Magnetic antenna

[kc5bsi]

I was given a magnetic base 1/4 wave 2 meter antenna and I want to use it in my grab-and-go bag. I've done some research and see that some operators put a square metal plate under the antenna and some run a ground wire from the plate to an unknown place. Maybe the case of the radio? Any help would be appreciated. Thanks in advance.

 

[gonefishn1]

You could use a cookie baking sheet or pizza pan under the antenna, no ground is required. The metal pan makes up the other half of the antenna and should be about 20 inches in all directions. Some people put the antenna on the file cabinet or refrigerator and this seems to work well also. Place it in the center of the roof on a car.

 

[kc5bsi]

You could use a cookie baking sheet or pizza pan under the antenna, no ground is required. The metal pan makes up the other half of the antenna and should be about 20 inches in all directions. Some people put the antenna on the file cabinet or refrigerator and this seems to work well also. Place it in the center of the roof on a car.

As a matter of fact I do have an extra pizza pan that I can liberate from the kitchen and give it a try. Thanks.

 

[mmckenna]

It doesn't need to be steel, unless you really need the magnet to stick. Just a conductive material.

You could lay a couple 40 inch lengths of wire in an "X" shape under the antenna and it will provide a suitable ground plane. Aluminum foil, metal window screen, and similar stuff will all work.

Something flexible would pack better into your kit.

 

[majoco]

Agreed with McKenna - make up a radial kit that you can just roll up and put in your bag - 4 reasonably flexible wires and a steel plate to stick the mag mount onto - radials need to be 19" inches minimum but the longer the better. I have made a plate just like that for sitting at a wooden BBQ table - the radials were made from 75 ohm coax of the type that the inner can be pulled out leaving a nice flexible braid. I did find it would only work with a handheld - if I used a mobile rig with a 12v battery the microphone lead picked up too much RF and I made a 5watt oscillator! I didn't dare try full power!

 

[kc5bsi]

Thank you for the reply.

 

[nd5y]

You don't need a plate. Cut some sections of a steel tape measure. You can roll up or fold them when not in use.

 

[mmckenna]

You don't need a plate. Cut some sections of a steel tape measure. You can roll up or fold them when not in use.

Excellent idea. I've got an old broken 25 tape measure I saved for just such a thing.
In fact, there are plans to build entire antennas out of tape measures. Easy to roll up...

 

[kc5bsi]

So many suggestions. I got the house to myself this weekend and I'll experiment with the various materials.

 

[KE5MC]

So many suggestions. I got the house to myself this weekend and I'll experiment with the various materials.

It's a good idea to add in your go-bag setup a small metal plate to keep on the base of the mag-mount when not on something bigger. Otherwise it will find ALL the small bits of steel laying around or attach itself to things you would prefer it not stick to.

Speaking from experience.

Mike