"Pete KE9OA" wrote in message
...
While it is possible that your analyzer isn't working, it is also possible
that you do have some wild variances in impedance with your current setup.
I
took a look at the return loss of one of my antenna systems with a
tracking
generator/spectrum analyzer combination, and did see some multiple
resonance
nodes. This measurement was done, using a Narda directional coupler, which
is flat out to 12GHz, as measured on an HP 8753E Network Analyzer.
Some sort of transfer standard such as an accurate 50 Ohm load would
verify
if your analyzer is bad.

Pete

Considering that all 3 antennas showed appropriate SWR readings on their
respective frequencies on my wattmeter with on-the-air tests, and the
analyzer showed wild SWR readings on the same frequencies, I'd say the
analyzer is at fault. Works perfectly at HF/VHF, so I basically have an
MFJ-259 in an MFJ-269 shell until they fix it.

UPS picked it up yesterday. Hopefully I will hear something within the next
2 weeks.

I must have been asleep when I made this post....................It was an
8717 or 8718............the 8753 only goes out to 3GHz!

Pete

"Pete KE9OA" wrote in message
...
While it is possible that your analyzer isn't working, it is also possible
that you do have some wild variances in impedance with your current setup.
I
took a look at the return loss of one of my antenna systems with a
tracking
generator/spectrum analyzer combination, and did see some multiple
resonance
nodes. This measurement was done, using a Narda directional coupler, which
is flat out to 12GHz, as measured on an HP 8753E Network Analyzer.
Some sort of transfer standard such as an accurate 50 Ohm load would
verify
if your analyzer is bad.

Pete

"Bob" wrote in message
...
I have a Diamond X-6000A triband antenna, and its SWR curves are 'wavy'
on VHF and a little on UHF, not the smooth symmetrical log curve one
might expect. It's likely the interaction of the other band resonances,
but nothing to lead me to believe it's broken.

I like the suggestion about trying a good quality dummy load on it (or
perhaps another analyser on the same group of antennas) before you
condemn the thing as junk.

Good luck!

B

I must have been asleep when I made this post....................It was an
8717 or 8718............the 8753 only goes out to 3GHz!

Pete

"Pete KE9OA" wrote in message
...
While it is possible that your analyzer isn't working, it is also possible
that you do have some wild variances in impedance with your current setup.
I
took a look at the return loss of one of my antenna systems with a
tracking
generator/spectrum analyzer combination, and did see some multiple
resonance
nodes. This measurement was done, using a Narda directional coupler, which
is flat out to 12GHz, as measured on an HP 8753E Network Analyzer.
Some sort of transfer standard such as an accurate 50 Ohm load would
verify
if your analyzer is bad.

Pete

"Bob" wrote in message
...
I have a Diamond X-6000A triband antenna, and its SWR curves are 'wavy'
on VHF and a little on UHF, not the smooth symmetrical log curve one
might expect. It's likely the interaction of the other band resonances,
but nothing to lead me to believe it's broken.

I like the suggestion about trying a good quality dummy load on it (or
perhaps another analyser on the same group of antennas) before you
condemn the thing as junk.

Good luck!

B

I am sure that it is quite possible that your unit has a problem, but still,
a directional wattmeter is not the absolute means of measurement accuracy.
When working in an RF lab, even the Bird 43 series elements need to be
calibrated against a power meter, such as an HP 437. I wouuld still try an
accurate 50 Ohm load for characterization.
Good luck.

Pete

"Andy Cogswell" SHORECOGS at COMCAST DOT NET wrote in message
news
"Pete KE9OA" wrote in message
...
While it is possible that your analyzer isn't working, it is also
possible
that you do have some wild variances in impedance with your current
setup.
I
took a look at the return loss of one of my antenna systems with a
tracking
generator/spectrum analyzer combination, and did see some multiple
resonance
nodes. This measurement was done, using a Narda directional coupler,
which
is flat out to 12GHz, as measured on an HP 8753E Network Analyzer.
Some sort of transfer standard such as an accurate 50 Ohm load would
verify
if your analyzer is bad.

Pete

Considering that all 3 antennas showed appropriate SWR readings on their
respective frequencies on my wattmeter with on-the-air tests, and the
analyzer showed wild SWR readings on the same frequencies, I'd say the
analyzer is at fault. Works perfectly at HF/VHF, so I basically have an
MFJ-259 in an MFJ-269 shell until they fix it.

UPS picked it up yesterday. Hopefully I will hear something within the
next
2 weeks.

I am sure that it is quite possible that your unit has a problem, but still,
a directional wattmeter is not the absolute means of measurement accuracy.
When working in an RF lab, even the Bird 43 series elements need to be
calibrated against a power meter, such as an HP 437. I wouuld still try an
accurate 50 Ohm load for characterization.
Good luck.

Pete

"Andy Cogswell" SHORECOGS at COMCAST DOT NET wrote in message
news
"Pete KE9OA" wrote in message
...
While it is possible that your analyzer isn't working, it is also
possible
that you do have some wild variances in impedance with your current
setup.
I
took a look at the return loss of one of my antenna systems with a
tracking
generator/spectrum analyzer combination, and did see some multiple
resonance
nodes. This measurement was done, using a Narda directional coupler,
which
is flat out to 12GHz, as measured on an HP 8753E Network Analyzer.
Some sort of transfer standard such as an accurate 50 Ohm load would
verify
if your analyzer is bad.

Pete

Considering that all 3 antennas showed appropriate SWR readings on their
respective frequencies on my wattmeter with on-the-air tests, and the
analyzer showed wild SWR readings on the same frequencies, I'd say the
analyzer is at fault. Works perfectly at HF/VHF, so I basically have an
MFJ-259 in an MFJ-269 shell until they fix it.

UPS picked it up yesterday. Hopefully I will hear something within the
next
2 weeks.

"Andy Cogswell" SHORECOGS at COMCAST DOT NET wrote in message
...
I bought an MFJ-269 from KC7SLO in September last year. When it arrived, I
tested it and found that the UHF portion did not display the correct SWR.
I
tested it with 3 different UHF antennas. It works fine everywhere else.
The
problem was that although on the air tests with the antennas all showed
them
with low SWR in the proper frequency ranges, the analyzer told me on every
one that they all had wavy SWR patterns. For example: 415mhz 1.7, 420mhz
2.5, 423mhz 1.2, 431 2.1, etc...

You don't mention it in your note, but are you in an area of high UHF usage?
Could it be strong signals from other nearby UHF stations who might be
influencing your readings?

The readings of 259's (I don't know about other models or other
manufacturer's analyzers) can be affected in the proximity (a few miles) to
AM (650-1650 kHz) radio stations when doing tests at 160m or even 80m.
Maybe similar effects are experienced with nearby UHF stations (Paging,
com'l comm, etc.).

good luck,

dale, kg5u

"Andy Cogswell" SHORECOGS at COMCAST DOT NET wrote in message
...
I bought an MFJ-269 from KC7SLO in September last year. When it arrived, I
tested it and found that the UHF portion did not display the correct SWR.
I
tested it with 3 different UHF antennas. It works fine everywhere else.
The
problem was that although on the air tests with the antennas all showed
them
with low SWR in the proper frequency ranges, the analyzer told me on every
one that they all had wavy SWR patterns. For example: 415mhz 1.7, 420mhz
2.5, 423mhz 1.2, 431 2.1, etc...

You don't mention it in your note, but are you in an area of high UHF usage?
Could it be strong signals from other nearby UHF stations who might be
influencing your readings?

The readings of 259's (I don't know about other models or other
manufacturer's analyzers) can be affected in the proximity (a few miles) to
AM (650-1650 kHz) radio stations when doing tests at 160m or even 80m.
Maybe similar effects are experienced with nearby UHF stations (Paging,
com'l comm, etc.).

good luck,

dale, kg5u

Your question tells me that you should be asking MFJ that question.

Only they will have the answer to what they can do and not do.

Your question tells me that you should be asking MFJ that question.

Only they will have the answer to what they can do and not do.