Antenna building question
 

I am new to all of this but when building a j pole, if the plan calls
for 1/2 inch and I go with a loarger diameter, say one inch, would the
spacing between the elements still be the same?

Stryped wrote:
"If the plan calls for 1/2 inch and I go with a larger diameter, say one
inch, would the spacing between the elements still be the same?"

Maybe not, if impedance of the line segment is important. See a chart
like Fig 19 on page 24-15 of the 19th edition of the "ARRL Antenna
Book". This shows "Characteristic impedance as a function of conductor
spacing and size for parallel conductor lines."

Best regards, Richard Harrison, KB5WZI

wrote:
I am new to all of this but when building a j pole, if the plan
calls
for 1/2 inch and I go with a loarger diameter, say one inch, would
the
spacing between the elements still be the same?
See http://www.vk1.wia.ampr.org/bulletins/jpole.html

w3rv

The GAP (inside distance) between the Two Legs of the Matching
Transformer is normally less than you can achieve using standard
plumbing fittings especially on the upper frequencies. So the
measurement is often doubled so to speak from 1/20th wavelength to
1/10th wavelength.
When increasing pipe diameter, don't forget the K-factor!
The 1/4 wave matching transformer will be slightly shorter, the 1/2
wave vertical will be shorter, and the GAP will be very slightly
narrower.
Since you cut one leg of the transformer in conjunction with the
vertical element as one piece, don't forget to shorten this pipe by
both reductions in length.

TTUL
Gary