[Amps] new amp race

[Jim Thomson]

Date: Sun, 21 May 2017 04:27:05 +0000
From: Bill Turner <dezrat at outlook.com>
To: Amps group <amps at contesting.com>
Subject: Re: [Amps] new amp race

On Sun, 21 May 2017 03:23:17 +0000 (UTC), Catherine wrote:

>I'd blame this more on sunspot lows than egos.  Egos have always been with us, but
>we are seeing unprecedented poor solar conditions. 

<REPLY  The answer to low sunspots is not a bigger amplifier, it's a bigger
<antenna. The biggest amp in the world won't help your reception. 

73, Bill W6WRT

##  The answer to low sunspots is to put all your  20-10 m ants into storage, and 
replace em with a 2 or 3 el 40m yagi...and a rotary dipole for 80m.   I only operate
at night these days, so 20-10m is a wasted effort. 

##  If say  20-17-15-12-10m  band conditions suck, or are dead,  the biggest monoband  yagi 
in the world  wont help your reception.   There is a law of fast, diminishing returns with
yagis.   A 204-BA has  6 dbd gain..per software. .  There is no monoband yagi made by
anybody that has 9 db gain on 20M.   So the extra 2  to 2.5 db gain of the heavy long boom,
mega buck 20m mono band yagi  wont buy you much of anything at the best of times..and nothing
at all on a dead band.   Simpler and easier to just double or triple your TX power..and get another
3 -  4.78 db..on all 9 bands. 

##   The 1.5 kw amp is exactly  11.76 db louder than 100 watts.   And thats a real 11.76 db, not
icom db.    The 1.5 kw amp will  work on TX on all  NINE amateur bands.... something the long boom,
megabuck 20m yagi wont do.  You cant work em if you cant hear em.   Well  you cant work em if they
cant hear you !     If station A cant hear station B, and vice versa.....and both are running 100 watts, the 
quick fix is to install a  6 to 11.76 db gain amp at both ends of the circuit.   Thats cheaper vs  installing
a bigger ant. 

## On 20-10m, you cant put up a bigger ant anyway, you are already maxed out, and you require 
something with  more than 2 to 2.5 db  additional gain to be of use. On a dead band, its a moot point. 

##  160-80-40-30m is a different ballgame.   A  80m rotary dipole, shortened types, are typ from 
52-55 foot long.  Windload and weight is minimal, but they have to be up at least 70 ft to be really
effective.  A 40m rotary dipole,  up at least  50 ft or higher, is very effective, typ  37-48 ft long,
weighs not a lot, and next to nothing for windload.   A 2 el, shorty 40m yagi  is very effective, as in 
apples and oranges  vs say an inverted vee.    W3JK of JK ants, now makes a shortened 30M ele for
either a 30m rotary dipole or a 2 or 3 el yagi.  32.4 ft eles  on a 12 ft boom for the 2 el 30m  yagi. 
He also makes a new 40M ele, that uses both T bars + coils..and is no longer than a 20M ele, also
available in either a rotary dipole or a 2 el yagi. https://jkantennas.com/antennas.html

##  Tubing is still cheap at DXE.   I just finished designing  a full sized 3 el 30m yagi  for a buddy.
Eles start at 1.75 inch...then  down to .375 at the tips.  Good for 120 mph wind, and handles 1 inch
of ice loading.   3.9 sq ft per ele.    The full sized REF  weighs  24.9 lbs..and less for the DE + DIR. 
Total cost for the tubing to build the 3 full sized 30m eles.... aprx 50.5 ft long for the  REF, ended up
being  $366.30  !    Then the cost of the 30 ft boom, clamps etc, etc. 

##  so low band rotatable ants are  doable, cost effective..and work good...for any part of the sunspot cycle.  

Jim   VE7RF