V.F.=.64 does seem a bit low, but if it's the type of line where the
wires are very close together, embedded in thick, solid polyethylene,
it's not too far out of line. It's easier to get a good short than a
good open, because of fringing effects, but the error from that should
be very tiny with small line at that frequency. If your analyzer
finds high impedance, too, try shorting the other end of the line and
see if you get the same result. Or look for a half-wave reflection of
the short back to a near-short again. Also, check the analyzer with a
physical short right at the analyzer. Is the analyzer for unbalanced
lines? If so, see if a simple ferrite bead choke balun on the line at
the analyzer makes a difference in the measurement.

Cheers,
Tom

(Richard) wrote in message . com...
What would be the best way to adjust a quarter wave of 75 Ohm twin
line using an antenna analyser? I just connected mine across the
analyser (open circuit) and looked for the freq where a short showed -
is that likely to be accurate? At 10.1 MHZ I ended up with a 15.7 foot
line which seems a bit short (low velocity factor).

73

Richard
G3CWI