You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
The Feb 2025 Radioddity Giveaway Results are In! Click Here to see who won!

Reply to thread

Message

Well, according to Maxwell a 1/4 wave has 5db gain over an isotropic and a 5/8 has 3 db gain over a 1/2 wave. Those are numbers I used to hear back in the '70s, not 1.2db for a 5/8 over a 1/2 and a 1/4 wave is .85db less than an isotropic like I've read lately.
It sounds like the ideal length is 7495 / mhz or 275.5" for a .6346 at 27.2 minus average circumference= 273" minus 10" top hat= 263" or 21' 11" for tuning at 27.2 but where do you measure on the I10k because it looks like it has a 45 degree plate at the base of the vertical radiator.
I would guess the most direct path and measure from the top bolt to the top hat 263" then adjust the trombone for middle C :blink:
I need to find a copy of Reflections by Maxwell. I found that interesting reading.
Thanks Marconi

<blockquote data-quote="Needle Bender" data-source="post: 343694" data-attributes="member: 13339">Well, according to Maxwell a 1/4 wave has 5db gain over an isotropic and a 5/8 has 3 db gain over a 1/2 wave. Those are numbers I used to hear back in the &#039;70s, not 1.2db for a 5/8 over a 1/2 and a 1/4 wave is .85db less than an isotropic like I&#039;ve read lately.It sounds like the ideal length is 7495 / mhz or 275.5&quot; for a .6346 at 27.2 minus average circumference= 273&quot; minus 10&quot; top hat= 263&quot; or 21&#039; 11&quot; for tuning at 27.2 but where do you measure on the I10k because it looks like it has a 45 degree plate at the base of the vertical radiator.I would guess the most direct path and measure from the top bolt to the top hat 263&quot; then adjust the trombone for middle C :blink:I need to find a copy of Reflections by Maxwell. I found that interesting reading.Thanks Marconi<img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f44d.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":thumbup1:" title="Thumbs Up&nbsp; &nbsp; :thumbup1:"&nbsp; data-smilie="27"data-shortname=":thumbup1:" /></blockquote>

[QUOTE="Needle Bender, post: 343694, member: 13339"] Well, according to Maxwell a 1/4 wave has 5db gain over an isotropic and a 5/8 has 3 db gain over a 1/2 wave. Those are numbers I used to hear back in the '70s, not 1.2db for a 5/8 over a 1/2 and a 1/4 wave is .85db less than an isotropic like I've read lately. It sounds like the ideal length is 7495 / mhz or 275.5" for a .6346 at 27.2 minus average circumference= 273" minus 10" top hat= 263" or 21' 11" for tuning at 27.2 but where do you measure on the I10k because it looks like it has a 45 degree plate at the base of the vertical radiator. I would guess the most direct path and measure from the top bolt to the top hat 263" then adjust the trombone for middle C :blink: I need to find a copy of [I]Reflections [/I]by Maxwell. I found that interesting reading. Thanks Marconi:thumbup1: [/QUOTE]

Top Bottom