Admiral 24C16 restoration - Videokarma.org TV - Video

bandersen · #1 01-29-2010, 03:56 PM

This set uses the 20B1 chassis which is almost identical to the 20A1 chassis in my Admiral 24A12 so I've been restoring them at the same time.

I picked this set up last spring. The cabinet is in really good shape except for a ring on top where there is some finish loss.

Always use a coaster!

The chassis is in pretty good condition too. It's covered in light rust and filthy, but intact otherwise. I can only find evidence of two capacitors being replaced long ago.

The CRT is losing is aquadag coating and is an odd brand "Nat'l Video Corp". It tests very good, but I do get an intermittent G1 short. Tapping on the neck makes it go away. I just might be trying the "remove short" function for the first time.

Here are the two chassis side by side. The one for this set is on the left.

Pretty much the only difference is that this one is wired for a 12LP4

leadlike · #2 01-29-2010, 04:12 PM

Maybe the short is in the base of the tube. It could be worth your while to desolder the thing and confirm that. It's also worth checking out your crt checker and making sure there are no out of tolerance parts there. I had a tube checker that would occasionally give a "shorts" reading on a known good tube. I traced out the circuit, replaced a resistor, and now it is a lot less finicky.

bandersen · #3 01-29-2010, 04:23 PM

Yeah, I knew what you mean so I tried two different testers. They both gave the same results - a very intermittent G1 short. Basically I can tap on the neck and the short goes away indefinitely. So if it is in the base, there must be a loose bit of metal floating around. I suppose it is worth checking, but what a PITA

bandersen · #4 01-29-2010, 04:38 PM

Luckily, the chassis cleans up very easily

Just a little Naval Jelly and a WD40 wipe down.

The turret tuner was filthy too with a thick, sticky film all over it. I used some Radio Shack control contact cleaner being careful not to wipe off the numbers.

bandersen · #5 01-29-2010, 04:45 PM

These Admirals are really easy to work on. Having a split chassis is a big part of that. It cuts down on the weight of the main chassis so it's easy to move around.

Just about done recapping

I still have some cleaning to do, but can't wait to fire it up

I'll be doing that later tonight - keep your fingers crossed!

Dan Starnes · #6 01-29-2010, 07:08 PM

Got my fingers crossed!!

bandersen · #7 01-29-2010, 10:17 PM

Quote:

Originally Posted by Dan Starnes

Got my fingers crossed!!

Thanks to Dan's crossed fingers, I've got some good news!

At first, nothing - no HV, no B+, no filament glow, then I realized I forgot to plug the cheater cord in

That's a 5AXP4 test CRT I've installed

With that hooked up, I was treated to a nice CRT glow and loud buzz from the speaker. At this point I still had the HV cage and tube shields off so I shut it down. While replacing those shields, I realized I also had left out one of the 6AU6s in the IF stages

Now, I've tuned it to channel 6 (OTA analog VHF station) and got some good sound, but the horizontal and vertical sync are all over the place

I tried a DTV converter box and got no sound and no picture

So I grab an alignment tool and reach around to the horizontal coil and start tweaking it. At one point I get a high pitched squeal, then at last a stable picture

Still no sound at all though. I had a similar issue with my 24A12, but not as bad. I went back to channel 6 OTA and can tune in both a good picture and sound. I'll try my blonder tongue modulator later, but next I'm going to try the 12LP4.

wa2ise · #8 01-29-2010, 10:20 PM

Dan Starnes · #9 01-29-2010, 10:39 PM

Congratulations,, that pic with the tubes a glowin is very cool.

bandersen · #10 01-29-2010, 11:43 PM

Thanks! I've reinstalled the 12LP4 and was treated to a mediocre picture.

I was going to call it a night, but decided to try one last thing. I had tested all the tubes in this set and they checked out OK. Even so, why not swap them out with the 24A12 set that's playing much better?

Still no sound, but the picture is much better! I swear this Honeymooners just happened to be on

If I tap on the CRT, the picture sometimes goes faint so that G1 short really is something to be dealt with.
Also, I need to track down which tube(s) was the culprit.
Finally, still some work to do on that audio

*zenithfan1* · #11 01-30-2010, 11:19 AM

Looks great Bob! That Naval Jelly really works wonders. That recap and new resistors look great too, I also like to install them that neatly

. Very, very nice work

edison64 · #12 01-30-2010, 12:50 PM

Great job, even Norton is getting ready to watch Captain Video...

Dan Starnes · #13 01-30-2010, 01:11 PM

That episode of the Honeymooners is priceless.

jeyurkon · #14 01-30-2010, 01:21 PM

Nice work Bob! I like the way you present most of your work the same day. I'm assuming you didn't do this all in one day!

That's some ion trap they have on there.

How do you keep the Naval jelly out of places you don't want? Just being careful?

John

Findm-Keepm · #15 01-30-2010, 03:19 PM

Your work is second to none. Your restorations are museum quality for sure!

The lead dress of your replacement caps makes me think you are either a very professional conservationist/restorer or have some form of OCD.

The problem-solution-result style of your pictures is amazing. I can't remember a time when I've ever thought of any repairs I've performed as being worthy of a photo - but every one of your photos tells a thousand stories.

I'm jealous to say the least.

Cheers,