Yaesu 847 power supply -linear vs. switching
I purchased a Yaesu 847 for both satellite and HF work. Since this is my 1st base-style transceiver I am now in need of a power supply. I was originally considering the Astron RS35M and am curious if linear or switching is the proper choice? Is there a Amsat BB favorite between switching and linear?
Thanks for any help!
Zach N4ERZ
My preference is for big linear supplies but perhaps I'm just an old fogey that prefers traditional design.
On 18-Feb-11 18:44, zach hillerson wrote:
I purchased a Yaesu 847 for both satellite and HF work. Since this is my 1st base-style transceiver I am now in need of a power supply. I was originally considering the Astron RS35M and am curious if linear or switching is the proper choice? Is there a Amsat BB favorite between switching and linear?
Thanks for any help!
Zach N4ERZ
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Is there a Amsat BB favorite between switching and linear [power
supplies]?
I won't speak to noise, which is the only potential issue with switching power supplies, but other than that, I am writing an article for QST that points out how the world of power and emergency power has changed drastically over the last decades. Entirely due to switching power supplies and regulators:
PROS: 1) A 90% reduction in size and weight 2) Laptop supplies that can supply 12v at 5 to 10 amps 3) Universal inputs 115V to 240V AC 4) * also run on 150 to 330 VDC 5) Hybrids and Electric Vehicles have Kilowatts of 150 to 330 VDC available 6) Home grid-tie solar has Kilowatts of high voltage DC available 7) 12VDC to 120VAC inverters are now sine and modified sine at 90%+ efficiency 8) * These internally run on 200 VDC or so. Easy to run great distances on small wire if you run them directly on HV DC derived from your Hybrid or Solar.
CONS: with today's litigious society and general ignorance (compared to the vacuum tube days when even cub-scouts built 2 tube radios with High Voltage), it is doubtful that QST will publish the article. They have rejected it before, but I keep whittling away at the details.
Bottom line, is that high efficiency high voltage DC is everywhere and because everything runs on switching power supplies that run internally on HV DC and regulators that accept a wide range of input, then HV DC could be the new universal power source.
Problem is, Hybrid and EV MFR's are not going to provide access to HV DC willingly due to safety an liability issues. Same for Solar installers.... Same for QST.
But you can get some of what I am writing about on this page: http://aprs.org/FD-Prius-Power.html http://aprs.org/alternative-energy.html
For example, buried in a Camry Hybrid is a nice compact stand-alone 14 volt 100 AMP DC/DC supply. Input can be 200 to 350 volts DC (which you can get from 120V or 240VAC with just some diodes).. Problem is, it is bolted to the $1000 salvage battery and the salvage guys won't sell it separately.
The Prius 100amp 14v supply is integrated into the huge drivetrain inverter and inseparable from that $3000 unit (salvage cost).
As we electrify transportation and anyone with good sun goes solar, HV DC will be something Hams will be getting used to again.
Bob, Wb4APR
Only thing I have to say is that Switching types are much lighter and are more transportable. I have owned big bruiser linears and they work OK-just find a sturdy shelf to put them on. If your requirement is 25Amps, get a 35Amp unit.(switching) Best to run cooler than at "load." Good luck on the article Bob. 73, Dee, NB2F
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Bob Bruninga Sent: Friday, February 18, 2011 2:55 PM To: 'Nigel Gunn G8IFF/W8IFF'; 'zach hillerson' Cc: [email protected] Subject: [amsat-bb] Linear vs. switching and HV DC
Is there a Amsat BB favorite between switching and linear [power
supplies]?
I won't speak to noise, which is the only potential issue with switching power supplies, but other than that, I am writing an article for QST that points out how the world of power and emergency power has changed drastically over the last decades. Entirely due to switching power supplies and regulators:
PROS: 1) A 90% reduction in size and weight 2) Laptop supplies that can supply 12v at 5 to 10 amps 3) Universal inputs 115V to 240V AC 4) * also run on 150 to 330 VDC 5) Hybrids and Electric Vehicles have Kilowatts of 150 to 330 VDC available 6) Home grid-tie solar has Kilowatts of high voltage DC available 7) 12VDC to 120VAC inverters are now sine and modified sine at 90%+ efficiency 8) * These internally run on 200 VDC or so. Easy to run great distances on small wire if you run them directly on HV DC derived from your Hybrid or Solar.
CONS: with today's litigious society and general ignorance (compared to the vacuum tube days when even cub-scouts built 2 tube radios with High Voltage), it is doubtful that QST will publish the article. They have rejected it before, but I keep whittling away at the details.
Bottom line, is that high efficiency high voltage DC is everywhere and because everything runs on switching power supplies that run internally on HV DC and regulators that accept a wide range of input, then HV DC could be the new universal power source.
Problem is, Hybrid and EV MFR's are not going to provide access to HV DC willingly due to safety an liability issues. Same for Solar installers.... Same for QST.
But you can get some of what I am writing about on this page: http://aprs.org/FD-Prius-Power.html http://aprs.org/alternative-energy.html
For example, buried in a Camry Hybrid is a nice compact stand-alone 14 volt 100 AMP DC/DC supply. Input can be 200 to 350 volts DC (which you can get from 120V or 240VAC with just some diodes).. Problem is, it is bolted to the $1000 salvage battery and the salvage guys won't sell it separately.
The Prius 100amp 14v supply is integrated into the huge drivetrain inverter and inseparable from that $3000 unit (salvage cost).
As we electrify transportation and anyone with good sun goes solar, HV DC will be something Hams will be getting used to again.
Bob, Wb4APR
_______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
At 10:54 AM 2/18/2011, Bob Bruninga wrote:
Is there a Amsat BB favorite between switching and linear [power
supplies]?
I won't speak to noise, which is the only potential issue with switching power supplies, but other than that, I am writing an article for QST that points out how the world of power and emergency power has changed drastically over the last decades. Entirely due to switching power supplies and regulators:
PROS:
- A 90% reduction in size and weight
- Laptop supplies that can supply 12v at 5 to 10 amps
- Universal inputs 115V to 240V AC
- also run on 150 to 330 VDC
- Hybrids and Electric Vehicles have Kilowatts of 150 to 330 VDC available
- Home grid-tie solar has Kilowatts of high voltage DC available
- 12VDC to 120VAC inverters are now sine and modified sine at 90%+
efficiency 8) * These internally run on 200 VDC or so. Easy to run great distances on small wire if you run them directly on HV DC derived from your Hybrid or Solar.
CONS: with today's litigious society and general ignorance (compared to the vacuum tube days when even cub-scouts built 2 tube radios with High Voltage), it is doubtful that QST will publish the article. They have rejected it before, but I keep whittling away at the details.
Bottom line, is that high efficiency high voltage DC is everywhere and because everything runs on switching power supplies that run internally on HV DC and regulators that accept a wide range of input, then HV DC could be the new universal power source.
Problem is, Hybrid and EV MFR's are not going to provide access to HV DC willingly due to safety an liability issues. Same for Solar installers.... Same for QST.
But you can get some of what I am writing about on this page: http://aprs.org/FD-Prius-Power.html http://aprs.org/alternative-energy.html
For example, buried in a Camry Hybrid is a nice compact stand-alone 14 volt 100 AMP DC/DC supply. Input can be 200 to 350 volts DC (which you can get from 120V or 240VAC with just some diodes).. Problem is, it is bolted to the $1000 salvage battery and the salvage guys won't sell it separately.
The Prius 100amp 14v supply is integrated into the huge drivetrain inverter and inseparable from that $3000 unit (salvage cost).
As we electrify transportation and anyone with good sun goes solar, HV DC will be something Hams will be getting used to again.
Bob, Wb4APR
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
I am rebuilding my 4.2kV PS for the 2m-8877. Does that qualify? QST still publishes high-power tube amplifier designs in their handbook. What's 150-250v amongst friends? Of course HV DC can badly burn or Kill you.
I was 14 years old when working on my DX-35 with 850vdc on the 6146 plate.
I agree that many hams these days aren't not trained to handle high-voltage with all the 12vdc solid-state electronics available. But QRO sspa are running at 50vdc and higher. There are rules for safe work on HV...time to review them.
73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-1.4kw*, 432-100w, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [email protected] ====================================== *temp not in service
At 12:01 PM 2/18/2011 -0900, "Edward R. Cole" [email protected] wrote:
I am rebuilding my 4.2kV PS for the 2m-8877.
That'll get you into AO-51. ;-)
I was 14 years old when working on my DX-35 with 850vdc on the 6146 plate.
I agree that many hams these days aren't not trained to handle high-voltage with all the 12vdc solid-state electronics available. But QRO sspa are running at 50vdc and higher. There are rules for safe work on HV...time to review them.
I know that's true. Even the large caps in high current 13v supplies. I thought I had things discharged and just to be sure before I started poking around with a screwdriver checking other things, I thought I would be sure the filter caps discharged, so I put the screwdriver across the terminals .....
You should have seen the spark.
KB7ADL
At 12:26 PM 2/18/2011, Vince Fiscus, KB7ADL wrote:
At 12:01 PM 2/18/2011 -0900, "Edward R. Cole" [email protected] wrote:
I am rebuilding my 4.2kV PS for the 2m-8877.
That'll get you into AO-51. ;-)
Not me! I'm not getting the blame for melting the AO-51 receiver.
I was 14 years old when working on my DX-35 with 850vdc on the 6146 plate.
I agree that many hams these days aren't not trained to handle high-voltage with all the 12vdc solid-state electronics available. But QRO sspa are running at 50vdc and higher. There are rules for safe work on HV...time to review them.
I know that's true. Even the large caps in high current 13v supplies. I thought I had things discharged and just to be sure before I started poking around with a screwdriver checking other things, I thought I would be sure the filter caps discharged, so I put the screwdriver across the terminals .....
You know arc welders run at low voltage,,,but lots of current. Discharging a large filter cap is a potential welding unit! Same goes for getting across the terminals of a large battery (a wrench or screwdriver laying across a car battery will cause a lot melting and possible overheat the battery enough to explode!
You should have seen the spark.
And a loud "bang" or "pop"? You ought to hear what 4kV sounds like when it arcs to ground!
Watch for burn and eye damage situations if working around high capacity/voltage systems.
Rule of HV: NEVER touch a HV circuit until it is verified that no voltage remains. Hooking/disconnecting HV probes to measure HV is always done with power-off/discharged. Connect the HV probe/meter and do not touch them when HV is applied. In commercial HV systems there is dead-man hook: a metal hook like a shepards crook with a cable to ground attached to a long insulated handle. You do not hold it to short HV circuits. YOU toss it onto the circuits and step quickly back. I was taught this at NASA where we had a walk in 100kV PS (think it was housed in a semi trailer). It ran the anode on 20kW s-band klystron amps.
ALWAYS inform someone when you are about to test HV (in case you need medical assistance). INSTRUCT them to NEVER touch you or go near the equipment if you get shocked/electrocuted. Show them how to shut down the Main Breaker on the house (but CALL 911 FIRST, because a lot of cordless phones quit when the power is off). DO NOT attempt CPR if you are not absolutely sure that power is off. In most electrocutions the heart goes into fibrillation and ordinary CPR will not revive a person. It will extend life if it can be done safely. Be sure to tell 911-operator that an electrical shock has occurred.
Most electrocutions above 240v are fatal. NO SECOND CHANCE! Sort of like falling off that 100-foot tower - you only do it once.
73, Ed - KL7UW, WD2XSH/45 ====================================== BP40IQ 500 KHz - 10-GHz www.kl7uw.com EME: 144-1.4kw*, 432-100w, 1296-testing*, 3400-winter? DUBUS Magazine USA Rep [email protected] ====================================== *temp not in service
On Feb 18 2011, zach hillerson wrote:
I purchased a Yaesu 847 for both satellite and HF work. Since this is my 1st base-style transceiver I am now in need of a power supply. I was originally considering the Astron RS35M and am curious if linear or switching is the proper choice? Is there a Amsat BB favorite between switching and linear?
Thanks for any help!
Zach N4ERZ
Zach:
I've had my FT-847 for many years, and have used it both for satellites and VHF/UHF terrestrial work. (Very little HF, but some).
It has never "complained" about any properly working power supply it's been hooked to. These include an Astron 20 amp linear PS, an Astron 60 amp linear, an Astron 35 amp switcher, car battery plus vehicle alternator, and others when I've brought it out to Field day. Runs perfectly with any of them.
In general, more power is better, because these amp suckers seem to multiply. My first PS, the 20 amp linear, worked fine with the FT-847, but when I added a linear amplifier for the 144-148 MHz band, the combined draw was too much. I've NEVER managed to draw more power than the 60 amp linear can provide, but it is an enormous pain (literally and figuratively) to pull it off its usual resting place in the shack and carry it up two flights of stairs to load into my SUV to haul out to Field Day. The 35 amp switcher has done a fine job for me, and the difference in weight is incredible, at least to a rickety old guy with worn out knees, like yours truly.
In fact, my FT-847 has NEVER refused to work for me, except for the time I set it up in a tent trailer for Field Day on a Friday afternoon, and a big wind storm came through overnight. When I arrived Saturday morning to complete final setup and get ready to operate, I found that the tent trailer was lying on its roof, with the FT-847's face planted in the ground and its back panel holding up one end of the tent trailer. At that point, the big knob on the front would not turn, but who could blame it? And best of all, the repairs cost $0.00! After Field Day was over, I brought it home, started a careful disassembly of the front panel, and discovered that the reason that the tuning knob wouldn't turn was because the steel sub-chassis onto which it was bolted had bent from the weight of the trailer on top of the radio. Some carefully-placed whacks with a big hammer fixed that. Put it back together and it's worked like a champ ever since. (I also used some toothpaste to polish up the scratches on the front face of the tuning knob, and you'd never know it had been treated so cruelly!)
In short, the 35 amp Astron (either linear or switching) will be plenty strong enough and reliable enough to power an FT-847 and a typical VHF/UHF amplifier, with power left over to run more small station equipment.
73 de W0JT
participants (7)
-
Bob Bruninga -
Dee -
Edward R. Cole -
Nigel Gunn G8IFF/W8IFF -
tosca005＠umn.edu -
Vince Fiscus, KB7ADL -
zach hillerson