[TenTec] TenTec Digest, Switching Supplies

[Robert Mcgraw]

I solved most all of my noise problems by replacing all of the WALL WARTS
with a common supply.  Hence, the switchers used for my HF station have
been confirmed as quiet RF wise.  They have temp controlled fans that run
at variable speeds as necessary depending on load and duty cycle of the
load.

I added a good CORCOM filter to the distribution strip for the TV,
surround system, DVR, Sat receiver and such.  That took the noise down a
couple of notches more.

I've not had any issues with the CFL's but I don't use the "dimmable"
type either.

73
Bob, K4TAX





>>
>> Sorry to drag this out but its a problem.  Noise generated by switching
>> supplies... I used the TenTec switcher that came with the Orion and it
>> was clean.  The build in switcher in my Icom 775 is also very clean.
>> They are good design.  But go buy a network router or switch, or have a
>> cable box installed in your house, or even in your neighbors house, and
>> you may get a lot of noise across the HF spectrum, with strong warbly
>> carriers at regular intervals. The switching supplies are basically an
>> oscillator that drives the power devices to produce the output voltage.
>>  Harmonics of that oscillator cover the spectrum.  Wall warts are
>> terrible sources, such as those used to power routers or cable boxes.
>> I had to replace the wall wart on my router with a traditional DC
>> supply to clean up one problem, but there are many other oriental wall
>> warts elsewhere in the house, all creating hash. I have HF mobile and I
>> can cruise the neighborhood and hear them as strong signals everywhere.
>   Nuff said.  73 Jim N4BE
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