the voltage regulation is done through the lm336 temperature stable voltage
regulator and the 2n2222 transistor along with the ca3240 op amp.
Even if these exact parts aren't available, clones, copies or very similar
chips are easily available...these things are cross referenced all the time.
Just try somewhere like digikey for the 3 IC's you need.
If you get the right parts, the guy can't say it's impossible anymore.
Butch, do you have the text file that describes the circuit?
I can send it to anyone who wants it.
I've updated the info on the Mcount frequency counter and that is about the
only tricky part.
I don't have a 209 or a 249 handy to modify, so I haven't emailed chuck
about the Mcount.
73
Colin, V A6BKX
----- Original Message -----
From: "Butch Bussen" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, May 14, 2013 8:54 PM
Subject: Re: Audible SWR meters, Analyzers, and DXCC antenna
> 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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