NEVER ground to hot water pipes - ALWAYS use the cold water pipe,
as it goes directly to the earth outside the building. The hot water
pipes are routed through the hot water heater(s) and are NOT a direct
path to ground.

==========================

Not entirely correct.

ALWAYS use the cold water pipe.

And if you have a hot water pipe ALWAYS connect that in parallel.

Two connections in parallel ALWAYS have a lower impedance than either of
them.

Hot water, wall-mounted, central heating radiators are convenient connecting
points.

If you have a gas pipe then make it a three-some.

And of course take advantage of the electricity supply ground via the
domestic power wiring.

If there's a 14-gauge wire running from a bedroom shack, through the window,
down the outside wall, to a bunch of buried radials in the back yard then
include it with the others.

The whole system is just a bunch of random length radials and, up to a
break-even point, the more the merrier.

If any one of the principal ground connections can be broken without having
any affect on the tuner settings then you've already gone far enough.

But whatever you have there's no guarantee you will be free of RF in the
shack. RF comes in through the windows, ceiling, walls, doors and floor of
the shack direct from the high-power near-field of the antenna. And you
can't criticise the antenna - it's only doing its job.

If in a bedroom, as a last desperate resort, take up the carpet or lino and
cover the floor-boards with chicken wire. Re-lay the carpet or lino. Connect
the chicken wire from two spaced points to the terminal at the rear of the
PA which is marked "Ground".
----
Reg, G4FGQ