[Elecraft] Cheap power supply for KBT2

[Bob McGraw]

I strongly agree with Jim, K9YC on this.

One way and place to start,  power the transceiver from a battery such 
as a lawn tractor battery.  Then dump the main breaker to the house.  
Make sure any UPS is also OFF.  Then turn off all of the individual 
breakers.  Check and note the level on the receiver with one antenna and 
normal settings on the receiver.  Don't change antennas or receiver 
settings.   Just note the noise level.    Turn the main breaker ON.  Go 
note the noise level.  There should not be any change.   Now, one 
breaker at at time, turn it on and note the noise level for each one.  
The next breaker on and note the noise level.  And continue the 
process.  Now, if you see or observe a noise increase with a particular 
breaker on, that says something on that circuit is causing noise.  Find 
out what it is and take corrective action.   It maybe necessary to 
replace something or to add a line filter at or to the offending item. 
Once you have completed the process with each breaker, and cleaned up 
your house, anything left is most likely outside of the house.   That 
would be the neighbor's house or power company.  Good luck with those, 
although most cases, the power company will be available to clean up 
their system.......but you have to be willing to find the general 
location of the source of the noise first, be it on a pole, transformer, 
night light, and etc.   As to the neighbors house......just buy some of 
their weed and be happy.   {Grow lights?}

It is a time consuming process but well worth the time.  Seems we add 
things and the noise comes up a wee bit, then we add something else and 
the noise comes up a wee bit more, and etc.    I just added some of 
those twinkling blinking Christmas lights.  My noise went up 
noticeably.  Guess I'll tolerate the noise until about Jan 2 or 3.  
You'd be surprised at the number of things that cause noise that I've 
thrown in the trash.  Best place for most of the junk.

73

Bob, K4TAX


On 11/25/2021 8:55 PM, elecraft-request at mailman.qth.net wrote:
> Message: 16
> Date: Wed, 24 Nov 2021 11:02:06 -0800
> From: Jim Brown<jim at audiosystemsgroup.com>
> To:elecraft at mailman.qth.net
> Subject: Re: [Elecraft] [K2] Cheap power supply for KBT2
> Message-ID:
> 	<89d0d3d2-6e46-4327-c5c3-555460f2575e at audiosystemsgroup.com>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> On 11/24/2021 6:29 AM, Chris wrote:
>> I use this, and it seems to be working very well.
> Have you checked it for noise, using techniques in this app note?
> http://k9yc.com/KillingReceiveNoise.pdf
>
> Most hams have so much receive noise that they can't hear. If you
> haven't gone through your home to get rid of your own noise sources,
> chances are you're one of them.
>
> 73, Jim K9YC