Hi Tom!

Thanks for sharing the ride. Not familiar with the antenna, but your
explanation seems reasonable to me, and I always enjoyed antenna theory
anyway, so was fun to think through it with you.

You've got a great team going there.

73,
Dave

-----Original Message-----
From: For blind ham radio operators [mailto:[log in to unmask]]
On Behalf Of Tom Behler
Sent: Saturday, 27 June 2015 9:09 a.m.
To: [log in to unmask]
Subject: Field Day Update From KB8TYJ

Hi, all.

 

Here's an update on my field day situation out here at the RV, based on some
things I did in the past hour or so.

 

First, the easy part:

 

I took a more detailed look at the Field Day rules, and I believe our friend
Steve (KW3A) is correct.  I think the best station classification for my
current situation is 1B, with an additional "commercial" designation that I
will enter into my Field Day report if I end up submitting it to the League.
I'm not terribly interested in competing for a high score, but I think this
is the fairest and most accurate thing to do, since class B is for club or
non-club one or two person portable.

 

As for my Alpha Delta DXCC antenna, I'm becoming more convinced that the
problem is with the way my antenna is configured, rather than with the
excess coax I have on the floor under my operating position.

 

Here's my thinking:

 

At the suggestion of Steved (KW3A), I had my sighted XYL (who is also a
ham), take a look at SWR readings, using the TS480's visual  meter.

 

What we found was interesting.

 

The SWR's are fairly good on 40 meters, with my SWR being below 2.5 to 1
across the band, except possibly at the very bottom.  The same is true for
15 meters.  Obviously, the auto-tuner in the TS480 can handle all of that
with no issues.

 

On 10 meters, my SWR's are above 3 to 1, even though the auto-tuner tunes
the antenna.

 

Of course, 20 meters continues to be the issue, with the meter seeming to
indicate that my SWR's are significantly above 3 to 1 across that band,
which is why the tuner won't tune the antenna.

 

I checked the amount of excess coax I have, and found it to be closer to
about 18 feet.  I thought it was more, but my XYL and I did more careful
measurements to give us a clearer picture.  I tried adding more coax, but
that really didn't seem to change anything at all as far as SWR's go.

 

So, my thinking is that my basic problem is with the way the antenna itself
is configured here.  The antenna is strung between three trees, and is up
about 30 feet.  The problem is that the trees on which the ends are
supported are at only about a 60-degree angle from the center.  In other
words, the antenna is much closer to what we might think of as a folded
dipole.  My thinking is that the tight degree angle between the center and
the legs might have especially negative effects in terms of de-tuning the
antenna on higher HF bands like 20 and 10 meters, for which there are
separate shorter elements on the DXCC, below the main 40 and 15 meter
element, which is at the top.

 

I don't know if this makes any sense at all, but it is my current thinking.

 

So, what I'm going to do is enjoy Field Day by operating on 40 and 15
meters, and I won't sweat the rest of this until after Field Day when I can
possibly try some other things.

 

I hope you guys don't mind my exxplanation here;  it's just that many of you
have been so helpful, and I thought I owed you some more detail if you are
interested.

 

I continue to be interested in any thoughts anyone has on what I describe
here.  Always willing to do more experimentation and troubleshooting as time
allows.

 

Tom Behler: KB8TYJ