Sentinel 430 restoration

[bandersen]

I cannot friggin believe that actually worked!

I followed your directions about 30 times with no luck. Just as I was about to give up I saw a brief flash. Still no emission though.
About 6 more blasts, whacks and flashes and I finally got it welded back on. The emission is really strong too!

I think it would have been easier if I had a 3rd hand

Thanks you so much for those crazy instructions. What a great forum

Time to try it out in the set. I'm kinda afraid to move it now though

[DaveWM]

How cool is tthat!

[Reece]

Great success story! Thirty times NO and then a big YES.

[Zenith26kc20]

I admire persistance!

[DaveWM]

My old boss had a poster on the way, "never give up" with a frog choking a bird that was in the process of swallowing the frog.

In contract negotiations the idea was aways the same, "out last'em"

[jr_tech]

WOW! it is nice to know that works!
A few months ago, I gave up on a 14" tube in a small DuMont portable... the cathode would connect on occasion if the neck was tapped, especially if the heater voltage was elevated, but it would not "stick". Since the set came with a spare jug, I just went ahead and changed it out. When I autopsied the gun, I found several additional welds that were very poor...somebody was having a bad day at the CRT plant.
Does Scotty (or anybody else) have the equipment to do a Laser rework?

jr

[bandersen]

More good news Here's a preliminary picture with the 16KP4A in the Sentinel chassis. I still need to do some tweaking of the focus coil, yoke etc. I'd say it's about 15% brighter and sharper than the other tube. I wonder if some of that is due to the dag coating which the other tube lacks.

I'm not sure which tube I'm going to leave in the set Either way it's nice to have a spare

[miniman82]

Nice, good to hear you were able to re-incarnate it!

[bandersen]

I hooked it up to my B&K 1077 and tweaked as best I could. There are a few issues to resolve:

The top is clipped.
The brightness increases from top to bottom. You can see that in the earlier pictures too.
The upper-right corner is dim.

I've done the best I can with the ion trap magnet, focus coil and yoke. Any thoughts ?

I think I'll poke around the vertical circuitry first to fix up the top of the picture.

[grimer]

---

[bandersen]

Thanks! That sure does look similar and you've done a nice job on it
It's good to know some else out there is working on one too. Other than the little 7" 400 series, I don't see Sentinels too often. I have the Sams and Beitman's for the 422 if you need a copy.

[bandersen]

I've just about got this set all squared away. First issue - the top being clipped and twisted was due to my 1077B being out of whack I really need to properly overhaul that bugger.

Second issue - the brightness gradient was due to the CRT being mounted at a bit of an angle. See that gap at the top - the tube is tilted back a little in the yoke.


I fixed that up and the brightness is uniform now. I just need to tweak that yoke rotation and lower the picture a little to take care of those dark bottom corners. So close to being done

[bandersen]

A few more tidbits about this set.

It has 14 channel positions - one blank before #2 and one blank after #13 ?!?

It also has a color converter. Would this have been for a color wheel ?


While looking through my parts stash, I came across a NOS Merit HOT for this chassis. Between that and the spare CRT, I should be able to keep this set running a long, long time.

[Charlie]

Is this a big drum tuner? It's likely those blanks could have strips installed for specifc UHF channels that were in your area... and they gave you provisions for two channels instead of just one.

I think it would be really cool to find an early set with a UHF channel strip installed. It's always possible to have one and not realize it. It would be easily overlooked. The tuner drum in my Zenith PH has a empty spot where one could easily be installed. The drum on my Bendix does not. Makes me wonder about the Sentinel 7" sets... there's an extra click in the tuner and it's not labeled on the bezel.

[rojoknox]

Greetings from FixitLand!

Originally Posted by Charlie

Is this a big drum tuner? It's likely those blanks could have strips installed for specifc UHF channels that were in your area... and they gave you provisions for two channels instead of just one.

I think it would be really cool to find an early set with a UHF channel strip installed. It's always possible to have one and not realize it. It would be easily overlooked. The tuner drum in my Zenith PH has a empty spot where one could easily be installed. The drum on my Bendix does not. Makes me wonder about the Sentinel 7" sets... there's an extra click in the tuner and it's not labeled on the bezel.

My '52 Zenith K1846R has a Channel 27 strip instead of Channel 3. When the set was new, KPTV Channel 27 was the only station in Portland, Oregon. We didn't get a VHF station until KOIN-TV 6 came on in 1953. Unfortunately for me, the folks from whom I got this set misplaced the Channel 3 strip long ago...

Take care,
--
J. E. Knox "The Victor Freak"