HFU HF Underground
Technical Topics => Equipment => Topic started by: TRI International on March 10, 2021, 1703 UTC
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What I'm looking for is a power supply that is 110 Volt Ac 1500 watt with 18 to 20VDC output for my linear. Any Ideas and price thanks in advance.
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You could check out eBay, there are often some esoteric used/refurb power supplies there that might be suitable. New is probably going to be expensive, assuming you don't want a Pride of China unit that will blow up in your face :)
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I checked ebay but not sure what Im looking for which sucks lol
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Commonly available 24V smpsu's all over eBay.
If you think they're manufactured in any other place than CH, think again! They aren't made in the US..
Despite the bad rep it mainly down to ignorance as they are in the main absolutely fine.
Try and stick with a branded version like; JCPOWER or MEANWELL.
Just parrallel up what you need 3x500W or 2x750W or whatever.
24V will adj down to 18V.
Btw, you're looking for a power supply for your linear, not a linear power supply as that's an analogue, i.e. not switching lump with a massive transformer etc.
Str.
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Commonly available 24V smpsu's all over eBay.
If you think they're manufactured in any other place than CH, think again! They aren't made in the US..
Despite the bad rep it mainly down to ignorance as they are in the main absolutely fine.
Try and stick with a branded version like; JCPOWER or MEANWELL.
Just parrallel up what you need 3x500W or 2x750W or whatever.
24V will adj down to 18V.
Btw, you're looking for a power supply for your linear, not a linear power supply as that's an analogue, i.e. not switching lump with a massive transformer etc.
Str.
Agreed. Why the strange voltage? Most switchers are adjustable to some degree, but 18 is not a standard voltage. A 24V supply should have enough range to drop to 21V or so, but that's about it.
+-RH
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Thanks for all the info to be clear I need to connect it to a power supply. (Nothing wrong with the amp it self lol)
Got it as a birthday gift the person that got it just thought you buy it hook it up to the battery and go but not the case :'(
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I agree on the 'Wierd voltage?'
Model number or piccies??
Str.
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MEAN WELL SP-750-24 SERVO STEPPER MOTOR Switching Power Supply DC 24V 31.3A 750W
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Pic of the amp please...
MEANWELL(while)!!
Pair of those will do nicely
Str.
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Sorry don't know how to insert a picture
https://www.ebay.com/itm/MEAN-WELL-SP-750-24-SERVO-STEPPER-MOTOR-Switching-Power-Supply-DC-24V-31-3A-750W/303353205303?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2648
Here is the link
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I think we're more interested in the amplifier itself, i.e. why the strange voltage requirement. Most stuff is going to expect either 12 or 24VDC for supply. I've never seen anything RF related that required 18-20VDC.
+-RH
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here are the Specification :
Power Input = 30-100 Watt SSB
Output Power = 800 Watt
Voltage = 17-20 Vdc
Transistor = 8 units IRFP150N ( Many in Ebay for $ 2 each )
Frequency = 2 Band 3,5-14 Mhz,
3.8Mhz = 600 Watt , Peak
7 Mhz = 800 Watt. Peak Power
11 Mhz = 500 Watt, Peak
14 Mhz = 300 Watt , Peak
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here are the Specification :
Power Input = 30-100 Watt SSB
Output Power = 800 Watt
Voltage = 17-20 Vdc
Transistor = 8 units IRFP150N ( Many in Ebay for $ 2 each )
Frequency = 2 Band 3,5-14 Mhz,
3.8Mhz = 600 Watt , Peak
7 Mhz = 800 Watt. Peak Power
11 Mhz = 500 Watt, Peak
14 Mhz = 300 Watt , Peak
Oh god no...
Do the innerds look like this?
(https://2.bp.blogspot.com/-ee6jP7Y1mb8/WxIopdARRoI/AAAAAAAAANw/RT2dbJxttJ4ICr0cdPvt3dkQSxvl3uVSwCLcBGAs/w1200-h630-p-k-no-nu/800%2Bgmb.jpg)
Another piece of sound advice...don't buy semiconductors off ebay. Many times the devices are restamped versions of smaller devices and they will fail prematurely...especially if the come from overseas.
+-RH
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Not sure the person said he got if off of ebay here is the name on ebay
Booster Amplifier HF SSB 800W Amateur 80m 40m 20m Peak 7Mhz Low Pass Filter
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I saw the pics...I wouldn't put that on the air if I were you. It also isn't built with enough heatsink to be reliable.
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Doesn't look the best and would be meant for short speach overs not long constant transmissions. The construction looks like a dog's dinner (I'm being polite BTW)
Good luck with it!
For your future reference pictures can be hosted on picture hosting websites that will generate a link.
All eBay items have an I.D. number.
Str.
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https://www.ebay.com/itm/MEAN-WELL-SP-750-24-SERVO-STEPPER-MOTOR-Switching-Power-Supply-DC-24V-31-3A-750W/303353205303?epid=664132724&hash=item46a1429237:g:eSIAAOSw~WJdxGpC (https://www.ebay.com/itm/MEAN-WELL-SP-750-24-SERVO-STEPPER-MOTOR-Switching-Power-Supply-DC-24V-31-3A-750W/303353205303?epid=664132724&hash=item46a1429237:g:eSIAAOSw~WJdxGpC)
https://www.meanwell-web.com/en-gb/ (https://www.meanwell-web.com/en-gb/)
André
CoolAM Radio - Shortwave
the Netherlands
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Thanks Cool AM, had purchased two of them they came in yesterday 8). Just have to install , setup and test lol.
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I'm coming in a bit late on this but if you decide to parallel two or more power supplies, one thing to watch for/be careful of is that the output voltages of the two (or more) power supplies have to be pretty well matched when under load. (There might be an output voltage adjustment.) If the output voltages are not well matched, you will get what I call "current steering" - current from the supply at the higher voltage will source current into the supply at the lower voltage.
The amount of current will depend upon the voltage difference between the supplies and the input/output resistance of the two supplies. (This is due to Ohm's Law.) The supply that is sinking current (the one that is taking in the current) may or may not be receptive to that current that is being "forced down its throat". It depends upon how it is designed. In some cases, you may actually then see its output voltage rise to correspond with the increasing current because the regulator can't sink current (i.e., accept current) well. You may not get what you expect when this happens and if one of the supplies is sinking current, it is not helping you by supplying current to the load, your amplifier.
The usual solution to this is to put diodes in series the output of all the power supplies before the junction where they are combined. This would keep the supplies from sinking current. However, in this case, you are talking about "lots of Amperes", and you would need to find some high current diodes and/or parallel the diodes to meet the current expectations when operating normally.
So, bottom line, if you don't want to go through the whole diode thing, just keep the power supply voltages pretty well matched while under load. You will know that they are matched if you actually see the double/triple current you expect and not somewhat less current at the load.
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The devices off eBay can be a copy of the originals from China like software programable hardware boards that worked fine for me. When it comes to RF devices I also had to get refunds from re stamped junk.
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Noisy Chineseium power supplies hooked to broadband amp with no output filtering and insufficient thermal dissipation for continuous use.
What could go wrong?