terminal of the flyback with a clip lead to ground and had a nice arc!

I shut things off and reconnected the CRT out of curiosity. The connector is still off of the tube so I used clip leads to connect it. I didn't expect to get anything since it had basically no emission in my tests, but I caught a glimpse of something on the bottom of the screen. After turning off all the lights and covering all the windows with pizza boxes, the picture below is the result. Keep in mind, that picture is over exposed. It's very dim in person.

Image

As the late Gordon Downie used to say, or sing rather, Nothing's dead down here, just a little tired. But this tube is more than a little tired! I may be able to fix that though. I'm going to try the brightener on it tomorrow and maybe try the poor man's rejuvinator as well! I will quite likely be buying a replacement CRT though.

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 Post subject: Re: 1950's Viking Television Questions
PostPosted: Mar Mon 18, 2019 6:18 am 
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Joined: May Sun 07, 2017 11:35 am
Posts: 550
Location: Belrose, NSW, Australia
Well that's a good result.

As I said in my post, any reading at all pretty much means you will see SOME light on the screen. That CRT has been cooked for many years by that brightener and it's well any truly stuffed.. I's say it was your application of more heater voltage that got you to where you are now.

You don't specifically need a 21ATP4, you can use just about any 21" 90 degree CRT and just plug it straight in.
Most common newer replacements were 21CBP4 and 21CBP4A, they don't need an ion trap magnet.

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