In the 30's when the mercury vapor tubes came along. I have QST complete
from 1926 to present plus most ARRL and the "other" HB and read thru the
oldies about 10 years ago after having them in storage since the 70's or so.
Your buddy Don has commented a few times also when he isnt on one of his OWL
kicks (-;
Carl
KM1H
----- Original Message -----
From: "Rob Atkinson" <ranchorobbo@gmail.com>
To: "Carl" <km1h@jeremy.mv.com>
Cc: "Roger (K8RI)" <k8ri@rogerhalstead.com>; <amps@contesting.com>
Sent: Saturday, April 14, 2012 6:19 PM
Subject: Re: [Amps] Filter Capacitors
> I'm trying to find out more about this but so far have only found
> instruction on avoiding ripple frequency resonance with a choke input
> filter. What were the old handbooks you looked at? I was looking at
> the '51 ARRL handbook. Thanks,
>
> 73
>
> Rob
> K5UJ
>
> On Fri, Apr 13, 2012 at 9:40 AM, Carl <km1h@jeremy.mv.com> wrote:
>> A choke is not a good idea unless great care is taken to
>> eliminate/minimize
>> the switching spike which is present with tube and SS rectifiers. A scope
>> is
>> mandatory especially if the choke and caps are not well overated for
>> voltage.
>>
>> For decades this spike has been mostly ignored in literature and finally
>> saw
>> daylight again when more boatanchor amps were being built and then the
>> audio
>> types got involved and developed their own versions of reality.
>>
>> I first noticed it about 10 years ago when checking ripple in a 2700V PS
>> and
>> had to dig into the old handbooks and QST's and saw the "ancients" knew
>> all
>> about it. I hadnt built a choke input supply since the late 50's and that
>> was simply using WW2 surplus from a BC-610 so obviously the design work
>> was
>> already done.
>>
>> Carl
>> KM1H
>>
>
>
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