Restoration question from beginner
 

Hello All.
Just purchased an older black and white TV/radio/record player combo.
RCA TA169.
The guy I bought it from suggested it was working. He had it plugged in when I went to see.
The TV did not come on (radio and recorder player worked).
I did not want to pursue a restoration (by me or a shop) without knowing the picture tube is OK.

The tube does have a faint light on the back when powered on and there is a bright dot on the screen when power is shut off.

Is this an indication that the picture tube is OK?

Thank you,

Frank

this is not, unfortunately, the only real way is to use a CRT tester.

A CRT tester is not definitive. A white spot on the screen does show that
its not absolutely dead.

If it is a color set odds are the boost rect that suppose the G2 pots is bad or the circuits biasing the gun need work. The dot on screen indicates you have some HV and some CRT electron gun emission....If it is a rectangular CRT color set any other deltagun CRT the same size should be swappable...you could rob one from a common Zenith CCII or RCA XL-100 from the mid 70s (those sets can often be had nearly free). Note in 1968 the government passed law requiring tubes screen area be changed from bulb diagonal to viewable area diagonal. The numbers at the beginning of an alpha numerical CRT type ID number indicate screen size (typically in inches). So a 25AP22 from 1966 would become designated something like a 23VAP22....the first letter of 1968 and newer parts typically had a V to indicate viewable area measurement standard.

If rectangular color and you like the cabinet I'd go for it and keep an eye out for a spare CRT just in case.

You really need a CRT tester or a friend with one when evaluating a set for purchase...There is a thread on ARFs TV section on how to do a crude test with a battery, DMM and a resistor. No matter what you test with knowing your tester is important....my B&K will show monochrome tubes that can produce a decent watchable picture at the top of bad and color tubes that are barely usable at the bottom of good.

No color in that set. According to radiomuseum.org, an RCA TA-169 was a TV/radio/phono combo with KCS43 TV chassis -- circa 1949 or so.

https://www.radiomuseum.org/r/rca_ta...43_rk135d.html

If you don't have a CRT tester, perhaps there is someone from an area radio/TV collector club who could lend you his tester. Here's a list of clubs:

http://antiqueradio.com/clublist.html

Costs nothing to ask! Even if the nearest club isn't next door, they might know someone closer to you.

Regards,

Phil Nelson

16GP4 metal cone CRT. Beware. The entire metal cone is connected to around 12,000 volts. Stay clear when the set is turned on.

"Really need a CRT tester" is kind of misleading. When you test the tube and it shows 'dead' they will say that the tube is 'asleep' and you will not know for sure if the tube is good or bad until you have it plugged into a fully functioning set. Of course, if you had a fully functioning set, you wouldn't need a crt tester. So really, you don't need a crt tester.

As for the metal cone crt, here's another tip. They never test good. From my personal experience with two of them, they test dead or very weak, despite being ok. I've also seen this in a couple of shango's youtube videos, same thing. Also, common knowledge says that they are very rarely any good. Yet somehow I managed to get 2 good ones out of 2. I think where that comes from is that they probably test bad, but are not necessarily bad. There must be something about the metal cone tubes that don't test properly, or, perhaps, they can still make a decent picture despite being very worn out.

My point is, testing the tube will yield no useful result. Unless, perhaps, you are such a seasoned repairman that you can divine the true meaning of the test results, be they bad or good. If you say the tv set will produce a white spot on the center of the screen, the crt is - at minimum - somewhat usable. Do not run the set for very long, the spot will burn into the screen.

That was my experience. My 16" metal cone checked very weak, and despite having a previously installed brightener on it, produces an excellent picture with no brightener. It produces a good picture within 15 seconds and about 3 minutes to peak.

https://i.imgur.com/Om5bkpW.jpg

https://i.imgur.com/hDwmMKm.jpg?1


Shango is an odd duck. I love his passion and enthusiasm but he's what we used to call a ham and egger. I stopped watching because he makes so many mistakes or says things that are factually incorrect.

John

Just don't mention the word “recapping” near Shango, or he may blow a fuse! :P
I still watch him as I find him amusing/ entertaining, but, he has gotten rather preachy a bit lately...

3 minutes to turn on a 5-tube radio, 27 minutes watching him switch between talk radio stations.

Well put. Shango is pretty much outside the usual restoration subject. It is amazing that he does manage to get things limping along, (for how long?).
I don't believe that I have seen him bring things into good enough shape to put in his living room.
Frank, that unit has a lot to it, a big project. The fact that it works as well as it does is rare for something so old. The date given in the Radio Museum could be off by the way, not everything at that site is accurate, but it is a good start. Be aware that TVs back then were watched in a dimly lit room, the screen was never as bright as modern sets. 1949/1950 was before stereo records come out, the phono cartridges (needles) will be hard on stereo records unless you change them out for stereo types. Don't run it until some restoration is done, otherwise hard to replace parts could be damaged. You can wake a CRT (picture tube) up by running it on a CRT tester for a half hour or more.

When he stuck that curtain needle hook in that ceramic cartridge on the 75 75rpm phonograph, I wanted to reach through my monitor and slap him into next week!:tears::tears::no:

I wake up sleeping CRTs on my B&K 466...at normal settings most wake up in 15 minutes, then you have to readjust cutoff to get correct emission readings....tubes that take more than twice that time I usually increase heater voltage to 1.4X it's rated voltage and let it cool till it wakes up beyond the ~15 second shift after the heater bump.

The shadow mask in color CRTs blocks ~80% of electron emission from reaching the phosphor so a tester designed to test color tubes will have the scale calibrated for color and monochrome tubes that have emission below what is good for color but reasonably above stone dead are usually watchable... knowing your tester and how it's readings correspond to actual performance on color and monochrome tubes is the difference between it being a rough guide/toy and an actual useful instrument.


On that video where shango abused that record at least it was a home recording...those are generally worthless unless the person recorded has been identified as someone famous....the recording may have been priceless to the surviving family but when they allow such a record to leave their family it generally becomes worthless and lost forever.
Shangos methods can be a bit unorthodox but on bad examples of sets that in some cases are barely worth using for parts he can't do much more harm beyond what time and neglect have already done. Depending on the vintage condition and intended use/desired reliability of a set I can respect doing the minimum to make something work....If you are only going to run something 5 minutes a year and it's a nice original example of the thing is a train wreck that isn't worth throwing spare change at a full recap/restore or even any work isn't necessarily needed. Sets of the 60s onwards have good enough caps that if they mostly work then it's perfectly fine to replace the minimum of parts to achieve proper opperation and leave all else alone.

I sorta want a CRT tester, probably woulda helped with that RCA I did back in Jan-Feb. The set works okay but has a weak jug. Goes silvery when you crank the brightness and takes a good while to get bright enough to watch. It still makes a watchable picture with the lights on so I can't complain too much.

As for Shango's methods, I aint even mad. He's able to do quick and dirty diagnosis without a shotgun recap. I've learned a bit by watching his channel. I usually fully recap my sets because I only have a few and I like to use 'em, also sometimes it just fixes mystery problems so I don't have to diagnose :D

I have a bk precision 490b, but the damn thing lies to me...

It always worked fine with all sorts of mono tubes, and 25vxxx tubes and projector tubes, and so on.

But when I hooked up my 21fjp22 that had been it storage forever,, VERY LOW emissions, scared the hell out of me, I thought the tube went dud in storage, took me a while to spot what was going on...
heater V @ 4vac, barely, it could not put out enough power for the heaters in the CRT. :scratch2:
So, I got a 6v 3amp xfomer and it came right up into the "really good" range on all 3 guns...
But, WTF? not enough power to light up a roundie? come on BK...

Perhaps the CRT is drawing excessive heater current due to poor vacuum...can you measure the current at 6.3 Volts to see if it is in spec (1.8 Amps). :scratch2:

jr

It's been working fine since the summer of last year.
https://www.youtube.com/watch?v=7V3etX2NsS4&t=18s

Just a few minor things to work out.
Vertical blanking / retrace not fully working, minor video streakimg , a few more old caps need to be changed, but not gonna pull chassis just for that, will wait till I try to fix IF problems ( alignment )

I'm guessing the 490 has only a switch to set heater voltage.
Different CRTs have different heater current which load the filament transformer differently...my 466 has a continuous heater adjustment knob and you set it by reading the heater voltage on one of the scales of it's meter....a CRT can draw as much current as it wants and you will still be feeding it the right voltage even if you have to set the coarse heater adjustment switch to a higher a range... Some of the low current 6.3V monochrome portable CRTs barely need adjustment of the heater pot, but a power thirsty roundy will need it set fairly high.

Being someone who jumped into a side-of-the-road-chassis with only the ability to test every other tube in the set and no previous tube set restorations, if you see a good filament and an indication high voltage is present I say go for it! As others have mentioned even older tubes that read weak usually still have useable life left in them without needing a rejuvinator.

correct, it only has 2 heater settings :(

https://i.ytimg.com/vi/cidneB0ziYE/maxresdefault.jpg

found the perfect pic on the net! :)

Shango - yes, he does get awfully preachy about it, but he has a valid point. He is being an actual repairman. That's what a proper repairman does, he diagnoses, pinpoints, and repairs only what is needed. The fact that he practices his proper repair strategies on tvs that've baked under the sun for decades is besides the point.

What most of the folks around here are doing are restorations, which is a completely different ball game.

I was just thinking about this the other day. In my Walter Mitty daydreams I think about making a video series showing young people how to troubleshoot and repair TVs, hifis, etc. so that these things don't all become cat beds once the current generation is no longer here.

But then...does repair really even exist anymore? I bit, I guess...but every one of these old sets that people are still pulling out of estate sales, basements, attics, garages, thrift stores and landfills don't need a repair. If the intent is to be able to watch it, you're going to go directly to a full restoration: anything less will eventually see it burn up or stop working again. I guess there are some newer, XL-100 generation and BPC sets that may benefit from repairs, but I wonder if in the future anyone is going to be interested in those pressboard consoles.

Asside from certain tanks like monochrome tube Zeniths from the late 50s on and portacolors every tube set that is used a lot (say over a hours a day) will need repairs every 6 months to 5 years even if it was restored prior to being made a regular watcher....tubes wear out, other parts occasionally let go, adjustments need touch up etc....to run these things you either have to know enough to do basic maintenance/troubleshooting or know a guy that can do it for you.

I'm in my late 20s so assuming I have a normal lifespan I should be actively keeping this hobby going another 40 years...there are some other younger hobbiests too. The repurposing trend will eventually fade.

I would be suspicious of the CRT. Going to a bright dot was often seen
even if the CRT is bad.
When you turn off the TV HV remains charged but there is no deflection
so any electrons being emitted by the still hot cathode. They all land on
the same spot & can fool you.
IMHO best to run the set for 1/2 hr then turn off all lights in the room.
If you see some raster but very dark odds are its the CRT.

Price is another factor. Others know better than me but being a combo
it probably aint worth much of anything......

SHANGO is what we call a "character" in N.H. He does do some amazing
things with mostly pure junk. He is worth watching, you can learn a lot
from his antics. Thing that drives me nuts is this cat can make a 4 course
meal out of a potato chip. BUT I still watch him:scratch2:

73 Zeno:smoke:
LFOD !

I am a recapper.... After working as a technician for 50+years, I know that most of the capacitors in a vintage TV, radio, or amplifier will be leaky. Once upon a time, when the stuff was relatively new, we only replaced defective components and tubes, as customers would not pay for a complete rebuild job. Today, the first color sets are 65 years old, and early B&W sets are even older.

In my experience owning likely 50 vintage TV's in all my years is that, overwhelming, the CRT's are decent. Many times very good. Once you find that the CRT is not completely dead, you have to try in with a restored chassis to really know what the story is.
The old "white dot" in the center of the CRT screen is not a bad situation, but it actually should not happen when all components are in spec. often CRT's that had many hours with it will have a light ion-burn in the center.

The dot on power off is normal for some models, there were even articles in 50s Electronic magazines on how to modify sets to suppress the dot.

For me the dot in the center would be a green light to move forward.
You know the CRT hasn't went to air, which is a huge bonus.
I didn't have a CRT tester till 2007 / 08 when a VK member gave me his old B&K.
Over all the sets I've worked on I haven't ran into many that had a bad CRT.
You could do the bare minimum, replace the electolytics in the power supply.
Replace wax/papers in the horizontal / hv circuit and get an idea even if the vertical isn't working and all you have is a flat line.
Myself, I would continue without hesitation.