Don't fail to use a safety spark gap between the grid and the filament terminals where the plate potential is above 2,000 volts.
Don't buy a motor-generator set if you have commercial alternating current in your home.
Don't overload an oscillation vacuum tube as it will greatly shorten its life. Use two in parallel.
Don't operate a transmitting set without a hot-wire ammeter in the aerial.
Don't use solid wire for connecting up the parts of transmitters. Use stranded or braided wire.
Don't fail to solder each connection.
Don't use soldering fluid, use rosin.
Don't think that all of the energy of an oscillation tube cannot be used for wave lengths of 200 meters and under. It can be if the transmitting set and aerial are properly designed.
Don't run the wires of oscillation circuits too close together.
Don't cross the wires of oscillation circuits except at right angles.