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Old April 30th 12, 12:08 AM posted to rec.radio.amateur.antenna
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On Sun, 29 Apr 2012 16:24:52 -0600, "Irv Finkleman"
wrote:

I have an MFJ-259B -- couldn't live without it, and with all the
stuff I gave away this was the one thing that I just couldn't part with.


For when you transmit into it by accident...
http://802.11junk.com/jeffl/pics/2011-12-03-Storm/
The MJF-259B is similar to the MFJ-269B, except that it lacks the
440MHz section. It's a very handy instrument, but is rather fragile
in that the detector diodes are connected directly to the RF
connector. One blast of too much RF, too much static electricity, or
even too much DC, and the diodes go poof.

Good move! I've always maintained that if you give me any old
piece of metal almost anywhere, I'd find a way to load it and get
on the air!


There's also the rain gutters.

This case now though, is the first time I ever went into a place
that seemed impervious to signals. I've often operated from
indoors with no problem, and here, the first time I flashed up the
receiver, thought it had gone dead -- that's how bad it was. The
first thing I did was checked the protective diodes on the
antenna connector and as soon as I found them OK, opened
the window and strung a short wire outside -- then everything
was 5/9 plus!


Welcome to the joys of modern energy efficient construction. The
walls are full of aluminum foil backed insulation for both thermal and
acoustic insulation. The windows are coated with Low-E Titanium
Nitride IR reflective coatings (40 ohms per square), which also blocks
RF. The roofing material is carbon doped (instead of asbestos) which
absorbs RF. The foundation is concrete, which also absorbs RF.
Meanwhile, the proliferation of microprocessors, switching power
supplies, and BPL like devices, offers multiple sources of QRN. You
had it easy at previous locations.

As per another sailor many years ago said, 'I have not
yet begun to fight!'


Fighting is easy. It's negotiation that drives me nuts.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Old April 30th 12, 02:12 AM posted to rec.radio.amateur.antenna
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Welcome to the joys of modern energy efficient construction. The
walls are full of aluminum foil backed insulation for both thermal and
acoustic insulation. The windows are coated with Low-E Titanium
Nitride IR reflective coatings (40 ohms per square), which also blocks
RF. The roofing material is carbon doped (instead of asbestos) which
absorbs RF. The foundation is concrete, which also absorbs RF.
Meanwhile, the proliferation of microprocessors, switching power
supplies, and BPL like devices, offers multiple sources of QRN. You
had it easy at previous locations.


I kind of fell behind in my knowledge of modern constuction.
I lived in my house for 29-3/4 years and even though I did
a lot of renos, the infrastruction remained basically the same.
It is good though that they are getting smart on energy
efficient construction and other things -- hopefully we will
leave our kids and grandkids with a world pointed in the
right direction.


As per another sailor many years ago said, 'I have not
yet begun to fight!'


Fighting is easy. It's negotiation that drives me nuts.


I'm on the air but not sure just how well I am getting
out, I don't want to measure it, I don't even care to
know since it is a whole different matter on QRP.
The proof will be in the pudding -- I may have to
wait for good band conditions, but the only
valid means of measurement will be the number
of QSO's and bands I can work.

From those lovely boxes of variable caps and
assorted inductors (some roller-inductors) and
a cheap 2nd hand 50ua meter I am going to build
up an artificial ground which is about as simple
a circuit as one can get -- the L&C in series and
make a sniffer out of the meter and a diode!. I
should have it all going in the next day or two --
as soon as I can get a round tooit. Yes. I admit --
I'm a master of procrastination

Well, on with the further adventures of
getting on the air to the point of satisfaction.
Is that a lot, I ask?

Thanks on the tips re the MFJ diodes. I'm aware
of them and can test and change them if need be.
So far, so good! I guess it wouldn't hurt to have
some on hand -- it's pretty inevitable that with
the experimentation etc, that I'll be doing some
or all will get blown before you can say poof!

Do you think that if I were to ask the management
here If I could have an aluminum ladder outside my
second floor window -- just to easy my mind about
the dangers of fire, they might agree?

Irv VE6BP



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558



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Old April 30th 12, 03:29 AM posted to rec.radio.amateur.antenna
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On Sun, 29 Apr 2012 19:12:01 -0600, "Irv Finkleman"
wrote:

It is good though that they are getting smart on energy
efficient construction and other things -- hopefully we will
leave our kids and grandkids with a world pointed in the
right direction.


Yep. It's happening, but very slowly and painfully. Ecology is
expensive in the short term, but worth the cost and effort.
Unfortunately, I've seen some abuse of power precipitated in the name
of the environment. Like all good things, environmental correctness
does attract a few flies.

I'm on the air but not sure just how well I am getting
out, I don't want to measure it, I don't even care to
know since it is a whole different matter on QRP.


Oh rubbish. There are plenty of ways to test your setup that doesn't
involve calling CQ and getting a subjective signal report:
1. You can login to one of the remote radios or receivers on the
internet, tune to an empty frequency, and listen to yourself.
http://beta.remotehams.com
http://www.dxzone.com/catalog/Internet_and_Radio/Online_Receivers/
2. You can join one of the internet QRP clubs.
3. Weak Signal Propagation Reporter Network
http://wsprnet.org
4. Reverse Beacon Network:
http://www.reversebeacon.net
5. You can listen for beacons to check your receiver and antenna:
http://www.ac6v.com/beacons.htm
Our local radio club also has a remote HF station controllable over
the internet (using HRD) but it's only for club members.

From those lovely boxes of variable caps and
assorted inductors (some roller-inductors) and
a cheap 2nd hand 50ua meter I am going to build
up an artificial ground which is about as simple
a circuit as one can get -- the L&C in series and
make a sniffer out of the meter and a diode!.


All an artificial ground does is tune out the ground lead inductance
so that it's series resonant at the operating frequency. In effect,
you're building a counterpoise. You could user your MFJ-259B or a
grid dip meter to resonate the ground lead, and forget about the meter
and detector. However, if you must use a meter, I suggest a
thermocouple RF ammeter. Getting it to heat up the series resistor at
5 watts might be a challenge, but it can be done. Otherwise, it's a
current transfomer, ferrite core, diode detector, and 50ua meter.
http://www.w1tag.com/RFA.htm

I'm a master of procrastination


I have a PHD in procrastination. Never do today what you get someone
else to do for you tomorrow.

Is that a lot, I ask?


Yes, if you try to do it all at once.
No, if you take your time, grind the numbers, do a little planning,
and invite all your friends to help.

Thanks on the tips re the MFJ diodes. I'm aware
of them and can test and change them if need be.


I could only test the diodes after they were removed. The 50 ohm
resistors in the circuit prevented easy checking with an ohms guesser.

So far, so good! I guess it wouldn't hurt to have
some on hand -- it's pretty inevitable that with
the experimentation etc, that I'll be doing some
or all will get blown before you can say poof!


Yep. My experience is that certain users tend to blow up diodes no
matter what they do, while others don't have any problems. I'm sure
it's the user, not the analyzer. Possibly static build-up or
ungrounded antennas. Dunno.

I've been fairly lucky replacing all 4 diodes without needed to
calibrate the device. However, if you find the readings off after
replacement, see:
http://www.w8ji.com/mfj-259b_calibration.htm
The procedure took me 2 full days on an MFJ-269B. It went much
quicker after I read and followed the instructions.

Do you think that if I were to ask the management
here If I could have an aluminum ladder outside my
second floor window -- just to easy my mind about
the dangers of fire, they might agree?


No. Someone will probably try to steal the ladder. 20ft ladders are
not cheap. I ran two u-bolts through the ladder base, and permanently
attached the u-bolts to two foundation blocks with half a bag of
concrete mix in the hole. Various attempts were made to steal it, but
nobody got very far with 30 kg of buried excess weight attached. The
connecting antenna wire also acts as a capacitive alarm when the HF
radio is not being used. All this was only possible because each
condo had its own private back yard.

Another problem with a 2nd floor ladder is that you will be feeding
the ladder from the top, rather than from the bottom. That will
possibly work, but probably not as good as feeding the ladder from the
bottom.



--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Old April 30th 12, 05:59 AM posted to rec.radio.amateur.antenna
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Posts: 220
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"Jeff Liebermann" wrote in message
...
On Sun, 29 Apr 2012 19:12:01 -0600, "Irv Finkleman"
wrote:

It is good though that they are getting smart on energy
efficient construction and other things -- hopefully we will
leave our kids and grandkids with a world pointed in the
right direction.


(snipped now and again here and there for brevity)

I'm on the air but not sure just how well I am getting
out, I don't want to measure it, I don't even care to
know since it is a whole different matter on QRP.


Oh rubbish. There are plenty of ways to test your setup that doesn't
involve calling CQ and getting a subjective signal report:
1. You can login to one of the remote radios or receivers on the
internet, tune to an empty frequency, and listen to yourself.
http://beta.remotehams.com
http://www.dxzone.com/catalog/Internet_and_Radio/Online_Receivers/
2. You can join one of the internet QRP clubs.
3. Weak Signal Propagation Reporter Network
http://wsprnet.org
4. Reverse Beacon Network:
http://www.reversebeacon.net
5. You can listen for beacons to check your receiver and antenna:
http://www.ac6v.com/beacons.htm
Our local radio club also has a remote HF station controllable over
the internet (using HRD) but it's only for club members.


I won't care about subjective reports -- I'll be happy if
my few paltry watts that do escape the antenna get me
any kind of response. I am aware of the remote
receivers but I don't want to get so busy using other
things that I won't have time on the air making
plain good old fashioned QSOs. I will have a peek
at the internet QRP clubs as long as I don't lose
on air time going to meetings -- even on-air!


From those lovely boxes of variable caps and
assorted inductors (some roller-inductors) and
a cheap 2nd hand 50ua meter I am going to build
up an artificial ground which is about as simple
a circuit as one can get -- the L&C in series and
make a sniffer out of the meter and a diode!.


All an artificial ground does is tune out the ground lead inductance
so that it's series resonant at the operating frequency. In effect,
you're building a counterpoise. You could user your MFJ-259B or a
grid dip meter to resonate the ground lead, and forget about the meter
and detector.


I considered that. I already have a group of radials
of various lengths on the floor -- I tied them together
with plastic ties for neatness, but with a ground tuner
I only need one which I plan to lay out along the edge
of the carpet -- that should make a neater job and if
I can tuck most of it under the baseboards it will not
frighten the houskeeper.

However, if you must use a meter, I suggest a
thermocouple RF ammeter. Getting it to heat up the series resistor at
5 watts might be a challenge, but it can be done. Otherwise, it's a
current transfomer, ferrite core, diode detector, and 50ua meter.
http://www.w1tag.com/RFA.htm


A simple diode detector may be enough, but if necessary
I'll have to line up ferrite core and get complicated.

I'm a master of procrastination


I have a PHD in procrastination. Never do today what you get someone
else to do for you tomorrow.


I was always good at procrastination however I did not consider
the part of having someone else do the work -- that's probably
why you have the PhD and I don't!!

Is that a lot, I ask?


Yes, if you try to do it all at once.
No, if you take your time, grind the numbers, do a little planning,
and invite all your friends to help.


That's the nice thing about being a retired senior -- I can take
all the time I want, and as you've seen in this thread, I'm
doing a lot of planning, and if necessary there I've got
lots of ham chums who will be anxious to lend a hand just
to get in here and see what I'm up to.

Thanks on the tips re the MFJ diodes. I'm aware
of them and can test and change them if need be.


I have the W8JI procedure tucked away in a safe
place on my computer where I may never find it again,
Thank heaven for good search tools.

I could only test the diodes after they were removed. The 50 ohm
resistors in the circuit prevented easy checking with an ohms guesser.


I never considered that -- oh well, it should only take a jiffy
to pop the diodes out although there is always Murphy to
take into account.

So far, so good! I guess it wouldn't hurt to have
some on hand -- it's pretty inevitable that with
the experimentation etc, that I'll be doing some
or all will get blown before you can say poof!


Yep. My experience is that certain users tend to blow up diodes no
matter what they do, while others don't have any problems. I'm sure
it's the user, not the analyzer. Possibly static build-up or
ungrounded antennas. Dunno.

I've been fairly lucky replacing all 4 diodes without needed to
calibrate the device. However, if you find the readings off after
replacement, see:
http://www.w8ji.com/mfj-259b_calibration.htm
The procedure took me 2 full days on an MFJ-269B. It went much
quicker after I read and followed the instructions.


Now there's a very unhamlike suggestion -- wouldn't stopping
to read and follow the instructions severely slow down the
calibration procedure?

Do you think that if I were to ask the management
here If I could have an aluminum ladder outside my
second floor window -- just to easy my mind about
the dangers of fire, they might agree?


No. Someone will probably try to steal the ladder. 20ft ladders are
not cheap. I ran two u-bolts through the ladder base, and permanently
attached the u-bolts to two foundation blocks with half a bag of
concrete mix in the hole. Various attempts were made to steal it, but
nobody got very far with 30 kg of buried excess weight attached. The
connecting antenna wire also acts as a capacitive alarm when the HF
radio is not being used. All this was only possible because each
condo had its own private back yard.


I've considered all the security precautions you took with the ladder.
At the moment I'm considering how to rotate it, and
wondering if I couldn't use a wooden ladder with lots
of wire stapled to it in a multiband Hentenna configuration!
I guess I may have to rethink it and take it one step at
a time! Now, I have to consider which rotor. Do you by
chance know offhand the wind load of a 20 ft Al ladder?
How about a folding ladder for the sake of extra length?

Another problem with a 2nd floor ladder is that you will be feeding
the ladder from the top, rather than from the bottom. That will
possibly work, but probably not as good as feeding the ladder from the
bottom.


I'll use double sideband so that it won't matter which end of
the ladder I feed it from!

Cheers, this is fun!

Irv VE6BP


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Old April 30th 12, 07:02 AM posted to rec.radio.amateur.antenna
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On Sun, 29 Apr 2012 22:59:25 -0600, "Irv Finkleman"
wrote:

I never considered that -- oh well, it should only take a jiffy
to pop the diodes out although there is always Murphy to
take into account.


Umm... the diodes don't quite pop out in a jiffy. You must first tear
apart the instrument just to get to the diodes. They're tiny little
devils, best handled with stainless SMD tweezers.
http://802.11junk.com/jeffl/crud/mfj-269b-diodes.jpg
They're the 4 black things labeled "COB". If you order some from
Digikey or Mouser, be sure to get plenty of spares. I dropped two on
my workbench, where they promptly disappeared.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558


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Old April 30th 12, 04:06 PM posted to rec.radio.amateur.antenna
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Posts: 220
Default Indoor Counterpoise For Random Wire Antenna


"Jeff Liebermann" wrote in message
...
On Sun, 29 Apr 2012 22:59:25 -0600, "Irv Finkleman"
wrote:

I never considered that -- oh well, it should only take a jiffy
to pop the diodes out although there is always Murphy to
take into account.


Umm... the diodes don't quite pop out in a jiffy. You must first tear
apart the instrument just to get to the diodes. They're tiny little
devils, best handled with stainless SMD tweezers.
http://802.11junk.com/jeffl/crud/mfj-269b-diodes.jpg
They're the 4 black things labeled "COB". If you order some from
Digikey or Mouser, be sure to get plenty of spares. I dropped two on
my workbench, where they promptly disappeared.


After I retired from the Navy I worked for Sony as a tech for 14
years and became pretty handy with SMD. When I retired from Sony
I kept my tools which included a headband magnifier and a few
different tweezers only one of which I consistently used. I do
recall losing one or two of the smaller SMD components but
I eventually learned to take precautions to avoid doing so..

With respect to taking things apart and then getting them
back together again I have to brag about my abilities. When
I had my first interview with Sony the asked me how much
of the work I considered electronic and how much was
mechanical. I estimated 90 percent mechanical (getting
the old part out and putting the new part in and then
the unit back together). I know now that it is more like
99.9%.

Oh well, I guess I'll just have to try and not blow
the diodes even though we both believe it will be
inevitable!

Irv VE6BP


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Old April 30th 12, 06:34 PM posted to rec.radio.amateur.antenna
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On Mon, 30 Apr 2012 09:06:53 -0600, "Irv Finkleman"
wrote:

After I retired from the Navy I worked for Sony as a tech for 14
years and became pretty handy with SMD.


I worked for Sony/Superscope in Sunland-Tujunga California for a short
while in the mid 1960's. Too far to drive from where I was living and
going to skool.

When I retired from Sony
I kept my tools which included a headband magnifier and a few
different tweezers only one of which I consistently used.


Does your former boss know about this? Is there a reward for turning
you in? If you're going to pilfer the tools, at least take something
expensive.

I left one company with my junk parts box, my collection of component
samples, a DVM, and my favorite screwdriver. I probably could have
taken a load of test equipment, as nobody seemed to care. I figured
the dumpster would be full of junk after the layoff/purge. I was
right and collected quite a pile of goodies from the dumpster. I also
suspected that my project notes would be thrown away, so I grabbed
those. Many years later, the company raised one project from the dead
and called asking if I had any history on the project. Like a fool, I
just gave it to them, instead of demanding payment.

Like all products, my ancient products eventually hit the surplus
market. Like all good surplus equipment, there were no manuals to be
found. So, like a complete fool, I scanned the manuals and posted
them to my web pile. I now waste far too much time answering
questions and helping with repairs. Lesson learned: Products tend to
rise from the dead and will haunt you like zombies.

I do
recall losing one or two of the smaller SMD components but
I eventually learned to take precautions to avoid doing so..


My standard precaution is to buy extra parts. The parts are cheap. My
time is not. I use metal egg trays for parts storage. However, I
also tend to tip those over or bury them in junk. My latest trick is
using semi-sticky window shelf paper to hold parts. That works great
after I remove the flies, bugs, and glue eating banana slugs.

With respect to taking things apart and then getting them
back together again I have to brag about my abilities. When
I had my first interview with Sony the asked me how much
of the work I considered electronic and how much was
mechanical. I estimated 90 percent mechanical (getting
the old part out and putting the new part in and then
the unit back together). I know now that it is more like
99.9%.


Agreed. When I started in engineering, it was 99.9% engineering and
0.01% politics. 15 years or so later, it was 99.9% politics and 0.01%
engineering. Productivity was about the same in both cases. Now that
I'm officially in the repair biz, my guess is about 33% repair, 33%
paper shuffling, and 33% customer ego support.

One nice thing about ham radio is that if I announce that I'm working
on a project, and I procrastinate enough, then one of the local hams
will eventually do it for me. See Tom Sawyer white washing a fence
for details on how it works.

Oh well, I guess I'll just have to try and not blow
the diodes even though we both believe it will be
inevitable!


Not really. As I previously ranted, only certain people seem to blow
up the diodes. If you haven't blown any diodes by now, you're
probably safe. Just don't loan it to any of your friends, especially
on Field Day[1]. What seems to kill the analyzers is the act of
plugging in and unplugging a PL-259 to the unit. The PL-259 is unique
in that the center pin makes contact before the ground. This is
what's commonly known as a lousy idea. If you've built up a static
charge with your clothes and shoes, and are holding the shield, you'll
discharge yourself through the center pin and directly into the
diodes. That's my guess(tm) as to what's happening. I now make it a
habit of touching the center pin to case ground, before plugging in.
No clue if it helps, but it seems like a good idea. The N connector
on the MFJ-269B should not have this problem, but they seem to blow up
anyway, probably due to a different failure mechanism.

Irv VE6BP


[1] Hint: Measure the DC voltage on the traditional Field Day
balloon supported long wire antenna, especially if there's some wind.
If the DVM doesn't explode, you're still not safe.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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Old April 30th 12, 07:26 AM posted to rec.radio.amateur.antenna
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Default Indoor Counterpoise For Random Wire Antenna

On Sun, 29 Apr 2012 22:59:25 -0600, "Irv Finkleman"
wrote:

I have the W8JI procedure tucked away in a safe
place on my computer where I may never find it again,
Thank heaven for good search tools.


Try "Search Everything".
http://www.voidtools.com
If you can remember parts of the file name or folder, it will find it
instantly.

The procedure took me 2 full days on an MFJ-269B. It went much
quicker after I read and followed the instructions.


Now there's a very unhamlike suggestion -- wouldn't stopping
to read and follow the instructions severely slow down the
calibration procedure?


I consider reading instructions a sign of weakness, especially when
customers are watching. When they see me reading the docs, they
usually ask if I know what I'm doing, or if I had done this before. In
order to maintain my image, I try not to be seen reading the docs.

However, I do read the instructions..... after I'm done, and only to
see if I missed anything. On the MFJ-269B calibration, and after
starting over for the 3rd or 4th time, I decided that it might be
useful to just do it right, reading from beginning to end.

At the moment I'm considering how to rotate it, and
wondering if I couldn't use a wooden ladder with lots
of wire stapled to it in a multiband Hentenna configuration!
I guess I may have to rethink it and take it one step at
a time! Now, I have to consider which rotor. Do you by
chance know offhand the wind load of a 20 ft Al ladder?


No, but I could probably calculate the wind load if I had the
dimensions. Ice load will probably be the worst case. However, I
don't think a rotatable ladder would be a good or useful idea. The
ladder is mostly vertical, and rotation of a vertical doesn't do
anything useful. I suggest you leave it leaning against the building
and live with whatever that produces.

Incidentally, if there's anyone living directly below you, they may
object to having the ladder block their view. My friend's ladder
antenna was possible because his condo was a townhouse arrangement,
where he owned both the lower and upper windows.

How about a folding ladder for the sake of extra length?


The 20ft ladder I used was a 2 section telescoping ladder. I had the
not so bright idea of changing the length in order to tune the antenna
to something near 1/4 wavelength. I also experimented with an
insulating sleeve between the two sections in an attempt to make a
vertical dipole. Both proved of dubious value as the best results
were from using the full length ladder and an antenna tuner.

I'm not sure what a folding ladder will do except to add weight and
attract unwanted attention. I just gave away two steel folding
ladders. They weighed far too much but were admittedly quite useful.

I'll use double sideband so that it won't matter which end of
the ladder I feed it from!


Be sure to tilt your radio vertically to match the antenna
polarization.

Cheers, this is fun!


If it were easy, it would not be fun.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
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