Hi Rik and Andy,
yes you are completely right.
>...but on LF Rrad <<< Rloss...
>...where Rrad is more like a few milli-ohms and
>the overall extra loss resistance totally dominates...
That's the point I've overlooked.
73
Clemens
DL4RAJ
>-----Original Message-----
>From: [email protected]
>[mailto:[email protected]] On Behalf Of Rik Strobbe
>Sent: Saturday, August 15, 2015 6:55 PM
>To: [email protected]
>Subject: RE: LF: Re: RE: Folded monopole - Food for thought
>
>HI Clemens,
>
>but on LF Rrad <<< Rloss, in that case it is very close to 6dB.
>And often adding a topload wire will decrease Rloss (footprint
>theory), so the actue gain will often be more than 6dB.
>
>73, Rik ON7YD - OR7T
>
>
>________________________________________
>Van: [email protected]
>[[email protected]] namens Clemens Paul
>[[email protected]]
>Verzonden: zaterdag 15 augustus 2015 19:28
>Aan: [email protected]
>Onderwerp: RE: LF: Re: RE: Folded monopole - Food for thought
>
>Hi Andy,
>
>>6dB more, not 3dB
>>Height squared
>
>I believe it's neither 3dB nor 6dB increase for ERP.
>What is squared by doubling the effective height is is Rrad.
>The increase in ERP is by far not so high and depends much on
>Rloss (ground and matching).
>Example:
>Rrad = 50 Ohm; Rloss = 50 Ohm => efficiency = 0.5
>Quadruple Rrad to 200 Ohm then efficiency = 0.8 => 2dB more.
>Other Rloss values give completeley different numbers for efficiency.
>
>73
>Clemens
>DL4RAJ
>
>
>>-----Original Message-----
>>From: [email protected]
>>[mailto:[email protected]] On Behalf Of Andy Talbot
>>Sent: Friday, August 14, 2015 10:38 PM
>>To: [email protected]
>>Subject: Re: LF: Re: RE: Folded monopole - Food for thought
>>
>>6dB more, not 3dB
>>Height squared
>>
>>'jnt
>>
>>
>>On 14 August 2015 at 22:31, Alan Melia
>><[email protected]> wrote:
>>
>>
>> The problem with a monopole at LF is that the effective
>>height is only half (approx) the physical height. For an
>>inverted L where the top length is at least twice the height,
>>the effective height is close to the physical height .....so
>>3dB more ERP. It may not matter so much on 160m (I used a
>>16foot centre loaded "tank-whip" at one time :-)) ) but where
>>
>>
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