In article ,
Paul Burridge wrote:

It ain't rocket science. Someone out there must know the
radiation resistance of such a telescopic whip (which has a
ground plane of just around 16 square inches contained within the
remote control handset) and the best way to couple it to a PA
with a 140 ohm output impedance?

Paul, standard CB antennas are loaded whips, for operation
at around 30MHz. Available in the CPC catalogue for about
£10 to £20, Perhaps you could start off with one of those
and modify to suit.

Note also that there is a 433MHz licence-free band for
short distance (100m) remote control. Pre-built Tx and
Rx modules are cheap, and a 433MHz antenna would be a
breeze.

www.cpc.co.uk or 08701 202530.

--
Tony Williams.

Perhaps you didn't see the earlier posts on the subject. The frequency
is 40Mhz (radio control band) and the tx output stage as it stands
puts out maximum power of 475mW with a 140 ohm resistor as load. I
only *need* 50mW ERP., however, so can stand to see quite a bit of
loss from an inefficient antenna. The antenna I will be using is a
telescopic whip - exactly the same set-up as you see with model
vehicle radio control transmitters- which is what it is, in fact.
It ain't rocket science.
Someone out there must know the radiation resistance of such a
telescopic whip (which has a ground plane of just around 16 square
inches contained within the remote control handset) and the best way
to couple it to a PA with a 140 ohm output impedance?

Google "electrically short"