Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
Joe Carefully consider expanding into switchers. The designs are quite varied. To repair them you really need a good high frequency scope, shielded isolation transformer, 0.18 ohm 1000 watt resistor load, and most of all a good schematic. Switcher parts are hard to find especially the low ESR capacitors (a common failure). Fixing an analog supply is a slam dunk compared to a switcher. I would not put one at a repeater site unless the site happens to be my home. Gran K6RIF At 16:49 7/17/2005, you wrote: Does anybody have a web site to look at IOTA power supply? I need to find some to replace my power supplies in the future. Bruce KD4BOH.- Original Message - From: Joe Montierth [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, May 25, 2005 2:22 PM Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and Noise? I have one of the 75 amp supplies working at a remote site. We have not seen any noise from the unit, but our equipment is all VHF and UHF, haven't checked it down in HF, but at UHF we have seen no problems. We have 20 UHF RX's and 6 VHF and have not seen any degradation. These IOTA's run much cooler than the analog Astron's, and are much smaller. I will probably be changing out all of the Astrons to these in the next few years, as conditions warrant. Joe --- Nick Papadonis [EMAIL PROTECTED] wrote: Hi Folks, I'm considering purchasing a 45A IOTA Switched Power supply to power a UHF Micor and am concerned about switch PS noise. Has anyone tried these supplies with UHF radios? Is noise experienced? Insight greatly appreciated. Thanks. -- Nick KB1GZN Boston, MA __ Do you Yahoo!? Yahoo! Small Business - Try our new Resources site http://smallbusiness.yahoo.com/resources/ Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/ -- No virus found in this incoming message. Checked by AVG Anti-Virus. Version: 7.0.323 / Virus Database: 267.9.0/48 - Release Date: 7/16/2005 YAHOO! GROUPS LINKS Visit your group "Repeater-Builder" on the web. To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service. No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.323 / Virus Database: 267.9.0/48 - Release Date: 7/16/2005
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
At 09:43 AM 7/19/2005, Gran Clark wrote: Joe Carefully consider expanding into switchers. The designs are quite varied. To repair them you really need a good high frequency scope, shielded isolation transformer, 0.18 ohm 1000 watt resistor load, and most of all a good schematic. Switcher parts are hard to find especially the low ESR capacitors (a common failure). Fixing an analog supply is a slam dunk compared to a switcher. I would not put one at a repeater site unless the site happens to be my home. On the other hand, a well designed switcher can easily outlast a linear. Heat kills, and a switcher dissipates a LOT less heat on any given load, than a linear supply. Jim Williams of Analog Devices, published a formula for predicting capacitor life in a given design. There are a number of factors that go into it, but the temperature term decreases the projected life of the caps by half, for every 10C rise in ambient temperature. This is true wether the cap is used in a switcher, or a linear supply. Without the formula, you can simply predict a cap's life in a moderate application, by using it's rated lifetime and the application temperature. If you look at Digi-Key's site, you'll see that each type of cap has a rating in so many hours, and so many degrees C. A cap rated for 2000 hours at 85C is going to fail roughly 4x faster than one rated at 2000 hours at 105C. Both will last twice as long if you run them 10C under their ratings. For the large electrolytics in a switcher, you can estimate ripple current requirements by the output current and the number of caps in parallel. Say an output cap in my IOTA died. I would replace the output caps, output diode, and probably the switching transistor as well, before even turning on the supply. To pick a new cap, I would look up the ratings on the existing ones in Digi-Key, and pick a similar, but higher lifetime unit. But, let's say that I couldn't find the ratings.. Ok, so it's a 55A output, and maybe there are three caps in parallel across the output. (I haven't opened it up) I divide 55A by 2 ( N-1 to be conservative) and look for caps rated at 25V and 27A, of roughly the same uF rating. Then I take what I find, and use the lowest ESR and longest lifetime ratings that will fit the case. If I can't satisfy that, then I use 55A/3 and try again. It's very unlikely that you can't find a similar or better cap to replace it with. If the original design used 16V parts on the output, I could stick with that, but I prefer more margin there. Always remember, the original manufacturer was cost constrained, and you really aren't. Adding another $1 to the cost is really not an issue to you, but adding another $0.05 may have been a real battle for the designer. The waste heat may also be affecting other devices in your system, depending on how you deal with removing it. Replacement caps do need to be chosen properly, but as time goes on, caps get better and better. Today's so-so caps have roughly the same ratings for ripple current and ESR as the exceptionally good caps of a few years ago. Similar for transistors and diodes. By the time yours fail, odds are that if they used state-of-the-art parts in the design, those parts are now good or average. Switcher parts are generally available through Digi-Key, or other similar sources. As to what you need to repair them, I disagree. Just plain common sense, and an understanding of how switchers work is enough. If you see a failed component, there is a reason that it failed, and there are other things that this failure will have overstressed. Fix all three, if possible. Sometimes the reason for failure is a design problem though, and that is a more difficult fix usually. A copy of Art of Electronics would be a better investment, IMHO :) Then again, the IOTA units are very reasonably priced, and you might just prefer to replace it with the then current models. Fixing an analog supply is probably easier, if we define fixing as replacing the blown parts. Otherwise, it's the same as a switcher, determine what failed, determine why it failed, and determine what else probably took some stress, and repair all three. If the fundamental cause is excessive heat though, you're pretty much stuck since linear supplies are by nature, wasteful and that waste ends up as heat, and heat kills. A final note on electrolytic caps, their failure modes are not limited to splattering their guts all over the inside of the box. Far more often, they go leaky, or they go open. I've seen 1000uF caps that read as 1uF on a cap meter, after a few years in service. Bad caps may or may not cause problems in your system, but the problems that they cause can be really difficult to find, if you don't approach with a suspicious eye. Caps are one of the few electronic components that really do have a finite lifetime, and a definite wear-out. An open cap does not filter like it
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
Dave's points are good, I'd like to point out a couple of other things. We have used Astron supplies for years, and overall have been happy with them. There are some drawbacks, mainly the analog design is very wasteful of power, and the units get very warm (hot). I have done some measurements, and a RM-50 will waste as heat about 480 watts when putting out 40 amps at 13.5 volts. An IOTA DLS-45 will waste about 136 watts as heat under the same conditions. Note that the RM-50 is only rated at 37 amps continuous, while the DLS-45 will put out 45 amps all day long. If you do the calculations on wasted heat, this comes to an additional 4147 KWh per year on the Astron, and an additional 1175 KWh/ year on the IOTA. If you live in an area with 10 cents/KHh power (typical) then your power savings in one year will be almost $300. Many of you do not run this kind of power continuously, but we do. Even at lower duty cycles you will probably realize these savings within 5 years, if you are paying for power out of your pocket. Even if I could not fix these power supplies, and even if I had to change it once a year, I would still be money ahead with the IOTA. Also, we do not use ours on commercial power, we use it at a generator site where our cost to generate power is about 30 cents/KWh. Did I mention that the Astron weighs 50 lbs and the Iota weighs 5.5? Joe --- Dave VanHorn [EMAIL PROTECTED] wrote: At 09:43 AM 7/19/2005, Gran Clark wrote: Joe Carefully consider expanding into switchers. The designs are quite varied. To repair them you really need a good high frequency scope, shielded isolation transformer, 0.18 ohm 1000 watt resistor load, and most of all a good schematic. Switcher parts are hard to find especially the low ESR capacitors (a common failure). Fixing an analog supply is a slam dunk compared to a switcher. I would not put one at a repeater site unless the site happens to be my home. On the other hand, a well designed switcher can easily outlast a linear. Heat kills, and a switcher dissipates a LOT less heat on any given load, than a linear supply. Jim Williams of Analog Devices, published a formula for predicting capacitor life in a given design. There are a number of factors that go into it, but the temperature term decreases the projected life of the caps by half, for every 10C rise in ambient temperature. This is true wether the cap is used in a switcher, or a linear supply. Without the formula, you can simply predict a cap's life in a moderate application, by using it's rated lifetime and the application temperature. If you look at Digi-Key's site, you'll see that each type of cap has a rating in so many hours, and so many degrees C. A cap rated for 2000 hours at 85C is going to fail roughly 4x faster than one rated at 2000 hours at 105C. Both will last twice as long if you run them 10C under their ratings. For the large electrolytics in a switcher, you can estimate ripple current requirements by the output current and the number of caps in parallel. Say an output cap in my IOTA died. I would replace the output caps, output diode, and probably the switching transistor as well, before even turning on the supply. To pick a new cap, I would look up the ratings on the existing ones in Digi-Key, and pick a similar, but higher lifetime unit. But, let's say that I couldn't find the ratings.. Ok, so it's a 55A output, and maybe there are three caps in parallel across the output. (I haven't opened it up) I divide 55A by 2 ( N-1 to be conservative) and look for caps rated at 25V and 27A, of roughly the same uF rating. Then I take what I find, and use the lowest ESR and longest lifetime ratings that will fit the case. If I can't satisfy that, then I use 55A/3 and try again. It's very unlikely that you can't find a similar or better cap to replace it with. If the original design used 16V parts on the output, I could stick with that, but I prefer more margin there. Always remember, the original manufacturer was cost constrained, and you really aren't. Adding another $1 to the cost is really not an issue to you, but adding another $0.05 may have been a real battle for the designer. The waste heat may also be affecting other devices in your system, depending on how you deal with removing it. Replacement caps do need to be chosen properly, but as time goes on, caps get better and better. Today's so-so caps have roughly the same ratings for ripple current and ESR as the exceptionally good caps of a few years ago. Similar for transistors and diodes. By the time yours fail, odds are that if they used state-of-the-art parts in the design, those parts are now good or average. Switcher parts are generally available through Digi-Key, or other similar sources. As to what you need to repair them, I disagree. Just plain common sense, and an
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
If you do the calculations on wasted heat, this comes to an additional 4147 KWh per year on the Astron, and an additional 1175 KWh/ year on the IOTA. If you live in an area with 10 cents/KHh power (typical) then your power savings in one year will be almost $300. We don't pay the power bill at our sites, but that is an angle I hadn't considered. Amusing, because I routinely design battery powered equipment, where every milliwatt is considered. Power factor is another issue that goes under the radar. The power factor on those Astrons is going to be pretty bad, and if you hang larger or better caps inside the case, it just gets worse. With a switcher design, the power factor can easily approach 90%. One of these days, I need to measure the astron that powers the club's machines. It would be interesting to know what temperature it's running at nominally, but from calibrated thumb, I know it's pretty hot. The club didn't want to get a switcher, because switchers are noisy. I've put many switchers through FCC part 15 testing, and have yet to have anything even show up on the spectrum plots from the switcher, either radiated or conducted. I haven't got the harness made yet for the new machine, but when I do, I'll be making the same measurements and more on this system. One that I plan to do, is to set up the SA, and have a look at exactly what noise the Iota outputs. When I'm working on the club's machines, I have to do what they want. On my own machines, I have no such constraints. :) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
Anyone have an idea how much power would be saved by running a MSF-5000 that is idle most of the time from a switcher instead of the stock heavy iron power supply?. The transformers produce a lot of heat just in standby mode. I have several of these machines on line and also a GE repeater with a big transformer. Dex, W4DEX Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
The easiest way to tell would be to measure the AC current draw in idle. Then measure the DC current draw in idle. You can get a pretty close watt figure by multiplying the amps times the voltage (115v) on the input side, and doing the same thing on the DC side. The difference between the two is your wasted heat. If you convert the watts to kilowatts (divide by 1000), then multiply your results by 8760, that will tell you the number of wasted KWH in one year. Example: .72 amps draw at 115 volts, 1.3 amps draw at 13.5 volts. .72 x 115 = 83 watts in. 1.3 x 13.5 = 17.5 watts delivered. This means 65.5 watts are wasted, or about 574 KWh/year. Joe --- Dexter McIntyre W4DEX [EMAIL PROTECTED] wrote: Anyone have an idea how much power would be saved by running a MSF-5000 that is idle most of the time from a switcher instead of the stock heavy iron power supply?. The transformers produce a lot of heat just in standby mode. I have several of these machines on line and also a GE repeater with a big transformer. Dex, W4DEX Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
One nit-pick: measure the actual AC line voltage and use it where Joe has 115v. Locally it's 118-123v, depending on the local load (i.e. lower on a summer day, highest during a winter night). And sometime when you have a free hour, wander around the house and count how many wall warts you have in use, and feel each one and see just how warm it is. Then if you want to see an interesting number, unplug each one, and take it and it's load and plug it into a power strip, or some strips that are daisy chained... I did this at a friend house and we ended up with about 20 plugged into a half-dozen power strips and totalling about 2 and a half amps of AC... He's got 112-114v of AC at his house so using 113 we get 255.2w ... divide by 1000 and times 8760=2235.5, or 2.2kw just in wall wart wastage. Think how many houses have that exact same situation. Might be worth putting a switch on an idle wall wart Or plugging the modem, inkjet printer and USB hub wallwarts into a power strip, and using the strip's switch to power down the entire computer system when it's not in actual use. Mike WA6ILQ At 11:24 AM 7/19/05, you wrote: The easiest way to tell would be to measure the AC current draw in idle. Then measure the DC current draw in idle. You can get a pretty close watt figure by multiplying the amps times the voltage (115v) on the input side, and doing the same thing on the DC side. The difference between the two is your wasted heat. If you convert the watts to kilowatts (divide by 1000), then multiply your results by 8760, that will tell you the number of wasted KWH in one year. Example: .72 amps draw at 115 volts, 1.3 amps draw at 13.5 volts. .72 x 115 = 83 watts in. 1.3 x 13.5 = 17.5 watts delivered. This means 65.5 watts are wasted, or about 574 KWh/year. Joe --- Dexter McIntyre W4DEX [EMAIL PROTECTED] wrote: Anyone have an idea how much power would be saved by running a MSF-5000 that is idle most of the time from a switcher instead of the stock heavy iron power supply?. The transformers produce a lot of heat just in standby mode. I have several of these machines on line and also a GE repeater with a big transformer. Dex, W4DEX Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
Think how many houses have that exact same situation. I know I suffer from this big-time. Lots of wall wart devices. They are going to switchers though, it's finally come to the place where the switcher is cheaper than the iron and shipping from China. Last year, I needed a new wart for something, and was surprised by a lighter than air 1A wart for $15, with adjustable output voltage, that is a switcher. It's still going, so acceptable quality I guess. Lots of devices plugged in at my place, and the devils that design them love to stick in digital clocks, so you don't want to unplug them. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
--- Mike Morris WA6ILQ [EMAIL PROTECTED] wrote: I did this at a friend house and we ended up with about 20 plugged into a half-dozen power strips and totalling about 2 and a half amps of AC... He's got 112-114v of AC at his house so using 113 we get 255.2w ... divide by 1000 and times 8760=2235.5, or 2.2kw just in wall wart wastage. Except that the formula is already in KWh, IOW not 2.2 but 2235 KWh per year! If he's burning that much juice (255 watts) then he's using a KWh every four hours! That's 60 cents a day just to run wall warts. Joe Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
At 05:18 PM 7/19/2005, Tony King, W4ZT wrote: One caution about these switchers. Many of the cheap switchers being made today both as chargers and supplies generate tremendous amounts of RFI. A number of my ham friends have experienced unbearable interference from these devices. Note that they have no part 15 certification and you can never locate the actual manufacturer to have problems corrected. It gets even worse when your NEIGHBOR has these devices. I'm sure it happens, but I haven't been hit with it. I have receivers that cover 0.1-2GHz, and haven't noticed anything. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
If I did that my XYL would string me by a wall wart ! :) shes tolerable to my hobby and I have to put up with cats ! - Original Message - From: Dave VanHorn [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, July 19, 2005 5:03 PM Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and Noise? Think how many houses have that exact same situation. I know I suffer from this big-time. Lots of wall wart devices. They are going to switchers though, it's finally come to the place where the switcher is cheaper than the iron and shipping from China. Last year, I needed a new wart for something, and was surprised by a lighter than air 1A wart for $15, with adjustable output voltage, that is a switcher. It's still going, so acceptable quality I guess. Lots of devices plugged in at my place, and the devils that design them love to stick in digital clocks, so you don't want to unplug them. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
Does anybody have a web site to look at IOTA power supply? I need to find some to replace my power supplies in the future. Bruce KD4BOH.- Original Message - From: Joe Montierth [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, May 25, 2005 2:22 PM Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and Noise? I have one of the 75 amp supplies working at a remote site. We have not seen any noise from the unit, but our equipment is all VHF and UHF, haven't checked it down in HF, but at UHF we have seen no problems. We have 20 UHF RX's and 6 VHF and have not seen any degradation. These IOTA's run much cooler than the analog Astron's, and are much smaller. I will probably be changing out all of the Astrons to these in the next few years, as conditions warrant. Joe --- Nick Papadonis [EMAIL PROTECTED] wrote: Hi Folks, I'm considering purchasing a 45A IOTA Switched Power supply to power a UHF Micor and am concerned about switch PS noise. Has anyone tried these supplies with UHF radios? Is noise experienced? Insight greatly appreciated. Thanks. -- Nick KB1GZN Boston, MA __ Do you Yahoo!? Yahoo! Small Business - Try our new Resources site http://smallbusiness.yahoo.com/resources/ Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
At 06:49 PM 7/17/2005, Bruce Nanney wrote: Does anybody have a web site to look at IOTA power supply? I need to find some to replace my power supplies in the future. Bruce KD4BOH.- I picked up one on ebay recently, very competitive pricing. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] IOTA Switched Power Supply and Noise?
I bought one about six months or so ago, but I don't remember where. Google should turn something up for you, that's how I found it. Richard, N7TGB -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] Behalf Of Bruce Nanney Sent: Sunday, July 17, 2005 4:49 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and Noise? Does anybody have a web site to look at IOTA power supply? I need to find some to replace my power supplies in the future. Bruce KD4BOH.- Original Message - From: Joe Montierth [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Wednesday, May 25, 2005 2:22 PM Subject: Re: [Repeater-Builder] IOTA Switched Power Supply and Noise? I have one of the 75 amp supplies working at a remote site. We have not seen any noise from the unit, but our equipment is all VHF and UHF, haven't checked it down in HF, but at UHF we have seen no problems. We have 20 UHF RX's and 6 VHF and have not seen any degradation. These IOTA's run much cooler than the analog Astron's, and are much smaller. I will probably be changing out all of the Astrons to these in the next few years, as conditions warrant. Joe --- Nick Papadonis [EMAIL PROTECTED] wrote: Hi Folks, I'm considering purchasing a 45A IOTA Switched Power supply to power a UHF Micor and am concerned about switch PS noise. Has anyone tried these supplies with UHF radios? Is noise experienced? Insight greatly appreciated. Thanks. -- Nick KB1GZN Boston, MA __ Do you Yahoo!? Yahoo! Small Business - Try our new Resources site http://smallbusiness.yahoo.com/resources/ Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] IOTA Switched Power Supply and Noise?
I have one of the 75 amp supplies working at a remote site. We have not seen any noise from the unit, but our equipment is all VHF and UHF, haven't checked it down in HF, but at UHF we have seen no problems. We have 20 UHF RX's and 6 VHF and have not seen any degradation. These IOTA's run much cooler than the analog Astron's, and are much smaller. I will probably be changing out all of the Astrons to these in the next few years, as conditions warrant. Joe --- Nick Papadonis [EMAIL PROTECTED] wrote: Hi Folks, I'm considering purchasing a 45A IOTA Switched Power supply to power a UHF Micor and am concerned about switch PS noise. Has anyone tried these supplies with UHF radios? Is noise experienced? Insight greatly appreciated. Thanks. -- Nick KB1GZN Boston, MA __ Do you Yahoo!? Yahoo! Small Business - Try our new Resources site http://smallbusiness.yahoo.com/resources/ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
