Routine Shutdown of KPA500: Use Front or Back Panel Switch?

[Paul Grigorieff]

I'm sure this is a simple question, but I could not find the answer in the Manual.

If you're turning the amp off (e.g., at the end of an operating session), must you
turn off the switch on the back panel (assuming the fan has quit running) or is it OK simply
to use the front panel switch for such shutdowns, leaving the back panel switch
ON most of the time?  Does the unit, after the fan has stopped, draw any power
when the back panel switch is ON and the front panel switch is OFF?

I'm assuming that the back panel switch is for use when wanting to kill power to
the chassis altogether, e.g., when servicing it.

Thanks!
   -Paul, N1HEL
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[k6dgw]

On 7/9/2013 4:14 PM, PGrig wrote:

> If you're turning the amp off (e.g., at the end of an operating session), must you
> turn off the switch on the back panel (assuming the fan has quit running) or is it OK simply
> to use the front panel switch for such shutdowns, leaving the back panel switch
> ON most of the time?

Just punch the front panel button and leave.  I've been doing it for a
couple of years, works great.  I unplug it when we're going to be gone
for awhile.

Does the unit, after the fan has stopped, draw any power
> when the back panel switch is ON and the front panel switch is OFF?

Probably, like everything else electrical these days, they just go to
sleep [don't know if they dream], but I think it's minimal at worst and
negligible most likely.  I unplug all of my stuff when we're leaving for
awhile just for additional lightning protection.  We get our water from
a well, 4HP pump, that overrides all the other little things in the
house except the A/C and oven in terms of electricity consumption.
>
> I'm assuming that the back panel switch is for use when wanting to kill power to
> the chassis altogether, e.g., when servicing it.

No! No! NO!! If you are going to service any part inside with any part
of the cover off, you unplug it!  I don't really know what the back
switch is for, I use the front switch and the plug, mainly because
that's what I can get to easily and what I understand.  I've never had
the cover off my KPA500 after I put it together, but believe me, if I
ever go in there for something, the plug will be out.

The DC voltages in the KPA500 are in the 70V range, probably won't kill
you but it *will* get your attention, however the 120/240VAC is another
matter.  We want you around and on the air Paul, unplug it.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2013 Cal QSO Party 5-6 Oct 2013
- www.cqp.org

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[mcduffie]

On Tue, 9 Jul 2013 16:14:47 -0700, PGrig wrote:

> Does the unit, after the fan has stopped, draw any power
> when the back panel switch is ON and the front panel switch is OFF?

Leave the switch on.  It draws 6 watts, as measured by my Kill A Watt.  With it
turned on at the front switch, it draws 12 watts, ready to key.

I have no problem leaving the whole thing running all day.  I shut down in times
of storms, and usually when I go to bed, but the rest of the time it runs and is
ready to key.

Gary
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[mcduffie]

On Tue, 09 Jul 2013 17:06:31 -0700, Fred Jensen wrote:

> > I'm assuming that the back panel switch is for use when wanting to kill power to
> > the chassis altogether, e.g., when servicing it.

Yes, assuming you do all the other things.

Procedure:
        Turn off front panel switch
        Wait for fan spindown and maybe slightly longer
        Turn off back panel switch
        Unplug from wall, or pull cord from back of unit
Reverse order when you are done.

> The DC voltages in the KPA500 are in the 70V range, probably won't kill
> you but it *will* get your attention, however the 120/240VAC is another
> matter.  We want you around and on the air Paul, unplug it.

Don't forget there's 270 volts used in the PIN diode switching circuit.

Gary
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