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#1
11-20-2011, 12:55 AM
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Admiral 16R12 restoration
Oh yes, it's another Admiral restoration project. This time it's not one of my sets though.
A friend dropped off a couple sets over the summer and asked that I restore them. They both use the 21B1 chassis. I swear once these are done I'm definitely going to work on some other brands for a while   First up is the 12R16 tabletop.    It's filled with W. German resistors.  The Silverama 17BP4B tests like new and all the transformers, yoke and flyback test good   I found a 14 Amp fuse in the HV cage - it should be 1/4 Amp  
Last edited by bandersen; 11-20-2011 at 01:08 AM. 
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#2
11-20-2011, 01:08 AM
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The first challenge was finding the correct schematic. At first I was using the scanned Riders vol 6 available from the ETF.
I quickly found differences though. For example there are 3 couplates in this set but none are shown in Riders.  Also, these power resistors differ from Riders and I found a germanium diode detector while Riders shows a 6AL5.  I did some research and it seems they made at least 22 production runs of this set  I discovered a faint 'RUN 14' stamped on the back and tracked it down in a Wallace Telaide. Here's an explanation of those power resistors.  I restuffed the electrolytics and replaced most of the old caps and out of spec resistors.   The first power up treated me to some nice audio for about 5 seconds then silence and no raster or HV. I just started checking the tubes and found a 12AV7 in the 12AU7 socket. Also this "TEL-A-SAVE" 6AC7 video output tube has a cathode short and shows no emission on my Hickok. 
Last edited by bandersen; 11-20-2011 at 01:16 AM.
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#4
11-20-2011, 05:59 PM
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#5
11-20-2011, 02:53 AM
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I found about 5 more bad tubes including the 6AV6 audio preamp. Replacing that solved the fading sound problem. Still no picture though but I do have about 14 KV.
Then I finally noticed that the single pole ion trap magnet is missing  I scrounged one from another set and was treated to this mess  That's with the brightness cranked all the way up. 
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#6
11-20-2011, 04:17 AM
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I tried a different ion trap magnet. Bingo
 Maybe the first one I tried is weak ?A little twiddling of the Hor. Lock coil on the back finally got me a stable picture    Just in time to catch the Outer Limits   Very bright picture!  There are some faint vertical lines on the left side. The set came with a 6AX4 installed in the 6W4 socket so maybe that's the cause. Or maybe the horizontal yoke cap. I'll try adjusting the Hor. Drive too.  I'm glad I can sleep in late today 
Last edited by bandersen; 11-20-2011 at 04:21 AM.
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#7
11-20-2011, 12:19 PM
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Bandersen wrote: I swear once these are done I'm definitely going to work on some other brands for a while.
No you're not.  You're the Admiral go-to guy! Look at how nice a picture almost right away.
__________________
Reece Perfection is hard to reach with a screwdriver.
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#8
11-20-2011, 03:38 PM
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This Admiral is going to come up really nice by the looks of things so far
And such a nice picture too. Is that a young Martin Sheen in one of those image shots?
__________________
Visit my Vintage TV & Radio Page - http://nzvintagetvradio.blogspot.com/ My YouTube Link - http://www.youtube.com/user/glenz1975?feature=mhsn
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#9
11-20-2011, 03:46 PM
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Yes, that is indeed Martin Sheen
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#10
11-20-2011, 03:52 PM
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LOL We'll see  I think I'll let you guys decide which set I work on next.
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#13
11-20-2011, 10:57 PM
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I replaced them right away with some modern power resistors.
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#15
11-21-2011, 07:28 PM
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I've been using Vishay / Dale silicone coated power resistors lately like these: http://www.mouser.com/MobileCatalog.aspx?page=726
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Hybrid Mode
