[TenTec] 80m antenna suggestion

[ARDUJENSKI at aol.com]

Chris
You did not indicate physical restrictions or limitations you may have 
(property size, etc.) or what operating parameters you are setting for your self 
(local or DX or both). Note by defining your goals and listing your expectations 
you then proceed to decide which lobe patterns you need to accomplish this and 
then seek out antennas that have the desired lobe patterns and with in the 
range of limitations or restrictions.

If unable to clearly define the desired operational goals then a good overall 
antenna is an INVERTED-L. This provides a pattern that employs both high and 
low angle lobe components and a 33 by 33 ft can be used on 160-10m and fed 
with 300 ohm line and on 80-10m will generally be able to be tuned to 1-to-1 with 
most auto transmatches. 

ALL ANTENNAS ARE A COMPROMISE. The more you expect it to do the more 
compromises you can expect.

You will see many folks blindly say loops or dipoles are the best. Well, from 
a compromise point of view the good gain in some directions will also have 
deep nulls in others.  Now if you look at low horizontal loops (less than 1/4wl 
in height) you will discover that many will claim it is a very quiet antenna. 
Depending on size and height you can have deep overhead nulls. Now the 
majority of noise comes from local (high angle) or over the horizon (low angle). By 
eliminating the overhead reception and minimizing the low angle by the 
developed set of lobes and nulls one would expect this to be quieter. Same is true 
with the INVERTED-L inthat you have both low and high angle lobes therefore noise 
wise in some locations it could be a bit more noisy than say a low dipole or 
vertical

Regarding your question on the affect of the roof, it is hard to say what the 
capacitive coupling is and hard to say if raising it 15ft or so above the 
roof will have any dramatic affect. Remember that 3dBi is only 1/2 S unit and 
rarely in a simple homebrew antenna will you accomplish significant gain 
especially on 80m.

Although not a specific answer I hope this gives you some ideas to ponder and 
an approach to take in making the selection. Alot like going to a gambling 
casino. You can learn about the game and maximize your chances of winning or you 
can be like some going in blind and be amazed by their wins and frustrated by 
their losses


Alan KB7MBI in Woodinville, WA
FISTS 5702 / ARS / Proud member of ARRL
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