After reading the remarks here and researching the past posts to the
newsgroup on the MFJ-269 I feel I have been missing out on a lot. The
best overall description I have found anywhere (including the MFJ web
site) is in the current ad in QST.

I ordered it Saturday morning and am eagerly awaiting its arrival.

John Ferrell, W8CCW

On Mon, 7 Nov 2005 07:12:20 -0500, "Bill" wrote:

Interesting....if there is something better out there what is it?......been
using a 259 since "98" and its done the job for me from beams-wires...co-ax
measurement....ans the latest, balancing out the 1/4 wave stubs on a Hygain
HighTower, as I added 17 meters to the array!!

"John Ferrell" wrote in message
...
After reading the remarks here and researching the past posts to the
newsgroup on the MFJ-269 I feel I have been missing out on a lot. The
best overall description I have found anywhere (including the MFJ web
site) is in the current ad in QST.

I ordered it Saturday morning and am eagerly awaiting its arrival.

John Ferrell, W8CCW

I am happy with mine. Only thing I can add is that it eats batteries, and my
unit does not like to work below 13 Volts. They do sell a tunable bandpass
filter for the lower frequencies. I tried a high pass filter - don't bother,
it messes up the phase.

Tam/WB2TT

Tam/WB2TT wrote:
Only thing I can add is that it eats batteries, ...

I run mine off an external rechargable 12v YUASA battery.
--
73, Cecil http://www.qsl.net/w5dxp

"Cecil Moore" wrote in message
. net...
Tam/WB2TT wrote:
Only thing I can add is that it eats batteries, ...

I run mine off an external rechargable 12v YUASA battery.
--
73, Cecil http://www.qsl.net/w5dxp

Never thought of that. I actually have a 12V, 7 AH Yuasa sitting on the file
cabinet. I would just have to keep it well charged.
Tam

Tam/WB2TT wrote:

I am happy with mine. Only thing I can add is that it eats batteries, and my
unit does not like to work below 13 Volts. They do sell a tunable bandpass
filter for the lower frequencies. I tried a high pass filter - don't bother,
it messes up the phase.

If you do want to measure antenna impedance with something like the MFJ
and have trouble (as I do) with local broadcasting and other RF, I
recommend using a "half wave" filter. This type of filter has reasonable
out-of-band attenuation characteristics and doesn't disturb the
impedance measurement too much. (Over a limited frequency range it
mimics a half wavelength of transmission line.) The impedance
disturbance will be the least when the filter is designed to
approximately match the measured impedance.

It's simply two cascaded pi sections, with each element having the same
value of X. For example, a lowpass looks like this:

---.---L---.---L---.---
| | |
C 2C C
| | |
----.-------.-------.---

For example, a filter with Z0 = 50 ohms (one which mimics a half
wavelength of 50 ohm line) has XL = XC = 50. One designed for 7 MHz
would have L = 1.14 uH, C = 455 pF. You can wind the coils on small type
2 or 6 powdered iron cores, and use the closest standard value (e.g.,
470 pF) for the capacitors. This filter will cause little impedance
disturbance at 7 MHz and, for load impedances near 50 ohms, at lower
frequencies also. A highpass looks like this:

---.---C---.---C---.---
| | |
L L/2 L
| | |
----.-------.-------.---

Again, XL = XC = the filter Z0. Make filters according to your
particular measurement needs. You can check the amount of disturbance
the filter causes by making a known impedance out of a resistor and
capacitor or inductor which is about equal to the measured impedance,
and measuring it with and without the filter.

If you can read German, there's a marvelous book describing how to make
a wide variety of measurements with an antenna analyzer, with tricks,
tips, and details. It's _HF-Messungen mit einem aktiven
Stehwellen-Meßgerät_ by Gerd Janzen, DF6SJ. It's available directly from
him at Hochvogelstraße 29, D-87435 Kempten, Germany.

Roy Lewallen, W7EL

"Roy Lewallen" wrote in message
...
Tam/WB2TT wrote:

I am happy with mine. Only thing I can add is that it eats batteries, and
my unit does not like to work below 13 Volts. They do sell a tunable
bandpass filter for the lower frequencies. I tried a high pass filter -
don't bother, it messes up the phase.

If you do want to measure antenna impedance with something like the MFJ
and have trouble (as I do) with local broadcasting and other RF, I
recommend using a "half wave" filter. This type of filter has reasonable
out-of-band attenuation characteristics and doesn't disturb the impedance
measurement too much. (Over a limited frequency range it mimics a half
wavelength of transmission line.) The impedance disturbance will be the
least when the filter is designed to approximately match the measured
impedance.

It's simply two cascaded pi sections, with each element having the same
value of X. For example, a lowpass looks like this:

---.---L---.---L---.---
| | |
C 2C C
| | |
----.-------.-------.---

For example, a filter with Z0 = 50 ohms (one which mimics a half
wavelength of 50 ohm line) has XL = XC = 50. One designed for 7 MHz would
have L = 1.14 uH, C = 455 pF. You can wind the coils on small type 2 or 6
powdered iron cores, and use the closest standard value (e.g., 470 pF) for
the capacitors. This filter will cause little impedance disturbance at 7
MHz and, for load impedances near 50 ohms, at lower frequencies also. A
highpass looks like this:

---.---C---.---C---.---
| | |
L L/2 L
| | |
----.-------.-------.---

Again, XL = XC = the filter Z0. Make filters according to your particular
measurement needs. You can check the amount of disturbance the filter
causes by making a known impedance out of a resistor and capacitor or
inductor which is about equal to the measured impedance, and measuring it
with and without the filter.

If you can read German, there's a marvelous book describing how to make a
wide variety of measurements with an antenna analyzer, with tricks, tips,
and details. It's _HF-Messungen mit einem aktiven Stehwellen-Meßgerät_ by
Gerd Janzen, DF6SJ. It's available directly from him at Hochvogelstraße
29, D-87435 Kempten, Germany.

Roy Lewallen, W7EL

I will have to try your configuration. I did C - L - C/2 - L -C, with
C=1000PF, L=2.2uH. According to SWCad, the gain is flat above 2 MHz, but
there is 120 degrees phase shift at 4 MHz, relative to the phase at 100 MHz.

Tam/WB2TT

I received the device and have started to use it. My only criticism so
far is that the soft case is too tight to allow easy operation of the
controls. I hope this will loosen up a bit with time.

It is amazing what you can learn about an antenna in such a short
time!
John Ferrell W8CCW

On Fri, 04 Nov 2005 19:43:07 GMT, John Ferrell
wrote:

I am considering ordering the MFJ-269 HF/VHF/UHF Antenna/SWR/RF
Analyzer.

John Ferrell W8CCW

John Ferrell wrote:
It is amazing what you can learn about an antenna in such a short
time!

My MFJ-259B is a really handy little gadget for learning.
So is EZNEC.
--
73, Cecil http://www.qsl.net/w5dxp

I agree. I took the ARRL course using EZNEC and cannot praise it
enough!
On Thu, 01 Dec 2005 13:41:01 GMT, Cecil Moore wrote:

John Ferrell wrote:
It is amazing what you can learn about an antenna in such a short
time!

My MFJ-259B is a really handy little gadget for learning.
So is EZNEC.
John Ferrell W8CCW

I was terribly disappointed in the MFJ case and sold it on Ebay then bought
an aluminum case off Ebay that works perfectly and has room for several
adapters and a cable or two as well as the instruction manual for the 269.
It is a great instrument but I wish they would fix the UHF switching
problem. Looks like a latching relay would solve the problem real easy, go
figure. Anyway here is a URL to one of the auctions:
http://cgi.ebay.com/NEW-ALUMINUM-HAR...cm dZViewItem

I also bought a laptop case from the same company and both were outstanding
quality. Good heavy side walls and nice interiors. Take a good look at the
interior dividers on the above auction. The 269 fits exactly.
Good luck and 73,
Ken


"John Ferrell" wrote in message
...
I received the device and have started to use it. My only criticism so
far is that the soft case is too tight to allow easy operation of the
controls. I hope this will loosen up a bit with time.

It is amazing what you can learn about an antenna in such a short
time!
John Ferrell W8CCW

On Fri, 04 Nov 2005 19:43:07 GMT, John Ferrell
wrote:

I am considering ordering the MFJ-269 HF/VHF/UHF Antenna/SWR/RF
Analyzer.

John Ferrell W8CCW