[time-nuts] UPS for my time rack
kb8tq at n1k.org
Sat Oct 10 13:17:02 EDT 2015
If you do *any* VLF, then anything with an inverter in it is going to be a potential disaster. It
will purely be a case of the inverter being at a frequency that bugs you right now. None of
the ones I have seen are tightly controlled in frequency. What they do today probably will not
be what they do tomorrow.
Indoors vs outdoors does not matter as much when a tenth wavelength is into the next county.
The inverter in one of these gizmos is effectively a 1KW transmitter at (say) 60 KHz. Yes filters
can help. They will rarely do the trick when you are trying to listen to something at 60, 120, 180,
240 or 360 KHz. Since that’s 60 KHz +/- lots, those “wiped out” segments are also pretty wide.
> On Oct 10, 2015, at 11:59 AM, Chris Waldrup <kd4pbj at gmail.com> wrote:
> Thanks for the comments this morning.
> I'm not looking for something huge, maybe in the under $200 range. Just enough for the Thunderbolt, laptop, and Agilent 53131A counter. I'd like a little headroom though, as I may add another Thunderbolt or a rubidium standard someday.
> I do like the 12 V battery idea. I run my ham gear off a 12 V gel cell (I'm mainly QRP so a 32 Ah cell works for me) and I have a 12 V distribution system with Anderson Power Poles on my operating bench.
> I do a lot of VLF and LF listening but my antennas are outside. Nothing at this time above 2 meters.
> I live in a very quiet rural area on top of a mountain in Tennessee. So not much man made noise at all and I wanted to keep it quiet emission wise.
> Thanks for all your help.
> Sent from Mailbox
> On Sat, Oct 10, 2015 at 10:05 AM, Mark Spencer <mark at alignedsolutions.com>
>> Hi over the last 10 years or so I've purchased several consumer / small office grade UPS's from sources such as Staples and Costco. I've never noted any RFI from them but I live in a (rf) noisy urban neighbourhood so any noise they put out is probably hard to notice.
>> Other than occasionally turning some of them off and on and seeing if I can see or hear any (additional) RFI on frequencies of interest I've never really looked for RFI from them.
>> Several years ago I started putting ferrite chokes on the feed lines for my antennas and have almost completely switched to double shielded cables for my amateur radio and time nuts activities.
>> Hope these comments are of some interest.
>> Mark S
>> Sent from my iPhone
>>> On Oct 10, 2015, at 6:20 AM, Chris Waldrup <kd4pbj at gmail.com> wrote:
>>> I have decided I'd like to get a UPS to put on the rack containing my Thunderbolt, the laptop that runs Lady Heather, and frequency counter.
>>> Has anyone had bad experience noise wise with the APC brand units like are available on Amazon and at Staples? I'd like to get one that doesn't generate lots of RFI. Thank you.
>>> Sent from Mailbox
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