what could be causing such a short wireless range?

[Jamesbeat]

I have been modifying an AEKII over the last few days.

I have modded the case and completely rewired the matrix to a wireless controller.
I haven't quite finished yet, but today I got the wiring finished and was able to test the keyboard for the first time.

It works great, (I'm typing on it now in fact) but the range seems rather short, only a couple of feet or so, which is pretty disappointing considering how much work I had to do to make it wireless.

Unfortunately, I didn't have the opportunity to use the keyboard that the controller originally came from, as it was already broken when I received it, but I can't imagine that the range would have been ~3'.

I have tried brand new Duracell batteries, and various positions, but the range never gets over about three feet.

The antenna is a wire loop that encircles the keyboard. I've tried repositioning this, but no luck.

Radio technology is not my strong suit, so I am hoping to get some ideas about where to begin looking for a solution to this problem.

I have a strong suspicion that the problem might be caused by the metal frame that the keys sit in (the original keyboard was rubber dome) but I really hope it's not, because there's not a lot I can do about that....

[mbc]

is the receiver (pc side) next to other electronics (speaker, monitor,...)?
ps. whats the wireless technology?

[Jamesbeat]

No, I should have mentioned that I cleared the area around the receiver. I thought at first it might have been the shielding in my laptop screen (I was using my laptop to test the keyboard) so I moved everything out of the way so it had line of sight.
The receiver is a separate unit on a usb cable, so I was able to move it around quite a bit.
The technology is regular 2.4GHz, not bluetooth.

Ripster: that Apple board is nice, but the reason for this project was to end up with a clicky mechanical wireless keyboard that looks retro and isn't bluetooth. I've spent too much time on it to throw it in the garbage and replace it with something that doesn't quite meet the criteria.

[kps]

I'm not an analogue guy, but roughly speaking, the problem is that your antenna, which was designed to fit in a bit of cost-reduced plastic, is now adjacent to a huge chunk of metal. You are drastically changing the input impedance and/or getting cancelling reflections.

Design a new antenna.

[Jamesbeat]

Oh dear, that's what I feared.
I was going to use another wireless keyboard that I had, but was given this one. Since the original one still (sort of) works and has a built-in trackpad, I decided to keep it as it is and use the broken one.
The antenna in the one I didn't use is just a small track on the pcb, but this one is a large loop of wire.

I know enough about antenna design to know that I don't know enough about antenna design.
Any pointers about where to begin looking?