Date: Thu, 19 Feb 2015 15:12:29 -0700
From: W0MU Mike Fatchett <w0mu@w0mu.com>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Mosley discussion
I am glad people keep buying inferior antennas/coax etc. It makes the
pileups that much easier to bust..........
Some people refuse to read, learn or educate themselves.
Mike W0MU
### I find it amusing that Mosleys gain claims are beyond absurd, not even
close to reality,
That was as of 5 mins ago..on their site.
##http://www.mosley-electronics.com/pdf/baluns.pdf Here mosley explains why
a balun is NOT
required for ANY yagi, a mosley or any other brand. More looney tunes.
##http://www.mosley-electronics.com/pdf/lossytraps.pdf here mosley explains
why their 50 yr old
trap design has No losses. And that gain is a function of ele spacing and
boom length..and not
what constitutes an element.
## http://www.mosley-electronics.com/pdf/trapdesigns.pdf Here mosley explains
their use of 10 ga
aluminum wire wound on a grooved polysytrene form. ( 10 ga aluminum wire is
not what I would consider
useful for winding anything. Grooved polystyrene is bad news..and will
severely lower the Q of any coil).
##http://www.mosley-electronics.com/pdf/feedsystems.pdf here mosley blathers
on about 52 ohm feed systems
and direct feeding their yagis with RG-8..and NO balun. ( RG-8 hasn’t been
made since the 70s. And nobody makes
52 ohm coax since the 70s.) Mosely is the only outfit that defy the laws of
physics..and eznec. Mosley is the only outfit that
can build a multi element yagi....and end up with 50 ohms at the
feedpoint..with no matching devices. And no folks, they don’t
employ an OWA design either. They back their info up with quotes from the
1952 arrl ant book, depicting how u can feed
a plane jane dipole in the center, with 52 ohms coax..and no balun. Fact is,
their trap losses + low Z yagi add up to
50 ohms..hence no matching device used. 30 ohm feed + 20 ohms of trap losses
= 50 ohms. No hairpin required, direct fed
with ..non existent 52 ohm RG-8. pretty slick. And all of this done with no
computer software designs, and no comparisons done
with other brands of ants.
## http://www.mosley-electronics.com/pdf/swritis.pdf Oh this one cracks me
right up. here Mosely drones on about
the unjustified MENTAL attitude of hams. They continue their diatribe with
the ... revolting development of swr.
Then in the same breath, they explain how a 5:1 swr is perfectly acceptable.
## http://www.mosley-electronics.com/pages/series/monoband.htm Check out
these gain claims.... beyond absurd.
Note how their 6 el 20m yagi has equal spaced eles. hey mosley, time to buy a
computer.
##http://www.mosley-electronics.com/pdf/pricesheet.pdf $2750 for a 5el 20m
yagi ? WTF ? $1800 for a 4 el
20m yagi, WTF ? heck a Hy-gain 204BA, new is $500.00 fact is, u can buy
all new tubing from dx engineering, along
with superb boom Material, SS clamps etc, and build a better yagi than anything
out there. Ok, so u have to drill a few holes
with ur drill press, so what.
## f12 still has the best concept for a boom to mast double plate setup, bar
none. EZ mount. Its patented, so nobody else uses it,
but easy to copy for the hb folks at home. I use 8 x 14 and 8 x 17 al plates,
.375 thick..+ DX eng super jumbo mast clamps. Bomb
proof. I also use it as a mast step.
http://www.mosley-electronics.com/pages/amateur/multibandhp.htm check this
junk out. lets take the 1st one on the list,
the infamous CL-33-M. http://www.mosley-electronics.com/pdf/amateur/cl33m.pdf
3 el tribander...on a 18 ft boom.
Check out the humongous gain figures. 7.3 dbd on 20m ( same as my F-12 5 el
20m yagi on a 36 ft boom).
8.1 dbd on 15M. ( heck , my f-12 6-el 15m yagi on a 36 ft boom is only 8.5
dbd).
8.5 dbd on 10m..... ( F-12 8 el 10m yagi on a 30 ft boom is only 8.8 dbd).
http://www.mosley-electronics.com/pages/amateur/ta33jrn.htm the infamous
TA-33jr, 3 el trapped yagi on a 12 ft boom. more gain
than a full size 3 el 20m yagi on a 20 ft boom. wait it gets better...8 dbd
on 10m ! And the 33 jr is rated for a whopping 250 w. now
why is that? Could it be the trap losses are so sky high ? those traps
are running hot with 250w. A local ham ran 1200w pep through
his 33 jr..on ssb, and no speech processing. The traps were beyond melted.
The polystyrene melts at a low temp amyway. It looked like
you had ran a propane torch on it. I Forget what ga al wire they used on the
puny traps. Think it was like 16 ga or 14 ga.
## My conclusion is mosley is selling amateurs a ..bill of goods. When a
Hy-gain 204BA is rated at 6.0 dbd on eznec... and is clearly
10 db louder than a TA-33 jr..... then the 33 jr must have negative 4 db of
gain. Mosleys best trapped yagis only rated for 600w.
Can u simulate trap losses on eznec ? If u can cook traps with 600+ watts on
rtty, Id say there is serious losses.
## Sure one could build a trap with minimal losses. .375 inch OD silver
plated copper tubing + a fixed ceramic vac cap would do the trick.
Air wound of course. But then the feedpoint Z would be way less than 50
ohms on 20m... and a hairpin would be required...which of course
wont work on any other band. Mosley makes a wondeful trapped yagi. We have
several here in town, and in the neighbourhood.
I talk right over them, with just 1200 w pep. Mosley is like water in your gas
tank. End of rant.
Jim VE7RF
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