[R-390] Silent R390A won't turn off

[Barry]

Good idea.  I fixed a similar problem in an R390A I owned by simply dismantling the microswitch, putting a drop or two of contact cleaner on the plunger and "flicking" it a few times.  I think welded contacts might be an issue but just a plain old gunked up plunger will also cause that.

Thanks,
Barry - N4BUQ

----- Original Message -----
> From: "Glenn Little WB4UIV" <glennmaillist at bellsouth.net>
> To: r-390 at mailman.qth.net
> Sent: Monday, March 16, 2020 9:48:54 AM
> Subject: Re: [R-390] Silent R390A won't turn off
> 
> Sounds like the power switch, a small micro switch, has welded its
> contacts closed.
> This is not uncommon.
> Best to run the R-390A from a buck transformer to reduce the line voltage.
> The R-390A was designed in an era where line voltage was less than today.
> Have a suitable on/off switch on the buck transformer and use it to
> power the R-390A on and off.
> 
> 73
> Glenn
> WB4UIV
> 
> On 3/16/2020 9:26 AM, Jim Bishop wrote:
> > After working fine last night, my R390A was turned off,
> >
> > It was turned to standby this morning long enough to fix coffee. It was
> > silent when switched out of standby and now will not turn off.
> >
> > Ideas?
> >
> > THAnks for any assistance,
> >
> > Jim Bishop
> >
> > 金永朋 (Golden Friend Forever)
> >
> > jim.bishop at gmail.com
> > Skype JDBishop5
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> --
> -----------------------------------------------------------------------
> Glenn Little                ARRL Technical Specialist   QCWA  LM 28417
> Amateur Callsign:  WB4UIV            wb4uiv at arrl.net    AMSAT LM 2178
> QTH:  Goose Creek, SC USA (EM92xx)  USSVI LM   NRA LM   SBE ARRL TAPR
> "It is not the class of license that the Amateur holds but the class
> of the Amateur that holds the license"
> 
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