Want to eliminate the long out of scale antenna that comes with the HL RC tanks? Well after talking to my brother the "HAM" nut he said why not just replace the antenna with an internal antenna and proceeded to explain to me how to do it. Here's what he said " just measure the section of antenna you want to replce then cut a section of laquered copper wire like you would find in a choke or coil from an old radio or power supply the same length as the anteena that comes with the tank. So I tried what he said and "HOT DAM!" worked like a charm. I place the tank at one end of the house and tested it out works perfectly. I could start and stop the tank activate the machine gun, the cannon fire drive train responded as it should. I paced off the distance from the tank to the transmitter and was 20 good paces which would be approximately 60ft. Here is how I did it:
1. I measured the antenna and it measured 13-1/16"
2. I cut a section of the laquered wire to that length
3 I took a piece of 1/4" hollow styrene tubeing 1-5/8" long drill a tiny hole near the one end.
4. I inserted the one end of the copper insulated wire into the hole and brought the end out of the end of the tube approximately 1/4-3/8".
5. I then wound the wire around the tubeing and secured the other end to the tubeing with some cyano
6. I then glued short standoff's on either end feeding the end of the wire through the one end
7. When the glue had dried I then un-soldered the antenna wire where it is soldered to the anntena stub keeping the 2 sections of black wire.
8. I then soldered the end of the black antenna wire to the end of the coil and tack glued it to the right inside panel of the hull.
Then I was test time... and it passed with flying colors.
Here are pics of the modification:
Pic 1 This shows the coil I used to get the laquered wire from I took the coil out of an old AT computer power supply. This pic shows the top view of the coil

Pic 2 side view of the same coil

Pic 3 Coil instslled in the HL PzrIII L