an antenna analyzer is a device that transmits a tiny bit of RF into an
antenna, and reads the reflected power, SWR and other variables depending on
the unit.
You don't tune them for anything other than frequency...it doesn't go in
line with the radio or anything. They are stand alone devices that connect
directly to the antenna.
Usually you select the band you want to check the antenna on, and use a VFO
style dial to tune the frequency until you ssee a dip in the SWR...or a dip
down to 50ohms or whatever measurement you are looking at.
The high end ones are auto ranging and will show the min/max swr stuff as
required.
So, there was one model, the MFJ 209 I think analyzer that was successfully
modified using a freqmite CW output frequency counter, and a voltage
controled oscelator.
You turned the frequency knob with the VCO turned on and foundd the null and
zero nulled the tone. Then, you checked the frequency with the freq mite to
see where the most resonant frequency occured.
Unfortunately, this was only possible on the MFJ 209 antenna analyzer and it
was a pretty invasive modification. This analyzer still goes for a couple
hundred bucks on the used market, and it's hard to find someone with the
technical expertees to install the modification properly.
Also, the MFJ 209 is difficult to find, and it only works for HF frequencies
I believe.
With tuners and HF being more forgiving, an antenna analyzer is really only
particularly useful for tuning VHF/UHF antennas, and mobile antennas for max
resonance.
The newer MFJ 249, 259 and 269 analyzers work in a similar way to the 209,
but they are unable to be modified using the original plan. These analyzers
will do VHF on the 249, and UHF as well on the 259 and 269 units.
I believe I did hear that a 249 was modified, but there was something that
was unstable or questionable about it.
You also had to add more mods to the unit to switch the frequency counter to
read VHF frequencies.
So, the cat has been out of the bag for a good long while with regard to an
accessible antenna analyzer. The issue was that an analyzer is not a cheap
piece of equipment, the original ham who did the mods stopped, and I think
parts became difficult to aquire IE the freq mite.
Also, with the updated analyzers the original plan doesn't work, so it kind
of fizzled.
I don't know anyone on list who actually had or has one of these units, or
if anyone had them after the initial unit was modified.
there are audio and text file instructions on how to do this entire mod if
you can find a 209, a cw or voice frequency counter and can get in and make
all the mods. Or, you know someone who doesn't mind putting the time and
expertees into it.
I'm not sure if the HamPod technology could somehow be used with newer
analyzer devices that provide a serial data output...perhaps.
The issue of course, is that these newer units with data output are as
expensive, or more so than a brand new ts590. So not allot of people who
may have the technical expertees and know how, can actually aford to either
modify their own unit, or buy one to play with. And, again, allot of guys
say they'd love something like this, but if it's going to cost a grand or
two, they will forgo the accessibility.
At the end of the day, you can buy an MFJ 269 for 500 bucks and get a
willing set of eyes to help for that once or twice a year you actually need
the thing.
How many here would pay $600 for a mostly accessible antenna analyzer?
Because that was about how much the MFJ209 was with the mods done to it.
The proof is in the pudding that no one wanted to and that is part of the
reason why it didn't go anywhere originally.
I know lots of guys would spend probably a couple hundred for something
that was accessible and did the trick, but even a new unmodified antenna
analyzer isn't cheap
Our ham club has an MFJ269 as part of the club's equipment and any member
has access to it upon request for tuning mobile or vertical antennas etc.
So, even hams who can see the thing are unwilling to lay out allot of cash
for one.
73
Colin, V A6BKX
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