View Single Post
  #5   Report Post  
Old December 27th 05, 04:07 AM posted to rec.radio.amateur.antenna
dansawyeror
 
Posts: n/a
Default measurement error or bad coax??

Roy, thanks.

1. The far end was open.

2. I used an 8405a and a directional coupler connected in reverse. I zeroed the
8405a open stub between the driven signal and the reflected signal. I then added
a coax segment and the feedline to bring the the 8405a back to near zero
deflection at a frequency near the frequency of interest. I then tweaked the
frequency to re-zero the reflected signal.

3. I believe the reading was 30R and 0j. The intention was to tune frequency and
the meter to one electrical wave length and reach zero x.

Dan

Roy Lewallen wrote:
Owen Duffy wrote:


Dan, you are a master of asking questions with partial / unreliable
information... and you have done it again!

Doesn't the Belden cable have a legible type marking?

How much RG58 did you add? (Why?)

What frequency did you make the measurement?

Was it 30+j0?

What was the objective of the measurement? If it was to determine
cable loss, does the Autek book give you a procedure for doing that?


Three additional questions:

What was connected to the far end of the coax when you made the
measurement?

How did you determine that the combination cable was one wavelength long?

What was the angle of the impedance, or the resistive and reactive (R
and X) parts?

Roy Lewallen, W7EL