I see several posts about APC UPS's being 'ok'
here in CE land (where requirements for IT kit are supposedly
(considerably) tighter than FCC 15 part B ) my experiences with APC
UPSes are mixed from the perspective of RF interference.
My antennas are 20+ M away from the shack, fed via underground coax runs
and baluns.
I have an APC back-ups which is fine, this is a small 'off-line'
consumer grade UPS and protects my shack PC
I have an APC smartups 1000 ( I have owned several of these over the
years ) and it's pretty noisy. It can be tamed completely with very good
AC input filtering, proper bonding to adjacent IT kit and a good
filtered outlet strip, but 'as supplied' BY APC these devices are not RF
quiet.
I managed to pick up a bunch of these superb IEC C13 outlet strips with
integrated RF filters a few years back at a radio rally and my only
regret is that I did not buy (many) more of them whilst they were
available cheaply.
http://www.olson.co.uk/iec320_filter.htm
I also had an APC smart UPS 5000 (5KVA) which is a big UPS designed for
a server rack. It was an RFI monster that required a substantial (&
expensive ) RF input filter to tame, happily it's now in a datacentre
instead of in the vicinity of my antennas
the smart-UPS series are fairly decent UPS units for the money and are
'line interactive' which means they can supply your IT kit with clean
power during periods of brownout or over-voltage without dropping back
to battery, they can however interact negatively with backup generator
systems if these use regulation that is not able to deal well with
sine-wave distortion AND the UPS accounts for a significant proportion
of the total generator load.
I also have several old (1990's ?) 'Chroma' UPS (rated for 1.4KVA I
think), a company I have never heard of. I got these for nothing and
they only required new batteries to restore to working order. They are
quite nicely made internally with substantial RF filtering built in.
They appear RF silent AND is online capable (your kit is always running
off inverted DC ) but there appears to be no (documented) way to monitor
these so I only use them for server builds etc as one of the essential
requirements of a UPS is the ability to signal to the connected machines
that the Power has failed and it's time to do a clean shutdown before
the batteries run out
in summary, your mileage may vary. It would help a lot of you defined
the UPS capacity required, desired runtime and what you are wishing to
protect.
On Tue, 2011-06-28 at 15:28 -0400, Dan Atchison wrote:
> Can anyone point me to some reviews of known RFI-free UPS's?
>
> Dan -- N3ND
>
>
>
>
>
>
> _______________________________________________
> RFI mailing list
> RFI@contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi
--
73
Brendan EI6IZ
_______________________________________________
RFI mailing list
RFI@contesting.com
http://lists.contesting.com/mailman/listinfo/rfi
|