As the title says does anyone know the correct placement for the signals patch? tried google but failed and have no reference for the Brits 
If you mean this: http://www.sofmilitary.co.uk/signaller- ... oduct,3222
then SOF says lower left sleeve.
6.5" above edge of cuff on lower left sleeve.
I have a small skewer hidden in the collar of my jumping jacket, and a razorblade in my gaiter, as well as my knife.
Cheers 
Hurray! I've been trying to find this out for my grandpa. 
Weapons:
King Arms M1928 Thompson Submachine Gun
AGM Sten Mk.II
CYMA M1911 EAP
I recently found a more complex answer for trade badges. Skills would be lower left arm, this would indicate that you are trained. Trades go on the lower right arm to indicate that this is your job. Instructors or others whose rank is based upon their trade would wear it above rank chevrons (or below the chevrons for warrant officers). Often when the trade badge is worn with the rank chevrons the older brass trade badge gets used. Officers would not wear trade badges.
Incidentally, when adding a trade badge to my Aussie service dress, the answer was simpler. Trade badges on Aussie uniforms go above the rank chevrons with no differentiation between skills, trades and ranks. I also used the brass version as the sewn on patches were not introduced as early in Australia.
