Admiral 17T1 restoration

[bandersen]

I'm just about done with a quick restore of an Admiral 17T1 I picked up recently. Really it's a 17T1 chassis in a 19A11 cabinet and a broken one at that.

Here it is in the previous owners basement along with a few other goodies.


Doh! I had been crudely glued back together and the piece fell out as soon as I put pressure on it. Also, a small section is completely missing.





I was surprised to find it had been recapped in the not to distant past and decided to power it up.


Check out that giant HV cap. It turned out to be a 0.05 uF - 10 times what the set calls for.


Well it sorta works with an unstable picture and weak sound.

[bandersen]

So I started poking around and quickly discovered two things.

One - The 17T1 chassis is not the same as the 19A1 in spite of what the Riders index states.

Two - Some of the new orange drops were not the right value!

With the correct schematic in hand, I went through and replaced all the bad components.




That got me a better image, but the sound was still bad.


So I fired up some gear and did an alignment. 3 MHz bandwidth isn't too shabby for a 7" set. The linearity is pretty good too.

Sound is much better now but there is a little hum even with the volume all the way down. Perhaps that's normal ?


I also installed a retrace blank and DC restoration modification.
The picture is pretty good but I see some ringing on the left side

[Phil Nelson]

Originally Posted by bandersen

Sound is much better now but there is a little hum even with the volume all the way down. Perhaps that's normal ?

My 19A12 does the same thing -- slight hum when the volume's turned down. Not enough to be bothersome in normal use.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

[bandersen]

Originally Posted by Phil Nelson

My 19A12 does the same thing -- slight hum when the volume's turned down. Not enough to be bothersome in normal use.

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

OK, I guess it's not that bad. I also noticed the power transformer gets warm after 15+ minutes of use. Not hot enough for me to be concerned but warm enough to notice.

[josephdaniel]

If its not too much trouble what console is that in the center of your first picture? I an still thinking about getting one in st.louis this summer but I don't know anything about it. Good thing the owner said it wasn't going anywhere!

[bandersen]

Originally Posted by josephdaniel

If its not too much trouble what console is that in the center of your first picture? I an still thinking about getting one in st.louis this summer but I don't know anything about it. Good thing the owner said it wasn't going anywhere!

I believe it's a 16" Philco. I passed on it and am not sure of the model #.

[bandersen]

A friend stopped by last night and I fired up the set. His first comment was how loud the hum was from the speaker so I'll take a closer look. I wonder if it's connected to the warm transformer somehow ? All the electrolytics have been replaced and are running cool.

[bandersen]

I tried everything I could think of to eliminate or reduce the audio hum/buzz and gave up. If I turn the volume up enough, it's not that noticeable. I have a couple other similar 19A1 chassis to restore and I figure I'll compare their performance.

As for the damaged cabinet, I swapped it out for a black one I cleaned and polished a while back. It's still not the proper 17T1 "Chinese grille" cabinet, but it will do

[Phil Nelson]

Very nice!

Regarding the audio, I wonder if some of that is simply normal vibration from the power transformer.

Phil Nelson

[dieseljeep]

I never saw one with the 6Y6G. All the sets I had, had the 6AS5. They still used the 6SQ7, though.
That must be an earlier model!

[Kamakiri]

I'm going to be doing this exact same set for a friend in about a month, nice work!

[bandersen]

Originally Posted by Phil Nelson

Very nice!

Regarding the audio, I wonder if some of that is simply normal vibration from the power transformer.

Phil Nelson

I'm pretty sure it's electrical in nature and I suspect there might be something wrong with the power transformer. I have a couple junker chassis I could grab a replacement from.

Originally Posted by dieseljeep

I never saw one with the 6Y6G. All the sets I had, had the 6AS5. They still used the 6SQ7, though.
That must be an earlier model!

It's definitely the newer version. The main differences being the audio output and addition of a vertical linearity control. I believe the beefed up that output tube because it's also used as a voltage divider.
Here's what the cabinet and knobs should look like.

Originally Posted by Kamakiri

I'm going to be doing this exact same set for a friend in about a month, nice work!

Thanks and good luck. I hope yours isn't as chewed up as this one was.

[Sandy G]

What was the deal on the KNOBS of thease things ?!? A LOT of 'em I've seen have that white, nasty gunk all over 'em...

[bandersen]

The type of plastic they used breaks down over time into that white crud. I soak them in a some warm diluted 409 and it floats right off.

[kvflyer]

Humidity and I think more importantly human contact, body oil, skin contact seems to me harbor the growth of that stuff. Acetate screwdriver handles in my basement get the same nasty growth. Stinks like vomit, just like Pridicta CRT face covers.