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[AMPS] parasitics in VHF amplifiers

To: <amps@contesting.com>
Subject: [AMPS] parasitics in VHF amplifiers
From: km1h@juno.com (km1h @ juno.com)
Date: Wed, 27 Aug 1997 11:32:21 EDT
On Wed, 27 Aug 1997 10:44:54 +0100 Peter Chadwick
<Peter.Chadwick@gpsemi.com> writes:
>Rich says;
>>- However, I would be more inclined to put a load C on the output end
>of 
>>the L and make it a Pi network tank.  
>
>Amen to that. I'd even consider using a Pi-L, bearing in mind that
>according to Part97.307(e) requires all spurious emissions in the band
>30 to 225 MHz to be at least 60dB down. Of course, a low pass filter
>would be the other approach, but it wouldn't be a negligible job
>producing one for these powers.

ICE sells a brute 3KW and 6KW rated LP for 6M Peter, and reasonably
priced.

I would argue against a Pi-L on 6M for home brew and let the LP clean up
the harmonics. That would still fulfill the FCC rules. 
On 6M a LP also cleans up a lot of TV and other band crud on RX. I use a
quality LP at the output of the xvtr to preclude a GIGO situation with
the amp. Ideally, one could use the ICE  BP filter (200W rated) at the
rig but that would restrict tuning down for EU ( the 48.240-260 ones) or 
VK/ZL video carriers.   

73....Carl  KM1H
>
>73
>
>Peter G3RZP
>
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