[Amps] SB-220 HV Transformer Wanted ; thread stolen for

[Jim Thomson]

##   I  can  toggle  bias on the back of the L4Bs so a pair  of  4-400s can 
be  used...with NO  bias.
But  I  forget the  idle current,  with  4-400s..and no  bias  on a L4B.

##  with  3-500Zs,   Idle  is  40ma  on  CW...and  100  ma  on  ssb.... 
using  10 x  1N5408s  In  series.  Same  L4B.
IMD  is  good on  1900 vdc  cw position....  625 watts  pep  out.   Ditto 
with   1290 watts  pep  out on  ssb  position.

Jim    VE7RF




-----Original Message----- 
From: dj7ww at t-online.de
Sent: Saturday, November 2, 2019 8:29 AM
To: 'Jim Thomson' ; amps at contesting.com
Subject: RE: [Amps] SB-220 HV Transformer Wanted ; thread stolen for

Jim,

OK, I read it in the context with tube GG amps.

I don´t use zero bias triodes in my glass tube amps but highµ connected
tetrodes. The pair of RS1002A in my L4B draw only 30mA, no key clicks and
IMD3 >30dB in SSB.
Those tubes are made for and run class B as well with grounded cathodes and
proper screen and bias voltages.

73
Peter

-----Original Message-----
From: Amps [mailto:amps-bounces at contesting.com] On Behalf Of Jim Thomson
Sent: Samstag, 2. November 2019 14:37
To: amps at contesting.com
Subject: [Amps] SB-220 HV Transformer Wanted ; thread stolen for

Date: Fri, 1 Nov 2019 19:54:21 +0100
From: <dj7ww at t-online.de>
To: "'Jim Thomson'" <jim.thom at telus.net>, <amps at contesting.com>
Subject: Re: [Amps] SB-220 HV Transformer Wanted ; thread stolen for

<No Jim,

<A PP RF amplifier does not need LP filters if using pi-net output
circuitry.

##  Im  talking  about a PP  SS  RF  amp.....  like  ur  typ 1.5 kw  SS
amp....or  xcvr.





<And a GG amplifier running class B does not generate key clicks, my main
amp
<is running ZERO bias class B for more then 40 years in CW and SSB.

##  any  high Mu  GG triode  operating  with  ZERO  BIAS  will  draw LOADS
of
idle  current....  and  is  operating  class  AB2.

##  Increase  bias  voltage,  till idle  current  drops  to  0-5  ma....
and  u  will  get  key  clix,
try it yourself.

Jim    VE7RF


<73
<Peter
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