Let me add a little insight here. I believe everyone agrees that a
series resonance would be disastrous for a plate choke. However for a
parallel resonance there are 2 distinct cases.
Case #1: Just below the parallel resonance Xl is very high such as
+j10,000 and Xc is also very high such as -j11,000. At a slightly
higher frequency the parallel resonance has a combined extremely high
impedance and very small circulating current.
Case #2: Just below the parallel resonance Xl is very low such as +j100
and Xc is also very low such as -j110. At a slightly higher frequency
the parallel resonance has a combined extremely high impedance but a
very high circulating current.
While both cases might mathematically work Case #1 is what we are
talking about for a plate choke. Case #2 might make sense with medium
value impedances for the plate choke if wanted to increase the impedance
for a specific small frequency range such as 160m.
Larry, W0QE
Carl wrote:
> Yep, the principle works from power supplies, audio and RF.
>
> I believe Bill is the one confused.
>
> Carl
> KM1H
>
>
> ----- Original Message -----
> From: "Jeff Blaine AC0C" <keepwalking188@yahoo.com>
> To: <dezrat1242@yahoo.com>; <amps@contesting.com>
> Sent: Tuesday, October 13, 2009 9:07 PM
> Subject: Re: [Amps] Checking Plate Choke resonance
>
>
>
>> Hi Bill,
>>
>> I am a bit confused on this.
>>
>> It's been a while - but I was thinking that I read one time on RM's site
>> about creating an intentional parallel resonance on the filament choke.
>> That's a different part, but it seems the principle would be the same.
>>
>> 73/jeff/ac0c
>>
>> --------------------------------------------------
>> From: "Bill, W6WRT" <dezrat1242@yahoo.com>
>> Sent: Tuesday, October 13, 2009 11:03 AM
>> To: <amps@contesting.com>
>> Subject: Re: [Amps] Checking Plate Choke resonance
>>
>>
>>> ORIGINAL MESSAGE:
>>>
>>> On Mon, 12 Oct 2009 23:17:39 -0700, "Hardy Landskov" <n7rt@cox.net>
>>> wrote:
>>>
>>>
>>>> Sweep
>>>> the frequency range you want to use and watch for series resonances.
>>>>
>>> REPLY:
>>>
>>> Watch for parallel resonances too. Either one will smoke the choke if
>>> they
>>> are
>>> in or near a ham band.
>>>
>>> 73, Bill W6WRT
>>> _______________________________________________
>>> Amps mailing list
>>> Amps@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
>
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|