[TowerTalk] Beam comparisons and costs

[Mike Sato]

I like the four classes of systems...and I realize this is a tower/antenna
reflector...but...

But these categories would be great for the major contests...it would help
to equalize the play-grounds for competition...similar to "car races".  In
NASCAR, they have restrictions on the car's specs...similar to USAC
racing...NHRA has different classes...etc...

The WPX is attempting to do this and majority of the comments are
favorable...

just my opinion...

Mike Kh6to



> -----Original Message-----
> From: owner-towertalk@contesting.com
> [mailto:owner-towertalk@contesting.com]On Behalf Of K7GCO@aol.com
> Sent: Thursday, April 27, 2000 6:41 AM
> To: towertalk@contesting.com; w7wjp@msn.com; w6kh@best.com
> Subject: [TowerTalk] Beam comparisons and costs
>
>
>
> 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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