Got an HD upgrade on my Receiver (went from a R22 to a HD21) a few months ago and lost my range in controlling my Receiver from my master bedroom (about 30 ft thru 3 inside walls). Had no problem with the R22 receiver, but have with the new HD21, as many others have also complained about on various forums. I decided to try modifying the 'new RC65R remote' that came with the new receiver (already had 2 RF remotes--1 LR/1 MBR) for an external antenna. The RF freq is 433 MHz per a forum mod on here, meaning that a 1/4 wavelength (WL)antenna would have to be about 7" (the actual remote internal RF antenna must be 1/8 WL as seen on the PCB run!). The inside of remote may be accessed by removing 6 screws--2 bottom, and 4 under gray oval trim that can be popped out. The RF PCB is piggy-backed onto the main PCB using sticky rubber mounts. Cut the PCB loop antenna 2 places (I 1st tried using Exacto knife, but then ground with a Dremel), scraped the solder mask over the 2 runs to get to the copper, and soldered 2 ends of an #18 solid Cu wire per attached dwg. Drilled a 1/4" hole in side of remote bottom, and ran loop thru to outside. Reassembled (had also used glue gun to keep wires on RF PCB apart and secure). [I opted to use an 8" wire for xtra lead length dress/routing of wire] Final result: Great RF control as had before with loop facing my LR receiver location. Dont know if it was just going external with the loop antenna; or probably more gain with 1/4 WL antenna vs. the internal 1/8 WL..?? B4 attempting this mod, know that you may ruin your remote and that you are responsible for opening it up if covered by a warranty. Altho, if one has basic soldering skills, this mod is a snap! BTW, after verifying mod worked, I sealed 1/4" hole on side with glue gun.