I'm new to the forum and I need some help.
I try to shorten the antenna of a handheld 27MHz transmitter.
Now the transmitter uses a 7mm diametre 865mm lenght telescopic antenna.
I would like to make a shorter antenna by wound 1mm copper wire to an 7mm izolator (naylon tube)
Can somebody tell me how long this tube and wire have to be and many times I have to wound the wire......