#31
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I plugged in all the tubes and everything else. After a few adjustments on the back of the chassis Bingo!
Still more to do but the picture is very encouraging. |
#32
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Well, my Fusistor is open. I'm thinking of getting a chassis mount resistor and mounting on the back of the HV with leads long enough to reach the plug in sockets. I'll use the original open fusistor connector.
If I use the 5.6 ohms I get 288V for the 275V B+ line. If I go to 12 ohms I get 273V. Of course the 12 ohm resistor runs hotter. Remember I fused the power in. Does this secondary need to be fused? |
#33
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After all that work I would fuse the secondary.
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#34
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I did the tuner today. I replaced the 1 paper cap and 10 resistors. 1 resistor I couldn't get to. Oh well. The 1/2W resistors were replaced with 1W and the 1W was replaced with a 2W. I then cleaned the tube sockets and used De-Oxit on the wafer switches. The tally is:
10 resistors replaced 5 out-of-tolerance 2 very close to being out-of-tolerance 3 were within tolerance. I then tried the tv again. I got a clearer picture. |
#35
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Crist, It looks like you are using metal film resistors. What voltage rating did you use for your 1W and 2W resisistors? I'm especially interested in the ones under the HV rectifier tube socket? Thanks, in advance.
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Audiokarma |
#36
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For the 1W I try to use carbon film, but will use metal film too. For the 2W they are usually metal film. The carbon film are 500V, the 2W are 350V.
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#37
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Today I added the new "Fusistor" and a 2A fast blow fuse. I had a 10 ohm 50W chassis mount resistor so I mounted it on the back of the HV cage. I then wired it to the original Fusistor connector. The 10 ohm value will give me a B+ voltage of 280V using my wall outlet which gives 123VAC. The normal B+ voltage is listed as 275V. This way when the HV cage needs to be removed they can be unplugged without any fuss.
I also installed the IF board cover. |
#38
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I then turned my attention to the CRT/Yoke. I removed the CRT from the shell and gave the CRT a quick wipe down.
I replaced the 2 680 ohm resistors (both were within tolerance) and the 120pf 5KV capacitor. I used a 120pf 6KV cap for that. I then cleaned up all the wiring and cleaned the connectors too. I then used my lacing cord to tie up each bundle neatly instead of the tape Philco used. I then cleaned up the inside of the shell. It had a lot of "soot" in there. Now nice and clean. |
#39
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I noticed that the wire going to the Plate Cap from the 6DQ6 Horizontal Output tube was missing some insulation where it enters the cap. I looked closer and noticed that the inside was was corroded green and needed attention.
I replaced the wire with some 20KV wire that I have. I also used a silicone grommet where the wire exits the HV cage. Dan Jones gave me this tip at his presentation at this years ETF Convention. All better now. Last edited by Crist Rigott; 08-21-2018 at 12:55 AM. |
#40
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Quote:
__________________
Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
Audiokarma |
#41
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Right! I'll make the correction. Thanks.
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#42
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Pardon the question of a rookie, but what did you use to clean the chassis? You do fantastic, detailed work. I wish my dexterity and eyesight were good enough to do work like you do. Quite impressive, and thank you for sharing your work with those of us trying to learn.
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#43
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Amazing work!
__________________
"I know it's true, oh so true, 'cause I saw it on TV"—John Fogerty |
#44
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Quote:
Then either it goes outside in the hot Texas sun, or it gets baked in the oven at the lowest setting for an hour. Then the controls are sprayed with cleaner and WD-40. Now its clean enough to work on. Thanks for the kind words. |
#45
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In 1965 I was working for Georgia Power Company and we bought a Tektronix storage oscilloscope - a big purchase back then. Included in the purchase price was a one day class by Tektronix. The Tektronix guy started off telling us how to periodically clean the interior of the scope. He recommended soap and water, just like your method of cleaning, Crist. If Tektronix recommends it on a $3000 scope, it should be OK for a Philco Predicta!
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Audiokarma |
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