Zenith console

[DaveWM]

good point. I seem to recall that there is an adj that is an add'l blue adj for convergence tied into that adj. I recall cause I was reading a service manual and it called out a final step for which I could not see the adj (was not on the dynamic board and I was only thinking of the reg 4 adj for manual (reg 3 and blue lateral). then they mentioned on some note the final blue adj that was a nut you loosed on the bottom of the yoke to tilt it some more, I guess to be done after purity.

When I get brave I may mess with that

All wrapped up around the axles on my philco roundie the the moment.

side note on the zenith, the vert out tube seems to be either just a loose socket mount or a soft mount socket with rubber that has deteriorated some. check you vert out tube and see if the socket does not rock around somewhat next time you are into it. I can see what looks like loose fitting rivuts on the socket flange.

[freakaftr8]

Yeah, my socket is weak. I need a new one soon, my set flatlines sometimes and I have to "bend the pins". Lol

[DaveWM]

ok here are a couple, in "the office" the format is reduced all around, on the commercial its the long format 16:9 i think its called.

in the zoom format where the whole pic is shown there is no noticable pincusion unless you happen to have some text (like the on screen display of the channel.

I am going to try to see how it looks with some OTA UHF analog later if I can get a better antenna.

It does not look to bad on the pics, I think the camera is not getting a good shot of it, seems worse in person.

[DaveWM]

update on the vert jitters, replaced C168 (.1 1kv) off the plate of the vert mult (6BA11). It tested fine for value but leaked badly at 450v (as high as my cap tester would go). I did not have a 1kv handy so I put two .22 630v in series. I will order up some .1 1kv next time I order from mouser. There was another .1 1Kv that is part of the horz eff coil circuit. it tested fine at 450v no leakage at all, but it will get replaced when I get those new ones. Not sure if its ok at the higher voltage.

I took the chassis out after struggling with one of the plastic connectors (what a pita). Anyway it was major league dirty, I mean disgusting, so I used the makeup brush (ask a girl), some compressed air in a can, and cleaned the underside. the top side got the same treatment and some slick stuff cleaner to get the goo off the chassis. Cleaned up the fly cage and anode lead, and the crt around the anode.

while I had the chassis out I checked some resistors, replaced one a emitter bias resistor that was a 10% that had drifted to about 30%. its on the only transistor in the set a video amp. I dont get why the bother to get a single transistor in the whole set.

I checked a couple of the screen bypass electro caps, all tested fine, good as new. amazing. I figured better to leave them in as I wonder if the new caps will last as long.

there was a .1 in the video path that couples the transistor video amp the video out tube. the audiophoole in me makes me want to go a change that out for a designer cap

while I had it out I check the crt, I had rejuved it on the red gun back when I got it, but I checked it again and it was a bit into the weak on my CR 70.

the tracking on the blue and green were very good the red dropped way down.

its gonna need a new 23v (I have one) but I just did not feel like taking the old until I put the chassis back in and made sure I did not goof anything.

I need to do a horz eff setting check. I never did that with this one, as the coil is in a place that is very hard to get out, but I just realized i can get at it from the bottom thru the service saver cover, duh...

oh there was one other out of spec resistor the cathode resistor on the vert multi. R115 should be 3300 was 4400.

I could not make out the tolerance it "may" have been a gold banded, but its hard to tell, the schematic does not say so I figured it was prob a 20% so it was not that far out. The vert circuit is working fine now so I decided to leave it alone.

the picture is really not that bad so I may just leave it for a while. it has a

25GP22A tube in it.

[DaveWM]

well the sams say 160ma on the hot, best I can do is 220ma.

gonna fool with it some more tomorrow. I swapped out the HOT, Regulator and damper tubes. No change.

the horz eff coil works but the changes are very very minor, maybe a 10ma swing max.

There is a 470 ohm resistor across the horz eff coil that the sams say to use only with a 6CJ3 damper.

My damper is marked as 6DW4/6CJ3

[DaveWM]

the eff coil current (jumper out) should be 180-220, I am right at 220.

Just for the heck of it I am going to check the bias voltage and waveforms of the HOT. Its only bias comes from the horz osc tube. should be -36v getting late so will check tomorrow, may just pop in a not horz osc just to see what happens.

[DaveWM]

swapped out the HOT with the alt 6LF6, changed the screen tap per the sams the the 230v, got the current down to 195ma (the other tap was a 375v).

I wonder if the 6HS6 (the sub for a 6LBL) on the lower screen tap would have still worked.

The 6LF6 was a pull but looked to be in very good shape. I will look into a NOS on later. the 6HS6 was a NOS (i tried a few, all the same 220ma).

gonna try another 6U10 before I start doing measurements and scope readings.

[DaveWM]

I forgot to check the line voltage, when I set it for 117vac I get 185ma.

clearly this set voltage regulation holds the HV very well. I am tempted to add some resistance to the screen to drop the HOT current since line voltage tends to be higher than that. Currently there is a 470 ohm resistor there.

there is also a confusing to me note on the sams. the is a 33k 2 watt resistor in the screen circuit (just before the above noted 470) R154, then in parens it shows 17k 5 watt. also not sure why a the lower resistor would have the higher wattage. thats odd, if anything I would have thought it to be the other way.

I also plan to add a B+ fuse like I did on the philco roundie and add a fuse to the HOT cathode circuit.

[DaveWM]

tried another 6U10 (triple triode, horz afc,osc,osc driver) just to see if it would have any effect, about the same, I am right at 185ma of the 180-220 scale when line voltage is set to about 117vac.

when switching out the 6u10 I did not get it seated very well, but was monitoring the current per the sams. I shot to over 400ma very quickly, so I unpluged and then reset the tube.

Seems like a design flaw, if that tube burns out you get NO bias on the HOT, which with out a fuse in the cathode circuit would do bad things fast.

I doubt the circuit breaker would save anything before a catostraphic failure.

Oh well just more of a reason to install that cathode fuse.

I guess back in the day a smoked HOT did not set you back 40-50$ just for the tube, not to mention getting a flyback.

Of course the real lesson is to know about how long you should wait for the raster to come up, and if it takes too long to turn off.

[ctc17]

My notes on that chassis show I was at 190ma. I think your ok Dave http://boxcarcabin.com/vintagetvs2.htm

[DaveWM]

got a couple more with one of my fav movie stars

I have tweeked the pic, this is that old tube with a weak reg gun pretty darn nice even with that.

I am not touching it now

[DaveWM]

I went ahead and replaced the remaining 2 1kv tubular caps. it had 3 originally, one was leaking and since I cant test that high a voltage I decided to go ahead and replace the other two. One was a .047 and the others were
.1 all at 1kv. One of those was the one in the vert circuit that I replaced a few days ago with the rigged up .22 630v in series. I did not like the idea of that so now its all good.

I still need to add the B+ and cathode fuse, but will button it up and watch for a while.