Ham Radio Antenna Mounting

I am wanting to add a 2m ham antenna to the TM. I'm thinking it would need to go on the back shell, and the coax would need to run next to where the factory ran the solar panel wiring, up the lift arm.

Has anyone done this or something similar (like a CB antenna)? If so, can you share your experience? Thanks in advance!

(I'm doing a "poor-man's" TM lo-jack using APRS. It'll let me know that my TM hasn't moved while in storage, battery voltage, and temperature inside and outside the TM - so the dog and the water tanks are comfortable, all via ham radio; The TM's solar panels will keep the radio equipment from drawing down the batteries; If I can figure out how to do it, I'll also have it send out "opened" or "closed" based on whether the TM is folded or opened up)

I haven't put a 2m antenna on the TM but I did notice a hard plastic FM dipole type antenna for the radio mounted on the lip of the forward shell. You might see where they put yours and mount in the general vicinity. Of course, it would be bad Karma to key the transmitter when you're listening to the radio ;-)

Phil
WB4YHC

[mjlaupp]

Before TM started using a dipole antenna, they mounted a fold down amplified antenna at the rear street side of the front shell. If someone with this antenna would post a picture you could see where/how it is mounted.

Mike

[wbmiller3]

Here ya go. Please ignore the junk stacked on top. Spring break is just around the corner!

I ended up mounting the antenna (NMO-type) on an angle bracket on the front shell. I screwed the angle bracket into the back molding on top of the front shell, just a bit streetside of the factor FM radio antenna (on a 2007). I put a 5/8 wave antenna there, and things *seem* solid enough. We'll see how it holds up - I wasn't thrilled about using the molding, but it seemed like the best bet.

I then used cable clamps to bring the coax down the side of the TM along the molding (I used the existing screws that attached the molding), and then tied to a black flatish cable and then to the lift arm, down under the TM, then up under the front street-side dinette seat.

Under the dinette seat, I have a rig-runner fuse panel. I also have the RTrak that this whole project was for. I used pop rivets to attach the RTrak to the wood on the side of the fridge, under the seat - it seems to have worked good, and the rivets worked without having to see what was on the other side of the wall.

Right now, the RTrak is sending out position updates via Ham Radio (I'll know if it gets moved!) and battery voltage (I now know for sure that the factory solar panel works while closed). I'm adding two sensors this week for temperature (inside and outside) and will be adding a sensor to measure the line voltage when the camper is plugged into utility power. I can view all of this on a handheld radio or via the internet.

I'll take pictures and post graphs of the voltage and temperature sensors after I get everything finished and figure out how to manage the picture posting! I've also got to post pictures of my fresh water and sewage solution, but haven't got around to it yet.

[Bill]

Originally Posted by grakin

I ended up mounting the antenna (NMO-type) on an angle bracket on the front shell. I screwed the angle bracket into the back molding on top of the front shell, just a bit streetside of the factor FM radio antenna (on a 2007). I put a 5/8 wave antenna there, and things *seem* solid enough. We'll see how it holds up - I wasn't thrilled about using the molding, but it seemed like the best bet.

Joel -

Keep an eye on it for a while. If I recall, that molding is held in place by nothing other than some silicone RTV on the back side serving as glue, and the white caulk around the edges. This same piece of trim came loose on my TM a month ago, so I pulled it off, cleaned it up, and re-installed it the same way. I don't recall seeing anything behind it that you could solidly attach an antenna to.

Bill

Too bad the sides of the TM are aluminum. If they were fiberglass you could easily fiberglass in a J-pole.

Bill, I *think* there must be some aluminum square tubing right behind that molding - I screwed into whatever was actually behind that molding.

[Bill]

Joel -

Yes, there is square aluminum tubing in there somewhere. I'm not sure it is *right* behind the molding, but it is there. When I had the molding off, I saw a lot of foam (spray foam?), covered by a sheet of foil-backed paper. I think this paper is to keep out drafts, but I can't be sure. At any rate, in one place the paper and foam had pulled back, and there was an aluminum framing member under there, surrounded by a fair amount of empty and/or foamed space. I'm sure it would have made more sense if I had peeled off the foam and foil so I could see the whole thing - but that didn't seem wise.

If you drove a screw and caught the aluminum, you're in good shape. It would have been very possible to drive a screw and miss the aluminum.

Bill

Very cool, Joel. I might have to get off my backside, do some studying and actually take the amateur radio test. I got my commercial general class radiotelephone license in the early 80s. Worked in radio 20 years before switching to network engineering. What class amateur license is require to use APRS?