"HFguy" wrote in message
news:OPV7g.5023$Rf6.4460@trndny05...
Brenda Ann wrote:
"HFguy" wrote in message
news:2qV7g.2085$Zf3.505@trndny01...

Brenda Ann wrote:

The SRIII is a different breed of cat, and has indeed suffered from
abysmal quality control. I have yet to see one that is properly
calibrated, and the are definately cheaply built. The SR1 and SRII, on
the other hand, are virtually indestructible, and are not made with
cheap plastic nor with cheap third rate components. The only two times I
have ever seen a switch fail on an SRII are when the owner thereof
decided to use their fist to turn on the radio.. and have never seen a
switch failure on an SR1, which had a heavy metal built switch.

When did GE start using varactor tuning in the SR instead of a mechanical
variable capacitor?


When the SRIII came out. Crappy system, too. Almost impossible to make it
track. I believe there's a DC/DC converter in there that boosts the
voltage up to enough to make an adequate frequency excursion.

I would think the varactor tuned circuit also had a poor 'Q' compared to
the mechanical capacitor design.

I'm not too conversant on varactors, e.g. their comparative ESR... but
purely from the point of view of an L/C tank circuit, 200pF is 200pF. The Q
of the circuit, all other things being equal, should remain close to the
same.