In article ,
"Frank Dresser" wrote:

"John Byrns" wrote in message
...
[snip]


Then why is the eye tube always connected to the audio detector and not
the AGC rectifier?

[snip]

The Radiotron Designer's Handbook 3 (p. 225) brings up this topic.
Basically they say, in radios with simple AVC seperated from the audio
detector, it's preferable to connect the eye tube to the AVC line. If the
radio uses delayed AVC, it's preferable to connect the eye tube to the audio
detector (through a decoupling network) if eye tube action is wanted on weak
signals.


Good point, I forgot about that aspect of the problem, which of course
also applies to delayed AGC developed off the audio detector diode. I
can't remember whether or not I was checking for delayed AGC when I was
rummaging through the schematics of eye tube radios to see if I could find
any where the eye tube was connected to the AGC line and the AGC rectifier
was connected to the IFT primary. Delayed AGC seems relatively uncommon
however.

Does anyone know of any examples of eye tube radios that take the AGC from
the IFT, without delay, and have the eye tube connected to the AGC line?


Regards,

John Byrns


Surf my web pages at, http://users.rcn.com/jbyrns/