> 300m is mighty impressive, but if that is completely directional from =20
> the board edge then perhaps less useful.
>=20
> Have you tried a Splatch?  Either that or the short helical =20
> recommended by Matt look fine, am just interested in how directional =20
> they will be.

I have tried the Splatch. The only long-range test I had time for
before the weather turned bad (and stayed bad, rain, 30C, 100%
humidity and then Christmas week came along) was with the board
(see below) standing vertically and the receiver whip also vertical.
The range comparison was with a vertical transmitter whip

I've wound a helical and tried it briefly, with a 50x80 PCB ground
plane. I got to about 80m, walking away with the receiver. What I
want to do next is place the receiver and walk away with the transmitter,
adjusting the helix for the best range, using the LED on the receiver

> I am assuming from their datasheet diagram that the ground plane
> can  just be the whole board ground plane, but you mention 38x90 =20
> specifically?

I meant 38 x 85. I'm not sure of its exact importance but in the Splatch
datasheet they say "Electrical specifications and plots measured on 1.50"
x 3.30" reference ground plane", so that's what I've started with. The
board overall is 38 x 100. 38 x 15 is a bare area for the Splatch, as in
their Recommended Mounting diagram

The weather isn't too bad today. I have time to do a horizontal test
and let you know. If Linx say the Splatch approximates a 1/4 wave
then you might expect the same 3D propagation. We shall see

Joe
--=20
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