[Amps] RF Chokes

R L Measures r at somis.org
Tue Jul 18 23:00:08 EDT 2006


On Jul 18, 2006, at 3:00 PM, Phil Clements wrote:

> The proof of the pudding is that the choke designed by W8JI  
> (Ameritron/RF
> Parts is the only solenoid-wound choke that is good for 9 bands  
> that I have
> ever encountered. The only explanation I can come up with is that  
> the gaps
> between the windings are the reason for success.

Parking resonances clear of Ham bands is just as easy without gaps as  
with.
>
> (((73)))
> Phil Clements, K5PC
>
>
>> -----Original Message-----
>> From: amps-bounces at contesting.com [mailto:amps- 
>> bounces at contesting.com] On
>> Behalf Of Will Matney
>> Sent: Tuesday, July 18, 2006 3:12 PM
>> To: ka1xo at juno.com; amps at contesting.com
>> Subject: Re: [Amps] RF Chokes
>>
>> Hal,
>>
>> Yup, they sure can still couple being in a straight line. The  
>> coupling is
>> weaker the farther aprat they are, but how much it takes to fully  
>> decouple
>> one from another, I don't know. Mounthing the sections at 90  
>> degrees does
>> de-couple them. It works the same as a grid dip meters coil. It  
>> has to be
>> parallel to the coil to be any good, not at 90 degrees. Parallel  
>> means
>> it's coupled to it and that the flux is cutting through both  
>> coils. I've
>> mounted power transformers at right angles if the had to be  
>> mounted close
>> together.
>>
>> Best,
>>
>> Will
>>
>> *********** REPLY SEPARATOR  ***********
>>
>> On 7/18/06 at 3:50 PM Harold  Mandel wrote:
>>
>>> Despite all the talk about how good the RF Parts
>>> plate choke is, and how it works on all bands, the
>>> current-handling feature is still a hurdle.
>>>
>>> For now, forgetting about the 1.5 ampere rating,
>>> do not the separated windings still couple because
>>> of their geometry?
>>>
>>> What do the real QRO folks do?
>
> Real QRO folks use the W8JI design, the Harris design, (ferrite  
> loaded) or
> two switched chokes in order to cover 9 bands.
>>>
>>> Hal
>>> W4HBM
>
>
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>

R L MEASURES, AG6K. 805-386-3734
r at somis.org





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