[TowerTalk] phasing multiband verticals

[N7mal]

I thought I would answer in one big email rather than 20 small emails so 
here goes:

Jack W6NF said:""How about cost? I, personally, can hardly afford a single 
325-foot run of
coax to my 65-foot DX Engineering verticals, much less two! If you have deep 
pockets, go for it, but some of us don't!""
Unfortunately there is a hard fast-n-rule that applies to any good antenna 
system. 'There is no free lunch.' If you want a good directional system for 
160/80/40 there is a price to pay. In your individual case phasing at the 
antennas is much more cost effective.

Jim N2EA said:""No reason hams couldn't do something similar, and just coil 
up the  phasing lines in a box. Switching could then be done with simple 
manual coax  switches.""
My most favorite system is what Jim is describing. In the mid 70's many guys 
tried this system and most were very successful. The ones that couldn't get 
it working made one really simple mistake.... The antenna switch 'MUST' be 
non-grounding. So many antenna switches ground the unused ports and this 
naturally shorts out the whole system. The system in it's most basic form is 
4 27ft phasing lines, 5 t-connectors, and a 5 position, non-grounding, 
antenna switch. The verticals are 80/40 multiband verts.

Dick K8ZTT said:""Actually the best spacing for their system on 40M is 49 ft 
(more than a
quarter but less than a half).   I use 1/2 because that gives me better 
cross fire gain at the expense of some end fire gain; and my verticals are 
on a NW/SE line (NE/SW would be better, but that wouldn't work at my QTH).""
Here is another of those meaningless numbers like 43. 49 like 43 has no 
relationship to 40 meters. Now if you had the proper test equipment(very 
expensive stuff) you could measure the field intensity of your antenna 
system and find the optimal spacing distance for your particular system. 
There are several variables in every vertical antenna system: ground 
conductivity, radials, size of vertical radiator,,etc etc. So you could 
conceivably end up with some spacing way beyond, or between, traditional 1/4 
or 1/2 wave spacing. For 99.99% of all ham radio applications the 
traditional spacing, 1/4 or 1/2 wave, is very adequate. In most ham radio 
applications a db is not that meaningful. In broadcast operations were tens 
of thousands of watts are involved a db may mean up to 1,000 household in 
the antenna field pattern.


Terry N6RY said:""I don't understand the problem with feedlines of 1/4 wl 
multiples.  Several popular amateur phasing schemes are specifically 
designed to use odd multiples of 1/4 wl lines.""
You are 100% correct sir. I left out the key word 'even'. So far I've never 
seen a system that does not rely on 'odd' multiple of 1/4 wavelength. Thanks 
for the correction.....


Jamie WW3S asked the original question: ""Looking to phase two multiband 
verticals, probably Butternut HF6, for 40m, using 1/4 wave spacing and 
either phasing lines or a hybrid. Looking for suggestions on how to switch 
them so I could continue to use either one as a multiband vertical or switch 
to the phased pair for 40m....""
Yes it can be, and has been, done. The verticals are separated by, the magic 
number, 43 feet. They are fed in phase with a balancing device. The 
impedance of the 2 verticals will be very low and needs to be brought up to 
50 ohms. You will not get directivity with this type of system but will get 
a couple of db's in gain in a circle. The biggest obstacle to overcome is on 
80 & 40. The verticals must be tuned to the exact frequency.

p.s. if I didn't answer one of the private emails send me another email. 
Thanks


MAL
N7MAL
BULLHEAD CITY, AZ
http://www.n7mal.com
Everyone in the world is
entitled to be burdened
by my opinion