[TowerTalk] Beam comparisons and costs

[K7GCO@aol.com]

In a message dated 26.04.00 06:29:48 Pacific Daylight Time, 
jari.jokiniemi@nokia.com writes:<< 
 
 Quite many of the comments on this reflector consider if a given antenna
 setup is worth the trouble and the money or not. In order to analyze this
 rigorously we need some numbers. 
 
 Let me begin by defining a few standard setups that show a remarkable
 difference in performance, say at the average around 10 dB each step in
 practical DX type of operating. Right, I'm not saying that the gains of the
 antennas differ much, they are really on the order of only a few dB between
 each setup step. The differences come mainly from the antenna heights and
 the related takeoff angle improvements. Remember, we are talking about DX
 only. You may argue that the differences as seen in practical DX operating
 are something else than 10 dB for each step (I have some doubts about the
 biggest setup, never tried one.) Ok, let's then just see how you see the
 differences and change the formulas accordingly. This is only the starting
 point for the analysis.
 
 And the standard setups are:
 
 A - small system - a 40 feet tower and an ordinary trap tribander (e.g.
 TH3).
 
 B - medium system - a 85 feet tower and two bigger trap yagis including the
 WARC bands
 
 C - big system - a 120 feet tower with 6 el monoband yagis for the high
 bands (including the WARCs) and a 3 el monoband yagi for 40. Phased wire
 vertical arrays for 80 and 160.
 
 D - a very big system - minimum 3 towers of at least 1 being minimum 140
 feet high. Stacked monoband yagis for all bands 40 - 10 m. Ability to send
 to at least two directions simultaneously on 10/15/20/40. Phased vertical
 arrays for 80 and 160.
 
 Then the prices. Suppose that the property to put up the systems is already
 there and is not taken into account in the calculations. Let us only
 consider the towers, basements, guy wires, rotators, cables, antennas, and
 building permissions (if required). Let us also allowe one to buy something
 new and somethind second hand. The price variations are of course quite
 remarkable, but let's anyway try to get some kind of a budgetary price. 
 
 I'd say that if you budget the following amounts in Finland you will quite
 probably get the system mentioned: A = $1000, B = $4000, C = $8000, D = ?no
 idea. Your QTH could have much different prices.
 
 And now to the first conclusion. Take the A setup as the baseline. The first
 10 dB enhancement in practical average DX operating costs $4000-$1000 =
 $3000, which is $300 per 1 dB. The price of the next dB is then $400. As the
 average one would conclude that the price of 1 dB is $350 when considering
 antenna systems between setups A to C. 
 
 Opinions, more accurate calculations? >>
 
 
*******You have an interesting comparison.  I don't think you include the 
cost of maintenance, headaches and perhaps insurance which goes up with the 
big ones (a full time crane is very handy). 

You are quoting "line of sight gains"  How about the gain advantage from a 
lower angle and opening the band sooner and holding it open later from the 
higher towers.  I and others have also observed what I call "DX Gains" from 
sharper vertical patterns based on comparisons of 2,3,5,7 element beams at 
the same height, stacked beams, the ability to select the top, bottom or both 
and it's advantages.  I have a special coax switch harness for that Lou 
Gordon and others like and it broadbands the SWR of the antennas also.  

I think your "A"is a waste of money and space.  For all practical purposes 
A&B can be combined just using a 5 band 2 element quad at say 50' with 
individual driven elements and coax switch on the tower like Antenna Mart 
has.  I have one I'm working one that max gain or F/B can be selected.  This 
is the "Primary Antenna" on one tower every one should have and is all 
band--even 6M can be added to it.  This and the multi-band RaiBeams are the 
"Standard Performance & Cost Reference" for which all other beams should be 
compared to for overall performance, cost, longevity, the least maintenance 
and headaches.  I got the impression your beams are mono-banders.  That takes 
6 towers and beams.  I can install and maintain the 2 element quad and 
RaiBeam all by myself without a crane or big installation stuff.  As you get 
older the ability to maintain big arrays become a physical and financial 
problem you got yourself into.  Problems go unfixed for long periods of time 
during retirement for many. I have a Tri-X 65' crank up tower and will have 
wire tracts on telephone poles for easy up and down to simplify my 
installations and reduce the over all cost of the installation over say 20 
years.  This long term cost is never considered by many.    

Assuming you already have the land and it's potential cost for several towers 
is stretching it although some have it.  It's out of the question for most at 
least until they retire like myself, can move and are in good health..  I 
just paid $110,000 for 6 acres out in the country with a modern house in S.D. 
near my home town so I can put up all kinds of low and higher towers and 
beams just for a few more dB's gain, at a lower angle and all it's 
advantages.  On a retirement budget I suggest stacking 2 element multiband 
beams unless you are going for top score in contests.  I have the big beams 
also and may bcome a contester going for top score.  Be financially prepared 
for all the hidden costs.  I know what they are after 60 years.  The 
technical challenges are costly but indeed very satisfying when you solve 
them.  (Would you beleive you can take that feeling to the grave with you but 
not the money it cost.  In your next reincarnation you will still feel that 
warm glow of success).  The price of the "DB EGO" is really the issue but I 
have no problem with it in the competitive activity of Ham Radio and the Long 
Haul Signal.  

There is another cost of reduced performance of poor connections in yagi 
antennas due to the wrong goop on the joints.  Raibeam uses the anti[seize 
with aluminum particles and circular clamps for a tight 360 degree conducting 
ring at diameter changes.  Others use techniques to make contact in small 
areas that loosen and conduction decreases, losses go up and patterns change. 
 Your comparisons and investments go down the drain.  Quad wires solder 1 
joint/element and electrical performance never changes.  We assume it will 
continue to work like new but that is not always the case and the competitive 
edge one invested in is lost.  

Another problem is that the frequency of high winds in increasing, therefore 
beams not on crank ups of some kind are suseptable to more damage and 
continued cost and delays.  k7gco.
 

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