1960s vintage 9" GE B & W Portable TV has no Picture
 

Hello Everyone today I had received from a friend of mine from church a 1960s vintage General Electric 9" Portable Black and White Television Set that when I got it home to test it out I got perfect audio but no picture, and from what I could see through the vent holes on the side of the unit most of the tubes that were visible through the vents were glowing like they were supposed to be, and from what I saw online on some YouTube videos about vintage television repair that if the video amp or the vertical or horizontal amp tubes are blown there isn't going to be a picture so I wonder if it might be a bad video amp tube or a bad vertical or horizontal amp tube inside the TV, or could the TV tube perhaps be blown? Although I thought that if a picture tube blew that there would be black sooty looking spots on the inside of the screen which there aren't any to be seen on the screen.

Any suggestions as to go about restoring this wonderful piece of history?

Pics are coming later when I have access to my camera.

There are many things that can cause a dark screen/no picture condition. The first thing I'd do is check for the presence of HV at the anode connector of the CRT. Be careful because there are many thousands of volts here and the CRT can hold a charge. A quick and dirty method to determine if HV is present is to draw an arc with a screwdriver. For a more accurate test, you meed a high voltage probe that will tell you exactly how much HV is getting to the CRT.

The HV Anode is the little rubber plug at the top of the picture tube towards the front of the tube am I correct?

Many ways to go depending on equipment & knowledge.

Its not a vert problem. That shrinks the pix top to bottom
sometimes so there is only a line going L-R.

Most video problems on old B&W sets leave you with a lit
screen so probably not that.

No HV will kill the pix. If audio good most likely its the HV
rectifier tube. IIRC its a 1X2 the tube the anode wire goes to.
On GE's the sockets used to corrode, check for green crap
on the tube pins & socket. You can usually detect HV by
putting the back of your hand near the SCREEN, you will feel
the static pulling on your hairs. BTW the socket can give you a shock
when off. The cap on the other end is safe when off.

A bad CRT is also possable. Run the set for a while in a room
with NO light. If you see a very dark image its probably a bad CRT.

Beyond that post the model # ( stamped on back).
Chassis # ( look on tube chart) and maybe a screen shot of
the chassis & a lot of us will try to help.

73 Zeno:smoke:

73 Zeno:smoke:

Well The Model Number of the TV is 9T001

Chassis number unsure as the tube chart is inside the cabinet and I had a heck of a time getting the cabinet apart the first time around, and I forgot to look for the chassis number when I did have it apart.

When I powered it on when I got home from church to see how it worked the audio was perfect minus a little buzzing noise that would come on when you turned the volume control but then would disappear when you jiggled the volume control slightly (more than likely a dirty pot), but as for the picture it was completely blank not even a slight hint of a picture (which you said if the picture tube was bad there would of been a slight picture still and mine has no picture at all which is why I think its not a bad picture tube but something else associated with the video circuit e.g. bad video amp tube.)

Update: I did some research and actually found out that my TV was from 1957 so actually my initial post title is inaccurate because I just assumed that the TV set was from the 1960s because of the TV having the built in 14-83 UHF tuner on it because I just assumed that all TVs from the 1950s just had VHF only because of what I had seen on most 1950s vintage TV sets I've seen at flea markets and antique malls and garage sales but now I know that apparently 14-83 UHF had been around as early as the mid 1950s at least (seeing as I had also seen an old Philco Predicta Television at the antique mall recently for sale that also had a 14-83 UHF tuner on it and the Predictas were only made in the 1950s from what I had heard and read so apparently what I had once known about 1950s TVs has changed...

This set is OLDER than 1960 It is in sams 359-7, which makes it about 1957 or so. I was thihnking it was that little set they sold in about 1963 or so...with the wrap-around chassis...but it is a LOT older. GE"s answer to the 8" 8PT-7030 style RCA SET.


You need to know if the FILAMENT Of the CRT is lit. I think this is a hot chassis set so it VERY likely has to be lit for the other tubes to be on.

I agree....it sounds as if you have lost HV.

It is POSSIBLE...that you have a low B+ problem. Low B+ MIGHT give you enough powert for the SOUND to work...but NOT the deflection and HV.

it is ALSO possible....that you have lost BOOST voltage. This is a voltage that is produced by yoke action and it is then ADDED to the main B+ voltage. Sort of hard to explain...but it helps to run the H-out and V out ckts AND voltages for the CRT. if it is LOW or GONE.. you will NOT get HV or very LOW hV and no raster.

Like others have said...do the 'static test" on the front of the tube and see if you get any "static cling" from the tube. Good static from it meant likely good HV.

Dumb question but, have you adjusted both the brightness and contrast controls? If it has an AGC I have also seen cases where misadjusting that can kill the raster.

My previous post before your post explained that I had figured out that the TV was indeed from 1957 and that the reason why I had guessed 1960s was because of the fact that the TV had 14-83 UHF built into the set which I thought wasn't available until the 1960s but apparently it was available in the 1950s as well, which for this TV to have the 14-83 UHF built in like it does means it must of been a higher end unit because I've seen "high end" console TVs from the same time period that only had the VHF only Tuner on them and yet this is a 9" portable TV that has UHF built into it (although apparently according to the tube location guide inside the cabinet this TV was available as a "VHF Only" model as well because it has a tube listed for the UHF tuner that says "tube used in UHF models only" which tells me this must of been GE's higher end model of this particular series of TV Sets.)

And Yes you are right, this is an "AA5" Series Strung set which tells me that like you said if I was seeing tubes glowing in this set that means that the Picture tube's filaments were glowing but apparently my H-V is probably low enough that its giving me sound but no picture/raster, so I will try the "static check" on the picture tube face when I power it up again and see if it has any H-V or not, and if no H-V then I guess I'll have to check the H-V Rectifier tube to see if its weak and or check the electrolytics to see if they may need replacement.

Just REMEMBER...the HV rect tube will NOT really show a visible filamanet....so you need to REPLACE it with as known-good one--to rule it out.

I believe I have a few of those tubes laying around in my tube stash which I don't have access to right now as I am at my parents house currently and my tubes are at my house that I live in, I'm staying the night at my parents house because I have to see a doctor in Indianapolis, Indiana which is a 3 1/2 hour drive from where I live and my mom and sister are taking me down there. anyways I probably won't get to actually do any serious servicing of the TV Set until tomorrow evening or Tuesday.

Anyways I hope I can get this TV up and running because I would love to use this TV in my office/workshop with a converter box just as a cool piece of functioning television history.

The HV goes in the base on that particular CRT, you can check for HV by touching the cap of the 1X2 with a insulated, ungrounded screwdriver, it should draw a small blue arc to air, this won't prove it's getting through the HV Rectifier but at least you'll know if the

The set will need recapped to work properly but before doing that I would try to get the CRT tested, the 9QP4 used in those sets was notoriously bad.

Well I certainly do not have a picture tube tester/rejuventator, so testing the picture tube is out of the question, but like I said the picture tube doesn't show any signs of being blown (most blown picture tubes I've seen color or black and white usually had a huge black "burn" spot in the middle of the screen, and this picture tube doesn't have any huge "burn" marks in the middle of the screen.)

The high voltage rectifier is a 1V2. All the tubes in that TV are single ended, including the CRT.

Check the ion trap position. It could have been moved. The CRT is certainly defective if it is the original and likely very dim, if a replacement.

OK, well since I don't have a picture tube tester/rejuvenator, how would I go about checking if the picture tube is "bad" or if it was the original or a replacement tube?
The person I got the TV from told me that the TV was used very little before it was put into storage for 40+ years which with that in mind would lead me to think that the picture tube should still be good, and the TV when I had it opened didn't look like it had any repairs made to the set from what I could see, plus the unit had PCBs in it for all of the circuitry and tube sockets which the PCBs showed hardly any heat damage which seemed to confirm my friend's story about it having low hours on the set.

Short of testing the tube the only way to find out if it works is to get the chassis working and see if it makes a picture.

First step would be to check for high voltage, since you have audio we can assume the basic power supply is working.

You can still check for HV at the 1V2 using the screwdriver method, you just have to hold it near the connection at the base of the 1V2 where the output of the Flyback connects.

it seems that's my only option right now, which is to check for H-V.
but the fact that the TV has no picture at all period and someone else on here told me that if the picture tube was "dead" it would still have a faint picture which mine doesn't even have a picture period leads me to think that the picture tube is more than likely still good yet (albeit not 100% after 60+ years) but just that the TV set has either a Low B+ issue or a Low or no High voltage issue.

I was just working on a very similar Hotpoint set that uses the same CRT as yours. I have a CT tester and my tube tested good so I went ahead and recapped the set and on first power up I had the same issue. Totally dark screen no matter what and I had good high voltage. All that was wrong was the ion trap needed to be adjusted.

Gregb

The set has a low B+ circuit. There is a large value input electrolytic cap that is probably dried out and lost value. As a result, the set won't produce HV and do much of anything, but hum. A cap pulled from a scrap solid state color set would be close.
The CRT is a blown glass bulb, similar to the 7JP4. As a result, rebuilts were never available. The CRT is probably OK.
The tubes are rather odd-ball type with 300ma heaters. Some types, seemed to only be used in that particular set.

That he said the sound was good made me think the B+ is okay, or at least ballpark.
It could still have horizontal oscillator problems keeping it from getting any high voltage, that's why I suggest checking that first. If it has HV and a dark screen then the Ion trap may be misadjusted, the CRT may be bad or it could have video problems.

The 9QP4 was a disaster, GE replaced a ton of them under warranty, the replacements may not have been much better. My own experience with these sets is not good as far as CRT's go, I've had to buy several junkers to get good tubes to fix my better sets.

There is some information on repairing these sets here: http://antiqueradios.com/forums/view...hp?f=3&t=91582

And some info on the Tube here: http://www.videokarma.org/archive/in...p/t-52670.html

They are so simple you can replace all the paper tube caps in an hour or so, a little more for the Electrolytics.

I've had to replace the Horizontal AFC Diodes on the ones I've done, they are Selenium and don't hold up.

Well I removed the 1V2 HV Rectifier Tube tested it (along with the rest of the tubes on the set) and everything tested perfectly, and so I put the tubes back in and plugged the tv set in and powered it on and sure enough after about 2 minutes I had a picture and it was a pretty decent picture at that (so I'm guessing the picture tube is still good), the only issue I saw was that the the height was not correct (it was too short the picture was relative to the actual picture tube size) and I tried adjusting the height adjustments and what not but the picture wouldn't fill the whole screen for some reason, which I'm wondering if the vertical Amp tube is about shot in this case.

Any ideas?

Like I said when I finally got picture it was pretty bright and seemed like it had plenty of life in it yet (the filaments were glowing nice and bright yet) just the height was out of wack and couldn't be made right with the adjuster on the back.

EDIT: The TV is now back to stage one where I had no picture (well actually it has picture but its barely visible) and it started doing this when I put the cover back on, but when the cover was off it was working just fine (minus the height being off) so I wonder if the 1V2 tube has a short in it that didn't show up on my tube tester, either that or the tube is actually just about shot but my tube tester for some reason thought it was still good.

sounds like if you got a picture at all, the main systems of the set are all functional, but maybe some portions are out of whack due to old caps and maybe other parts like resistors that havnt aged well. Re-capping any electrolyitcs and paper caps would be a good place to start. The set is working enough that you may be able to see gradual improvment as you replace suspect parts. If you read through the other threads mentioned above, that will give you ideas of parts that frequently require replacement in this set. Check the controls, too, a dirty brightness or contrast pot can make troubleshooting interesting... and the more aging parts you replace, the more reliable the set will be in use, hopefully.

That's what I was just thinking, probably bad electrolytics and paper caps and some bad resistors as well, which should be pretty easy to replace in this set since it has PCBs instead of actual metal chassises to work with, I also noticed that in one of the bottom vent holes I saw a pretty large selenium rectifier that could also be causing some issues...

Yes, doesn't sound like there's much wrong with the set apart from aged components. Start with the more likely offenders, and measure resistors as you go.

That's probably what I will do, the large Can caps will be tricky to take care of because they're sitting in funky locations in the cabinet as for the paper caps (which are plastic cased "good-all" caps which are notorious for going bad due to age) are going to be easier to replace and should be easily replaceable with mylar or polyester caps. the resistors should also be easily replaceable as I have a large stash of 1/4 and 1/2 watt resistors which appear to be what's mostly inside the TV. I don't have a service manual for the TV so maybe someone could dig one up for me and send me a copy. :-)

What # H-out and damper tubes does this set use?

Works then dont....... Do some light tapping around.
Probably a bad tube or PC connection. It would be better
to get it somewhat running 1st. That way you can test
as you go when recapping. Two big advantages:
If you make a mistake there isnt much to check. Also if
you change a cap & it makes a big change for the good
you file it in your mind for future use.

73 Zeno:smoke:

Horiz out is a 18A5 octal base and the damper is a 17H3, IIRC, a 9 pin miniuture The 18A5 is similar to a 25AV5.
It seems that this is the only set, that used these tubes. Two other strange tubes are 10C8 and 12CT8.
Leave it to GE, as they owned their own tube plant. :D

By the sounds of it that set and my Hotpoint are one in the same. Those are the tubes my Hotpoint uses as well. I just have a few finishing touches and mine will be done.

Gregb

Yeah and I tested all of the tubes in the unit except for a couple of the tubes and they all tested excellent on my emissions tube tester which means that the tubes apparently have low hours on them. All of the tubes inside this TV set are all the original GE Tubes (except for the 1V2 rectifier tube which i swapped out for a NOS Motorola 1V2 tube I had laying around in my tube stash.)

That makes sense because Hotpoint was owned by GE for many years before it became a Subsidiary of Whirlpool in the 1980s.

Well what's weird is that the pitcure tube is definitely working as the filaments are glowing nice and bright like they're supposed to be, but for some reason the tube just isn't wanting to develop a nice bright and even picture for some reason which tells me that somehow the B+ just isn't high enough to bring the picture tube up to its proper brightness and screen size, either that or the H-V circuitry is in need of a recap as well as the B+ circuitry.

I've heard mentioned in here several times about an "ion trap" which can get moved and cause trouble with the picture tube, my question is, what the heck is the "ion trap" and where is it at in the TV, and how does one go about readjusting the "ion trap"?

Another question that's slightly off topic but not really, and has to do with the tuner on this TV and others like it I've seen from the same time period, and that is, why is it that a lowly portable tabletop TV set like mine and or like the old Philco Predictas have built-in UHF Tuners in them but yet every single full-sized "high end" console I've seen from the same time period only had a VHF Only tuner in them with no built-in UHF Tuner in them?
Was there something about the portable/tabletop units that made them easier to install built-in UHF Tuners in them than the giant Consoles? Or was it something else? I just think its weird that a considerably lower-end TV would have Higher-end features than a Higher-end TV of the day would have.

The sets probably were sold in a UHF area or maybe
were latter converted with kits.
Some places like Hartford Conn. were most UHF. Between
NYC, Providence & Boston there was only #3 & #8 left.
All the newer stations had to go on UHF.
So sets sold there usually had UHF tuners. In 1964 all
sets built to be sold in the US had to get UHF.
An interesting early UHF promo for Zenith UHF here.

https://www.youtube.com/watch?v=7lu5jqXaHRE

I will leave the ion trap to others. I know but its not my era
so I may get something wrong !

73 Zeno:smoke:

GE seemed to market some sets under the Hotpoint brand from 1957 to 1960. The model numbers were also the same.
There was a Hotpoint plant in West Milwaukee, dishwasher and disposal products. It was next to the GE med systems complex.
AFAIK, GE never sold the Hotpoint line. They were still being built in Louisville, KY and probably Mexico.
There was news that GE was selling their appliance line to Electrolux. IDK if it ever transpired. :scratch2:

Milwaukee has been a UHF town from early on, but I never saw a 9" GE or a 8" RCA with a UHF tuner. I know the 9T Ge was available with UHF, per the service manual. It used a small transformer to power the heater for the 6AF4, so it was probably factory.
BTW, if the ion trap was never moved, don't move it for now, until you establish reliable high voltage. If it has to be removed for disassembly, mark the trap and the CRT neck with a Sharpie marker so it can be replaced in the exact same position. Once the set is working well, you can try to adjust it for maximum brightness, but it might not be needed. Just a bit CW or CCW.

OK, well for right now I'll definitely try to replace any of the old capacitors in the unit first and see if that helps any with bringing back the picture any or helping with making the H-V section more reliable as it seems that the H-V section of the TV is somehow affected by me hitting the TV's cabinet when its assembled which is more than likely due to failing caps, in the TV.

What do you suggest as far as Capacitors to use in this TV set? I'm wondering because I know these sets used sometimes 1kV capacitors in them and 1kV caps aren't readily available anymore not even on most of your antique electronics restoration websites and even if they are they're quite spendy.

I just use the 630 volt yellow caps from http://justradios.com
I don't recall any caps over 600 volts in this set but there may be one or two.

The Electrolytic can can be replaced by individual caps, they can be relocated closer to their connection point if it makes it easier.

The Horizontal AFC diode looks like a tiny electrolytic on the PC board, I've replaced it using a pair of common Silicon diodes.

Carefully remove the connector from the base of the CRT and check the pin where the HV goes in, it'll be the pin that's all by itself, sometimes it corrodes or the solder goes bad.

OK well I have some pictures now of the Unit and of the picture its giving off, maybe there's a clue as to what's wrong with it and what it needs by looking at the picture, I didn't have anything hooked up to the TV set when I took the picture it was just white noise.

It has a vertical problem or the vert is way out of
adjustment. Start with the vert osc / output tubes.
It may be all in one tube. Do not believe the checker 100%.
They lie almost as much as a politician. If not a tube recap JUST
the vertical one cap at a time followed by a test. Dont change
disc caps unless cracked or burned. They almost never go.
Also check resistor values.

I cant tell but if you have snow & a waterfall sound from audio
it will probably work to some extent. At this point the CRT seems fair,
probably as good as you will find for what it is.

73 Zeno:smoke:

Uncle Sam is holding this deal up for antitrust reasons. If it went through, there'd only be two major appliance makers in the US.
http://www.bloomberg.com/news/articl...staff-ibky1vil
http://www.reuters.com/article/2015/...0PB5RM20150701