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Re: Computer Woes...



Reicher, James schreef:

>Speaking as someone who is NOT a rocket scientist, but as a ham, a
>software designer and developer, and a satellite enthusiast, could
>someone explain what is wrong with the Mode J article?  The authors
>clearly state that their conclusions are by no means scientific and make
>no claims that they've made measurements.  They merely state that this
>seems to work for them.
>
>Can't some articles be written for laymen?
>
>BTW, what is MOST embarrassing is mis-spelled words and poor grammar,
>especially in this day of spell-checking!   
>
>
>73 de N8AU, Jim in Raymore, MO
>
To see what all the fuss was about I checked the article.
That I can see in first glance is that they are not suffering from tirth 
harmonics from the 2m signal but from overload from the base 2m signal.
With this in mind all they needed was a high pass filter, this is what 
the 70cm side of a diplexer is.
What makes me wonder why they would put a 50ohm load on the 2 meter 
side, it won¥t do anything for the filtering of the 2m signal on the 
70cm side.

If they really had harmonic problems then the diplexer in this 
configuration would not have worked as the harmonics are passed on just 
like when there is no filter.
In that case they needed a low pass filter in the 2m antenna line, this 
could have been the 2m side of a diplexer.

A better way would be a stub filter that drains the harmonics in the 2m 
line and a stub filter that drains the 2m signal in the 70cm line.
It takes some calculations to find the right length of coax line to make 
the filter from but the construction itself is as simple as soldering a 
connector :)

73 de Andre PE1RDW
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