Absence of Signals Burnt out rectifier valve Broken down filter capacitors Open-circuit field winding or filter choke Short in H.T. by-pass capacitors Open circuit cathode resistors H.T. supply line open circuit Open circuit R.F. or I.F Coil Shield can shorting to grid cap Disconnected wiring Faulty valve socket or speaker connection Low B+ Voltage Radio Station Missing Radio is not turned on Radio is missing

Poor Volume Weak valves Low H.T. or filament voltage Poor alignment Open circuit R.F. or I.F. coils Faulty volume control Incorrect valve types Leaky high voltage caps Your Hearing Aid is Faulty Radio is too far from your ear Partner has removed long wire antenna

Distortion Open circuit bias or grid resistors Audio feedback Low emission valves Incorrect voltages Leaky coupling capacitors Gassy output valve Radio not designed for Led Zeppelin (Relocating Tuner to 693 Magic should cure problem)

Crackles & Whistles Faulty resistors Faulty capacitors Loose contacts at sockets Dry joints Faulty output transformer Faulty power transformer Ineffective valve shield( Whistles in particular) Faulty valve Poor wiring layout Poor alignment You are listening to New Years Celebrations Radio is on fire

Hum Poor filtering Short between cathode & heater Poor shielding on audio leads Bad rectifier Faulty electrolytic capacitor Singer didn't know the words

Severe Hum Shorting electrolytic capacitor Internal fault in rectifier Shorted field coil or H.T. choke Several singers didn't know the words

No Shortwave reception Dirty wave change switch Resistors high in R.F. stages Weak frequency changer valve Low H.T. voltage

Low High tension Weak rectifier valve Faulty power transformer Incorrect speaker Faulty valve Partner is satisfied you won't burn house down

Rectifier glowing red Direct short on H.T. Line. (e.g. Electro filters) Somebody put a 3 pin plug on the battery cables

Output valve red Open circuit anode on output valve Open circuit output transformer Speaker unplugged Incorrectly aimed Spray Pak during restoration Set is on fire