Topband: Receiving antennas

[Paul and Abbi Elliott]

Hi Tom

A little over a year ago you answered some questions I had about feeding
untuned loops (you had previously mentioned the good results you had with
arrays of untuned loops).  Below is a short excerpt from your response.
-------
> Is it enough just to put a good choke balun on the feedline where
> it attaches to the untuned loop?

That's all I do. It works very well for me.

> Is it practical, or desirable, to match
> the very low impedance of the loop  to the coax?

I don't bother with that. It will improve signal level, but that isn't a
problem with a good preamplifier.
------
At Dayton last year you described your receiving array of four 20', top
loaded verticals, each with a 70 resistor and 31 micro henry coil in series
 between the base of the vertical and the feed point.  Are the top loading
and tuning of the verticals just to improve the signal level from them?
Does the top hat do anything electrically that just making the vertical
taller would not do? (I am thinking of something 20' tall, than putting a
9' s/s  whip on top of that)  Is there any problem with phasing that
untuned verticals have in an array that untuned loops do not have? 

I know that you have good engineering reasons for your design.  Space
prevents me from using guying and/or large top hats; but even if I cannot
install the best system, maybe I can get something (better high angle
rejection of the verticals?) that will be an improvement over what I have.
None of the European openings of the past several weeks to the east coast
and midwest have produced any copy here in southeast NM.
 
Thank you for your postings. I have learned much from them.

73

Paul Elliott W5DM 

  



  

  



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