Help with Antenna Trimming

[Se7en]

I have a Tram 1150 2m mono band NMO antenna I'd like to cut down for 440mhz. Preferably between 430-450mhz (Yes that is Canada's band plan but i do not have any repeaters here that covers 420-430Mhz). The antenna is bottom loaded coil with a long stainless steel whip that is 49" long. How much do i need to trim? I have as meter so checking wont be an issue, Just don't want to start chopping without some helpful tips.

 

[KC9Q]

Vanilla,

I looked at the Tram 1150, and it looks to be a 5/8 wave 2 meter monobander. I don't think this antenna can be trimmed or used for the UHF band. I found a tuning/cutting chart for 2 Meters only.

You could get a 2 Meter 1/4 wave whip and use it for both 2 Meters and UHF also (i.e., 1/4 Wave at 2M is also a 3/4 wave at UHF). I don't know why you are trying to make a 2 Meter antenna work on a UHF frequency band?

Mike

 

[Se7en]

Vanilla,

I looked at the Tram 1150, and it looks to be a 5/8 wave 2 meter monobander. I don't think this antenna can be trimmed or used for the UHF band. I found a tuning/cutting chart for 2 Meters only.

You could get a 2 Meter 1/4 wave whip and use it for both 2 Meters and UHF also (i.e., 1/4 Wave at 2M is also a 3/4 wave at UHF). I don't know why you are trying to make a 2 Meter antenna work on a UHF frequency band?

Mike

It is a extra antenna I am not using. I have a diamond nr22l on the mobile and a duplexer and no 70cm antenna. Since this tram is not in use I figured I could cut it for 70cm.

 

[vo1ks]

It's unlikely the antenna will work on 70cm as the coil is use for matching at 2 meters. If you want to mess around with it, take off the original stainless steel whip and put on a piece of 12 gauge wire. Trim and cut the wire and experiment. If you find something that works use the wire as a template to trim the stainless whip.