After posting the K5XI CQ WPX CW score, several of you inquired about the
"stacks." About a year ago, K5XI asked me to design an "optimum" system
for 20 and 15 meters (within reason). The object was primarily DX, but
optimized for both stateside and DX Contesting.
For DX only, rotating towers might have been the answer, but for contests,
the antennas must be independently rotatable. Vertical stacking modeled
the best. The design arrived at was 4 high stacks with the mean height
between the stacks, when in phase, at a multiple of a wavelength. That
wasn't a huge challenge on 15, but on 20 it required breaking the magic
200' barrier and committing to obstruction marking and lighting.
The final result is as follows: 20M - 5el @ 35', 105', 175', 255'
15M - 5el @ 70', 117', 164', 205'
For you purists, the stacking distances are somewhat mitigated by guying
considerations. The 20 meter tower is Rohn 55 and the 15 meter tower is
Rohn 35. The 20's are being turned with the new TIC rings. The 15's are
being turned on DX Engineering sidemounts with Create RC5A-3's. All of the
antennas are DX Engineering. Oh yes, there's one more killer antenna, an 8
element 10 @240' (my favorite). K5XI also has three more towers for 40, 10
and a throw down 20-15 stack.
The results: On Saturday mornining of CQ WPX CW, I owned 14.001 for about
three hours. High stack on longpath, low stack on JA, until the band
opened to Europe. Then, high stack on Europe, low stack - one on JA and
lowest one on South America. What a hose!
We also owned 15 meters both days, splitting the stacks between Europe,
JA, South Pacific and South America, depending on time of day. We worked
one European and a several Africans on 10.
Was it all worth it? Yes! We will never overcome the east coast advantage
to Europe, especially on 40-80-160, but this sure helps on the high bands.
On another note:
I've just delivered my last issue of The NCJ to ARRL for publication.
Thanks for all of your support the last four years. The magazine has
grown 30% in circulation and 33% in page content. I hope that you will
show Trey the same support you have shown me.
I'm going to sign off the reflector, as well. It has been costing me
upwards of $50 a month in connect charges and toll call charges. You can
still reach me via Compuserve or via Internet, on a less frequent basis.
I hope to see you on the bands more often, however!
73 and DX,
Tom, K5RC (and Midge, KC5AFO)