[AMRadio] Re: new antenna...


Brett gazdzinski brett.gazdzinski at verizonbusiness.com
Tue Feb 6 13:50:14 EST 2007


> The traps aren't necessary since you are using tuned feeders. You are 
> forcing your antenna SYSTEM to resonance. Traps are useful to 
> force the 
> antenna itself to resonance, which is more important if your 
> feedline is 
> coax.
> > 
> > I don't know what that would do the SWR on the feedline,
> > it might move the current and voltage points around, but it
> > might be better overall then 100 feet. 
> > 
> > What do you guys think would happen if I added loading coils? 
> > 
> In my opinion it adds more variables and complexity with no 
> advantage to be 
> gained. 

Not traps, just loading coils.
On my last 80 meter antenna, about 3/4 the way out 
on each end I installed some B+W coil stock over an insulator,
the coils were about #18 wire, close spaced, about 1.5 inches in
diameter, and I managed to get about 100 feet of wire to
resonate on 3880 with no swr, coax fed.
 Full power was no problem.
The mast and coax went bad so I took the whole thing down.
Its main problem was it was lengthwise over the house
and got into things, and into the neighbors stuff also. 
I still have the coils.
 

> 
> Do you have a lot of noise on receive, Brett? Is there 
> something with your 
> antenna's current performance you're dissatisfied with? Or 
> are you just 
> trying to verify it's as good as it can be, from a 
> theoretical perspective? 

Not sure there. One would have to do an A/B comparison
because of band conditions and noise levels.
More of a theoretical question as I don't plan on screwing
with antenna's till it gets warm out (if then).
Just wondering if the antenna itself was a low swr
at say 3880 with loading coils, if it would receive 
any different at all.
Both the signals and the noise went up with the new
antenna, over the old 80 meter antenna, 
or the 40 meter dipole tuned up on 80.
I would say everything went up 10 or 20 db on the new
antenna, signals and noise.


I am still not sure how the antenna works on 40.
It tunes up fine, but I think 40 has been sort of dead,
or has had little activity lately.

Brett
N2DTS


> 
>  -Larry/NE1S




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