Cleaning rotary switches in Philips PM5134

[Kiriakos GR]

My own Philips PM5134 function generator, this started having issues at the switch, this be relative to AM modulation.

In order an analog function generator, this to create complex signals, this using a combination of several active circuits.
At the specific instrument, they are a number of eight round switches, in a common axle.
Switch contacts these are silver plated.

About servicing end repair:
As first suspect this is the age of soldering work.
First action this should be fresh soldering of all eight round switches.

If this does not help?
Next and a more drastic step, this is round switches row, un-soldering and disassembly for a deep clean.     
These switches they are large beasts, after cleanup an thick layer of grease this must added too.

This is a brief description of this process, and it is posted here as a warning, this is not an easy repair.

 

[Kiriakos GR]

Philips PM5133 / PM5134  general troubleshooting tips







Note: They are not other parts....  Half repair attempt.

[Kiriakos GR]

Here comes one last pack of tips.. 

My Philips PM5134, this is not vandalized due careless use.
All potentiometer they are undamaged.
Frequency counter and Vpp measurement, both working and deliver acceptable accuracy, an good test point this is the frequency of 2KHz.

The quick tip, this is use the instrument first by testing it for a few days.
Rotary switches these might recover all by them self , from any bad contact issues.
In my case at second day of testing, PM5134 controls and specifically these rotary switches, they started to improve.

If you are up to, using any contacts cleaner spray,  then leave the instrument first with out power, for three hours.
And also wait for five hours prior testing the instrument.
 

[Andrew-88]

ITTSB blog, this keeps Philips PM-5134 popularity alive.
This week, eBay Germany, one PM5134 this switched hands for 154 Euros.   

[Kiriakos GR]

I still have positive feelings for my PM5134.
Despite the fact that it copper transformer, this making mechanical noises (Bzzzz sound), its an unusual split core design.