Mobile antenna

[HogDriver]

I know having a tuned antenna when transmitting is important. I also know the bigger the antenna, the better for receiving. My experience seems to corroborate this. I have a choke that im using, though I don’t know if it really makes any difference. My intent it to create a whip that works well with 800, but also the rest of the spectrum. I read, that a 1/4 vhf tuned for 155 mhz or so also works well with uhf and 800, but my performance with that setup was disappointing, so I went back with a vhf whip tuned to 159 on top of the choke, on top of a 12 inch (850 mhz), the whole thing about 55 inches long. Thoughts?

BTW, this is for a scanner…no transmitting! This is magnetic-mount on a Truckbox, behind the cab on my pickup, as I park in my garage and clearance is an issue if I put it on the roof.

 

[mmckenna]

A resonate antenna is going to work better. 55" is a bit long to be 5/8ths wave on VHF, and unless you have a proper coil at the base, you've got a mess. Trying to make a 5/8th's wave VHF antenna work well on UHF and 800 isn't going to result in something that performs well.

You can dink around with all kinds of stuff trying to make an antenna do something it wasn't designed to, and in the end you might end up with something that works marginally on many bands. Fun to experiment with, but never going to work well unless you have the maths behind your design to make something that resonates well on the bands you want, and the test equipment to proof it out.

There's really good antennas out there that will do what you want. Larsen NMO-150/450/800 can be hand cheap and will be an excellent performer on VHF, UHF and 800MHz.