[Elecraft] UPS Can Be a Noise Source

[Richard Lamont]

On 31/08/17 22:56, Jim Brown wrote:
> On 8/31/2017 11:35 AM, Tox wrote:
>> I had a couple racks of APC
>> SmartUPS 2000 units with daisychained batteries to give extended
>> holdup to
>> a couple of racks of telecom and server hw. No clue how RF noisy those
>> units are, though.
> 
> All of the APC units for which I've seen spec sheets are FCC Part 15
> Class A (the industrial spec, ILLEGAL to sell for residential use,
> roughly 20 dB worse than Class B).

I had a SmartUPS 750, and it was very bad. Put out crud all the way from
VLF to VHF. I threw it away in the end. In the shack I use a much older
APC Back-UPS 500 for the computer, which doesn't seem to cause any
problems. I've had to replace the battery every 3-4 years, but that's to
be expected.


73,
Richard G4DYA