[MRCA] AN/PRC-108 Antenna

[B. Smith]

  On "modeling" the difference between a seven (7) foot whip and the 
three foot whip be sure and include the ground radial system otherwise 
your software results will not be accurate.
Z



On 6/26/2018 8:56 AM, Ray Fantini wrote:

"Assuming that any vertical would be a poor compromise would there be 
any real difference between using the super short three foot vertical as 
opposed to the seven foot vertical? Can anyone model what the difference 
would be?"

> So the question is this, I am in the process of building up some sort 
> of small whip antenna for my PRC-108 transceiver. It has rocks for 
> both 3.885 and 5.357 installed being it operates on both USB and AM. 
> Happy with the way it works when used with its 50 Ohm output driving a 
> dipole or inverted V but the idea now is to have a vertical whip for 
> backpack portable operation over short distances, things like Dayton 
> or other field events.
>
> The radio has an internal loading coil and second output that can 
> drive a short antenna but the problem is that I will have to fabricate 
> the adapter plate, mount and antenna from scratch. I have two choices 
> for the antenna that I am currently looking at. The first choice is a 
> seven foot whip antenna but I do not have a base for that antenna yet, 
> and it appears that it would be a rigid non flexible base if I build 
> one. The second antenna is just a little over three feet long but has 
> a spring base and good attachment point. I would prefer to work with 
> the shorter whip being it’s mechanically better and also would avoid 
> some of the issues that the long antenna with the rigid base may get into.
>
> At the frequencies this radio operates at both antennas would be way 
> short and I think what the radio originally had was a ten foot whip 
> but the possibility of finding that is right up there with Hens teeth. 
> Assuming that any vertical would be a poor compromise would there be 
> any real difference between using the super short three foot vertical 
> as opposed to the seven foot vertical? Can anyone model what the 
> difference would be?
>
> Ray F/KA3EKH
>
>