Amps
[Top] [All Lists]

[AMPS] LP Filter Performance

To: <amps@contesting.com>
Subject: [AMPS] LP Filter Performance
From: jono@enteract.com (Jon Ogden)
Date: Tue, 30 Mar 99 17:14:56 -0600
>I believe it was John Belrose who wrote in QST Technical Correspondence
>several years ago. He measured and reported that the topology as used in
>ham LP filters had a minimal effect on performance at to at least a 2:1
>VSWR. 
>
>I would be concerned with high VSWR on 10/15M.
>
>I'll bring in a ICE filter to work and play on the network analyzer with
>various resistive loads.

Thinking more in depth, perhaps it doesn't matter so much.  At the VHF 
frequencies of interest where you want the atennuation to occur, any HF 
ham antenna is likely going to look like a HORRIBLE VSWR anyhow.  So you 
won't be in a 50 Ohm system.  And outside of its passband a filter 
doesn't have a 50 Ohm input or output impedance anyhow.  It's more like a 
dead short!

So yep, I am likely concerned about nothing.

73,

Jon
KE9NA


--------------------------------------------------------------------------
Jon Ogden

jono@enteract.com
www.qsl.net/ke9na

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


--
FAQ on WWW:               http://www.contesting.com/ampfaq.html
Submissions:              amps@contesting.com
Administrative requests:  amps-REQUEST@contesting.com
Problems:                 owner-amps@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm


<Prev in Thread] Current Thread [Next in Thread>