[Elecraft] k3 switching supply

[Marc Veeneman]

Emory, I've relied upon the power cable for grounding without giving a separate wire or strap any thought.  Today sometime I'm going to run a ground strap between the K3 and PowerWerx to see if that helps.  Thanks for sharing your experience and thanks for the suggestion.

I'm not sure why I didn't think of that myself.  It's just that I never think of a power supply in terms of station grounding. 

73,
Marc  W8SDG




> On Jun 17, 2015, at 7:45 AM, <ejkkjh at gmail.com> <ejkkjh at gmail.com> wrote:
> 
> Marc,
> I have two of those power supplies, both without the meter.  I did have RFI from one of them when I had power for a keyer connected to the front power pole connectors, disconnecting it, RFI  went away.  I also had a problem with RF getting into the transmit signal.  When I connected station ground to the power supply that went away, I think it was a ground loop.  With these changes I now have no RFI from either one.
> Hope this helps.  73
> Emory  WM3M
> 
> -----Original Message----- From: Marc Veeneman
> Sent: Wednesday, June 17, 2015 6:34 AM
> To: Fred Townsend
> Cc: Elecraft Reflector
> Subject: Re: [Elecraft] k3 switching supply
> 
> Fred, you could be right about the meters being the problem.  There are times when the birdies will be quite stable, and other times when the move completely across the P3 (or PX3) 40 kHz display in a dozen or so seconds. At this moment they are stable but the meter reads a, also stable, 1.9 amps at 14.0 volts.
> 
> I’ll keep an eye on that.
> 
> I bought directly from PowerWerx but my e-mail to them about the problem went unanswered.  Maybe a phone call is in order — and I think I’d like them to substitute the meterless version.
> 
> I wish I had your foresight.  Instead I relied on the reviews I could find on the Internet.  :-)
> —
> Marc W8SDG
> 
>> On Jun 17, 2015, at 3:02 AM, Fred Townsend <fptownsend at earthlink.net> wrote:
>> 
>> Marc I do RFI for a living. When I purchased my PowerWerx I made sure it was returnable if I found noise on it. I checked and found everything was well below published specifications so I retained the supply and have very successfully used it in the Sierras where there is virtually no man made noise which makes it sheer joy to operate. This unit was purchased before the model with LED displays was even available.
>> 
>> Back in the days where commercial transmitters had scores of meters it was standard practice to shield those meters so RF would not leak out of the transmitter cabinet. I traced a problem in one HP unit to an unshielded LCD display. I suspect it may be the LED display itself in your PowerWerx that is causing your RFI. Personally I do not see the need of the meters when I can read the voltage on the K3 itself. After all it is the voltage at the K3 that counts. Not the voltage at the power supply.
>> 
>> 73, Fred, AE6QL
>> 
>> -----Original Message-----
>> From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of Marc Veenemanno made
>> Sent: Tuesday, June 16, 2015 3:26 AM
>> To: elecraft at mailman.qth.net
>> Cc: NE9U - Jasper
>> Subject: Re: [Elecraft] k3 switching supply
>> 
>> Mine is 6 months old, the version with the LED display, and the moving birdies on 80 and 75 meters are so strong and so annoying that I turn the supply off and operate from batteries if I operate for only an hour or so. I’m sorry I bought the PowerWerx even though it is good looking and a nice size for my small operating desk.
>> 
>> Apparently their quality control is a variable, just like my birdies.
>> —
>> Marc  W8SDG
>> 
>>>> On 6/16/2015 1:22 AM, NE9U - Jasper wrote:
>>>> I was about to order a switching supply for portable/dxpedition use and thought the one on elecraft site must be a good one, but i see it is getting poor reviews on eham.net for RFI/noise generation issues.
>>>> 
>>>> anyone have suggestions for a good quiet k3 switching supply?
>>>> 
>>>> scott  ne9u
>>>> 
>>>> 
>> 
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> 
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