[TowerTalk] coax stubs /bandpass filter
jim at audiosystemsgroup.com
Mon May 24 08:58:34 PDT 2010
What page and photo or schematic are you looking at? Its been a few months
since I looked through his book, but I dont recall any circuits where stubs
were not somehow connected in parallel with the line.
On Mon, 24 May 2010 15:57:05 +0200, Stein Roar Brobakken wrote:
>I got his book from W2JVN now, but there is two schematic I think looks like
>the shield of the stubs is just connected shield to shield and NOT further
>to a BOX f.ex. to empty can with SO-239 on top...
>Am I right what I see ??? that the shield of the coaxstubs is not mixed to
>the shield of the coax from PA ? its not look that on pictures I seen from
>This is late into the book when you have 2nd Harmonic stubs in inverted-V
>shape, and the shield is just connected into the top of where the coax meets
>73 LA6FJA Rag
>Fra: towertalk-bounces at contesting.com
>[mailto:towertalk-bounces at contesting.com] P vegne av Jim Brown
>Sendt: 29. mars 2010 09:37
>Til: towertalk at contesting.com
>Emne: Re: [TowerTalk] coax stubs /bandpass filter
>On Mon, 29 Mar 2010 08:58:24 +0200 (MEST), Stein Roar LA6FJA-K3RAG wrote:
>>I have made a set of coaxstubs for bandpass filter, but it is not enough
>>Is it normal with 20-30 db attunation ??
>Yes. See http://audiosystemsgroup.com/Coax-Stubs.pdf This is a first draft
>that I'm still working on.
>>We had big problems during WPX SSB as LN5O we experienced that the stubs
>attunate enough between 20 40 & 15m...
>You need to buy W2VJN's excellent book on this topic. You can order it for
>Inrad (the filter people). Also, there are several very useful articles by
>QST. They are referenced in the tutorial (link above).
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>TowerTalk at contesting.com
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