xEM AC upgrade possibilities

I have searched all over but have not found anyone that has asked this… How complicated is it to make the antenna “pig tail” longer? I got my garage wired up and I am laying out how I am going to do my Harley. Everywhere that I want to put the antenna is a long way away from under the seat (pretty much only place I can hide the big box, plus all the fuses are there. Even with my garage, I could make the wiring look SO much better if I just had more wire from the actual controller box to the antenna. I am a little nervous about ripping into one of the controllers so I wanted to ask on here first.

1 Like

I took mine off and then re-attached it. It basically just solders on in two spots. You could make an extension by soldering in some wire (insulate connections), BUT I have no idea how far you could go without degrading the signal.

Also, I think it’s coax. You might be better off just putting a longer piece in. BUT, I’ve never taken the antenna case apart. Don’t know how it attaches. Or if case can be taken apart.


Good call, Somebody will jump on here and correct me, BUT this is what I would do. I’m not saying it is correct or it would work, this would be my process.

Since you are making it longer, you don’t need to cut anything. I would just do some testing as I went.
Don’t cut the actual antenna end.
I would:-
Open the Unit
Take a photo of the Wiring :camera_flash:
Desolder the antenna wires
Add an extension to the length you want from the Board to the “pig tail” match colour to colour, or your coax wires.
Do some testing (Scan implant, Proxmark values)
If it works and you are happy with the range, then Tada, If not:-
Halve the added length
Test values and operating, if it works increase the length by half you removed, if it doesn’t, then halve again…Rinse repeat until you have a satisfactorily operating antenna…

Looks Like @ODaily beat me to answer, anyway that’s what I would do… Incorrect or not!

1 Like

I meant the antenna wires or coax mainly. If I could make my antenna wire about 4-5ft long I could hide everything on my harley and no one would see anything… would look super slick. My garage I was thinking I could leave the box in the attic and just run the antenna down so nothing is in sight except the antenna. But I didn’t even think about the signal.



Yeah, the coax between box and antenna.

Signal loss / degradation may or may-not be an issue. We need an expert opinion here.

I INVOKE @Satur9

Also not sure where you’d get more tiny co-ax like that.

For the garage, how about drilling a hole through the wall. Unsolder the existing coax, then put it through the hole and re-attach. Box inside, antenna outside.

Awesome! Now I know what I am doing on this long weekend :wink:

Sorta have it like that now but was trying to think of a way the box will not even be visible from in the garage. If I can put it all up in the attic the only thing visible will be the wire running down the wall and out the wall.

Drywall? Put it inside the wall.

Or inside some simple container in that general area. Something that looks like it belongs.

1 Like

1.2m to 1.5m…Wow that is quite long.
Let me find a post that may give you some idea of what to expect with degradation

1 Like

This. If you cant hide it out of sight, hide it in plain sight!


Okay, I found it, Follow the link to get the whole situation, But in short
TomHarkness ( The Guru :person_in_lotus_position:‍♂) took an xAC antenna and connected it to a Proxmark Easy, not the same, but you will see he talks about the tuning. Your case will be slightly different because you are extending for what it is tuned for… blah blah blah
Again follow the link for pictures,

1 Like

The garage door sliders are too close to the wall and I wont be able to cut it open and patch it nicely. (already thought of that lol)

Last thought.

They make access panels for drywall. They’re usually installed someplace where you might need to get at the plumbing. For instance, on the outside of the wall of a shower stall, so you can get to the backside of the valve.

They come in a huge variety of sizes and styles, are designed to blend in, and are cheap and available at any home improvement store.



Nah but 4realz, 4-5 feet is alot for an antenna extension. It affects the impedance significantly. I’m not sure what exactly you’re doing here, @Steven1727. Do you want the reader to be in your attic and unlock your garage door and start your Harley in your garage in one fell swipe?


Not to mention that if yoy did want to add that much and keep a similar impedance the cost of the extension would cost half the bike!

Seriously high quality coax is really expensive!

I think he originally asked about fitting to the Harley but mentioned he could do with extending the garage one as well


Does this really play into effect? HDMI cables can be made of gold, doesn’t mean it will work.

Wouldn’t you need a way to amplify and power it?

1 Like

Oh hell yeah, the difference with coax cable is astronomical when you talk about rf (TBH probably not too much at this frequecey considering the joint between the different coax portions will be awful from a loss perspective)

At several MHz your loss between 2 cables can vary by 20db.

1 Like

High quality AV cables are a racket because the viewing/listening device itself needs to be expensive enough to process the difference in signal quality (which they seldom are) and in the end our shitty sensory organs can’t tell the difference anyway.

When you’re talking RF communication between two processors, signal quality does make a significant difference. It can be the difference between a 1 and a 0. We’re not just talking about the metal that the signal is being transmitted over (although that does play a part). There’s also the distance between the signal wire and the grounding jacket, and the dielectric properties of the material between the two, which affects the capacitance of the signal channel. Then there’s any Inductance or resistance introduced by the length of the wire and the interface between the wire and the connectors. All of these factors affect impedance, which can create signal reflections or distortions depending on frequency. The maximum length of the signal wire is also affected by the rise time of the signal.


Hehe, I couldnt be bothered to explain all that (I’m supposed to be working) but had a feeling you would bite @Satur9 :wink: