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Just 'playing' with some numbers you furnished...
A 1/2 wave of wire sticking out of a 1/8th wave of tubing. Does that remind you of something? How about a Zepp, or a 'J'-pole? Not the 'classic' lengths, but close, sort of.
(And no matter what that SWR meter says, the 'X' below it tells the story when using a '259'.)
Something else you might consider. What determines the impedance of coax cable? It's the diameters of the center conductor and the shield (outer tubing) and the electrical characteristics of the insulation between the two, right? That impedance (Z) is always composed of (R +/- J) and varying the dimensions of the cable changes that 'R' and 'J' (or 'X' if you're using a '259).
Doesn't that make the 'tubing' an impedance matching device? Not a very 'handy', or convenient way of doing it, but certainly possible.
- 'Doc

<blockquote data-quote="W5LZ" data-source="post: 400674" data-attributes="member: 129">Just &#039;playing&#039; with some numbers you furnished...A 1/2 wave of wire sticking out of a 1/8th wave of tubing.&nbsp; Does that remind you of something?&nbsp; How about a Zepp, or a &#039;J&#039;-pole?&nbsp; Not the &#039;classic&#039; lengths, but&nbsp; close, sort of.(And no matter what that SWR meter says, the &#039;X&#039; below it tells the story when using a &#039;259&#039;.)Something else you might consider.&nbsp; What determines the impedance of coax cable?&nbsp; It&#039;s the diameters of the center conductor and the shield (outer tubing) and the electrical characteristics of the insulation between the two, right?&nbsp; That impedance (Z) is always composed of (R +/- J) and varying the dimensions of the cable changes that &#039;R&#039; and &#039;J&#039; (or &#039;X&#039; if you&#039;re using a &#039;259).&nbsp; Doesn&#039;t that make the &#039;tubing&#039; an impedance matching device?&nbsp; Not a very &#039;handy&#039;, or convenient way of doing it, but certainly possible.<img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":)" title="Smile&nbsp; &nbsp; :)"&nbsp; data-smilie="1"data-shortname=":)" />&nbsp;- &#039;Doc</blockquote>

[QUOTE="W5LZ, post: 400674, member: 129"] Just 'playing' with some numbers you furnished... A 1/2 wave of wire sticking out of a 1/8th wave of tubing. Does that remind you of something? How about a Zepp, or a 'J'-pole? Not the 'classic' lengths, but close, sort of. (And no matter what that SWR meter says, the 'X' below it tells the story when using a '259'.) Something else you might consider. What determines the impedance of coax cable? It's the diameters of the center conductor and the shield (outer tubing) and the electrical characteristics of the insulation between the two, right? That impedance (Z) is always composed of (R +/- J) and varying the dimensions of the cable changes that 'R' and 'J' (or 'X' if you're using a '259). Doesn't that make the 'tubing' an impedance matching device? Not a very 'handy', or convenient way of doing it, but certainly possible. :) - 'Doc [/QUOTE]

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