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|Power Strips||KV5WS||1 week, 3 days ago|
|UPS's may provide surge protection, but that's not their main purpose. They automatically switch from AC mains to a battery-powered inverter when AC is lost. There's no guarantee that a lightning surge (or some such) won't get through before the switch over happens.
Some (more expensive) UPS's may always run the load off the DC inverter. That would give more isolation from the AC line. But I've never seen that in a consumer unit.
73 Martin AA6E
|Power Strips||KV5WS||1 week, 4 days ago|
|It's hard to answer this question. There are thousands of power strips out there. There are some standard marks to look for, such as a UL rating. This hardly guarantees much, but if a model doesn't have this, it's something to worry about.
The big differences are internal -- the quality of wiring, contacts, switches, etc. They are very hard to judge on the shelf.
My guideline is to avoid the cheapest products. I've seen $2 no-name power strips. Don't trust these in any important application. Look for solid construction (e.g. metal), a switch that feels and looks substantial, and ideally a circuit breaker and pilot light.
Then there's the whole question of surge suppressors in outlet strips. You will see all kinds of claims, even "insurance" against appliance damage. My attitude is that something is probably better than nothing, and a higher "joule" (energy absorbing) rating is better than lower, but I would not trust my valuable gear to protection from a cheap power strip. Stick with known name brands if you can find them, and be prepared to pay a little more. Also, be VERY sure your 3rd wire ground pin is truly connected to your power ground.
For what it's worth, I'm using a Belkin 10-outlet switched strip in my shack, model F9D1001-15. No smoke so far.
73 Martin AA6E
|What can I learn?||WB5EMX||3 weeks, 6 days ago|
| (It's customary to give your callsign and first name. Most of us use our callsign as the ARRL username. You can change your username if you want.)
I think the answers to your questions are mostly yes, except that with just an SWR measurement, you won't be able to calculate the actual complex impedance at your feed point - or anywhere else. SWR does not tell you about phase, so you can't distinguish inductive from capacitive from resistive terminations. It will tell you the frequency where your antenna is resonating, so it will tell you whether to lengthen or shorten it for a desired center frequency.
If you want to do a complete measurement, you'll need a vector antenna analyzer. They're not cheap, and most hams get by without one, I think.
Without an analyzer, you can still do interesting experiments besides finding resonance. You can terminate a line with a short circuit, an open circuit, or any known impedance and get an idea of line loss and nominal impedance.
Many people obsess about getting 1:1 SWR. It's really not necessary, especially for HF frequencies. As long as your SWR is less than 2:1, most transmitters will work fine. If you have an antenna tuner, you can use 3:1 or even more, accepting some extra attenuation.
It sounds like you'd enjoy reading the ARRL Antenna Book! (It's a bit more practical than Terman.)
73 Martin AA6E
|Linux Mint and LotW||K2ADK||on 19/4/13|
|I understand that new versions of the LoTW clients are in the works. They should be a big improvement.
|Linux Mint and LotW||K2ADK||on 16/4/13|
I installed a copy of Mint, because I'm interested in other distros. (My base system is Ubuntu.)
It looks like Mint is almost identical with Ubuntu, as far as software downloading is concerned. You install TrustedQSL the same way.
Running Terminal (i.e., command line), type 'sudo aptitude install trustedqsl' and everything should download OK. The two programs are tqslcert and tqsl. You can make desktop icons for them, but they're not provided automatically.
73 Martin AA6E
ARRL Technical Advisor