wrote:

------------------------


The one thing I noticed about WD40 is when used to clean the old
mechanical tuners in TVs it would detune them until most of it
evaporated, LPS2 was much better for that application.


** WD-40 and LPS2 are near identical products, same ingredients in the same percentages and both use CO2 as a propellant.

It is *NUTS* to spray any oil bearing fluid onto RF circuitry - oil has a much higher dielectric constant than air. It therefore adds capacitance to any coil, wiring, PCB pattern or tuning gang it lands on.

The correct procedure with rotary TV tuners was to apply some WD-40 to a small piece of paper which is then wedged between the moving contacts while the tuner is turned. This cleans up the contacts nicely while preventing any oil getting on the RF coils.

Anecdote 1:

I once had a customer who decided to fix his FM tuner by spraying WD-40 all over the PCB and tuning gang. Afterwards, the stations had moved half way across the dial.

It took me a over an hour hour, using various solvents to get the oil off everything and put them back where they were. A tiny bit of WD-40 on the bearings of the gang fixed the noise he has been getting.

Anecdote 2.

Folk who run RC cars and boats can end up with a wet, non functioning radio receiver - so they reach for the WD40. Big mistake.

The correct procedure is to wash the PCB in denatured alcohol (aka Metho) and then allow to dry in the sun or using hot air.



..... Phil