>
>. . .and in order to acquire a Q of c. 2, you make the following
>modifications to your SB200:
>
>
>1.
? The factory-stock tuned inputs had a Q of approx. 1. To obtain a good
match for a solid-state radio, make the Xc of the input cap for the tuned
circuits roughly 25-ohms for each band. / 50-ohms/25-ohms represents a Q
of 2 ("Care and Feeding..." definition). Remove turns as needed from
orig. tuned input inductors. Adjust L and C-out for best SWR on each
band. Install fixed values. (note - touching HV while making SWR
adjustments may result in injury or death.)
>2.
>3.
>
>
>Please fill in the blanks Rich. Simply stating a Q of 2 is
>better/mandatory/necessary/neatokeen doesn't help a great deal.
>
>Art
>
>-----Original Message-----
>From: owner-amps@contesting.com [mailto:owner-amps@contesting.com]On
>Behalf Of measures
>Sent: Monday, October 02, 2000 9:06 PM
>To: Cherry, Mark; AMPS
>Subject: Re: [AMPS] SB200 Retrofit
>
>
>
>>
>>Hello all,
>>
>>I would like to rebuild the power supply/filter/rectifier board in my
>sb200,
>>but am having problems finding the filter caps.
>
>Electrolytic caps are more compact than they were 30-yrars ago, so don't
>expect to find an exact replacement. Odds are that you are going to wind
>up with more C in a shorter case. The main thing is to get 35 mm dia.
>units. .
>
>>I know that Harbauch had
>>such a replacement, but he is not offering them at this time.
>>
>>Would also like to replace the high voltage string of 3 resistors, but have
>>heard that more lower value resistors would be better than a few of higher
>>value.
>>
>>One final thing...The swr input to the amp seems a little high on 15 and 10
>>meters. Can the input circuit be tuned, I had heard that one should not
>>fuss with this, or is there something else I might look at.
>
>The input tuned circuit Q is too low for solid state radios. You need a
>Q of c. 2.
.....
- Rich..., 805.386.3734, www.vcnet.com/measures.
end
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