Looking for SG-239 Smartuner feedback, pros and cons
Kodiak Bear
experince with this tuner good or bad. Does it work as advertised or is it
oversold? What gotcha's are there with this piece of equip? Does it work
with a Yaesu FT-847? Does it work with an ICOM-706MKIIG?
Thank you,
Don, KC8RDO
CAM
I vaguely remember SGC saying that it will punch holes in the laws of
physics - it won't. It is a good antenna tuner but has lossess just
like any other tuner. It works with any source of RF over a certain
amount (5-10 watts?). What a remote tuner does is eliminate feedline
losses due to SWR > 1:1. For that purpose, it is excellent.
--
cheers, CAM http://www.qsl.net/w5dxp
Anthony Duffy
adjusting network installed at the base of the antenna. It works with
the elements connected to the terminals the same way adjusting a tuning
network at the base of the antenna does. The handy thing is that it's
automatic, actually tunes the elements to resonance instead of faking
the radio into thinking it has a good SWR (ie; antenna tuner at the
radio), and can be used on any radio with a minimum of a 3 watt output
(for this model). It can also be used with allot of different styles of
antenna including a multi or single turn loop.
It's going to be my next acquisition too.
As for the down side, any antenna that is reduced in size and
compensated for using coils and caps will be less efficient (some more
then others). But not as bad as using traps from what I've read (and the
antenna is still quite large). Oh, and it does have minimum radiator
lengths depending on what band your going to be using it on.
If you'd like a better idea on how it works go to SGC World. There is a
link to their publications where they have downloadable manuals and also
one on using their products with stealth antennas. It was an
interesting read.
73, Tony
VA3ATD
London, Ontario.
Charles Johnston
Here is the URL for nearly 30 reviews of various SG tuners
http://www.eham.net/reviews/products/3
--
73 / DX
Charles T Johnston
Prescott, Arizona - U.S.A.
cha...@ab7sl.com
AB7SL - Ham Radio Pages
Official W9INN Antennas Page
www.ab7sl.com
J M Noeding
wrote:
>cheers, CAM http://www.qsl.net/w5dxp:
The No-Tuner, All-HF-Band, Horizontal, Center-Fed Antenna is our old
friend, the 80 meter halfwave dipole dressed up a bit. By varying the
length of the 450 ohm ladder-line feeding the antenna, we can achieve
an SWR of less than 2:1 on all frequencies on all HF bands with the
exception of the lowest part of 80m
well, I would still use my tuner although I must admit that a VSWR of
2:1 isn't that much
73
Jan-Martin
--
remove ,xnd to reply
Mark Krubsack
plus shipping. Used maybe 24 hours. Includes smartuner, manual,
original packing, and the case as described at
http://www.wireservices.com/n9zrt/SG-239/case.html.
It worked great, but I prefer my old manual Drake MN-2000.
Mark Krubsack,
ke...@arrl.net
Jerry Oxendine
coupler actually tuning
the radiating elements to resonance. The only way to do that, unless I am
just dead wrong, is
to physically lengthen or shorten the whip, dipole, or long wire to do that.
While I don't mean
to put down tuner/couplers, nothing beats a resonant antenna. I still
believe the various HI Q
HF antennas such as Bugcatchers and screwdrivers will stomp a coupler.
Again, they do work
by reducing SWR, but they still exhibit losses, and you STILL have a
non-resonant radiating
element out there
73
Jerry
K4KWH
Anthony Duffy <a.d...@sympatico.ca> wrote in message
news:3C38AA59...@sympatico.ca...
Anthony Duffy
limited space etc they can help out the same as inserting an L-Network
at the base of some antenna designs does. Even the screwdriver antenna
uses a very large coil to tune an 8' whip antenna that would resonate on
10m down to 80m. These outfits just happen to switch coils and caps in
and out to do the same thing. And as a bonus that are automatic to boot
:-) !
73, Tony
VA3ATD
London, Ontario
"Necessity is the mother of all invention" and HAM Radio too!
CAM
> While I don't mean to put down tuner/couplers, nothing beats a resonant antenna.
Jerry, a non-resonant antenna will radiate just as well as a resonant one.
A non resonant 102 ft dipole fed with ladder-line on 40m is essentially
just as efficient a radiator as a resonant 40m dipole fed with coax.
K7JEB runs a Texas Bugcatcher mobile with an SGC-230 tuner used for
broadbanding. The difference between the performance at resonance
and the performance off resonance is measurable but essentially
negligible.
CAM
>
> I have to agree with there on having a resonant antenna is best, but in
> limited space etc they can help out the same as inserting an L-Network
> at the base of some antenna designs does. Even the screwdriver antenna
> uses a very large coil to tune an 8' whip antenna that would resonate on
> 10m down to 80m. These outfits just happen to switch coils and caps in
> and out to do the same thing. And as a bonus that are automatic to boot
> :-) !
One advantage that the very large screwdriver coil has is that it radiates.
The iron core toroidal coils in the SGC don't radiate much. Another factor
is that a screwdriver antenna is center-loaded while an SGC driven antenna
is base loaded. I measured an SGC driven whip in a 75m mobile shootout.
It was 14 dB down from a Bugcatcher plus top hat. Virtually all of the
RF power was soaked up by the SGC.
Anthony Duffy
or at least it looks like it. The SG coupler suggests using the whip
antenna on 40m and up and 23' of wire for 80m and up as a minimum. The
manual for the LDG version mentions that it was designed to be used to
take an antenna and resonate it 1 band above and below it's design, i.e.
a 40m antenna for use on 80m & 20m. For Wire antennas and ladder line
fed antennas there is a 4:1 balun available.
73, Tony
CAM
>
> That's interesting... I thought the screwdriver antenna was base loaded,
> or at least it looks like it.
I use a three ft optional extension on the bottom of mine. Thus, the
center loading. In any case, the sleeve that covers the coil is part
of the bottom radiating section below the coil.
> The SG coupler suggests using the whip
> antenna on 40m and up and 23' of wire for 80m and up as a minimum.
Seems if it is 23' minimum on 80m, it would be 11.5' minimum on 40m.
An SGC-230 plus a 11.5' whip would be a little over one S-unit down
from a screwdriver on 40m.