Sorry, I didn't read it that way. And in a Pi-L network the output C
components are by design at the midpoint of the network.
Yes, without knowing the values of L, it is a challenge {best guess} to
figure the correct values for C and the network center is unknown as well.
73
Bob, K4TAX
----- Original Message -----
From: "Dr. Gerald N. Johnson" <geraldj@storm.weather.net>
To: <tentec@contesting.com>
Sent: Sunday, February 08, 2009 10:14 PM
Subject: Re: [TenTec] Ig drift on amps
> On Sun, 2009-02-08 at 21:36 -0600, Bob McGraw - K4TAX wrote:
>> The output of the amp is indeed a Pi-L network. These work great and
>> have
>> been in BC transmitters very successfully for years. I wish more
>> companies
>> would use Pi-L networks in their amps. Better attenuation of harmonics,
>> lower currents in the coils and components and a better match. All at
>> the
>> cost of increased costs.
>>
>> I can't imagine any amp today being able to handle a 300 ohm load on its
>> output at rated power. That's an SWR of 6:1.
>
> He was talking about the design impedance at the junction of the Pi and
> the L. Higher than the load Z, lower than the plate Z. 300 to 600 ohms
> are common values for that mid point in the output network. Higher takes
> more L section coil and a higher loaded Q but allows smaller load
> capacitors.
>>
>>
>> 73
>> Bob, K4TAX
>>
>>
>
>
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