"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... It was obvious that the analyzer was
displaying the wrong SWR on every antenna.
I would consider that a pretty poor test of the analyzer. Find a known good
50 Ohm termination ( at 70cM) and use it to test the analyzer. Although you
did not state it, I assume you are testing these antennas through a length
of coaxial cable- unless you account for the cable's electrical length and
loss, the readings will not be accurate.

Dale W4OP

"Dale Parfitt" wrote in message
...

"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... It was obvious that the analyzer was
displaying the wrong SWR on every antenna.
I would consider that a pretty poor test of the analyzer. Find a known good
50 Ohm termination ( at 70cM) and use it to test the analyzer. Although you
did not state it, I assume you are testing these antennas through a length
of coaxial cable- unless you account for the cable's electrical length and
loss, the readings will not be accurate.

Dale W4OP


Yup ... those reading look a lot like 100' of old RG-58 with a
short or open at the other end ;-)

--

... Hank

Hank: http://horedson.home.att.net
W0RLI: http://w0rli.home.att.net

"Dale Parfitt" wrote in message
...

I would consider that a pretty poor test of the analyzer. Find a known
good
50 Ohm termination ( at 70cM) and use it to test the analyzer. Although
you
did not state it, I assume you are testing these antennas through a length
of coaxial cable- unless you account for the cable's electrical length and
loss, the readings will not be accurate.

Dale W4OP

I've tested the other antennas (HF and VHF) at the end of the coax with the
analyzer and they show the same results as on the air tests with the
wattmeter. When I switch to UHF, the results are completly different between
my on the air tests and the analyzer. I'd say this is a good indication of a
problem. I also tested one of the UHF antennas at the antenna, with a small
jumper, about 8 feet in length.

"Dale Parfitt" wrote in message
...

"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... It was obvious that the analyzer was
displaying the wrong SWR on every antenna.
I would consider that a pretty poor test of the analyzer. Find a known good
50 Ohm termination ( at 70cM) and use it to test the analyzer. Although you
did not state it, I assume you are testing these antennas through a length
of coaxial cable- unless you account for the cable's electrical length and
loss, the readings will not be accurate.

Dale W4OP


Yup ... those reading look a lot like 100' of old RG-58 with a
short or open at the other end ;-)

--

... Hank

Hank: http://horedson.home.att.net
W0RLI: http://w0rli.home.att.net

"Dale Parfitt" wrote in message
...

I would consider that a pretty poor test of the analyzer. Find a known
good
50 Ohm termination ( at 70cM) and use it to test the analyzer. Although
you
did not state it, I assume you are testing these antennas through a length
of coaxial cable- unless you account for the cable's electrical length and
loss, the readings will not be accurate.

Dale W4OP

I've tested the other antennas (HF and VHF) at the end of the coax with the
analyzer and they show the same results as on the air tests with the
wattmeter. When I switch to UHF, the results are completly different between
my on the air tests and the analyzer. I'd say this is a good indication of a
problem. I also tested one of the UHF antennas at the antenna, with a small
jumper, about 8 feet in length.