Motorcycle Radio Antenna

Yes, Will be a lot better.

Put it on a metal part, that serves as base. A plate is best.

For best results, ground that plate to your electrical and mechanical minus.

Trimming will be most necessary for the AM stations.

Yes

Seems as if I provided a detailed answer to this question previously, but it didn't show up.

The short answer, as given by myself previously, and others, is yes. An antenna about a meter long is best for the FM broadcast band (BCB). If the antenna is used only for FM BCB reception then no antenna matching/ tuning is necessary. That is only for AM BCB reception.

You will need to run coax between the radio and the antenna; not simply the wire hanging out of the radio. The reason is that coax is shielded, and it will provide protection against rfi pickup from your ignition system and other electrical noise sources. Nowadays your motorcycle may well have a computer on it checking all sorts of functions, and that can be noisy. Relative to rfi, you want to mount the antenna as far away from noise sources as possible. I would expect, but cannot say for certain (not knowing the bike) that the best placement would be as far back as possible.

Coax can be any commonly available 50 or 75 Ohm, or whatever you can get at a specialty store that sells automotive aftermarket add-ons. If the antenna also is used for AM BCB reception, then the coax is very different, and you need to make sure it is the low capacitance type. I would avoid that if you aren't getting AM reception; the low capacitance coax has a fragile center conductor, and the vibration of a motorcycle isn't its friend.

The coax shield must be 360 degree peripherally terminated at each end. As another response said, the antenna should be mounted to a plate; the plate should be grounded to the motorcycle frame. If done this way the rf connector at the plate end will give a good ground. At the radio end, the termination is taken care of by the antenna connector, but it will work much better if the radio chassis is also grounded to structure.

If you are getting lots of rfi from the cycle, get back and we can cover rfi mitigation approaches beyond the good bonding techniques cited here.

emc_c

There is not an external antenna connection on the Shark radio. Do you connect the shield to the chassis of the radio and the antenna wire to the antenna wire of the radio?

If you are doing a large amount of touring and the radio is important to you, consider leaving the standard antenna on and add an XM satellite receiver that you tune to one of the FM stations on your radio. Since I have XM, I can't go back to all the commercials and the hassle of trying to find a relevant station while I am driving. If you get tired of one style of music, click on to another. It is worth every penny of the monthly charge for me.

ThermalSprayGuy

Put it on your helmet along with the other things you carry on it. Kidding aside, the information you have recieved is solid. Use a stiff enough whip to keep it from hitting you or a passenger in panic situations.