[TowerTalk] Why does KT34XA/KT36XA stink on 15 ?

[Mike Smith VE9AA]

Steve, 

 

I don't know why it stinks, however, the way I test antennas here MAY help
you determine if the 40m beam interacts or not.

(yes, I read what you said about SWR)

 

What I'd do is get on 15m midday when it's open to USA, EU and AF and pick a
frequency and send:

TEST N2IC TEST over and over for about a minute.  Less will even work. 15-20
hits from skimmers is about right.

Then, move QRG 5kHz, move your 40m antenna 90 degrees and rinse repeat.

Do this over and over, moving your 40m antenna and QRG a little each time.
Make a note on what QRG you were on when your 40m antenna was North, East,
South and West.  Most of the skimmers are to your NE, so that why I
suggested Midday.

There aren't so many in SA, AF or AS, but from where you are, you may be
able to get enough results on a good day from JA.who knows.

Through the week, you could fire a cannon across 15m and not disturb anyone.

 

Then pull up the RBN website, search for your call and correlate beam
headings of your 40m antenna with the frequencies you've been on.

ie: 21.025MHz, 40m beam was West, 21.030MHz 40m antenna was East etc.  If
you get too many hits, you'll have to stop

partway through, write down some data or catch some screengrabs etc.

 

For example, you might see that every time your 40m yagi is west, your EU
skimmer hits avg 6dB less. (I am just speculating)

 

You'll eventually get enough data to determine for yourself that no, the 40m
beam is not affecting me at all, or possibly

determine that yes, "when the 40m beam is west" (for example) I am 6dB
weaker in EU.

 

I've done this exact scenario literally hundreds of times on a dozen
different antennas here.  It's time consuming, but it works.

I sometimes will try it every few hours for a couple days and put all the
data into a spreadsheet and come to the conclusion that antenna A always
works best into EU at the beginning of an opening to EU and antenna B is
good into USA midday.  Takes a lot of data, but patterns emerge.  QSB is
working against you, so that's why you need lots of hits, for the averaging.

 

Good luck and thanks for all your help with N1MM+ and the many contest Q's

 

Mike VE9AA "NB"

 

 

 

Mike, Coreen & Corey

Keswick Ridge, NB