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

The shorter antenna designs - read this as less than 1/4 wavelength or like the 5K is shorter than a 102" whip - the "R" value changes - goes lower - when the antenna is shorter than it should be.

- it then has to add length by using inductance (coil wind) to restore that "X" value
- but it cannot compensate of bring the R-value back up to 50Ω
- to make the SWR Impedance closer to 50Ω the XL is added
- but adding that extra wire cannot bring back R except for being what the antenna "appears as" to the system - an antenna with a Lower R - which means it's offset by winds of wire to balance out Z to be closer to 50Ω
Your R value even though the antenna is shorter - helps to reduce the needs of the antenna having to REQUIRE extra wire because it can't make up the difference in height "Big R versus Little R ". - which helps reduce the dependence of Z (Impedance) requiring XL and XC having to make up the difference (your Conjugate used by the antenna)
Just leave it be. LOW SWR to the radio seems to be more important that to attempt to re-work values for an antenna design - you're better off to design your own antenna in various lengths and see R as different - it can even change by location on the vehicle itself - be ready.

<blockquote data-quote="Handy Andy" data-source="post: 785108" data-attributes="member: 52309">The shorter antenna designs - read this as less than 1/4 wavelength or like the 5K is shorter than a 102&quot; whip - the &quot;R&quot; value changes - goes lower - when the antenna is shorter than it should be.<ul>
<li data-xf-list-type="ul">- it then has to add length by using inductance (coil wind) to restore that &quot;X&quot; value</li>
<li data-xf-list-type="ul">- but it cannot compensate of bring the R-value back up to 50Ω</li>
<li data-xf-list-type="ul">- to make the SWR Impedance closer to 50Ω&nbsp; the XL is added <ul>
<li data-xf-list-type="ul">- but adding that extra wire cannot bring back R except for being what the antenna &quot;appears as&quot; to the system - an antenna with a Lower R - which means it&#039;s offset by winds of wire to balance out Z to be closer to 50Ω </li>
</ul></li>
<li data-xf-list-type="ul">Your R value even though the antenna is shorter - helps to reduce the needs of the antenna having to REQUIRE extra wire because it can&#039;t make up the difference in height &quot;Big R versus Little R &quot;. - which helps reduce the dependence of Z (Impedance) requiring XL and XC having to make up the difference (your Conjugate used by the antenna)</li>
</ul>Just leave it be. LOW SWR to the radio seems to be more important that to attempt to re-work values for an antenna design - you&#039;re better off to design your own antenna in various lengths and see R as different - it can even change by location on the vehicle itself - be ready.</blockquote>

[QUOTE="Handy Andy, post: 785108, member: 52309"] The shorter antenna designs - read this as less than 1/4 wavelength or like the 5K is shorter than a 102" whip - the "R" value changes - goes lower - when the antenna is shorter than it should be. [LIST] [*]- it then has to add length by using inductance (coil wind) to restore that "X" value [*]- but it cannot compensate of bring the R-value back up to 50Ω [*]- to make the SWR Impedance closer to 50Ω the X[SIZE=2]L[/SIZE][SIZE=4] is added [/SIZE] [LIST] [*][SIZE=4]- but adding that extra wire cannot bring back R except for being what the antenna "appears as" to the system - an antenna with a Lower R - which means it's offset by winds of wire to balance out [I][B]Z[/B][/I] to be closer to 50Ω [/SIZE] [/LIST] [*][SIZE=4]Your R value even though the antenna is shorter - helps to reduce the needs of the antenna having to REQUIRE extra wire because it can't make up the difference in height "Big[/SIZE][B][SIZE=4] R[/SIZE][/B][SIZE=4] versus Little [/SIZE][SIZE=3][B]R[/B][/SIZE][SIZE=4] ". - which helps reduce the dependence of Z (Impedance) requiring X[/SIZE][SIZE=3]L [/SIZE][SIZE=4]and X[/SIZE][SIZE=3]C [/SIZE][SIZE=4][B]having to make up the difference[/B] (your Conjugate used by the antenna)[/SIZE] [/LIST] Just leave it be. LOW SWR to the radio seems to be more important that to attempt to re-work values for an antenna design - you're better off to design your own antenna in various lengths and see R as different - it can even change by location on the vehicle itself - be ready. [/QUOTE]

Top Bottom