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Old 5th Jan 2008, 6:25 pm   #1
brianc
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Default Pye LV51/F modifications

I've just picked up an LV51/F (in pretty good nick too!) so I went to the TV CDROM to get the service info printed off. I noticed that there were a couple of sheets (and a new circuit diagram) which covered modifications which should have been done during the working life of the set.

Now, if these mods have not been done, should, as a general rule, these be done during the restoration?

I have to assume that they were for improvements in picture/sound quality and/or reliability and not to "cheapen manufacture" which so many production life mods are for.

What is the consensus of opinion about this - to mod or to leave as the last person to use the set in anger left it?

Cheers
Brian
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Old 5th Jan 2008, 6:33 pm   #2
Steve_P
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Default Re: Pye LV51/F modifications

Restore is as it is, and see if any are actually needed.

Cheers,

Steve P.
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Old 5th Jan 2008, 9:22 pm   #3
brianc
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Default Re: Pye LV51/F modifications

Here's the sheet describing the mods. Unfortunately, it does not detail what they do!

If you have the Vintage TV CDROM, the complete .pdf is under pye\LV30.

Cheers
brian
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Old 5th Jan 2008, 11:11 pm   #4
Brian R Pateman
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Default Re: Pye LV51/F modifications

As is stated at the top of the list of mods, these were to improve results in fringe signal conditions.

At this period it was usual to design the circuitry for optimum operation in the primary service area and to "back fit" improvements as problems were highlighted from dealer feedback.

As I would imagine most of us are using programme material from simulated sources, the conditions for our signals will replicate the strong signals which would originally have been associated with the primary signal area.

Not having the manual to hand for this particular set I might be wrong but I would assume the changes to be associated with improving performance if the sync and initial signal stages to cope with the weaker fringe signals.

Indeed many sets were produced in two distinct versions, one of which would be "tweaked" for fringe areas and identified with a suffix to the model number.

In answer to your question, I'd tend to restore to the original design and implement the mods if there was a need to do so.

Regards,
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Old 7th Jan 2008, 11:07 am   #5
brianc
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Default Re: Pye LV51/F modifications

You're right Brian. Checking with the two schematics, all the mods are in the sync and sound areas. As my LV51/F is a fringe model, I assume that the factory mods are incorporated (such as the grounded grid RF stage). One interesting mod is the removal of an AGC-type volume control and the incorporation of a more normal AF control. This is the first fringe model I have acquired and it will be interesting to do some tests to compare it with my LV30.
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