The day pack I use for SOTA activations was purchased many years ago for the purpose of bushwalking day walks, and really wasn't designed for it. It is a Berghaus Cubic 30, 30 litres capacity.
The 7m squid pole sits in a drink container pocket, unfortunately it has only one so have to put my drink container inside, awkward to get out and takes up extra room. Also only being 30 litres capacity find it bulging once I load up with radio, antennas, food, clothing etc. Plus the squid pole is a loose fit meaning it flops about and catches on branches...
So went looking in the local walking/camping stores for a better one. Most seem to have flimsy mesh drink pockets and too small or too large. Finally found a suitable pack, a Katmandu Katun 40.
The drink pockets are big and deep, tough fabric that is molded into the pack. Plus a couple of compression straps keeps the squid pole nice and secure. And there are 2 pockets so the drinks container fits on the other side :)
Being 40 litres there is more room for all the junk I carry, I'll probably fill it up with something...Still have to carry it all though :(