What power supply do you use to power your rig?

[deephaven]

I'm contemplating getting an HF rig (100W o/p) but it will need a 13.8 volt power supply. Are there any recommendations? I'm trying to find one with over-voltage protection so that the rig doesn't blow up if there's a PSU fault 

[setq]

I use a 2/4A one of these for any radio stuff I do (mainly low power). Not terribly engineered. Basically a transformer, bridge, big smoothing cap and discrete regulator with a standard 2n3055 as the control element. It delivers what it says on the tin. It doesn't have overvoltage protection however:

https://www.rapidonline.com/voltcraft-fixed-voltage-linear-power-supply-bench-526121

Pick one conservatively based on the current you want to pull.

Ultimately, do you really trust a power supply to self-manage its failure? I wouldn't! I'd stick an SCR based crowbar on the output and an inline fuse between the power supply and the crowbar. The SCR will clamp the voltage low and blow the fuse if there is a failure, saving your equipment.

[voltz]

Hi, the PSU needs to be able to supply at least 20 amps. Preferably more like 25-30. But 20A is a standard current draw for 100 watt HF rigs.
 
Over voltage protection comes in two flavours, crowbar (brute force shorting of the output terminals leading to blowing an internal fuse) or an over voltage sense circuit which trips the supply relay killing the PSU until a reset button is pressed.

There is a wide choice of PSUs on the market. Some are massively expensive, others are quite cheap around £100 but need modifying to bring them up to a more professional standard. As you say, you dont want to risk blowing up an expensive HF radio for the sake of a few pounds to upgrade the PSU. There are plans on the internet for doing this. Like fitting a quieter and more efficient fan, better heatsinks, better RF suppression and over voltage sensing. etc.

I cant recommend any particular type, many PSU are identical inside but have different branding labels, but i hope this info gives some general pointers to look out for and consider.

[David Hess]

I have a big linear Astron for all of my radios but would consider any fixed 12 volt supply that has service documentation available.  A more economical option might be to find a used Astron or similar and refurbish it yourself.

[GreyWoolfe]

I have a big linear Astron for all of my radios but would consider any fixed 12 volt supply that has service documentation available.  A more economical option might be to find a used Astron or similar and refurbish it yourself.

+1 on the Astron, they are nice power supplies.  Both of my current radios have built in power supplies but when I had my Kenwood TS-850, I used an Astron RS-35M.  I powered the 850 and my 2 meter radio.  I now use a RS-12A for my 2 meter base station and have a VS-35M sitting on my workbench that I won at a club Christmas banquet.  On the RS-35M that I sold and the VS-35M, I did the inrush current reduction mod shown here, http://www.repeater-builder.com/astron/inrush/astron-surge.html and added a bleeder resistor.  I also replaced the bulbs in both with 110 degree wide angle white LEDs after one of the bulbs burned out on the RS-35M.  If you want to do the LED mod, I found that taking power from the output will shut off the bulbs a lot faster than using the voltage source the bulbs had.  With the original source, the LEDs would take about 45 seconds to a minute to go out, taking the power from the output, the LEDs go out in a few seconds as the bleeder resistor drains the main filter cap.

[deephaven]

Thanks for all your comments, guys. I think an external crowbar would be a good choice as it will be something known - and tested!

[donmr]

I use an AGM battery and a Charles brand charger.  This brand is a simple analog charger with no LEDs, uProcessors, etc. and thus produces very little RFI.  The charger can deal with you drawing power as it is charging.

[David Hess]

I have a big linear Astron for all of my radios but would consider any fixed 12 volt supply that has service documentation available.  A more economical option might be to find a used Astron or similar and refurbish it yourself.

+1 on the Astron, they are nice power supplies.

They are ok and I just used them as an example because they have service documentation available at least for their linear ones which use pretty standard discrete pass element LM723 designs with foldback current limiting and output thyristor crowbar protection.  If I have any complaint about them, it is that they should put plastic caps over the exposed TO-3 power transistors on the back because if the shield of a connected coaxial cable touches them, bad things™ are likely to happen.

[setq]

Those cheap voltcraft ones have covered transistors and a big warning sticker!

No LM723. They appear to have designed their own one with discretes.

[deephaven]

Anyone had any experience of using a switch mode PSU while operating on the HF bands? I was looking at the MyDEL MP-30SWIV which is reported to have over-voltage protection. The "Noise Offset" control might be a bit of a giveaway!

[David Hess]

Anyone had any experience of using a switch mode PSU while operating on the HF bands? I was looking at the MyDEL MP-30SWIV which is reported to have over-voltage protection. The "Noise Offset" control might be a bit of a giveaway!

A "Noise Offset" control is suggestive about the difficulties involved with powering HF gear from a switching power supply.  I assume the control varied the switching frequency to move noise away from the RF channel being used.

Some switching regulators are specifically designed to keep switching noise away from the 455 kHz IF and AM broadcast bands.

Commercial HF transceivers have gotten away with integral or external switching power supplies from the manufacturer but I do not know if special precautions were taken or if they were just low noise.

[AF6LJ]

I have a big linear Astron for all of my radios but would consider any fixed 12 volt supply that has service documentation available.  A more economical option might be to find a used Astron or similar and refurbish it yourself.

I have used many different power supplies all but one were linear.
The current supply I am using is an Astron 25 amp linear supply.
They are bullet proof....
As an example of the above statement, a friend WA6MHZ had an Astron 35 amp supply backing up a large Gel Cell.... I was helping Pat one day do odd jobs around his shack and I asked about the 2 meter simplex radio he had set up, why it was not working...
His reply "it quit working sometime last year, I haven't got around to finding out why". Well it was still turned on and so was the power supply running it, that is when I found out about the Gel Cell it was hooked across. It seems sometime several months back the battery shorted. The Astron was running into a dead short for something like nine months...
I removed the battery, cycled the power on the supply and all was good again.

Yah Get an Astron Linear supply.
The switchers have OEM modules in them.
I don't trust them as much.

[deephaven]

Thanks for that great story, Sue. I'm surprised that there wasn't a hint of a smell having that powering into a short circuit for so long. Maybe it has fold-back current limiting?

Altron is less common in the UK, but I might be able to find one.

[David Hess]

The current supply I am using is an Astron 25 amp linear supply.
They are bullet proof....
As an example of the above statement, a friend WA6MHZ had an Astron 35 amp supply backing up a large Gel Cell.... I was helping Pat one day do odd jobs around his shack and I asked about the 2 meter simplex radio he had set up, why it was not working...
His reply "it quit working sometime last year, I haven't got around to finding out why". Well it was still turned on and so was the power supply running it, that is when I found out about the Gel Cell it was hooked across. It seems sometime several months back the battery shorted. The Astron was running into a dead short for something like nine months...
I removed the battery, cycled the power on the supply and all was good again.

Yah Get an Astron Linear supply.
The switchers have OEM modules in them.
I don't trust them as much.

The Astron 723 based linear power supplies implement foldback current limiting so it is not surprising that they can survive an indefinite short.

[AF6LJ]

The current supply I am using is an Astron 25 amp linear supply.
They are bullet proof....
As an example of the above statement, a friend WA6MHZ had an Astron 35 amp supply backing up a large Gel Cell.... I was helping Pat one day do odd jobs around his shack and I asked about the 2 meter simplex radio he had set up, why it was not working...
His reply "it quit working sometime last year, I haven't got around to finding out why". Well it was still turned on and so was the power supply running it, that is when I found out about the Gel Cell it was hooked across. It seems sometime several months back the battery shorted. The Astron was running into a dead short for something like nine months...
I removed the battery, cycled the power on the supply and all was good again.

Yah Get an Astron Linear supply.
The switchers have OEM modules in them.
I don't trust them as much.

The Astron 723 based linear power supplies implement foldback current limiting so it is not surprising that they can survive an indefinite short.

The heatsink was so hot you couldn't hold your hand on it....
The surprise was that for as hot is it was, it worked just fine...
Those are bullet proof designs...

[David Hess]

The Astron 723 based linear power supplies implement foldback current limiting so it is not surprising that they can survive an indefinite short.

The heatsink was so hot you couldn't hold your hand on it....
The surprise was that for as hot is it was, it worked just fine...
Those are bullet proof designs...

The only thing required is sufficient power derating, which is easy to control with foldback current limiting, at the maximum expected operating temperature.  The almost literal rule of thumb is is that you cannot continuously hold a thumb or finger against about 75C which is a pretty reliable case temperature for a power device so just being that hot is not a big deal.

Better of course is to also include thermal protection which I do not see on any of the schematics for the 723 based Astrons but I did confirm the use of foldback current limiting.  One thing I notice is that they all use the same pair of 2N3771 pass transistors from 12 to 70 amps; I wonder if Astron grades them and puts the best ones in the highest current supplies.  Their frequency compensation is also very conservative.

[deephaven]

Do the Astron units have over-voltage protection?

[msraya]

I use a commercial cheap Diamond GZV-4000 for 5 years and no problem, It can power two rigs, not heat. No RFI nor hash.
Only I change fan to another no noisy computer cheap fan and no noise from fan.

Manuel
EA7EE

[AF6LJ]

Do the Astron units have over-voltage protection?

Yes most models do, you can find some that do not, some of the older ones.

[SeanB]

The Astron 723 based linear power supplies implement foldback current limiting so it is not surprising that they can survive an indefinite short.

The heatsink was so hot you couldn't hold your hand on it....
The surprise was that for as hot is it was, it worked just fine...
Those are bullet proof designs...

The only thing required is sufficient power derating, which is easy to control with foldback current limiting, at the maximum expected operating temperature.  The almost literal rule of thumb is is that you cannot continuously hold a thumb or finger against about 75C which is a pretty reliable case temperature for a power device so just being that hot is not a big deal.

Better of course is to also include thermal protection which I do not see on any of the schematics for the 723 based Astrons but I did confirm the use of foldback current limiting.  One thing I notice is that they all use the same pair of 2N3771 pass transistors from 12 to 70 amps; I wonder if Astron grades them and puts the best ones in the highest current supplies.  Their frequency compensation is also very conservative.

I would think not, just use a bigger heatsink for the higher power units, with the upgraded transformer, bridge rectifier and smoothing capacitors.  I would also guess on the units over around 30A there will be 3 or more power devices in parallel, either by just modular placement of the same smaller heatsink plus 2 transistor and emitter resistor block, or a bigger number of devices on a common heatsink.

The drop off of gain in a power bipolar transistor is not easy to select for, it will almost always drop to a low level ( some will actually have a gain of  less than 1 at some point) at high current, so the only solution is parallel units so each has a much lower current flow, or use a really large die which has the same reduced current per unit area of silicon. 60A with 2N3773 transistors in switching needs around 20 parallel devices to get any hope of getting the drop down to the lowest levels, and driving the base with around 15A to get it there.

[djacobow]

No love for the switchers here, eh?

Well, I have a powerwerx sps-30-dm. It works fine. It is very compact. It does not generate hash on the amateur bands. It has a fan that comes on under load, but my rig's fan is louder.

I hadn't really considered the possibility that the PSU might fail and take the rig with it. That would be unfortunate. Is this a common failure mode with switchers, like the output get stays stuck on?

I also have a REALLY cheap Pyramid psv-300 that in use to power a 2m rig. Build quality is pretty bad, but no problems. Radio is cheap TYT so destruction would not be a tragedy. Actually, pretty happy with the setup.

[CJay]

There are plenty of tales about converted server supplies being excellent for use on amateur bands, bearing in mind they can be used to power many tens of thousands of pounds worth of server they tend to be rather well engineered and I am lead to believe the HP ones are really rather good in terms of RFI

[FlyingHacker]

Check reviews in eHam.net. Many modern switching supplies get top ratings for use on HF. They also use way less energy for something that will be on a lot.

[borjam]

I've got two power supplies. A Daiwa SS-330W and a Grelco G1320M.

Grelco is a Spanish manuafcturer of power supplies, and their linear series has been well known for 30+ years. It's a rather simple design with 2N3055 transistors for regulation and a crowbar over voltage protection.

I got the linear power supply because for now I am using a window antenna and the switching power supply is a bit noisy. The linear is, of course, radio silent. The downside of the linear supply, it's large and heavy.

[TheBay]

Microset PT-135 35a Linear here, VERY happy with it.

There is a long thread on here about a C.E.P. I bought