To: | towertalk@contesting.com |
---|---|
Subject: | Re: [TowerTalk] real world formula for the length of a quarter wave transmission line |
From: | Jim Lux <jimlux@earthlink.net> |
Date: | Wed, 13 Feb 2013 21:07:22 -0800 |
List-post: | <towertalk@contesting.com">mailto:towertalk@contesting.com> |
On 2/13/13 11:39 AM, n2mm@comcast.net wrote: Help, I lost my antenna handbook. Does anyone know the formula that is fairly accurate for a 75ohm quarter wave tranformer for my 80m quad. is it 234xVF or 246 x VF 3e8 m/sec free space speed of light 300m/microsecond 80m is 3.75 MHz 80meters*VF gives you one wavelength that's 80*3.28 ft = 262.4 ft so a 1/4 wavelength is going to be 262.4/4*VF ft or 64.6*VF feet for 3.5 MHz -> lambda = 300/3.5 = 85.7 meters = 281 ft for 4.0 MHz -> lambda = 300/4 = 75 meters = 246 ft So, for a top of 75meters 1/4 wave, it would be 246*VF/4 or 61.5*VF _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk |
<Prev in Thread] | Current Thread | [Next in Thread> |
---|---|---|
|
Previous by Date: | Re: [TowerTalk] Using Mouser parts to build HyGain rotator quick-connect cable, K8RI |
---|---|
Next by Date: | Re: [TowerTalk] real world formula for the length of a quarter wave transmission line, Jim Brown |
Previous by Thread: | [TowerTalk] real world formula for the length of a quarter wave transmission line, n2mm |
Next by Thread: | Re: [TowerTalk] real world formula for the length of a quarter wave transmission line, Jim Brown |
Indexes: | [Date] [Thread] [Top] [All Lists] |