I'm looking at purchasing an MFJ269 antenna analyser and keen to hear
experience of others in this group regarding this or similar analysers.
Appears to be ideal if it is as good as MFJ claim.


Hi Peter,

I can highly recommend the Rigexpert AA-200A:
http://www.rigexpert.com/index?s=aa200

Unlike the MFJ unit, this is a full vector analyzer. You can also save
plots and then transfer them to your computer for archiving. The lates
firmware allows measurements at both 50 Ohms and 75 Ohms and I believe
one can now also move the reference plane to the end of the coax.
Batteries last forever, it's about 1/4th the weight, can display data in
both graphical and tabular format.
I've owned the MFJ, Autek, AEA and Timewave- the AA-200A blows them all
away. Oh yeah, the signal source is synthesized and can make a very nice
signal generator that is rock stable.

Dale W4OP


Except that it looks like the RigExpert has an untuned detector, just like
the others. The schematic SUBVHF6.pdf shows a couple of RF switches and a
AD8307 log detector. The PLL synthesizers are up at 1+ GHz, so maybe
there's a filter and mixer somewhere else. I couldn't find a block
diagram.

Hi Jim,
I'm way up in the NC mountains, so I cannot speak regarding the AA-200A
front end.
I know when I lived in West Palm FL, the MFJ was totally wiped out by a
nearby AM broadcast station.

73,
Dale W4OP

Dale Parfitt wrote:
I'm looking at purchasing an MFJ269 antenna analyser and keen to hear
experience of others in this group regarding this or similar analysers.
Appears to be ideal if it is as good as MFJ claim.


Hi Peter,

I can highly recommend the Rigexpert AA-200A:
http://www.rigexpert.com/index?s=aa200

Unlike the MFJ unit, this is a full vector analyzer. You can also save
plots and then transfer them to your computer for archiving. The lates
firmware allows measurements at both 50 Ohms and 75 Ohms and I believe
one can now also move the reference plane to the end of the coax.
Batteries last forever, it's about 1/4th the weight, can display data in
both graphical and tabular format.
I've owned the MFJ, Autek, AEA and Timewave- the AA-200A blows them all
away. Oh yeah, the signal source is synthesized and can make a very nice
signal generator that is rock stable.

Dale W4OP

Except that it looks like the RigExpert has an untuned detector, just like
the others. The schematic SUBVHF6.pdf shows a couple of RF switches and a
AD8307 log detector. The PLL synthesizers are up at 1+ GHz, so maybe
there's a filter and mixer somewhere else. I couldn't find a block
diagram.

Hi Jim,
I'm way up in the NC mountains, so I cannot speak regarding the AA-200A
front end.
I know when I lived in West Palm FL, the MFJ was totally wiped out by a
nearby AM broadcast station.

Yah, on the low bands I sometimes have problems with a local AM station.
It's probably endemic to most analyzers.

My thoughts on the MFJ line of analyzers is that within their
limitations, they are very good. I bought one and it just works fine for
me. The original one I bought had a problem at around 10-11 months. I
think that someone was messing with it in a high RF environment without
the dummy load on the RF connector. Somehow got a major dose of RF. Sent
it back to MFJ,and the replacement works just great. I don't loan it out
any more.

My biggest con is that it uses a lot of AA cells, no big deal. I'd buy
another one in a minute if needed.

My new loaner is an older MFJ SWR bridge - since that is what most
people are worried about anyhow.

- 73 de Mike N3LI -

Michael Coslo wrote:
My biggest con is that it uses a lot of AA cells, ...

I solved that problem with a Velcro'ed gel cell.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com

My biggest con is that it uses a lot of AA cells, ...
I solved that problem with a Velcro'ed gel cell.

I don't know about the '269, but the '259 practically GOBBLED batteries!
I currently use an Autek VA-1 and have been reasonably happy with it.

--Myron A. Calhoun, W0PBV.
Five boxes preserve our freedoms: soap, ballot, witness, jury, and cartridge

"Owen Duffy" wrote in message
...
"Peter" wrote in
. au:

Hi all

I'm looking at purchasing an MFJ269 antenna analyser and keen to hear
experience of others in this group regarding this or similar analysers.
Appears to be ideal if it is as good as MFJ claim.



Peter,

Effective exploitation of the capability of this type of analyser depends
on a sound understanding of transmission lines, and of the instrument's
own limitation. The availability of these analysers at low cost, and the
perception that they are a magic bullet has lead to a lot of pseudo
technical nonsense being proposed. The magic is more in the user's
capability than the box, and buying the box doesn't buy knowledge and
understanding... but the device can help develop knowledge and
understanding.

I have not used a '269 (though I have extensively used a '259B), but I
suspect that it does not display the sign of X. Estimation of the sign of
X in the '259 and similar instruments is an issue, and confuses many
users. There are propositions that sign of X is easily determined from
the slope of X with frequency at a point... but whilst that is true for
an ideal passive component, it is not true in general.

These instruments are often used in pursuit of the questionable goal of
resonance, and the instrument used to show resonance by observing X=0, or
X approximately zero, or a local minimum for X at some frequency on the
assumption that X changes sign at that point and that resonance of
something is indicated.

I wrote some notes entitled "In pursuit of dipole resonance with an
MFJ259B" at http://vk1od.net/blog/?p=680 that canvasses the behaviour of
the instrument in such an application, and flags the issues in
measurement. You may find them interesting.

Others have raised the issue that these instruments use a broadband
detector, which works fine so long as the internal oscillator has low
harmonic content and dominates the detector. If you let one of these
things time out, the oscillator is shut down, and if you see indication
on the meters, then energy from another source is of sufficient magnitude
to be concerned about the accuracy of measurements.

Owen

Thanks Owen for the information and your notes "In pursuit of dipole
resonance with an MFJ259B"
My intended use for the device is to get a bit of view on what's going on
with my various home brew antennas and matching devices and for my own
curiosity to compare theory with real world.

I must admit I had assumed that the 269 analyzer display the sign of the
reactance, I will have to reread the ad.

Regards


Peter VK6YSF

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

"Peter" wrote in
. au:

....
I must admit I had assumed that the 269 analyzer display the sign of
the reactance, I will have to reread the ad.

Ah, you were looking for honesty in advertising!

The online guff on the MFJ259B says:
"Read Complex Impedance as series resistance and reactance (R+jX) or as
magnitude (Z) and phase (degrees)."

The MFJ259B definitely does *not* show phase angle or reactance as
negative for cases where X is actually negative.

The same words appear in the MFJ269 online page, so it may also be a
misrepresentation.

I see in the MFJ269 manual, the same pretence over the sign of phase and
reactance. It contains the words "Besides Z, an angle between zero and 90
degrees is shown. This angle represents the phase difference between
current and voltage at the terminals of the analyzer."

Of course, a phase angle between "zero and 90 degrees" does not represent
"phase difference between current and voltage at the terminals of the
analyzer" in the case of a capacitive impedance.

Honesty in advertising... think again.

Owen

"Owen Duffy" wrote in message
...
"Peter" wrote in
. au:

...
I must admit I had assumed that the 269 analyzer display the sign of
the reactance, I will have to reread the ad.

Ah, you were looking for honesty in advertising!

The online guff on the MFJ259B says:
"Read Complex Impedance as series resistance and reactance (R+jX) or as
magnitude (Z) and phase (degrees)."

The MFJ259B definitely does *not* show phase angle or reactance as
negative for cases where X is actually negative.

The same words appear in the MFJ269 online page, so it may also be a
misrepresentation.

I see in the MFJ269 manual, the same pretence over the sign of phase and
reactance. It contains the words "Besides Z, an angle between zero and 90
degrees is shown. This angle represents the phase difference between
current and voltage at the terminals of the analyzer."

Of course, a phase angle between "zero and 90 degrees" does not represent
"phase difference between current and voltage at the terminals of the
analyzer" in the case of a capacitive impedance.

Honesty in advertising... think again.

Owen

What was I thinking! I was impressed with what was being claimed.

I will continue with my product research and you can expect me to float some
other manufactures device on this group soon for comments.

Peter VK6YSF

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

"Peter" wrote in message
...

"Owen Duffy" wrote in message
...
"Peter" wrote in
. au:

...
I must admit I had assumed that the 269 analyzer display the sign of
the reactance, I will have to reread the ad.

Ah, you were looking for honesty in advertising!

The online guff on the MFJ259B says:
"Read Complex Impedance as series resistance and reactance (R+jX) or as
magnitude (Z) and phase (degrees)."

The MFJ259B definitely does *not* show phase angle or reactance as
negative for cases where X is actually negative.

The same words appear in the MFJ269 online page, so it may also be a
misrepresentation.

I see in the MFJ269 manual, the same pretence over the sign of phase and
reactance. It contains the words "Besides Z, an angle between zero and 90
degrees is shown. This angle represents the phase difference between
current and voltage at the terminals of the analyzer."

Of course, a phase angle between "zero and 90 degrees" does not represent
"phase difference between current and voltage at the terminals of the
analyzer" in the case of a capacitive impedance.

Honesty in advertising... think again.

Owen

What was I thinking! I was impressed with what was being claimed.

I will continue with my product research and you can expect me to float
some other manufactures device on this group soon for comments.

Peter VK6YSF

Again- look at the RigExpert A-200A. Batteries seem to last forever, it's
USB upgradable and it DOES resolve the sign of R +/-JX.

Dale W4OP

"Dale Parfitt" wrote in message
...

"Peter" wrote in message
...

"Owen Duffy" wrote in message
...
"Peter" wrote in
. au:

...
I must admit I had assumed that the 269 analyzer display the sign of
the reactance, I will have to reread the ad.

Ah, you were looking for honesty in advertising!

The online guff on the MFJ259B says:
"Read Complex Impedance as series resistance and reactance (R+jX) or as
magnitude (Z) and phase (degrees)."

The MFJ259B definitely does *not* show phase angle or reactance as
negative for cases where X is actually negative.

The same words appear in the MFJ269 online page, so it may also be a
misrepresentation.

I see in the MFJ269 manual, the same pretence over the sign of phase and
reactance. It contains the words "Besides Z, an angle between zero and
90
degrees is shown. This angle represents the phase difference between
current and voltage at the terminals of the analyzer."

Of course, a phase angle between "zero and 90 degrees" does not
represent
"phase difference between current and voltage at the terminals of the
analyzer" in the case of a capacitive impedance.

Honesty in advertising... think again.

Owen

What was I thinking! I was impressed with what was being claimed.

I will continue with my product research and you can expect me to float
some other manufactures device on this group soon for comments.

Peter VK6YSF

Again- look at the RigExpert A-200A. Batteries seem to last forever, it's
USB upgradable and it DOES resolve the sign of R +/-JX.

Dale W4OP
Thanks Dale

I have just had a look at the RigExpert site. Look impressive, but the
MFJ269 at about $400US was about my limit.
I think I will take a step back and conduct a more scientific review of all
of the antenna analyzers on offer, there for you should get sick of my
postings over the next couple of weeks/months.
I must say that the ability to save and analyze data on the lap top is an
appealing feature.

Regards

Peter VK6YSF

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

Peter wrote:

I have just had a look at the RigExpert site. Look impressive, but the
MFJ269 at about $400US was about my limit.
I think I will take a step back and conduct a more scientific review of all
of the antenna analyzers on offer, there for you should get sick of my
postings over the next couple of weeks/months.
I must say that the ability to save and analyze data on the lap top is an
appealing feature.

Regards

Peter VK6YSF

http://members.optushome.com.au/vk6ysf/vk6ysf/main.htm

Have a look at the AIM 4170 at http://www.arraysolutions.com/

I have that and a MFJ analyzer.

For a quick antenna adjustment, the MFJ is easier to use.

For in depth analysis, the AIM can't be beat.

If I had only one, I would prefer to have the AIM.


--
Jim Pennino

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