transciever TM751

[Thomas Arman]

Hmmm, this is what I thought was the  formula for 1/4 wave resonant antennas
2992/freq in MHZ EXAMPLE 2992 divided by 155.0 = 19.3 (inches)

You may think this isn't exactly correct, but the 2992 is compensated for "end effect" - which means - the traveling 'wave' tends to 'stretch' itself a bit beyond the end of the antenna (like a ghost image). The THINNER the wire, the more pronounced the effect, AND the narrower the bandwidth. This is why most TV antenna elements are THICK. It's not just the support thickness gives, it the bandwidth of the reception frequency and the reduced end effect. 


So 2992/315 = ~ 9.5"

Tom
On Sep 29, 2014, at 9:59 AM, Thomas Henry <tjhjr at mac.com> wrote:

> Doug,
> 
> What are the lengths or your elements and Vertical radiator?  The measurements on the site might not be for a ¼-wave.
> 
> For a quarter-wave I use 234/Freq (in MHz) to get my element length. Using that, I get .75” for each one.
> 
> If my calculation is correct, it would not only take up a lot less space, but it would easily fit in a drop-ceiling or corner of a room.
> 
> Tom
> 
> 
> On Sep 26, 2014, at 9:12 PM, Doug Kiekow <dougy at iphouse.com> wrote:
> 
>> I've been using ground-plane antennas to gain a bit of extra range. There is a great tutorial on how to build one at http://cocoontech.com/forums/topic/126-how-to-build-an-antenna-for-your-x-10-receiver/
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