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#1
01-30-2010, 11:10 AM
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My Sparton Junior 410 is a 620 Console
It looks like this cabinet was designed for a larger chassis (also). The wood has the channels where a larger radio could be slid into place, but a smaller frame was manufactured and mounted for the smaller 410 radio. This cradle is built of the same veneered wood as the cabinet, not finished, of course, so it must have been built at the cabinet factory. It has a nice metal Sparton model plaque on the back. It says 620.
This radio was a basket case, all delaminated and falling apart, but, my wife liked it. After a couple of weeks and some long and not inexpensive parts searches it looks and plays good. The worst problem was an open secondary on the CT windings to the grids on the 2 483's. I disassembled the transformer and fixed the open. I do not think that I ever would have found a factory replacement - for a reasonable price. Last edited by Phlogiston; 01-30-2010 at 11:18 AM. 
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#3
01-30-2010, 11:28 AM
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Well, thank you.
If you like this one I'll post some pics of my Sparton 61/62, also just completed. Russ
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#4
01-30-2010, 12:50 PM
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Very nice job on that one, finish turned out super.
How tall is this set? Do you think this was a highboy that someone cut the legs off of? A lot of that was done post 1930 as people "modernized" their leggy sets. What makes me think so is that the controls are so low to the floor now.
__________________
Reece Perfection is hard to reach with a screwdriver.
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#5
01-30-2010, 01:58 PM
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The top is about waist high, for me, so around 3 ft high. It did not look to be cut down. If someone did, they did a very good job even in the shape that it was found, it was level.
This unit came from an old TV tech's estate. I purchased a load of "stuff" that he had stashed away in a barn - which a tree fell on. So everything had been damp - or worse. His papers and Sams came with the lot. It looks like he retired in 1957 so this was likely obtained by him sometime before that. In all likelihood it was brought in because of the failed interstage transformer. In place of the 2 483 output tubes was an 01A  (could have caused the failure) and a 71A.Russ
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#6
01-31-2010, 02:18 AM
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Nice set
 Did you manage to find a pair of 483 tubes ?I have a Sparton Jr. with a 400 chassis. Both 483s were missing  I only found one 483 tube after a few months of looking so I ended up using 71As.
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#7
01-31-2010, 09:33 AM
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I think that a lot of people use the 71As in place of the 483/183 tubes. I did find a pair of 483s for this radio.
The max plate voltage of a 71A is 180V with a plate current of 20ma with a grid voltage of -40.5V. The (max?) normal plate voltage for a 183 is 200V with a plate current of 20ma and a grid voltage of -45V As I recall, I measured the B+ 180 - 200V while working on this one. For a while I used 45,s with the filaments wired in series, an easy mod. They worked, but this was before I had the interstage transformer working. I was using a substitute that was not a good match and vol was low. Also I am not sure how wiring the filaments in series affects the "self bias" since this adds a resistor to one leg (the other tube filament). The specs on a 45 give you a lot of room to make adjustments. The max voltage is 275V with a plate current of 36ma and a grid voltage of -56V. You know that an 182A has almost the same specs as a 183, but they may be even harder to find. The Sparton manual says to never mix 482B and 483s. It looks to me like you could mix 182A (482A) and 183s at the risk of adding a little hum to the audio.
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#8
01-31-2010, 09:48 AM
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By the way, those old Sparton documents list this 620, so they must have made a few of them, but I have never seen another. A search on the net does not turn up much.
Russ
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#9
01-31-2010, 04:33 PM
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My other Sparton (931) uses a couple 182s. Thank goodness it came with a couple good ones. I've never seen one for sale.
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#11
02-02-2010, 08:15 AM
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Quote:
http://cgi.ebay.com/Unused-Cardon-C-...item5639502705 Usual disclaimer - not mine, no connection, and I've only slept in Kentucky once.... Cheers,
__________________
Brian USN RET 22YRS (Avionics/Cal) CET-Consumer Repair and Avionics ('88) "Capacitor Cosmetologist since '79" When fuses go to work, they quit!
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#12
02-02-2010, 09:41 AM
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Quote:
Thank you. The other sparton pictures are in this thread: http://videokarma.org/showthread.php?t=246995 Russ
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#13
02-02-2010, 09:47 AM
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Quote:
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#14
02-02-2010, 02:39 PM
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Quote:
 The pair I have are newer ST style Sylvania 182Bs
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Linear Mode
