Adding AVC to Early Model 70 - Need Opinion - Printable Version

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+--- Thread: Adding AVC to Early Model 70 - Need Opinion (/showthread.php?tid=1762)

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Re: Adding AVC to Early Model 70 - Need Opinion - etech - 03-16-2009

Hi guys,

I was doing some reading on this topic elsewhere and came across this posting by Jgrady. It seems to confirm what Ron has reported about sensitivity issues with avc controlled Philco 70.

Quote: John PS this particular 70(nonAVC) is one of the most sensitive broadcast band radios there is when it is working right. I think it works better than the later 70 with AVC,by a wide margin...odd

Any thoughts?

Ed

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Re: Adding AVC to Early Model 70 - Need Opinion - etech - 03-18-2009

Well, once I finish the restoration of my 70, I guess I will have to try it both ways, both with and without avc, and see what happens. I will report back.

Ed

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Re: Adding AVC to Early Model 70 - Need Opinion - Ron Ramirez - 03-18-2009

An early Model 70 without AVC will be super-sensitive...because, with no AVC to reduce the gain of the receiver on strong broadcast signals, the receiver is operating at "full throttle" all of the time. On a later Model 70 with AVC, the gain will vary depending on the strength of the received signal due to the AVC action.

I used to have Ed Locker's modified 70 schematic around here somewhere, but with my newer computer currently being dead, I'm not sure if it is stored on it or not.

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Re: Adding AVC to Early Model 70 - Need Opinion - etech - 03-18-2009

Hi Ron,

Ed was kind enough to email his schematic to me for the model 70 with avc. If you need it, I can email it to you.

Ed

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