Forget the trap idea.
Put a 1/4-wavelength of 75-ohm coax between your 50-ohm feedline and
the feedpoint. The antenna will work on both bands if you use a tuner
at the rig.
Don't ask me why, but I've worked almost 200 countries on 30m with a
good signal using the above antenna.
Don
N8DE
Quoting Ron W8RJL <youngron@verizon.net>:
> Rick, you are correct, I was in a rush and had my thinking backwards.
>> From the feed point to the trap should be 1/4 wave for 30 meter ~23 feet
> depending on conductor diameter.
> The trap should be resonant at about 10 MHZ. It is better to error on the
> low side.
> On 40 meters the 23 foot section plus the inductance of the trap plus what
> is above the trap resonates on 40 meter.
> Feed impedance depends on many factors including the numbers of radials.
> 73, Ron W8RJL
>
>
> ----- Original Message -----
> From: "Richard (Rick) Karlquist" <richard@karlquist.com>
> To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
> Sent: Monday, April 19, 2010 1:52 AM
> Subject: Re: [TowerTalk] 1/4 wave vertical question
>
>
>>
>>
>> Ron W8RJL wrote:
>>>> From the bottom of the vertical to the bottom of the 40 meter trap will
>>>> be
>>> about 32 feet depending on the diameter of the vertical. The larger the
>>
>> The trap should be a 30 meter trap located about 24 feet up.
>>
>> Rick N6RK
>> _______________________________________________
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