General features
Philips model 531U
|
Radio type |
AC or DC mains powered table radio |
|
Circuit type |
Superheterodyne, 475kHz IF with delayed AVC |
|
Dimensions |
|
|
Cabinet |
Veneered wood, cloth grille, celluloid dial in Bakelite bezel, cardboard back cover. |
|
Loudspeaker |
200mm, moving coil, permanent magnet |
|
Main controls |
Tone, volume/on-off, tuning and waveband/PU switch |
|
Extra controls |
Power line antenna/outdoor antenna selector |
|
Connections |
Antenna, ground, PU, external high impedance loudspeaker |
|
Power |
AC, 110-245V in 6 steps, 65W |
Wave
bands
|
MW |
200-570m |
|
SW1 |
13-40m |
|
SW2 |
35-90m |
Circuits
and Tubes
|
RF preamplifier |
CF3 remote cutoff pentode |
|
Oscillator and mixer |
CK2 octode |
|
IF amplifier |
CF3 remote cutoff pentode |
|
Audio amplifier, detector and AVC |
CBC1 duodiode-triode |
|
Audio power amplifier |
CL2 8W pentode |
|
Rectifier |
CY indirectly heated power diode |
|
Heater current regulator |
C1 or C9 resistance tube according to mains voltage |