[TowerTalk] To Shunt feed or Not to Shunt feed??

Richards jruing at ameritech.net
Mon Jul 7 18:49:38 EDT 2008

That is a fair question.   I believe the answer depends upon the type of 
antenna you are constructing, and the circumstances and location where 
you install it.

If you are speaking about constructing a standard dipole cut for the 
frequency you intend to use it on, you can most likely do well without 
antenna analyzer;  just be careful how you measure the wire elements. 
Similarly, for an all band doublet, perhaps longer than 135 feet, where 
length is not a major issue, and you will use a broad band transmatch, 
and I am sure there are other types of antenna,  which can be 
constructed as resonant and with low SWR without making substantial 
adjustments.   I suspect it turns on the antenna design, and how 
predictable it will perform in a given location -- not all antennas 
being amenable to immediate use upon even careful  construction without 
some - and sometimes substantial - adjustment.

Conversely, I suspect other antenna designs require substantial 
adjustment, either inherently because of design, or because of the 
installation location (i.e.,  where resonance or SWR may be shifted or 
altered by proximity to other antennas, metal objects, height above the 
earth, etc. -- without being too specific here...)   In these cases, one 
can use an antenna analyzer to avoid a lot of experimentation and trial 
and error adjustment, which may include many trips back to the operating 
position in the shack, to see how adjustments affect results, and how 
the antenna works with the rig.

So, I am sure you can live a good life without an antenna analyzer. 
However, I figure it is kind of like air-conditioning in your home: you 
can live without air conditioning most anywhere in the USA, but once you 
have it, you never, ever live without it again!     I put up one of 
those silly ham stick dipoles last weekend, mostly as an experiment and 
for fun, and as a possible travel antenna to put in my camper trailer -- 
  and it would have been an awful thing to adjust without the antenna 
analyzer (MFJ-259B).   Parenthetically, it performs rather well -- far 
exceeding my expectations.  From Michigan, I reached Massachusetts, 
Connecticut, both Carolinas, Louisiana, Texas, and several points in 
between.   Of course, this only whets my appetite for a "real" antenna...

Happy trails and good luck with any project you begin!

Happy trails and 73.    ----  Richards - K8JHR ----

Tom Osborne wrote:

> I been putting antenns up for over 50 years and only had an analyzer for the 
> last 2 years.  For the first 25 years didn't even have a SWR bridge. 


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