>Rich: Thanks for your reply. I made another check , in circuit, and find a
>deep dip at 26.5 . !! could this be enough to reduce the output on ten
>mtrs.??
** I don't know, but if enough power is absorbed by the choke, a choke
fire seems likely.
>And for that matter, the output on 15 is down somewhat also, altho
>not to the extent that 10 is.!! the chokes in question measure about
>129uh.!!!
> Still having phun(tearing my hair out)
** When in doubt, punt or remove turns.
> carl / kz5ca
>----- Original Message -----
>From: "2" <2@vc.net>
>To: "carl seyersdahl" <carlseye@tampabay.rr.com>; " AMPS"
><amps@contesting.com>
>Sent: Friday, February 07, 2003 8:25 AM
>Subject: Re: [Amps] amp rf chokes
>
>
>>
>>
>> >In searching for some answers to problems of low rf output on 10 mtrs. I
>ran
>> >some tests on the plate choke and here's what I found. With ends shorted
>I
>> >found a deep dip at 20.8 mc.- -34.00 ---and 25 5 mcs.
>> > With the ends open I found deep dips at 20.5 and 27.00 mcs.
>>
>> 27MHz is within 4% of the 28MHz band.
>>
>> >My handbooks
>> >all say to short the ends for these tests but say nothing about the
>results
>> >with the ends open.
>>
>> That's seemingly because less than a few of the guys who wrote about
>> amplifiers actually built 'em. I too read the handbooks, and it took the
>> experience of an 8169 choke fire to tell me that checking the choke
>> shorted was not a slam-dunk. It seems to me that checking the choke
>> wired in place is more likely to result in less smoke.
>>
>> > what I need to refresh my feeble brain is whether any of
>> >these findings could result in low power on 15 and 10 mtrs.The 6% of
>freq.
>> >that I often hear seems to say "not to worry", but does anyone have any
>> >comments on my findings ???
>>
>> The +/- 6% does not apply to shorted chokes -- perhaps because chokes
>> are usually not operated into a short ? However, the open test on the
>> bench will get one into the ballpark. The best test is wired in place.
>>
>> have phun, Carl
>>
>> - R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
>> www.vcnet.com/measures.
>> end
>>
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>> http://lists.contesting.com/mailman/listinfo/amps
>
>
>
- R. L. Measures, a.k.a. Rich..., 805.386.3734, AG6K,
www.vcnet.com/measures.
end
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