Larsen hand-held antenna questions

[kny2xb]

Good Evening;

I have two questions

First, does anyone have a preferred dealer for ordering a Larsen commercial antenna from?

Second [warning, off the wall crazy question here], would a quarter wave at 155 MHz perform as a three-quarter wave at 465 MHz?

I was crunching numbers, lengths, wavelengths, etc for a base antenna I'd like to build,
and I was curious if an antenna like this would work on both MURS [the 154 MHz channels anyway] and GMRS

Would there be any advantage to going this route over a UHF 1/4 wave, 1/2 wave or 5/8 wave?

More to the point, I'm curious if this would work on a portable antenna

If this is feasible, I'd order a KD4-155-HQ3 VHF 1/4 Wave for my ICOM F4GT-2 [9½ inch]

If not, I'll buy a KD14-465-HW UHF 1/2 wave instead [16 inch]

[ Before anyone points it out, I know that I'll also have to buy an adapter to use a BNC antenna on my ICOM, I remembered lol ]

Thank you in advance

 

[mmckenna]

I've used Tessco ( TESSCO - Wireless & Mobile Communications Products: Antennas, Cable, Towers, Test Equipment, Tools, Mobile Phone Accessories ) for a lot of purchases, and while they do have a $50 minimum, they've usually got what I need in stock.

A VHF 1/4 wave will work on the correct UHF frequency as a 3/4 wave. The only issue is that a 3/4 wave antenna has some funky radiation patterns that might result in it performing a bit worse in certain situations. I've done this on 2 meter VHF ham band with a VHF 1/4 wave and the 70cm ham band. Works just fine and the SWR is not an issue. This was a mobile install though with a darn near perfect ground plane. One thing to remember with a hand held radio is that on the lower frequencies, the radio itself doesn't usually provide a whole lot of ground plane, but since you are working on UHF, this shouldn't be an issue.
Because of the funny radiation pattern when using a VHF antenna on the UHF bands, you -might- find that it will not work as well as a properly tuned antenna. Although, since antenna design is 49% math and 51% witchcraft, the only way to know is to try.

 

[SCPD]

What will happen is that you will radiate more off the ends, than the sides. If you want to sort of point the radio in the direction of the repeater you are wanting to make, it may play. But like mmckenna said, you're not radiating equally in all directions when you do this.

 

[kny2xb]

Thank You Both for your input

I think that I'll go with the UHF half wave instead

Right now I don't have the money to experiment and get poor results

I'd rather go for something that's been proven to perform well, and I presume the half wave has the better track record

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I just Googled ¾ wave patterns and actually found a RR post from 2007

One of the replies states that they are out there and are rare

There is no such thing as a full wave verticle antenna for any frequency. The design will not work electrically. The only full wave antenna design that I know of is a Loop.

The longest fractional wave verticle that does work is a 3/4 wave but you don't see a lot of them offered commercially but they are around. The hamstick people make a 3/4 for 2 meters but there is not enough difference to be gained really over a 5/8 wave.....which is the most popular design. To get longer and see added gain from there you start getting into colinear 5/8 designs which are two 5/8 sections, one atop the other. Hustler makes a popular one for 2 meters and this model # is CG - 144

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Soooooooo, again, I think I'll go for the Larsen ½ wave, and down the line for $20.00 or so, I'll buy and try a Smiley ⅝ wave and see how they compare

Thank you again for the advice