Date: Sun, 21 May 2017 04:27:05 +0000
From: Bill Turner <dezrat@outlook.com>
To: Amps group <amps@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
_______________________________________________
Amps mailing list
Amps@contesting.com
http://lists.contesting.com/mailman/listinfo/amps
|