On Nov 21, 2005, at 2:07 PM, Kenneth D. Grimm, K4XL wrote:
> R.Measures wrote:
>
>> On Nov 21, 2005, at 12:08 PM, wc6w@juno.com wrote:
>>
>>
>>> Hi Jan,
>>> The theory behind those "sectioned" chokes is that all the
>>> resonances will fall somewhere friendly. In the real world they
>>> tend to behave rather similar to contiguously wound solenoids.
>>>
>>
>> In my experiences, this was also the case, Marv. The notion that two
>> choke sections can be decoupled by placing them end-to-end instead of
>> at right angles is quite laughable.
>>
>> cheers
>>
>>
>>> For some background info on plate parallel feed RF chokes and
>>> alternative solutions see:
>>>
>>> http://wc6w.50webs.com/wc6wamps/index.html?fr62.html
>>>
>>> 73 & Good afternoon,
>>> Marv WC6W
>>>
>>>
>>> -- jan <jan@on6zg.be> wrote:
>>> Hi,
>>>
>>> I´m building a HF gs35b amplifier, but i´m having a problem with the
>>> rf
>>> choke in the High voltage line.
>>> On 15meters the choke gets hot.
>>> Has anyone got specifications for building a 160m to 10m rf choke?
>>> I´ve
>>> found several amps with a choke like this inside:
>>> http://www.kvindesland.no/yl2qm/images/rfc.gif
>>>
>>> thanx for any help
>>> ON6ZG, Jan
>>>
> OK, now on behalf of us non-cognoscenti, are you guys saying that the
> segmentation of a solonoidal plate choke cannot be wound so as to
> avoid resonances at undesired frequencies?
Yes
> I don't want to waste my time trying to wind a new choke for my amp
> that
> does unhappy things every time I try to use it on 24 MHz if it is a
> known fact that
> segmentation doesn't work.
> Anyone want to guarantee this? :-)
Ken -- I built two quite similar single-layer solenoid-wound HV RFCs
suitable for one 4a tube such as the 8171. One RFC had gaps like the
one shown in the Handbook, the other one had no gaps. The HF
resonances were shockingly similar. The lesson here is believe not
everything in print. Decoupling RFCs is best done by placing them at
right angles.
- " I do not feel obligated to believe that the same God who has
endowed us with sense, reason, and intellect has intended us to forego
their use."
- Galileo Galilei
end
>
> 73,
>
> --
>
> Ken K4XL
> k4xl@arrl.net
>
> *** BoatAnchor Manual Archive ***
> On the web at http://bama.sbc.edu and http://bama.edebris.com
> FTP site info: bama.sbc.edu login: anonymous p/w: youremailadr
>
>
>
Richard L. Measures, AG6K, 805.386.3734. www.somis.org
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