1/4 wave VHF antenna to 5/8 wave UHF ?

[nobody]

Family just found a quarter wave VHF antenna (NMO) I bought several years ago for a fire department radio. I couldn't get that radio programmed so the antenna and coax sat up for a WHILE. I already have an antenna for my two meter radio and have thought about using the old quarter wave VHF for a mobile GMRS radio or a 70cm radio.
My question is, is it practical? Will it need a coil of some sorts to work on UHF? The best I could find on the net was using an old quarter wave VHF as a 3/4 wave UHF antenna but no mention of actually cutting / tuning the antenna. Do to my terrain and intended (simplex only) setup I feel the 5/8 wave would serve me best. Based on the antenna calculators it appears I would have to shorten it a little. The antenna is a Maxrad and the base of the stinger / whip is coiled up to form the contact with the mount. Not sure if I could get it coiled up enough to insure a good contact with the base? Don't have any other need for it at the moment.
Still gotta get the radios programmed and the license.

 

[Shockwave]

Any end fed 5/8 wave will need an impedance matching coil at the base just like the end fed 1/2 wave will. Only the 1/4 wave and 3/4 wave antennas can be directly fed. Out of those two the 1/4 wave is vastly superior to a 3/4 wave. The 3/4 wave will concentrate its radiation at an extremely high useless angle. You'll get much better line of sight with the 1/4 wave or 5/8 wave if you can match it.

All 3/4 wave end fed antennas are very poor performers except for the Sigma IV design which controls the out of phase radiation responsible for the high angle. The only other time we see commercial use of a 3/4 wave is when it's a dual band antenna and the higher frequency usually gets compromised performance having to deal with the 3/4 wavelength.

 

[nobody]

Well that answers that question.

Read that about the 3/4 waves.

Maybe I can find some other use for the antenna. Thanks.