[R-390] *A* Improvements

[Perry Sandeen via R-390]

GM List,
 
Wow!  The list has
sure come alive.  So here are some on
topic ideas.
 
I have some thoughts on *A* improvements that might be attempted
by the technically gifted and equipped.  Some I’d like to try to do some of them when are move to CA finally gets
settled down.
 
1. The 17 MHz crystal oscillator gets pulled by the AGC
applied to the mixer tube.  How about a
cure?  A FET isolation circuit?
 
2.  The level of the
PTO shifts over the 1 MHz range which affects the radio sensitivity.  How about a TTL chip biased so there is a
constant level square wave for the mixer?  Might have to be padded for the right injection level. (And suitable
coupling capacitors of course.)
 
3.  The crystal deck
might be able to locked to a PLL circuit for accurate injection
frequencies.  Also feeding a TTL chip to acquire
a constant RF output value?
 
4.  Bill K.(SK)
developed a SSB converter using the LM 1496 DBM chip for an article published
in ER magazine for the SP 600.  Adapting it
to an *A* might be simpler to implement that the Capt. Lee 6BE6 PTO mod.
 
And speaking of the LM 1496 perhaps it might be adapted to
replace some of the 6C4 mixers.
 
After all, there are no *sacred* circuits in the *A*, just
some that are now possible to implement with SS devices just like what has been
done on the PS when SS diodes became 4 cents apiece.   Now
26Z5*s cost an arm and a leg with the price continuing to rise over the years.
 
I have some more ideas if someone wants to contact me off
list with a new email.  That will save me
grief with the Yahoo system.
 
Regards,
 
Perrier
 
*One test is worth more than a million opinions.* Anon