I got mine off ebay. It is hard to find actual NOS but really the used ones if working pulls at worst should not need more than a recap. The 1200w on up can be a bit pricey but the 800-600W range can be had often under $16 with free shipping. Often they do not come with a mains power cord. Some do not have a 3 prong plug at all but get their mains power from the blades/pins on the back of the unit.
Since these are designed to have logic controls telling it what to do 98% need to be "hot-wired" for lack of a better word to function outside of their native back pannel server interface you normally find them in. IN most cases there will be 2-3 pins that must be grounded to power it up and you have to hard wired some wires or connectors to it to get the power out in a safe easy to hook up to way.
They do not plug and play you have to adapt them. Each type converts a bit differently.
A lot of them are functional from 100V to a bit more than 240V. Some though are only operational at 220V+. In the USA the ones that will not work bellow 220V tend to be much cheaper since so few people have any wiring beyond the circuit break prewired for anything other than 120. On the other hand in Europe these units command top dollar since that is not an issue. In the USA you will see 1500W IBM 220V+ only units sell for $16 sill sealed in boxes.
You can use a 10K resistor to prob and multimeter on low voltage power supplies bellow 48V. It is easier though to either locate someone that has already figured it out and has tossed up a pin out. If you stick to the known models and conversion methods it would make life easier. Once you get the hang of that then get into figuring out less well-known units.
I hear some of the Sun/Cisco units made by Sonny will fire up just turning them on and that there is no real conversion other than installing wires to the output pins and turning the power switch on. No experience with them.
HP DBS-600PB is prop. the easiest conversion on earth but they are getting harder to find and only do a bit more than 40amps. HP and Dell 12Vpower supplies in the 750-1300W range tend to be the most popular models and have well-published conversion documentation.
Tallman what are the model numbers off your unit's? I can at least tell you if I have any documentation on how to convert them. Two of my 3 units are well documented but one is an oddball and not well documented at all and took some digging to find an already figured out conversion.
The biggest issue with some units is how tightly regulated they are. A lot of them are 11.895 volts and while you can get a lot of them to function up to 13.3V any higher and they will start to trip a fault under load.
The upside is they are 80%-98% efficient and can function 24/7 a listed output and most will allow upwards of 110%-120% of listed output without overheating or tripping a fault so long as the load builds and is not sudden.
A lot of people in this hobby like to have 13.8V-15V and few of these will allow that sort of voltage. The few that will require internal bypassing of smd components before they will allow you to crank up the power to 13.8 without a fault.
If I recall properly MFJ's older ALS-500 solid state rf amps that used Toshiba 2SC2290's said in the owners manual that for every volt bellow 14V that unit lost 84 watts of output power compared to it's rated output at 14V. It was designed for use in a car and car's 12V system is not at 12V unless the battery is dead most of them are in the 13.8V-15.5V range depending on brand, tempature and condition of the battery.
So in order to get cheap price and insane durability we give up some voltage when converting a server supply. In base operation, our antenna systems are so much better than in a mobile that most of us do not care about the loss.
If you go used you can often get a 750W server supply for $9-$12 often with free shipping. If add in $6-$12 for high temp long life cap's that is a steal. You would have to spend $145+ to get close to that and it would not be built anywhere near as well!
Since these are designed to have logic controls telling it what to do 98% need to be "hot-wired" for lack of a better word to function outside of their native back pannel server interface you normally find them in. IN most cases there will be 2-3 pins that must be grounded to power it up and you have to hard wired some wires or connectors to it to get the power out in a safe easy to hook up to way.
They do not plug and play you have to adapt them. Each type converts a bit differently.
A lot of them are functional from 100V to a bit more than 240V. Some though are only operational at 220V+. In the USA the ones that will not work bellow 220V tend to be much cheaper since so few people have any wiring beyond the circuit break prewired for anything other than 120. On the other hand in Europe these units command top dollar since that is not an issue. In the USA you will see 1500W IBM 220V+ only units sell for $16 sill sealed in boxes.
You can use a 10K resistor to prob and multimeter on low voltage power supplies bellow 48V. It is easier though to either locate someone that has already figured it out and has tossed up a pin out. If you stick to the known models and conversion methods it would make life easier. Once you get the hang of that then get into figuring out less well-known units.
I hear some of the Sun/Cisco units made by Sonny will fire up just turning them on and that there is no real conversion other than installing wires to the output pins and turning the power switch on. No experience with them.
HP DBS-600PB is prop. the easiest conversion on earth but they are getting harder to find and only do a bit more than 40amps. HP and Dell 12Vpower supplies in the 750-1300W range tend to be the most popular models and have well-published conversion documentation.
Tallman what are the model numbers off your unit's? I can at least tell you if I have any documentation on how to convert them. Two of my 3 units are well documented but one is an oddball and not well documented at all and took some digging to find an already figured out conversion.
The biggest issue with some units is how tightly regulated they are. A lot of them are 11.895 volts and while you can get a lot of them to function up to 13.3V any higher and they will start to trip a fault under load.
The upside is they are 80%-98% efficient and can function 24/7 a listed output and most will allow upwards of 110%-120% of listed output without overheating or tripping a fault so long as the load builds and is not sudden.
A lot of people in this hobby like to have 13.8V-15V and few of these will allow that sort of voltage. The few that will require internal bypassing of smd components before they will allow you to crank up the power to 13.8 without a fault.
If I recall properly MFJ's older ALS-500 solid state rf amps that used Toshiba 2SC2290's said in the owners manual that for every volt bellow 14V that unit lost 84 watts of output power compared to it's rated output at 14V. It was designed for use in a car and car's 12V system is not at 12V unless the battery is dead most of them are in the 13.8V-15.5V range depending on brand, tempature and condition of the battery.
So in order to get cheap price and insane durability we give up some voltage when converting a server supply. In base operation, our antenna systems are so much better than in a mobile that most of us do not care about the loss.
If you go used you can often get a 750W server supply for $9-$12 often with free shipping. If add in $6-$12 for high temp long life cap's that is a steal. You would have to spend $145+ to get close to that and it would not be built anywhere near as well!
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