GE roundie - Page 2 - Videokarma.org TV - Video

DaveWM · #16 06-20-2012, 08:27 AM

looks like the CRT is near dead, cooking it now but not looking good. Oh well for 10$ I don't feel bad about it.

Zenith26kc20 · #17 06-20-2012, 08:55 AM

This set may have what is known as a crystal ringing color circuit (hope I remember that right). It doesn't have a color oscillator or a color killer. Burst excites the crystal and that provides the 3.58 signal. It is a bit weird to deal with.....

DaveWM · #18 06-20-2012, 02:59 PM

pulled the HOT and VOT, dialed up the voltage to about 60v no smoke, went up to about 90v sound out of speaker (snow sound) see some wiffs of smoke around the replaced resistor, on of the cans feels a bit warm, but its right next to a big sand resistor. hmmm.

I am going to leave it at 45v for a while and try again, but looks like going to have to pull it and check those filters before risking a full power startup.

DavGoodlin · #19 06-20-2012, 03:17 PM

Quote:

Originally Posted by Electronic M

Same here...I was beginning to wonder.

PS:CTC17, have you been smoking the same stuff as that Sanjarali cat?...Misa no standingunder what yousa sayin'.

Hey - at least no one here seems gislan.

DaveWM · #20 06-20-2012, 05:18 PM

went a ahead and tried it again, after jiggling the RF amp tube I was able to get a clear strong audio. I will prob give it a shot in a while with everything in, keeping an eye on the HOT cathode current of course.

DaveWM · #21 06-20-2012, 05:59 PM

good sound, HV comes up fine, HOT current about 185ma, horz just out of lock in range, can not flop the lines. Going to try some new tubes in a bit.

DaveWM · #22 06-20-2012, 06:27 PM

new 6BH11 got the horz to lock it, color working but a bit weak, contrast weak, and some odd horz shifting like a hum bar, but not a regular moving event.

I am going to try a new AGC tube and video out. The horz locks but can't flop both ways (lock at the end of the range). there are a few ceramic tube caps on the sweep board. The vert sync is not strong but it is there. Need to check the basics like the B+ etc... waiting on the service manual book for that.

DaveWM · #23 06-20-2012, 10:38 PM

well the ckt breaker popped so I guess I need to pull the chassis and check out the filters caps to see if they are shorting.

strike that not the breaker but a bad connection at the chassis interlock, but I do see a hum bar now so will check for HK shorts and if all good then will pull the chassis and check the filter caps.

DaveWM · #24 06-21-2012, 06:03 PM

after testing a couple sections of the cans, which tested a bit low (50uf vs 80uf) AND did not respond very well to an attempt at reforming I decided to go ahead and recap. This set only has two cans wiith good access to them so they were easy to buzz off with the bone cutting saw. I then used a long sharpened piece of music wire to cut hole thru the bottom. the long drill make it easy to go thru the bottom without getting near any of the parts under the chassis. Going from the bottom lets you place the neg lead right at the edge near a twist tab, then place the positive lead right at the can terminal. this make it a bit easier since you dont have to try and configure the caps to have a central neg lead, I use radial lead caps since they are much less expensive and fit under the can well, I will alum tape the can back just to keep it there for reference. the other advantages of this method is you don't have to waste time trying to remove the old can, and all the lead dress can be left alone, just wrap the pos leads around the term and your done. After replacing the filters I will power it up again just to be sure I have not messed anything up, if it works then I will start checking some of the low voltage brown drops, as they have a history of getting "weak".

DaveWM · #25 06-21-2012, 08:51 PM

argh, replaced caps still have a wandering hum bar, will check the rest of the tubes for HK, did not do the tuner/IF yet.

did adj the AGC, working as it should. Still very low contrast, I was hoping replacing the can caps (one was the video amp cathode bypass) would help there, no joy.

Got some other stuff to take care of so will have to give it a rest for a few days.

ctc17 · #26 06-21-2012, 10:44 PM

Quote:

Originally Posted by Zenith26kc20

This set may have what is known as a crystal ringing color circuit (hope I remember that right). It doesn't have a color oscillator or a color killer. Burst excites the crystal and that provides the 3.58 signal. It is a bit weird to deal with.....

Yes, like the p0rtacolors. Seems to be much more reliable to me than the standard 6gh8 driven crap. I am always having issues with the color staying locked on the rca style sets.
The GE way of doing it always seems to work, its just very hard to get the color right. There are a few adjustments that are very touchy. I do have a NOS 19" GE with this decoder that works well though.

DavGoodlin · #27 06-22-2012, 07:37 AM

Dave - is that the CB-21 chassis? I worked on quite a few GE from 60's but never saw that one. DG

DaveWM · #28 06-22-2012, 07:49 AM

I think so, I remember seeing a C on the back will check later.

Chroma board as a bunch of trimmer pots on top and some trimmer caps on the bottom.

dieseljeep · #29 06-22-2012, 10:32 AM

Quote:

Originally Posted by ctc17

Yes, like the p0rtacolors. Seems to be much more reliable to me than the standard 6gh8 driven crap. I am always having issues with the color staying locked on the rca style sets.
The GE way of doing it always seems to work, its just very hard to get the color right. There are a few adjustments that are very touchy. I do have a NOS 19" GE with this decoder that works well though.

I always refered to the larger screen GE's as glorified Portacolors.
Proves out the meaning of the letters, GE. Good enough.
I got a few of those as freebees. I scrapped them all, as flybacks were bad. The last one I had, had an RCA hi-lite CRT that was perfect. I installed it in a Zenith roundie. Man, what a picture! I wasn't about to waste that great tube in a lousy Ge.

DaveWM · #30 06-23-2012, 11:06 AM

using a brightner on it make the CRT produce an OK pic, good enough to continue trouble shooting anyway. There is something odd going on with the tint, does not really seem to phase shift from magenta to green like my oher sets (including my porta color). I have a service manual coming so hope to gain some insights into how to trouble shoot the chroma. The upside is the HV section seems fine, fly runs cooler than most other color sets. Still have to hunt down the hum bar and contrast issue (maybe just the weak crt on contrast). there is no bias adj on the CRT either.