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 Sanyo ctp7607
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 Return to top of page · Post #: 1 · Written at 8:53:00 PM on 20 July 2011.
Phil Shields's Gravatar
 Location: Albury, NSW
 Member since 20 July 2011
 Member #: 962
 Postcount: 5

Hello all, I used to work in the Sanyo factory in Wodonga and have just finished restoring the CTP 7607. It had an open circuit vertical coil in the yoke and I had to unwind it, locate the open circuit and rewind it again. Works well. Still tracking down over video white tearing. I have converted a set top box to have an RF output at channel 0 so it all works well. Fun to watch and has an excellent picture.

PS if anyone has a Pye pedigree stand I could buy let me know.
Phil.


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 Return to top of page · Post #: 2 · Written at 10:01:02 AM on 21 July 2011.
Cool386's Gravatar
 Location: Blue Mountains, NSW
 Member since 30 June 2011
 Member #: 944
 Postcount: 30

The 1970's Sanyo CTV's seem to be more prone to dried out electrolytics than other Japanese sets.
Tearing on peak white, if it's not an AGC problem (easily tested by using a weak signal) will be distortion of the video waveform, preventing the sync separator clipping the luminance signal properly. If you have a CRO this is easily checked; if not, replace all the electrolytics between the video detector, video amplifier and sync separator.

However, incorrect modulator drive from a digital box will also cause the same problem.

One quick word on deflection yokes fitted with rubber wedges to set the convergence, which is applicable to many later models of CTV. The rubber breaks down, becomes conductive, and results in a yoke with shorted turns. There was a whole lot of failures in the mid 1990's with these.


 
 Return to top of page · Post #: 3 · Written at 8:45:47 PM on 22 July 2011.
Phil Shields's Gravatar
 Location: Albury, NSW
 Member since 20 July 2011
 Member #: 962
 Postcount: 5

Thanks for that. I don't think it is the set top box as I'm rf modulating through the antenna and it works fine on other TVs. I have ruled out AGC, it has to do with the ABL or there about. I'll change all the caps there. I was hoping to see white level going into the sync pulse but it happens so infrequently I miss it on the CRO. I'm trying to simulate it somehow but I only have an old pattern generator. My son has an old video camera and I can probably simulate it with that. I didn't know about the conductive rubber wedges..thanks for that.
Phil.


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`•.¸¸.•´><((((º>`•.¸¸.•´¯`•.¸.•´¯`•...¸><((((º> J

 
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