General:

Very simple build tuner made by Philips in Belgium in 1980.

 

Special features:

This tuner is a member of the Philips "Black Tulip" range audio gear.
Matching: pre-amp 22AH270, power amplifier 22AH370, MFB box 22AH586 and more.
There were 2 versions produced by Philips of this 170,
the early 1 version and the more common later 2 version, that seem to have some improvements.
 

Specifications:

Philips 22AH170
Tuning Bands: FM, MW, LW
FM Tuning Range: 87.5 to 108 MHz
Frequency range: 25 - 14,000 Hz (+/- 3 dB)
Harmonic distortion: less than 1% mono
Intermodulation distortion: less than 1% mono
Signal-to-noise ratio: 45 dB
Crosstalk damping: 30 dB
Output voltage: ~ 0.5 Volt per channel
Output impedance: 5k Ohm.
Power supply: 220/250 volts
Dimensions: 78 x 482 x 280 mm.

 

Front ^

ready to service ^

 

User Manual:

Click here to download the user manual PDF format in Dutch

Schematic:

This tuner has a very simple FM front-end, it incorporates 3 transistors, 2 moving coils combined with fixed caps for tuning.
The MF is also very simple: 1 transistor, 1 coil, 1/2 IC, 1 ratio detector. 1 AFC circuit.
It has a TDA1005(A) stereo decoder and 2x a two transistor final LF stage.
MW & LW reception is ok, but no internal ferrit antenna present, so it works only with a external antenna.
The power supply is very simple. No stereo/mono, no muting, no noise filter switchable options.
No 75 Ohms antenna socket, only 300 Ohms balanced FM antenna connetable via DIN connector.

click here to download the service manual of the Philips 170

 

Modifications:

The used electronic parts are of good quality, but aging is an issue so some parts should be repalced.
Due to the very simple power supply some resistors may be burnt and need to be exchanged.
The pcb design is rather poor.
Set the transformer from 220V~ to 230 or 240 in Europe, due to the detrimental voltage rise from 220V to 240V~.
If you use shielded cable to the output sockets, hum & noise will be less.
Version 2 of the 170 lacks the 32V line in the power supply and is little different at some points.
Twist all AC lines and power supply wires.
Small heatsink on the TDA1005A is better for stable operation of the IC.
You may very easely add a 75 Ohms antenna socket.
For the rest there is not much to upgrade, this tuner is not enough high quality to invest much in, its ok as it is.
 

Restore on the way inside, replacing the silly red/brown/black wire by shielded cable, to get the noise-floor down v

Restore ready, this is how the tuner looks inside after the upgrade ^

 

 

Matching pre-amp 22AH270 ^

 

 

Sound:

The sound of the restored Philips 170 is acceptable, the FM reception is better than you would expect.