[NLRS] 50Mhz antenna modeling question

[tom ring]

If I have a chance this weekend, I'll see what I can do.  If it needs to stay 
at 2.5 or 3 feet long, it is already at about what you can achieve.  Gain is 
boom length limited.  If you can give me a max boom length, I may be able to 
give you a solution you can use.

tom
K0TAR

On 16 May 2007 at 17:23, Matt Burt wrote:

> 
> 
> I have built a few antennas for six and now feel the need for something small
> enough for the rover and yet capable of a little forward gain.
> The last three roves my delicate 6M moxon has been damaged due to a mis-hap with
> a tree on my route (one tree is 6 blocks down the road on the only road that
> leaves the subdivision).  As always I will try to get my antenna up as high as
> possible ... but not much more than 20 ft is very practical. Of course I have
> used 3 or even a four element at 15-18ft and had good luck. 
> 
> Any way armed with an old DOS program for calculating dimensions I came up with
> a 2 ele 50Mhz antenna of the following specs:
> REF 117.3"
> DIR (DRV) 116.53"
> BOOM: 30.7"
> expected forward gain 4.74 dBd
> F/B not very good
> element size .375" (maybe .50" at center)
> My plan is to feed the driven element with a T match and 1/2W length piece of
> coax tuned for 50.140.
> The "Z" looks like 49 ohms with some inductive component
> Any modelers out there that can duplicate my numbers?
> 
> KF0Q 
> 
> 
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-----------------------------------------
Tom Ring K0TAR, ex-WA2PHW  EN34hx
85 Westphalia GL Albert
96 Jetta GL The Intimidator
taring at taring.org

What happens if a big asteroid hits the Earth?  Judging from realistic 
simulations 
involving a sledge hammer and a common laboratory frog, we can assume it will 
be pretty bad.
                - Dave Barry
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