On Jul 19, 2006, at 11:35 AM, Phil Clements wrote:
>
>> I did an experiment by winding two single-layer HV-RFCs with similar
>> L, but one with gaps and the other without. There was minimal
>> difference in the measured self-resonances.
>>>
>>> This miss-information has been promulgated in the ARRL Handbook and
>>> other
>>> sources.
>>
>> Correct.
>> The theory sound great, but the results aren't. cheers, Phil
>
> The gaps on the RF Parts choke are very wide... 1.5 and 1 inch
> respectively.
> There are no resonances in any of the 9 ham bands. If the same
> amount of
> wire is close-wound on the same form, there will be a resonance on
> one of
> the bands between 30 and 10 meters. This choke has been working for
> me on
> many projects.
A HV-RFC with 2.5 inches of gaps wouldn't fit in most Amateur Radio
amplifiers. As I recall, the gaps in the ARRL choke design were
considerably smaller. For smalerl enclosures, right-angling saves
space.
>
> Enclosed is a pix of the Harris ferrite-based choke. It is 115 uh;
> first
> resonance is 32 mhz. (yes,I know, beware of the phosgene!)
32MHz should be phosgene-free at 29.7MHz.
>
> The parasitic suppressors are cute also, one center-tapped Lsup
> coil, and
> one 33 ohm Rsup.
Do the suppressor colors coordinate with the paint on the cabinet?
>
>
> (((73)))
> Phil, K5PC
>
> <Harrispltchoke.jpg>
R L MEASURES, AG6K. 805-386-3734
r@somis.org
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