Even if you go to a rooftop vertical (e.g. R-6000 or similar),
install a high quality common mode choke ("line isolator")
right at the antenna.? The commercial antennas do not have
sufficient built-in choking, particularly for "pathological"
(odd multiples of 1/4 wave) lengths of feedline.? ?I needed
a line isolator where my feedline enters the shack (and will
build a better one for the antenna when I next do maintenance).

Depending on the space available and feedline length, you may
want to consider a G5RV or ZS6BKW antenna.? With them you can
terminate the ladder line outside the shack with a *high quality*
common mode choke/line isolator and bring coax back to the rig.

In either case, I would recommend K9YC's "Choke Cookbook" for
common mode choke/line isolator designs:
? ? <>
Table 3, on page 8 gives several designs for multi-band, two
toriod chokes.? The "160-20" design would be ideal for a
G5RV/ZS6BKW (used on 80-20 or 80-17) and the "30-10" would be
a great add-on choke for a vertical like the R-6000.

73,

? ? ... Joe, W4TV


On 2025-03-04 10:37 AM, Gilbert Baron W0MN via wrote:
> I have done the required calculations and meet the requirements. Nevertheless I tend to agree that it is the direct exposure you refer to. Come nicer weather I may switch to a different antenna that does not need ladder line. Padhans a rooftop vertical while tis 85 year old can still do it.? ?
>
>? ?
>
> Outlook LT Gil W0MN
>
> Hierro Candente Batir de Repente
>
> 44.08226 N 92.51265 W EN34rb
>
>? ?
>
>? ?
>
> -----Original Message-----
> From: [email protected] <[email protected]> On Behalf Of Joe Subich, W4TV via
> Sent: Tuesday, March 4, 2025 8:58 AM
> To: [email protected]
> Subject: Re: [DXLab] RFI Continues on WinWarbler
>
>? ?
>
>? ?
>
> If your problem is not uncontrolled common mode RFI, it is direct RF Exposure.? If direct RF Exposure is causing your problems, you are probably in violation of part 97.13 (c).? Have you performed the calculations required to assure compliance with the regulations referenced in 97.13(c)?
>
>? ?
>
> 73,
>
>? ?
>
>? ? ? ... Joe, W4TV
>
>? ?
>
> On 2025-03-04 8:44 AM, Gilbert Baron W0MN via wrote:
>
>> I put on toroids on all things that enter the PC.
>
>>
>
>> I have followed many thigs to try to get good ground system .
>
>>
>
>> I HAVE NO PROBLEMS WITH ANY OTHER PROGRAM BUT WINWARBLER IS USELESS ON
>
>> 20m AT > 300? Watts.
>
>>
>
>> Antenna is fed with ladder line and? 12 feet of the line is indoors so
>
>> I assume this is RFI. I have no? problems on even higher frequencies
>
>> with Coax Fed Dipole.
>
>>
>
>> I do find it strange that ONLY WinWarbler FAILS. I END UP WITH 2
>
>> COPIES RUNNING. If I terminate? ALL with Launcher it terminates? only
>
>> one? of them (ALL OTHER APPS DO END) and forces a Restart of? PC to fix.
>
>>
>
>>? ?
>
>>
>
>> It looks I need a different antenna system that does not require the
>
>> ladder line? feed. I can run WinWarbler with? no problem on other
>
>> bands and o 20 M into dummy load.
>
>>
>
>>? ?
>
>>
>
>> What does anyone think? Am I? stuck. I guess I could try returning to
>
>> my Older W10 Machine? that had NONE of this? trouble, even before
>
>> spending 100 for Toroids. The Toroids did help a lot since more than
>
>> WinWarbler was failing before? installing? them.
>
>>
>
>>? ?
>
>>
>
>>? ?
>
>>
>
>>? ?
>
>>
>
>>? ?
>
>>
>
>> Outlook LT Gil W0MN
>
>>
>
>> Hierro Candente Batir de Repente
>
>>
>
>> 44.08226 N 92.51265 W EN34rb
>
>>
>