KPA500 Power Switches

[Keith O'Brien]

I took delivery of my KPA500 a few weeks ago and I am pleased with it. However
I was some what disappointed that the manual did not come with a schematic diagram of
the amplifier. This has got to be my first piece of ham radio equipment that I have owned
in half a century that did not come with a diagram.


The lack of a schematic now leads to this question. Just what is it that the front panel ON
switch is turning on and off ? The rear panel power entry module switch does kill all
power to the amplifier, but the front panel switch when Off, leaves some circuit power up.

Anyone know what is left power on when the front panel switch is OFF and the rear

panel switch is On ?


Having the main On Off power switch on the rear panel is a bit of a inconvenience in my shack.Also having just only one RF output connector is problematic. Guess that is what the KAT500
with it's 3 Output connectors is for....


Keith N4ZQ
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[Dick Dievendorff]

The front panel on/off switch is an input to the microcontroller.  The
microcontroller runs all the time that DC power is applied. The back panel
switch interrupts the microcontroller's power supply.

When the front panel turns the KPA500 off, it turns off the HV power, dumps
the power into the fans, releases all the internal relays, and turns off the
front panel display.  The microcontroller stays on to monitor the serial
port.  The KPA500 can be turned "on" again by a command from the KPA500
Utility or another program attached to the KPA500's serial port.

A lot of consumer electronics, including my TV set and phone, aren't really
"off" unless unplugged.

73 de Dick, K6KR

-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Keith O'Brien
Sent: Wednesday, August 29, 2012 6:53 AM
To: [hidden email]
Subject: [Elecraft] KPA500 Power Switches

I took delivery of my KPA500 a few weeks ago and I am pleased with it.
However I was some what disappointed that the manual did not come with a
schematic diagram of the amplifier. This has got to be my first piece of ham
radio equipment that I have owned in half a century that did not come with a
diagram.


The lack of a schematic now leads to this question. Just what is it that the
front panel ON
switch is turning on and off ? The rear panel power entry module switch does
kill all
power to the amplifier, but the front panel switch when Off, leaves some
circuit power up.

Anyone know what is left power on when the front panel switch is OFF and the
rear

panel switch is On ?


Having the main On Off power switch on the rear panel is a bit of a
inconvenience in my shack.Also having just only one RF output connector is
problematic. Guess that is what the KAT500
with it's 3 Output connectors is for....


Keith N4ZQ
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[WB4SON]

There is about 10 watts of power consumed when the front panel push-button
has turned the unit off.  That's the power that is running the internal
supply and the microprocessor.  That's why I use the switch in the back.

73, Bob, WB4SON
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[Alan Bloom]

10 watts is 240 watt-hours per day, or about 3 cents, depending on your
local utility rates.  If you use the amplifier once a day, you have to
decide if it's worth 3 cents not to have to reach around behind the
amplifier to turn it on when you start operating and then reach around
again when you finish.

If you typically go for weeks between operating periods then it
definitely makes sense to turn it off.

Alan N1AL


On Wed, 2012-08-29 at 10:28 -0400, Bob wrote:
> There is about 10 watts of power consumed when the front panel push-button
> has turned the unit off.  That's the power that is running the internal
> supply and the microprocessor.  That's why I use the switch in the back.
>
> 73, Bob, WB4SON


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[Richard Squire - HB9ANM]

That's right, Bob, I switch the K3 off, then wait until the KPA500's fan is silent to pull the station's main switch, so the whole station is OFF, including the rotator, W2, SteppIR controller, etc. - no power consumption at all...
Makes me save up to 5 cents a day (we seem to have higher rates here).
Which means I very seldom use the switch on the rear panel, except when fiddlling around with cables, etc. as recommended in the manual (yes, I did read it, hi!)

73
Richard - HB9ANM

WB4SON wrote

There is about 10 watts of power consumed when the front panel push-button
has turned the unit off.  That's the power that is running the internal
supply and the microprocessor.  That's why I use the switch in the back.

73, Bob, WB4SON

[Jim Brown-10]

On 8/29/2012 11:32 AM, Alan Bloom wrote:
> 240 watt-hours per day, or about 3 cents,

I wish that were true. But I'm paying a peak rate of $0.34 per kWh, and
we do lots of things to minimize our power use in that penalty area.  
Indeed, one of my mental cost justifications for buying the KPA500 was
that its instant-on feature saved the cost of keeping the filaments of
my Titan going when I was in the shack. So I really would like that
front panel switch to kill power to the unit, not just to the
microprocessor.

73, Jim K9YC
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[Nick_L]

Or at least LED on front panel reminding that back switch left on

73, Nick VE3FJ


On 8/29/12 7:46 PM, Jim Brown wrote:

> On 8/29/2012 11:32 AM, Alan Bloom wrote:
>> 240 watt-hours per day, or about 3 cents,
> I wish that were true. But I'm paying a peak rate of $0.34 per kWh, and
> we do lots of things to minimize our power use in that penalty area.
> Indeed, one of my mental cost justifications for buying the KPA500 was
> that its instant-on feature saved the cost of keeping the filaments of
> my Titan going when I was in the shack. So I really would like that
> front panel switch to kill power to the unit, not just to the
> microprocessor.
>
> 73, Jim K9YC
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>

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