Hi all,
Thanks for the kind replies on my question about using the AT-11MP as the
tuned input for an amp. My goal was to simplify the wiring/construction of
the front end and get a wonderful swr as a bonus. For the cost of the kit
& fun of assembling it, it seemed like a nice idea that might be a slick
solution.
I hadn't considered the insignificant flywheel effect in this circuit. If
a solution to use the auto tuner was to add only one capacitor between the
cathode and ground to raise the Q, that would be fine. To have to switch
the individual caps depending on band would defeat some of the simplicity
I hoped to achieve.
Since it looks like the AT-11MP alone won't do the job, I'll just have to
make a series of tuned inputs perhaps like the old Amp Supply
toroidal/mica cap variable - tuned input did & with the reed relays
switching inputs. It did work well as I'd put one of these in my old
SB-220, replacing the slug tuned wonders Heathkit provided & never
regreted it.
Who knows, maybe I'll find one of those old tuned inputs at Dayton & save
myself some bother.
Thanks for the time & help.
Cheers,
Gary
KA1J
>
>
> At 09:29 PM 4/18/02 -0500, Gary Smith wrote:
> >I was thinking it might be nice to use one of the
> >automatic tuners like the AT-11MP instead of making a fixed tuned
> >input. Seems like the AT-11MP would find a nice match regardless
> >of where I tuned.
>
> If you had a capacitor between cathode and ground who's capacitive
> reactance is say 1/5 of the cathode resistance and if the AT-11MP
> would match it then you should have your fly-wheel effect and a Q of at
> least 5. However, this may require switching in a different capacitor
> for each band.
>
> 73
> Bill wa4lav
Gary
Gary Smith
http://musician.dyndns.org
"Man is a social creature who does not like his fellow beings"
- Mark Twain -
|