[R-390] Cleaning the Megacycle bandswitch

[Guido Santacana]

You are correct Larry I had a bad experience using Deoxit on a Phenolic
wafer switch in a multiband radio.Since then I never sprayed Deoxit on
Phenolic wafer switches. What I did with the R390A was to apply it with a
fine brush only on the contacts being extra careful to avoid letting much
Deoxit on the wafer. It worked but your mileage may vary. I am sorry about
not mentioning that detail before but thanks for bringing it up.

73s

Guido

On Wed, Oct 10, 2018 at 8:02 PM Larry H <larry41gm at gmail.com> wrote:

> I believe that most of the RF deck switches are ceramic, so a little
> cleaner or solvent on them is not a problem.  But, the 2nd xtal osc switch
> is phenolic and it can absorb chemicals and damage it by reducing it's
> insulating characteristic.  Care to not get any cleaners or solvents on
> them is important.  Deoxit is good to use on them, but not on  the phenolic
> part.
>
> Regards, Larry
>
> On Wed, Oct 10, 2018 at 7:32 AM Guido Santacana <gsantacanav at gmail.com>
> wrote:
>
> > What I have done to clean the switch in the rf/crystal deck is to go over
> > it carefully with a camel hair brush dipped in Deoxit. This is done just
> > before returning the RF deck to the main chassis. When everything is back
> > in its place I move the switch through all bands. It has worked for me.
> >
> > 73s
> >
> > Guido KP4FAR
> >
> > Sent from my iPhone
> >
> > > On Oct 10, 2018, at 9:37 AM, dog <agfa at hughes.net> wrote:
> > >
> > > It appears that the gain in my 390A will change over time. I've tried
> > changing tubes to no avail. Then I noticed that if I rocked the Megacycle
> > Change the gain goes back to 'normal' and stays there for a while. It's
> > also noisy changing bands. What is the recommended procedure to clean
> that
> > switch?
> > >
> > > Dave
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