[Boatanchors] Choke Info Needed

[Carl]

Low C was only before higher values became readily available/affordable and 
pretty much confined to pre WW2. In a modulator with a 5-25H or higher 
swinger input and 40+ uF output C the ripple is not audible. This assumes 
that the driver stages are well filtered to eliminate the GIGO effect. 
Minimum bleeder current is needed to keep the HV from soaring and once the 
modulator tubes are on they provide the remaining bleeder stabilzation. The 
resultant HV variation in a Class B modulator is better than most SSB 
linears.

In an AM only RF amp many do away with the choke and use a lot of C when a 
low impedance transformer is used. However when using old high impedance 
iron a choke input is recommended with SS rectifiers and mandatory with 
866's. I use only SS in all the power supplies and a mix of transformers and 
filter schemes.

Carl
KM1H


----- Original Message ----- 
From: "mac" <w7qho at aol.com>
To: "Carl" <km1h at jeremy.mv.com>
Cc: "Mark K3MSB" <mark.k3msb at gmail.com>; "List Boatanchors" 
<boatanchors at mailman.qth.net>; "Kenneth D. Grimm,K4XL" <grimm at sbc.edu>
Sent: Friday, October 09, 2009 12:06 AM
Subject: Re: [Boatanchors] Choke Info Needed


> Yep, traditional along with caps of no more than 2-4 mfd and 2 or 3 
> sections strung together to get the ripple down.  Saved a little  bleeder 
> current, though......
>
> Dennis D. W7QHO
> Glendale, CA
>
>
>
> On Oct 8, 2009, at 5:16 PM, Carl wrote:
>
>> Its a traditional lower cost, lower weight way to do it in a  variable 
>> current circuit.
>