Sony KV-1320U (Japanese market) Trinitron restoration

[Electronic M]

Originally Posted by dtvmcdonald

Tom: I bought a Sola transformer to power my color and pre-WWII sets. Its a 1 kW unit and works great.

But it hums loudly and drives me crazy, so I'm still using a Variac and a
Kill-a-Watt to set it.

Do you know here to get constant voltage transformers that don't hum or buzz?

The only ones I've seen that don't buzz are the factory ones in Zenith Chromacolor II sets, and the secondaries on those aren't right for a tube set.

I run an air filter 24/7 that makes white noise, and hide the transformers behind a console in the far corner of the room on a dogleg of the room I can't see from viewing position to minimize it's volume...If I cared a bit more about the hum I'd build what Hollywood calls a sound blimp or put it in a different room.

Especially when I moved in but still sometimes the power grid makes one non-negotiable... when there's MANY bloom inducing grid voltage dips a minute unregulated B+ sets become unwatchable.

[cj_reha]

Originally Posted by jhalphen

Hi to all,

"Alastair" in the UK claims (in 2013) to have obtained good results reactivating 1st generation Trinitron tubes (the 12" 330AB22) :

https://www.radios-tv.co.uk/communit...ation-updated/

Note: the site is sometimes geo-blocked for security reasons.

Best Regards
jhalphen
Paris/France

Interesting - bookmarked, thank you very much! I will try this on the original CRT once I have the set finished. I have nothing to lose and it sounds like a fun experiment.

As far as progress on the KV-1320U: I'm pretty far in to the mechanical part of the CRT exchange. I got the chassis and CRT/front panel divorced without incident; it mostly followed the OEM Sony manual instructions, with an exception for some of the wiring on a terminal strip on the CRT shield. But a quick reference photo took care of that





Miraculously, none of the yoke plastics or mounting hardware broke! I was very pleasantly surprised...





I'm thinking once I have the replacement CRT fully dressed I'll start pre-emptively recapping the chassis before putting it all back together. Not having the yoke and CRT in the way gives me really good access to a lot of parts I'd otherwise really struggle with, and I already know most of the set works as it came up with full deflection and snow. More soon...

[zeno]

The PCB's are hinged so most things are easy to get at.
Zeno

[vol.2]

Originally Posted by cj_reha

I will try this on the original CRT once I have the set finished. I have nothing to lose and it sounds like a fun experiment.

Would definitely be interested to see you try to restore it. Although I think it's worth noting that the person who tried that experiment never actually reported on the tube working in a chassis

All we know for sure is that the emissions looked better for at least some amount of time after he did it. It never made it back into use in the scope of that thread

[cj_reha]

Originally Posted by zeno

The PCB's are hinged so most things are easy to get at.
Zeno

Definitely serviceable in situ, but eh, I have it all apart, why not...

Been trying to do the hardest boards first. The IF-related circuits are a bit tedious with all the soldered shields, but I bought a new soldering iron recently which has been making quick work of it all. Metcal RF irons are no joke!





I love these 2SC403A's - seen a lot of them in Sony IF/color circuits. The "leads" appear to be nothing more than gold foil. I have a precious few used spares, but am still super careful working around them. I can't imagine how fragile they are...

[vol.2]

Originally Posted by cj_reha

Metcal RF irons are no joke!

Very jealous! A decent soldering iron is at the top of my list right now, but I don't think it will be quite as nice as that one.

I've been using the same Digital Tenma station that I bought from MCM Electronics in the late 90s. I never bothered replacing it because it kind of "just works" and it gets very very hot. The big issue is that it takes a minute or two to be usable.

I have a precious few used spares, but am still super careful working around them. I can't imagine how fragile they are...

The original parts are still available NOS from some guys in the US on ebay if you are dying to keep it original, but there is also a short form datasheet out there that has all the specs.

[cj_reha]

Originally Posted by vol.2

Very jealous! A decent soldering iron is at the top of my list right now, but I don't think it will be quite as nice as that one.

I've been using the same Digital Tenma station that I bought from MCM Electronics in the late 90s. I never bothered replacing it because it kind of "just works" and it gets very very hot. The big issue is that it takes a minute or two to be usable.

I was surprised by how relatively inexpensive they were. There is a pretty decent used market for parts which allowed me to put together a complete setup with a pile of tips for under $400 - probably the best investment in the bench I've ever made. Up until I got the Metcal I used a Weller WES51 I got for my 16th birthday (23 now) for literally everything from tube work to fine-pitch SMD soldering. It's a fine iron, but with the volume of stuff I work on, I kept running into situations where it really struggled and was clearly at the edge of what it was capable of. So far the Metcal is knocking it out of the park!

[cj_reha]

Just a quick update for tonight - pulled apart and cleaned the high voltage box. The Toshiba 3AT2 looks original. I don't think it's necessary to test - I don't really put stock in testing high voltage rectifiers, since it's so far out of their nominal operating range - but I do need to remember to check the final anode voltage when everything is put together.

[vol.2]

Originally Posted by cj_reha

Just a quick update for tonight - pulled apart and cleaned the high voltage box.

That tube is very pretty. Love to get one of those sets at some point, but I'm swimming in projects already!

I had a thought that maybe it would be a good idea to really check the flyback casing for hairline cracks or deep lines, and to preemptively cover anything in heat resistant silicone or whatever that stuff people use on them is.

[cj_reha]

Originally Posted by vol.2

I had a thought that maybe it would be a good idea to really check the flyback casing for hairline cracks or deep lines, and to preemptively cover anything in heat resistant silicone or whatever that stuff people use on them is.

The donut is in really good shape in this particular case, it should be fine