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  #16  
Old 04-17-2013, 04:11 PM
lucvic lucvic is offline
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Join Date: May 2012
Posts: 21
In these days I don't hve my camera,
I hope tomorrow yes, plate of 15tp7 and cathode of
CRT correct?
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  #17  
Old 04-19-2013, 06:01 AM
lucvic lucvic is offline
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Join Date: May 2012
Posts: 21
Hi guys,

last evening I tried to make a photo of the signals requested
but I found a new issue.
The signal at the videodetector was suddenly disappeared.
Seemed a bad contact but in 2 hours I didn't fix this.
After various simple checks I was very sad of this but the
signal magically re appear. Can this be a problem on high frequency
down converter or oscillator?
This set have two inputs VHF and UHF and two different tuners.
Since starting on this project I have used a VHF signal I didn't try to switch on the UHF signal.
I will try again to fix the issue tonight.

thank you
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  #18  
Old 05-26-2013, 02:58 PM
lucvic lucvic is offline
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Join Date: May 2012
Posts: 21
here I am,
today I had some time to work on this TV.
I found some differences in voltages at electrolytic caps
(anodes of the tubes).
This difference was because I substituted the the diodes (2 PY82) with one 1n4007 with a resistor 82 ohm in series. This was a mistake because the 82 ohm is the resistance of one tube but the PY82 are connected in parallel.
Now the vertical sync is more stable but the sound have some troubles yet.
ASAP I will post some images.

thank you for your help
Attached Files
File Type: pdf PY82.pdf (207.8 KB, 10 views)
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  #19  
Old 06-23-2013, 10:23 AM
lucvic lucvic is offline
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Join Date: May 2012
Posts: 21
Hi dear all,
some work on this project in these days,
I found some docs on this set,
various vawes are shown and the first I see is the amplitude
at grid of output video amplifier.
The value I have i 2.5V pk to pk.
This value in doc is between 2.5 to 8 V pk to pk.
So I figure there are troubles in tuner or IF, or a overload of these two
sections.
AGC seems to work propely because bias of IF tube increases if I slightly disconnect the antenna.

Any suggestion on verify I can do?

many thanks
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