[AMPS] Rocky Point effects

Jon Ogden jono@enteract.com
Fri, 10 Mar 2000 22:02:21 -0600


on 3/10/00 8:52 PM, measures at 2@vc.net wrote:

>> Why don't YOU tell me.  After all, you have all the AMPS archives.
> 
> This info is in Will's 1M-word grate parasitics debate archive.

You know the answer.  Tell us.

>> 
>> Well, gee, Rich.
> 
> If you bring Jesus Christ into this thread, I'm outta here, Jon. No
> foolin'. 

???????

I'm a person of faith.  But my faith and ham radio amplifiers have nothing
to do with each other.  So why would I bring it into this thread?

What's ur point?
 

>> Therefore, VHF energy will never reach the
>> bandswitch.  We've pointed this out to you before, but you always bring up
>> the resonance in the cap.
> 
> True.  The Tune-C only acts as a Z-step up transformer when it is
> slightly off resonance.  In the great debate archive, there is an example
> that illustrates what seems to be taking place across open contacts in
> bandswitches during a parasitic event.  If you are interested, I can
> describe how to find it.

Why not tell us the example itself if you know it?
>> 
>> So, at resonance, the cap would look like something other than a low
>> impedance to any energy at the frequency of resonance.  However, at any
>> other frequency, it still looks like it's low impedance.
> 
> With one L network, Z can be stepped up >10,000 times.  An L network is
> never ever resonant.

What's the L network?  The plate choke and tune C??

>> 
>> Therefore, in order for the VHF energy to make it to the bandswitch, the cap
>> has to be resonant at the anode resonant frequency.
> 
> no  The cap must be resonant either slightly above or slightly below the
> anode res. freq. 

OK.

> 
>> And I believe that
>> would be a parallel resonance no a series resonance (I forget).
> 
> a nearby series.resonance would fill the bill.

I'd agree that nearby would still allow some energy to get to the
bandswitch.

>> 
>> So if the resonant frequency of the cap is different than the resonant
>> frequency of the anode, how does the VHF energy make it to the bandswitch?
> 
> When the Tune-C resonance is nearby it acts like a Z step-up L-network.
> Dead on the resonance, the Tune-C is a virtual short and the parasitic is
> a dead duck.  .  

You've explained yourself well.  Thank you.

No more questions.

73,

Jon
KE9NA


-------------------------------------
Jon Ogden
KE9NA

Member:  ARRL, AMSAT, DXCC, NRA

http://www.qsl.net/ke9na

"A life lived in fear is a life half lived."


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