xEM AC upgrade possibilities

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,

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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?

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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.

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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:


Original question was about the Harley yes. I can make the garage work just figured if I could extend it it would look nicer being hidden in the attic with just the antenna coming down.

Here is my idea: blue circle is where the battery and fuse panel are, red circle is general area where I would like to put the antenna. On bikes most of the wires are ran down the frame under the gas tank, I was hoping I could do the same with this. But if it’s going to really hurt the performance of the antenna I can try to find another place to put it.


I’d say it’s worth a try. Desolder the antenna wires from the board inside the xAC and splice on an extension, see if it still works


Give it a go, I’ve done and seen worse done, just make sure to use coax or at the very least shilded wire.


+1 on using good quality coax.

You might lose a bit of read range, but I’m guessing it’ll still work. The xAC has such insane range that I suspect you’ll still be fine

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I was curious, so i checked.

I just picked the smallest dia coax cable at digikey, in the shortest spool (25’), and it prices out as 61.89 plus shipping.

Check It Out.

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And they have to in stock :+1:

Had a close look at an xAC for other reasons. The cable is marked as “M17/119-RG174 50 OHM MIL C 17”.

Google found some pretty close (and cheap) matches. Google it.

The actual antenna is potted in place. You might could extend the existing co-ax, but I don’t think you’re gonna replace it entirely without a fight.

Just info for the future if you ever wanna try it.


See now you got me wondering could we mount an SMA into the box, really short cable(non exitstant) on the antenna with SMA and then you could use off the shelf cables :thinking:


Glad I got you thinking about that! I didn’t think anything remotely close to that… Pretty much the only thing I understood out of that was off the shelf lmao.


I had to extend my antenna for my door lock and I only extend it about a foot but I just used a small gauge power cord. Everything works well and the read range is still good.