I'm guessing someone here has a 259B. I bought a used one that was
damaged in shipping. I sent it to MFJ for repair and it came back
with continued issues, one of which was when I would have it tell me
the coax loss of a 350' length of RG-213, the result was 12dB. I knew
that was wrong so I tried it into a bird dummy load with a 4' length
of coax and again the result was 12dB. When attached to an antenna,
the farther from resonance, the lower the claimed dB.
I returned it to MFJ citing this example as an obvious error. They
repaired it and I just got it back today.
I have the exact same results. If the center conductor is inserted, I
see a small dB value but when the shield makes contact with the
259B, it behaves as above.
If there is no coax attached, it reads 0 dB.
To offer exact numbers, I just attached my 350' of RG-213 connected
to a 160M inverted L and:
@ 1.825MHz SWR is 1:1, R=53 X=5
Push the mode button once and it goes to Coax Loss and it shows 12dB
If using the same antenna & coax, I adjust the tune control on the
259B to evaluate 2.373MHz
the SWR shows 7.3 R=17 X=66 and the coax loss shows 1.1dB
I am at a complete loss as to what is going on, Based on 350' of RG-
213 and using this calculator http://www.timesmicrowave.com/cgi-
bin/calculate.pl I expected to see around .9dB loss not 12dB
So either I am missing the point of how to read the loss or this unit
is still incorrectly reading the line loss. If that's the case, I
can't feel secure about anything it's revealing. I really want to
know the radiation resistance at the antenna to know if I am seeing a
significant difference with additional radials. I just don't trust
Is there something I am doing incorrectly? Or is this still defective
after two visits to MFJ over the last three weeks?
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