David
You are correct
Dan Schaaf
K3ZXL
"In the Beginning there was Spark Gap"
www.k3zxl.com
----- Original Message -----
From: "David J. Sourdis - HK1A" <hk1kxa@hotmail.com>
To: <towertalk@contesting.com>
Sent: Monday, April 19, 2010 1:16 AM
Subject: Re: [TowerTalk] 1/4 wave vertical question
>
> Tell me if I am wrong: The trap should be for 30m band, 10,1 MHz, not for
> 7MHzFrom the bottom of the vertical to the bottom of the 30m trap is
> around 1/4WL at 10.1 Mhz. NOT AT 7 MHz.At 7 MHz the RF is not trapped and
> uses the whole lenght of the antenna.
>
>
> 73
>
> David
> HK1A
> EC5KXA
> ex-HK1KXA
>
>
>
>
>> From: youngron@verizon.net
>> To: towertalk@contesting.com
>> Date: Sun, 18 Apr 2010 21:33:15 -0400
>> Subject: Re: [TowerTalk] 1/4 wave vertical question
>>
>> >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
>> diameter of the vertical the shorter for a given frequency. The length
>> above
>> the trap to resonate on 30 Meters will depend on the inductance of the
>> trap.
>> I don't know what you are using but usually the 30 meter length would be
>> measured from the top of the 40 meter trap. Put it up, run SWR curves
>> for
>> both bands and adjust length to resonate on each band. 73, Ron W8RJL
>>
>>
>> ----- Original Message -----
>> From: "Dan Schaaf" <dan-schaaf@att.net>
>> To: "Tower and HF antenna construction topics."
>> <towertalk@contesting.com>
>> Sent: Sunday, April 18, 2010 9:27 AM
>> Subject: [TowerTalk] 1/4 wave vertical question
>>
>>
>> >I am building a 1/4 wave vertical for 30 and 40 meters with a coax trap.
>> > In order to do the initial measurements, can anyone tell me if the 30
>> > meter length includes the trap or if the 30 meter length stops at the
>> > bottom of the trap or in the center of the trap?
>> >
>> > Dan Schaaf
>> > K3ZXL
>> > "In the Beginning there was Spark Gap"
>> > www.k3zxl.com
>> > _______________________________________________
>> >
>> >
>> >
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>> >
>>
>>
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