It is pretty simple, I have professional this type the antenna , OK provide to work on 163MHz, but without special tuning work well on 145MHz , we try to make it little longer according wavelength but no need. Inside matching stub there is capacitor and coil to compensate difference length, it is possible easy tune to 145MHz.

I have military police version for small radio.

This is so simple to make , original had rod from measuring tape 4 difference length connected together , matching stub, one capacitor ceramic trimmer and one coil with tap on 1.5 turn , this is connected center of connector.Connector is military not usual, I have female connector so I will be made some kind adapter for BNC connector. Also for fun I will be made replica using telescopic rod (from old portable TV)Choke no need if you use only one coil with tape for hot point, down end of coil ground on connector , in military this worked well.

You can do same replica , only one limitation component is surge voltage on capacitor. But this isn't impossible mission. I found few good and simple idea for high voltage capacitor DIY.

I send you Mr Alan like I promise , professional antenna, end feed 1/2 lambda. I send some photo and schematic diagram.

If this work on professional police radio, and 20 MHz low on amateur radio(on my IC-2E) it must be simple work. On the original antenna you have only connector , coil and trimmer capacitor(ceramic), and it is so small dimension. Amaze how possible but work, now I must make connection from original connector to BNC , all antenna is lightweight so I have intention to make another(telescopic)for my hand held radio.

Zoran 9A3HP

P.S. No need choke

The pipe looks just like a "snow plow flag stick". Whaddayoucallit...

Road office sometimes uses those instead of treetops to mark roadside, curb etc.

Come spring, you can gather it from ditches :)

Where do you get the "Orange" PVC Pipe?

I live in the USA and have never seen it here, but it would be nice to have.

Thank you for the interesting projects.

Adrian