RadioDaze... No, it has two wire leads from the speaker with 1" ~ 1 1/2" bare wire. That's why I was looking at the more expensive Pyramid power supply. But I'm open to suggestions....
Thanks,
Keith
2 questions...
1: Is the power supply you are looking at is a `Linear', IE: A big transformer, diodes, capacitors for initial filtering, and a solid state regulator circuit. Or is a `Switching' similar to the one you have in your desktop computer?
With the first you won't have to worry too much about any `noise', RF or otherwise, being generated that might cause you problems with the powered speaker or the receiver. But, you are going to be paying the price of the weight of a big transformer to get the current you may end up having to deal with along with also having to deal with heat generated by both the transformer and the regulator circuit. (This later point becomes even more important in question #2.)
With the second power supply, while there will still be some heat to deal with it will be somewhat less but, the big `bug-a-boo' that comes with it is the generation of assorted `noise' due to how it works. IE: It first take the AC from the outlet on the wall and turns it in DC, next it runs through a circuit that chops it back up into AC again but at a *much* higher frequency than the 60Hz from the power company. It *IS NOT* a sinewave but instead is a squarewave and because of this there are all sorts of `harmonics' produced, some of which could well end up being close enough or even right on a frequency you may be interested in. Now there *are* `Switching' power supplies out there that are very quiet but, you have to *pay* for them compared to the `linear' ones!
2: How much power are you going to need? And... I am *not* just talking about right now! Some *may* argue but, *I* usually rate most `base/mobile' scanners to consume around 2A per unit, SWLing/HF receivers *I* usually rate at *at least* 2A and generally actually usually get a tad bit more generous and rate them at 3A. Powered speakers can run anywhere between as little as 1A to 1½A for the smaller ones and I have seen some that have come with as large as 3-4A power supplies. (Some of those were a bit more than just a speaker with a cheap amp installed in the same cabinet and instead also had both the Amp & some sort of `noise reduction?' circuit and, heaven only knows why, a `Sub Woofer' and associated circuitry. Personally I have generally stayed pretty much away from `powered' speakers around my home installation with the only exception being a couple GAP `Hear-It' speakers w/digital noise reduction that are used with my SWLing/HF receivers to remove anything I haven't been able to remove via what the receiver has `on board' or via the antenna `chain' via something like a TimeWave ANC4 unit. [Whoops! There is *another* thing that uses the power supply and I've got it rated at a *possible* `Belt-N-Suspenders' 2A draw.]) Remember... Design and figure for the worst case and you will end up with considerably less `gotchas' down the road.
Now you may be wondering just what this all has to do with what power supply you end up with... {GRIN!} Well... For quite a few years I had my shack pretty much powered, IE: All but a few things that got very little use *and* could be run off of either batteries or a `WallWart' whenever I did need to use them, off of an old DELCO `Linear' power supply I originally used to power the old Delco car radios when I was repairing them. This supply had enough `balls', 35A *Surge*, to handle the old mechanical `scanning' *tube* type radios of the `50s-`60s which used a monsterous solenoid to `****' the mechanism before it was let go to mechanically scan. (Talk about `Bear skins and Stone knives `Tech-no-golly'!!) However as things progressed over the years, while the Delco still is a darned good power supply `minor?' things like it using *germainium* transistors as the main devices in the regulating circuit, *Monster* capacitors, and a few other quickly getting hard to get replacements for parts I decided to get something a tad bit newer. It also helped that I found myself going from 2 or 3 scanners, 2 or 3 SWLing/HF receivers, to having 8 or 9 scanners, 4 SWLing/HF receivers and a lot of other `goodies' like the aforementioned TIMEWAVE ANC-4 `phaser', several `active' antennas, the occasional use of a couple 2-3 HH scanners, ETC.. For all this the old DELCO just wasn't quite enough.
OK, so I first tried several brands of `Linear' power supplies and while they worked fairly well they were big bulky and tended to also generate a *lot* of excess heat. They also demanded a lot from the AC supply current-wise *all the time* whether they were lightly loaded or `cranking' right at their `top end'. SWMBO used to complain about the noise of the fans if she dropped into the `shack' at a time when I had one of them heavily loaded. After a while, after visiting another `scannist's'/SWLer's shack and noticing the almost total lack of noise from fans in his `Switching' power supplies I decided that I needed to go with a `Switching' supply. It was then that I discovered that even there there were some better than others in regards to another kind of `noise'.
The first couple I tried, I discovered that they could produce another kind of `noise', *RF noise*! On top of that each of those produced their noise in different parts of the RF spectrum. Fortunately, the dealer I was then dealing with was nice enough to take back the offending devices several times until I found one that was actually quiet. I'll admit that I also under rated what I was actually demanding from them which is why I mentioned my ratings earlier. Currently I am now using a Samlex SEC-1223 25A `Switching' power supply but am considering adding another supply just for my SWLing equipment and am trying to decide between a Samlex SEC-1235SM 30A, Alinco DM-330MVT 30A, or a Jetstream JTPS30M 25A. (The last 2 have an adjustment to help eliminate/move the RF noise & also have the ability to lock in a preset voltage making the chances that someone or something might change the front panel setting to a setting one might not want since they can both go as high as 15VDC.)
I also have a power setup that uses a `switching' type supply that can also keep a set of `deep discharge' 12V batteries charged and allows switching, almost seamlessly, between the house current and the batteries should there be an `outage'. It's original useage is actually for `marine' use so that one can have `ship' or `shore' power for one's 12VDC equipment. That setup is in a `camp trailer' currently I don't recall just who made it. However, there is, somplace here on RR, a `thread' about it as at least one RRer other than myself who uses it for his home shack as a custom `UPS' which is where *I* discovered it.
Anyway... One of the other things that recommend using a `Switching' power supply over a `Linear' one is their size. The `Switching' ones are quite a bit smaller Amp per Amp-wise than the `Linear' ones. As long as one takes proper precautions for good airflow around them they can be fitted into much smaller spaces than a similar output `linear' one.
Oh, yeah... {WAN GRIN!} *If* one is interested in creating their own `custom' `UPS' the people at Mountain West have a nice little gadget that can use you power supply as a charger for a 12 battery or two and when the power decides, or someone decides to make the power, go out it will switch your shack over to the battery/batteries just like a `UPS' does for your computer. Combine a good `Switching' power supply, that, and a battery or two and you'll keep on listening even when everyone else around you is `in the dark' and the whole `lashup' can be easily hidden away almost in a desk's footwell and be tailored to fit whatever `size' your shack is and your pocketbook allows because you can get the pieces `as needed'/`as you can afford'.
BTW, any spelling errors are most like caused by the steady stream of cats I've had to deal with. {GRIMACE!} I'm going to have find whatever new hole they have discovered and try and close it. I suppose I should be happy that the, Samoyed/Golden Retriever mix, dog hasn't been able to find a hole it can get through?
