--- In ham_amplifiers@..., R L Measures <r@...> wrote:
On Sep 29, 2006, at 4:53 PM, pentalab wrote:
--- In ham_amplifiers@..., R L Measures <r@...>
wrote:
RICH SEZ...Now the bad news: Without W8JI, the "recognized
amplifier expert", Charles Thomas Rauch, Jr., and his
statements
such as the laws of AC circuit analysis do not apply to VHF
suppressors; and VHF resonant circuits can't ring, but HF ones
can, things will definitely be less entertaining.
### this is one soap opera I don't wanna ever hear again!
RICH SEZ... Why read it more than once?
### One has to be either a complete nutcase or bored.... to read
thousands of postings on.. "parasites"
RICH SEZ ..before I started the grate parasite debate with Tom I
was warned by a Ham in Manhattan that he wins debates in the eyes
of his groupies by never backing down, even on issues that, to a
RF-savvy person, make him look the clown. In my opinion, this is
probably something he picked up from his father, Charles Thomas
Rauch, Sr. - editorial - If I go to my grave with a bunch of
newbies believing Tom's statement that Ni-Cr alloys have reverse
RF skin-effect, VHF resonances can't ring, et cetera, I will not
be resting in peace and that's for damn sure.
### Any RF software program that contains RF skin effect
analyis... for doz's of different alloys... at any freq will
tell one... in seconds flat.... that NI-CR alloys DON'T have
reverse RF skin effect. Rauch is full of it.... the software
just said so. Gee, that took all of 3 seconds to punch it into
the software analyis.... what's next... how no commercial
manufacturer of SSB gear is even allowed to use 2 x tone tests
for IMD testing anymore ? [ 2 x tone testing is flawed, by
juggling the freq of the tones about... you can easily hit a sweet
spot where IMD drops, in the real world, nobody uses it]
### Rich, I think you are a.. " #5 " on the Energram
personality trait book [#5's love to argue]. Did you get burned
in the high school debating team ??
### The best way to solve parasitic problems in a TL-922 SB-
220/221 is to REMOVE all 6 x 200 pf bylass caps + 2 x RF
chokes from sockets... and toss em !! Strap all 6 x grid
pins to chassis ..with wide strap..... end of problem.
The grid resonance in a stock TL-922 is in the high 80MHz range.
The grid resonance with the grid pins strapped to ground is
typically about 1MHz lower. How does this make the amplifier more
stable at the 120MHz resonance in the anode circuit?
### Well, this IS the $64K question for sure. I don't have a
clue. All I know is... when the 6 x grid pins are strapped
directly to chassis.. with wide strap... on a SB-220/SB-221.. TL-
922... some Henry amps....... they become rock stable.... WITH the
stock OEM parasitic suppressor's !!!
### Step 1 is to strap all 6 x grid pins to chassis. Now...
IF a parasitic still occurs.... THEN add either [a] nichrome....
or [b] add a real suppressor... made from a globar wound with
strap... and just enough turns to kill the parasitic.
### Why anyone would wanna leave in the 6 x 200 pf caps + 2 x
chokes is beyond me. By directly grnding the grids you now [a]
drive the amp with 20-25 watts LESS power on ALL bands or [b]
really drive the crap outa the amp with the SAME drive power as
b4.... and... [c] eliminate all parasitic problems.. and leave in
the stock oem suppressor's ..... and [d] do the 160m mod
easily, since the grids are now bonded to the chassis.....
otherwise you gotta ADD another 1000 pf ..PER socket...plane
nuts.
Jim VE7RF
Rich, AG6K
