[Elecraft] KX3 power supply

[John Kramer]

Don

Thanks for the reply. I have thought long about it, and decided I would rather not risk damaging
my KX3 for the sake of a cheap PSU. I live too far away from the factory to risk damaging
the KX3 - it cost me $ 450.00 just to ship my new KX3 to me in June.

I will leave the cheap eBay PSU for some other project, or the trash. I have plenty of other 
regulated, stable PSU’s that supply the correct voltage, so I will continue using them.

I would never forgive myself if I damaged my KX3 by using a cheap eBay PSU.

Thanks for all the replies

73
John, ZS5J







On 19 Jan 2016, at 1:18 AM, Don Wilhelm <w3fpr at embarqmail.com> wrote:

John,

I would suggest that you put a diode in series with that supply - rated
at 5 amps.  That will reduce the voltage by the amount of the diode drop.
Running the KX3 (or any other device) above the specified maximum
voltage is done at your own peril - it may work, but it taxes the
regulators and other devices.

73,
Don W3FPR

On 1/18/2016 3:43 PM, John Kramer wrote:
> Someone on this reflector suggested a power supply off eBay, that could be used
> with the KX3 about 2 months ago. It is intended for Toshiba laptops. So I bought one,
> this is the one…
> 
> http://www.ebay.com/itm/15V-5A-AC-Adapter-Charger-Power-Supply-For-Toshiba-Tecra-A6-A7-A8-A9-A10-Laptop-/381356162365?hash=item58ca993d3d:g:Yk0AAOSwMmBVxX22 <http://www.ebay.com/itm/15V-5A-AC-Adapter-Charger-Power-Supply-For-Toshiba-Tecra-A6-A7-A8-A9-A10-Laptop-/381356162365?hash=item58ca993d3d:g:Yk0AAOSwMmBVxX22>
> 
> It terminates in the right plug for the KX3 and is rated at 15 volts at max 5 amps, and only sells
> for $ 7.79 including free shipping from Hong Kong.
> Anyway, it is cheap as chips so I bought one, and it arrived today. I hooked up to a volt meter
> and see it is 15.4 volts. I know it is better for TX IMD to have higher voltage supplied to the
> KX3 rather than a voltage too low, but I am concerned that 15.4 volts may be too much
> for the KX3. I see in the KX3 manual specs, that recommended supply voltage is 8 - 15 volts.
> I would hate to hurt my KX3 with over voltage……anyone know if there would be any short
> or long term problems with running 15.4 volts to the KX3 ? It is just slightly above the
> maximum recommended supply voltage
> 
> 73
> John, ZS5J.
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