Which april qst article? My friend built it, and the one chi which is a
regulator or something, he says is very very critical. I can't remember
the number, and it may not be a regulator, but all I can tell you is it
doesn't work. The guy knows what he is doing, worked as an engineer for
the government for years doing neucliar testing and all that. I guess
he has given up on it, so at this point I don't even have one that isn't
modified.
73
Butch
WA0VJR
Node 3148
Wallace, ks.
On Tue, 14 May 2013, Gary Lee wrote:
> the mod for the 209 analyzer uses off the shelf parts. A 556 dual =
> timer, and I have forgotten the other dual op amp chip. Nearly the same =
> circuit as in the april qst article.
>
> Gathering parts to attempt the build after dayton. If I can make it =
> work, I plan to try the mfj swr meter mod bill mentions.
> I will try if successful to get our club bo take it up as a project.
> More as I go along.
>
> Gary Lee
> [log in to unmask]
>
>
>
> On May 11, 2013, at 11:30 PM, Butch Bussen <[log in to unmask]> =
> wrote:
>
>> I boughtone of those and had a friend who said he'd modify it for me =
> as=20
>> per the article in qst 4 or 5 years ago. It appears to use a very=20
>> special chip and he still hasn't built it, guess I'll scratch that=20
>> one...
>> 73
>> Butch
>> WA0VJR
>> Node 3148
>> Wallace, ks.
>> =20
>> =20
>> On Sat, 11 May 2013, John Miller wrote:
>> =20
>>> The 209 will go to VHF. I have one though it's not modified, because =
> of what
>>> you say I don't know anyone willing to modify it and I'm not =
> comfortable
>>> doing it.
>>> ----- Original Message -----
>>> From: "Colin McDonald" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Saturday, May 11, 2013 10:07 PM
>>> Subject: Re: Audible SWR meters, Analyzers, and DXCC antenna
>>> =20
>>> =20
>>>> 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.
>>>> =20
>>>> 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.
>>>> =20
>>>> 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
>>>> =20
>>>> 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.
>>>> =20
>>>> 73
>>>> Colin, V A6BKX
>>> =20
>>> =20
>
>
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