> > The coil in the "B" model measures 19 uh...very adequate for a Q of
> > 10-12 on 160m. (1100 ohms plate load)
>
> Sounds high from what I remember. Was that measured in place,
> with the top on?
I'll put the top on and report what I measure...good point.
>
> > > 2.) Add a swamping resistor on the input
> >
> > You don't have to....a 100 ohm swamping resistor is standard,
> > unless some "HFer" has cut it loose!
>
> The swamping resistors I remember are fairly inductive. They
> mostly disappear on ten meters, even if they are there.
Probably true. It is one of those that are in a gold metal rectangular
case. 100 ohms @ 25 watts.
>
> > > 3.) Check the bleeders. Dentron used carbon (an absolute no-no)
> > > resistors and sized them, in some models, so the 2 watt resistor
> > > dissipated 2.2 watts. Bleeders always should be metal, not carbon.
> >
> > This must be a late "B" model I have...it has 120k ohm MOF's in it.
>
> Or it was fixed.
> >
> > Denny used two 1 ohm 1 watt resistors in parallel at the
> > base of the plate choke.
>
> 1/2 ohm is not a glitch resistor. It is only useful as an indicator that
> shows when the tubes are bad.
Will add a 10 ohm HV glitch resistor, a step-start for the transformer
primary, and a big diode in the negitive HV rail today. Also I am going
to bypass all of that blower speed control stuff and let it rip full blast.
(((73)))
Phil, K5PC
--
FAQ on WWW: http://www.contesting.com/FAQ/amps
Submissions: amps@contesting.com
Administrative requests: amps-REQUEST@contesting.com
Problems: owner-amps@contesting.com
|