LOL - I was until 4am that night http://www.jawaspot.com/smilies/tired.gif I kinda liked that piece sign too, but the stain had to go.

Although I haven't given up on this CRT, I couldn't resist picking up this Motorola chassis with a 16RP4A for $15

I hope it arrives in one piece!

Does anyone have a schematic specifically for a Sentinel 430 ?

I'm currently working from Sams set 124 Folder 9 which covers models 420, 423 and 424. That's the best they had to offer. It's close, real close, but I'm encountering subtle differences in the sync separator, dc restorer and horizontal circuits.

I also checked Beitmans 1951 which has 412-416, 420, 423, 424. Beitmans 1952 has 438-444 :dammit:

It's been a couple very, very frustrating weeks, but I think I'm in the home stretch. First, I liberated a replacement pot from my Airline set. Then, I discovered that not only did the sync/dc restorer circuit differ markedly from the schematic, but some parts were only connected at one end! Apparently, someone was tinkering with it way back when. I decided to rebuild it from the ground up according to the schematic.
Now I had a much brighter picture, but the horizontal sync went to hell :smilemad:
It appears I was wrong about this CRT - it still has some life in it :thmbsp:
http://farm5.static.flickr.com/4022/...6b55f43f_b.jpg

So, I started putting old parts back in (or new parts with the old values regardless of what the schematic called for) following the reference picture I had taken. Finally, when I got to the horizontal phase inverter, I got my sync back :D
Only problem now is the retrace lines are very prominent.
http://farm3.static.flickr.com/2740/...5e429daf_b.jpg


I remembered seeing an article at the ETF on a retrace mod and dug up this page. I was surprised to find that this mod was already in this set, but it wasn't doing the job. I experimented with the RC values and finally, got a bright, stable picture with no retrace lines :banana:
http://farm3.static.flickr.com/2762/...ba448d49_b.jpg

Time to fire up a test pattern and get that picture all squared away!

Hey that's awesome!!
:banana::yippy::grnbounce:yippy::banana:

Yeah, sometimes it seems there's simply no mercy, and then when you least expect it, it works!

Congrats! :thmbsp:

I have one of those B&K 440's it always show the crt as worse than my Sencore CR-70. And always the CRT seems better than what the 440 says.

Also the Sencore seems very good at the rejuv mode, have had good luck with it.

just something to think about.

My parts chassis with a 16KP4A arrived today. It was really, really well packed!
http://farm5.static.flickr.com/4039/...fd74ed238e.jpg

http://farm5.static.flickr.com/4065/...3f5698b6_b.jpg

It turns out this a very nicely restored Motorola chassis. Does anyone recognize the handy-work ?
http://farm3.static.flickr.com/2753/...40982407_b.jpg

I wonder what happended to the cabinet :scratch2:
http://farm5.static.flickr.com/4011/...b4e591f8_b.jpg

Here's the GE 16KP4A.
http://farm5.static.flickr.com/4017/...13c5b452_b.jpg

Unfortunately, it reads absolutely 0 on both my CRT testers :( :tears: :dammit:
Maybe it's just a loose cathode connection inside the base cap ?
http://farm5.static.flickr.com/4001/...246d3f89_b.jpg

I suppose worse case scenario I have a really nice parts chassis for my Motorola 12K2 and a tube for Hawkeye to rebuild.

Thread jack: That's a pretty simple mod, I'd like to use it on my Philco which shows retrace lines at high intensity. Problem is on the Philco, the pic tube cathode is used for brightness and the grid is driven by the video amp tube. How could I change this simple circuit to work with the grid vice the cathode, if that's even possibe? I assume I'd need a phase inverter, and a coupling cap at the very least.

Looks like someone's done all the hard work for ya on that one! Yes, one of the pins in your socket could need resoldering. I had a NOS 21EP4 that gave a dead element on one of the pins and feeding more solder in the pin fixed that... then tested like new.

And if resoldering the pins doesn't help you can always try the re-weld the cathode trick as a last resort.

John

I'm glad you asked - I had the same problem with this set!
What I did was feed the vertical pulse into the cathode along with the brightness control and leave the video grid alone. It wasn't working at first because the 0.05 cap on the cathode was filtering it out. So i cut that down to 0.02 and reduced the resistor to 3.9K.

I hope this helps.

I took the base off - it was loose already. It's not a bad solder joint :tears:

Here's the best photo I could manage. To my eyes it looks like the cathode connection is OK, but I can't see all of it. What's the cathode re-weld trick ?

http://farm5.static.flickr.com/4022/...9f1605c5_b.jpg

:grnbounce
:yippy:

Every once in a while I get lucky!

Thanks, I'll have to give it a shot.:thmbsp:

that chassis looks a LOT like the motorola TS-14 I am working on.

It's a TS-60. I have a TS-23 that looks the same too. They made a bunch of chassis that were all very similar.

This is from the Sencore CR31A SuperMack manual, so I don't know if it works with all rejuvenators.

John