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Re: [TowerTalk] Gain, F/B, Low SWR What to choose

To: TOWERTALK@contesting.com
Subject: Re: [TowerTalk] Gain, F/B, Low SWR What to choose
From: Bill via TowerTalk <towertalk@contesting.com>
Reply-to: Cqtestk4xs@aol.com
Date: Wed, 8 Apr 2015 07:51:05 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Roger makes a good point about which antenna to  choose.
 
To me gain and a low SWR was most important.  Where I have  lived, F/B has 
never really mattered.  In fact, a low F/B ratio is pretty  good to have if 
you are a contester either in FL .
 
>From FL, 40 degrees is EU which means the back faces the South  
Pacific...not much QRM from that direction.  JA is around 325 degrees,  which 
means the 
back of the beam faces South America...not a big deal  either.  And, 
because the F/B is not all that great, in contests I get lots  of calls from 
VK/ZL 
when I'm beaming EU.  The same is true for SA when I'm  beaming JA.
 
Now, if I lived in W1-land F/B would be quite  important.  I doubt I'd want 
to hear W4s and W5s while running  EU.
 
As always, one size does not fit all.  It's critical to do  some serious 
thinking about your location before buying that  antenna.
 
K4XS/KH7XS
 
 
In a message dated 4/8/2015 8:13:42 A.M. Coordinated Universal Time,  
K8RI-on-TowerTalk@tm.net writes:
 
It  depends on the type of operation and your location.
With a few notable  exceptions and the power you run, MOST multi element 
antennas have  enough/ample gain.  Needing a rugged antenna narrows the 
field.   We don't have a lot of wind and I believe we are still in a 70 
MPH area,  but heavy ice is not uncommon.

>From Central MI when pointed at the DX  short path (except South 
America) There are heavily populated areas  putting strong signals when 
the bands are open, So in my case the  preferences favor   F/B with a 
fairly wide (and low)   SWR  curve over absolute gain.

Antennas are both pricey and  heavy.  The C31XR takes a couple of healthy 
hams to put in place as  does the
SteppIR.  A nearby ham  has a SteppIR  and it took  a crew to carry it to 
the tower.  It took several to hold it while he  attached the tilt 
plate.  I think its been up around 5 years and I  believe he has been 
able to do all or most servicing by himself since  then.  He occasionally 
shows up on here so he might make a  comment.

I 'm sure he likes it, but haven't had any discussions with  him about it.

Different bands, but I've found even the rather small F/B  of sloapers on 
75 and 40, as well as the low angle off a good vertical  allowed me to 
work stations I couldn't hear for stateside QRM with  dipoles.  It's less 
of a problem on the higher bands, but it's still  a problem most times.

IIRC you don't have to sacrifice much forward  gain to get a good F/B.  
I'm not talking about designing for max F/B,  but a reasonable compromise 
of good F/B and low SWR over the areas I  operate. I think the gain 
should still be "good enough".  OTOH   I don't have the time, money, 
equipment, or expertise to find out for  sure.

I have far too many projects and too little ambition to do them  justice 
when it takes me 20 minutes just to install a UHF, or N-type crimp  
connector.<:-))  Maybe I should consider the big SteppIR with 6  meters.  
Then there would be an excess 45G in the neighborhood that  currently 
only holds sloapers.

73

Roger  (K8RI)

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