Meet FIREFLY: Lightweight, Improvised Portable Relay Nodes (EASY!)


Throwing this out there as a concept and a memory marker, as I’m in the middle of rebuilding the front axle on the Land Cruiser and when I went to look for the crucial component, I couldn’t find it…

Last night it occurred to me how to easily make an outside mount vehicle package to accommodate the goTenna Mesh. The major component would be an old mag mount CB antenna base. Yep, a big ol’ magnet intended to be slapped on your car.

Once I find the one (or more) I know have, I have a short length of 1 1/4" PVC that I will cut so it can be attached to the magnet and allow the GTM to be strapped in. I’m thinking a clear plastic drink bottle could be cut to cover the whole unit for weatherproofing, but maybe the Dole fruit jar would work? With a screw down cap, it would be more secure.

I plan to experiment and post pics soon, but there’s the idea. It can be easily mounted on the hood, roof, or tail hatch of about any car (unless it has aluminum or fiberglass bodywork, of course where magnets don’t really work :smirk: ). It’s easy to detach and secure or charge the battery. You could even rig a power cord for the vehicle to supply 5v to it. Bluetooth should work with the glass windows, especially on the hood or rear deck. IIRC, Bluetooth worked with it on my roof…until it fell off anyway. :cry:


Got the truck put back together. Went to Harbor Freight to get more nitrile gloves - I went through about 150 pairs, as this is a really messy job. Radio is a lot less messy than trucks, let’s do something nice, clean, useful. Something radioy.

This is the latest cool new auto radio accessory, brought to you by goTenna and UMESH’s busy Guerilla :gorilla: Design Team – the Fire Fly Mobile.

While it’s not quite like CB – thank goodness! :violin: – the Fire Fly Mobile takes advantage of the Bluetooth found in every goTenna Mesh to let you mount your GTM unit where it can do some good – outside of the muting radio barrier of the Faraday cage effect produced by being inside a typical metal bodied car.

You may have said…Whhhhaaatt?

It’s this easy. Here’s the pieces.

Pic #1 pieces


Having some pics issues tonight so started another Reply in hopes this solves it. Here are your parts.

The plastic jar in this case is from a one pint (16 oz) size container of Nathan’s Famous Sweet Horseradish Pickles (yum! :sunglasses: ) Other jars may serve, but it needs to be a little taller than your GTM.

The key to this project is finding a big magnet. I was still looking for the one I know I have but can’t find when I came across a pair of magnets (Item 65528) in Harbor Freight much like the CB antenna mount I’ve been thinking of, in this case they call them “decor hooks.” These are basically a magnet said to be able to hold up to 65 lbs with a picture hook on one side.

The circular piece of foam came as a separator between the magnets, but works great as the pad in the jar lid. You drill out the rivet holding the picture hanging hook and bolt the magnet onto the lid. I’m going to revise mine to be somewhat sturdier but this is whats holding it together now. Basically it needs a bigger fender washer to avoid the plastic jar lid flexing.

The foam rings (more lile squares) are leftover from the watertight “Apache” containers.

Here’s a way to keep your GTM on the dash.

A better location is out on the hood.

But I didn’t like the clear look and had some paint and a piece of masking tape, so I revised things to look better.

Luckily enough, in that position it clears the garage door, looks great, and works great. I’ve got notions to power it from inside, but for now it’s a temp arrangement. It could also be painted completely and that would look great also. I left the clear area so I could see the status light on the GTM flash.


Blown loudspeakers are a good source for mag mount magnets. A lot of them come apart pretty easily. And many of them have a huge magnet/cone size ratio.


True that.

To keep them from scratching the paint, etc, Zagg, another generic screen protector, or another protective film layer should be applied to the magnet surface that will contact the vehicle.

The HF magnets/“decor hooks” have the protective film already on the item, which is another reason they’re a great bargain. Here’s a pic of the HF magnet packaging.

BTW, did about a 100 mile road test today with the Fire Fly Mobile. Considering I was ony testing the FFM, I decided to leave the GTM out – just in case, considering I’ve already had one GTm do a death dive off my roof. As it turned out, it wasn’t bothered a bit by 70 mph speeds, gusty crosswinds, or the relatively rough ride of the Land Cruiser. The Fire Fly Mobile hung in there gamely.


If you have a screw-on lid, then changing the “skin” on your Fire Fly Mobile is easy. You could even paint it so you could match different color bodywork. Or you could paint up several differently to match the holidays, etc, which would be lots easier than decorating the yard. :smirk:

Also, I wanted to avoid people thinking the FFM is some odd warning light (the Land Cruiser is NOT a school bus) and with it having enough clearance to stay on the roof to get in the garage here at home, I decided on a different look for my FFM.

Painting the whole thing green makes sense if it’s going to be on the roof out of sight, as there’s no way to easily see the LEDs flash as there would be if it was located on the hood as I originally thought would be the case.

This makes it look like a big fat stubby antenna. While it’s size is a bit unusual, stubby antennas are rather unremarkable and common, achieving a bit more stealth.

That, the intense magnet, and being six foot above the ground and in the middle of the roof also keeps some n’er-do-well from getting grabby with it.