This page will chronical the hacking I did to the 75mw transmitter I purchased  on ebay.  The system is manufactured by Racewood Technology.
Mad Scientists beware
My standard disclaimer for all my projects:  These hacks worked for me, but could very well kill or maim you.  You are expected to understand all the risks involved and take them on of your own volition.
11/11/2001:  Hacked in a microphone and dc-dc converter (the silver thing on the right) so that the transmitter could be run from a 4 cell battery pack.  The panasonic camera shown here runs on 5v, so it gets it's power directly from the battery.
11/13/2001: Installed a patch antenna on the receiver.  Here I've just opened up the case.  The cover on the RF section comes off easily, as it is not soldered on.  The second picture shows a close-up of the 'can' with the cap off.  You can see the signal wire soldered to a small pad on the PCB, and the shield is soldered to the can.   I unsoldered the coax, unscrewed the nut that held the antenna on, and remove the antenna.
In this picture I've soldered on the new patch antenna.  I got the patch from an unused xcam receiver.  I maintained the original coax from the patch.  I just soldered it on to the board exactly as the original antenna did (see picture above).  I have the antenna resting on a short column cut from a length of foam pipe insulation.  I'm not sure that it matters that the antenna not rest on the receiver, but I didn't want to chance it.

**HINT:  Thread the coax through the metal loop that held the original antenna so that you can get the case shut again!
I had no use for the original antenna, so in the interest of science I carefully cut it apart to see what was inside.  I found a dipole arrangement made out of copper traces on a small bit of PCB.  The lower trace is soldered to the coax shield, and the upper trace is soldered to the signal wire. It is very interesting to note that the dipoles are only 22mm each, which is significantly shorter than I would have expected.  Also, I suspect that the coverage of this antenna was compromised by the fact that copper traces were used.  The 'face' of the trace would act as a good receiver, but imagine a signal impinging edge-on to the trace... I think that reception would be affected.
12/2/2001: I've finally got around to building and testing a groundplane antenna on the new transmitter.  A very generous friend from the RC-CAM community sent me some odds and ends with 50ohm coax and sma connectors, and I was able to modify one of them into the new antenna.  This picture shows the completed unit.  The sma connector was already attached to the coax when I got it, and I simply followed the instructions for my "sturdy groundplane antenna" to modify the end of the coax.

This is the airplane setup with the new antenna.  The dc-dc converter and microphone are on top of the wing, and the 4 cell battery is on the nose, just in front of the wing (you can see it's power connector in the picture).  The antenna is mounted precariously on the side of the plane to get the main signal wire as low as possible without scraping it on the ground.  The camera is under the far wing at it's trailing edge.  You can sort of see it in the picture directly on the opposite side from the transmitter.  This setup has provided the best signal coverage and range so far, and I haven't even really flown to the transmitter's limit yet.  Range?  I wish I knew!  I need a range finder!
02/22/2001:I repackaged the transmitter using 'better practice' construction techniques learned from my newer transmitters.  The dc-dc converter has been glued to the back of the transmitter along with the microphone, and the whole thing wrapped in clear shrinkwrap.  The system still runs on 5v, I just included the 9v battery for size reference.