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  #76  
Old 02-08-2019, 11:30 AM
old_coot88 old_coot88 is offline
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Quote:
Originally Posted by Gleb View Post
...make sure that it made out of copper (not an ohmic wire).
Did anybody other than Zenith use that?
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  #77  
Old 02-08-2019, 06:09 PM
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I don't know exactly about US-made sets but I met 'ohmic' HV heater windings in some early Russian televisions. Just a precaution to be sure that it's not your case.
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Last edited by Gleb; 02-08-2019 at 06:18 PM.
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  #78  
Old 02-08-2019, 10:59 PM
Crist Rigott Crist Rigott is offline
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Quote:
Originally Posted by Gleb View Post
I don't know exactly about US-made sets but I met 'ohmic' HV heater windings in some early Russian televisions. Just a precaution to be sure that it's not your case.
Mine uses wire. It does use a 3.9 ohm resistor. Which was replaced.
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  #79  
Old 02-08-2019, 11:06 PM
Crist Rigott Crist Rigott is offline
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Today I tackled the HV cage mod. I cut away the corner and made a triangular filler piece. Then cleaned it up and painted it a silver color. I wanted it a bit different color than the chassis.

I then finished up wiring the HV cage. I replaced all the HV wire, except the HV lead to the CRT.

Then I could finish up wiring in the Yoke wires. All done except the 300 Ohm twin lead from the Tuner to the terminals. Then on to first power up.





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  #80  
Old 02-09-2019, 06:31 AM
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AlanInSitges AlanInSitges is offline
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The suspense is killing me.
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  #81  
Old 02-09-2019, 12:56 PM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by Crist Rigott View Post
Both tested excellent.
What make is the CRT? I thought I saw the GE logo.
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  #82  
Old 02-09-2019, 01:28 PM
Crist Rigott Crist Rigott is offline
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Originally Posted by dieseljeep View Post
What make is the CRT? I thought I saw the GE logo.
It's a GE.
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  #83  
Old 02-09-2019, 10:27 PM
Crist Rigott Crist Rigott is offline
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I did a power up today. It went well with no smoke. HV is a 14.5KV. All of the controls seems to be working. Audio is good. Video not so good.

I'm getting a negative picture of low quality. I swapped out the video diode with a 1N60 and made no difference.

Any suggestions as where to look?. I haven't tried direct video injection yet. That's next.



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  #84  
Old 02-09-2019, 10:47 PM
old_coot88 old_coot88 is offline
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Are you sure the diode isn't backwards?
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  #85  
Old 02-10-2019, 01:03 AM
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Also check the integrity of the M7 coils, and ensure the connection of the cathode/grid of the picture tube is correct.
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Last edited by Gleb; 02-10-2019 at 07:50 AM.
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  #86  
Old 02-10-2019, 01:49 AM
Crist Rigott Crist Rigott is offline
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Guys, thanks for the suggestions.
The CRT showed weak when I tested it again. I put it on the Beltron and now shows very strong.
I powered up the set again and basically the same thing, but with a better picture. I tweaked the H. Drive and Lock controls but no difference. Then I tweaked the Bias control. Bingo!
I think I need to clean up and finish up the CRT and its mounts, then look at doing an alignment.
Though I'll double check the above suggestions first.

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  #87  
Old 02-10-2019, 10:33 AM
old_coot88 old_coot88 is offline
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Nice! (obviously the det.diode is not backwards).
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  #88  
Old 02-10-2019, 12:56 PM
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jr_tech jr_tech is offline
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Great work! congratulations!

I am wondering about this “bias” control... does it set cut off of the CRT? Where is it located in the circuit?

jr
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  #89  
Old 02-10-2019, 02:18 PM
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electronjohn electronjohn is offline
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Super! (Nice metalwork on the HV cage, too!)
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  #90  
Old 02-10-2019, 04:42 PM
Crist Rigott Crist Rigott is offline
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Quote:
Originally Posted by jr_tech View Post
Great work! congratulations!

I am wondering about this “bias” control... does it set cut off of the CRT? Where is it located in the circuit?

jr
Here is a section of the schematic from Sams. It is R9. Below it are the Alignment instructions that talk about setting the Bias Control. Frankly, how or why its there is above my pay grade.



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