Samelex Power Supplies with a K3
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Anyone using a SEC1235 with there K3? Much RF hash?
John N1JM |
Re: Samelex Power Supplies with a K3
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"Anyone using a SEC1235 with there K3? Much RF hash? John N1JM"
I do. No hash at all. I did make a few mods to my unit. I enabled the fan so it runs at low speed all the time (it can still go to full speed if necessary), and I added a pair of PowerPoles to the back. Info in the "Reviews" section of my website at www.ad5x.com. Phil - AD5X ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by John_N1JM
I read the Eham reviews about how quiet the fan is and that it seldom even
runs so I bought one. I used it to power the K3. The fan came on after about 3 minutes of receive mode operation and it was louder than anything else in the shack. I hate fans, except when I'm sleeping! The fan attempts to dischage out the bottom of the supply (strange). Also, the voltmeter stayed pegged at 15v however the voltage output was really 13.8. I had no RF hash although one time I held my AM transistor portable up close to it and it really wiped it out but so will most switchers. I unhooked the fan and ran it that way for a few weeks until one day the over temp. sensor shut it down. I also have the little MFJ switcher and it performs just as well and cost less but it too has a disgusting little fan. Finally, I went back to my Aston 35m which has no fan and helps hold down the desk. Ahhh....No noise, No hash....Just nice clean DC. 73 Steve N4LQ ----- Original Message ----- From: "N1JM" <[hidden email]> To: <[hidden email]> Sent: Sunday, May 23, 2010 12:17 AM Subject: [Elecraft] Samelex Power Supplies with a K3 > > Anyone using a SEC1235 with there K3? Much RF hash? > > John N1JM > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/Samelex-Power-Supplies-with-a-K3-tp5089932p5089932.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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> Finally, I went back to my Aston 35m which has no fan and helps hold down
> the desk. Ahhh....No noise, No hash....Just nice clean DC. I've been dealing with the same issues as I transitioned from a 20 year-old Astron RS-35 to an HP bench supply and an Astron switcher. In each case, both supplies use loud rotational fans. Recently, I've added fan speed control with a PWM controller. Instead of limiting the fan's speed through current alone, a pulse-width-modulator controls speed by producing short pulses of voltage. Speed is then controlled by the duty-cycle of the circuit's pulse train. After trying several attempts to smoothly control rotational speed with series resistors and voltage-dividers, I found several low-cost PWM kits (~ USD $20) available that accurately control speed down to slow levels without stalling. In the case of the SS-20, I created two threshold steps, one to engage when the heatsink temperature rises above a pre-determined amount. However, after adding the PWM controller and letting the idle speed rest where no noise is heard, enough air flows to keep the higher speed from kicking in, except when I key down into a load for more than a minute. Paul, W9AC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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Paul....It makes me wonder if they couldn't just put a decent heat sink on
those switchers and virtually eliminate the fan or at least make it very rare to ever turn on. I realize they want to keep them small and lightweight and I guess fans are cheap and light but I sure do hate the racket they make! Steve N4LQ ----- Original Message ----- From: "Paul Christensen" <[hidden email]> To: <[hidden email]> Sent: Sunday, May 23, 2010 8:40 AM Subject: Re: [Elecraft] Samelex Power Supplies with a K3 >> Finally, I went back to my Aston 35m which has no fan and helps hold down >> the desk. Ahhh....No noise, No hash....Just nice clean DC. > > I've been dealing with the same issues as I transitioned from a 20 > year-old > Astron RS-35 to an HP bench supply and an Astron switcher. In each case, > both supplies use loud rotational fans. Recently, I've added fan speed > control with a PWM controller. Instead of limiting the fan's speed > through > current alone, a pulse-width-modulator controls speed by producing short > pulses of voltage. Speed is then controlled by the duty-cycle of the > circuit's pulse train. > > After trying several attempts to smoothly control rotational speed with > series resistors and voltage-dividers, I found several low-cost PWM kits > (~ > USD $20) available that accurately control speed down to slow levels > without > stalling. In the case of the SS-20, I created two threshold steps, one to > engage when the heatsink temperature rises above a pre-determined amount. > However, after adding the PWM controller and letting the idle speed rest > where no noise is heard, enough air flows to keep the higher speed from > kicking in, except when I key down into a load for more than a minute. > > Paul, W9AC > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Phil Salas
Phil: Some are complaing about loud fan noise. Do you have that with yours? I don't think your review mentioned fan noise as I recall. 73, John N1JM |
Re: Samelex Power Supplies with a K3
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I have used one at Field Day for years. Works great no issues.
If you have a problem with fan noise, put the box on the floor. You don't need it on the operating table anyway and moving it away from the radio can't hurt the rfi issues. Craig Buck k4ia On May 23, 2010, at 10:18 AM, N1JM <[hidden email]> wrote: > > > Phil & Debbie Salas wrote: >> >> "Anyone using a SEC1235 with there K3? Much RF hash? John N1JM" >> >> I do. No hash at all. I did make a few mods to my unit. I >> enabled the >> fan >> so it runs at low speed all the time (it can still go to full speed >> if >> necessary), and I added a pair of PowerPoles to the back. Info in >> the >> "Reviews" section of my website at www.ad5x.com. >> >> Phil - AD5X >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> > Phil: > > Some are complaing about loud fan noise. Do you have that with > yours? I > don't think your review mentioned fan noise as I recall. > > 73, John N1JM > -- > View this message in context: http://elecraft.365791.n2.nabble.com/Samelex-Power-Supplies-with-a-K3-tp5089932p5090818.html > Sent from the [K3] mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I have one too works great. No noise that I can attribute to it.
I have an Astron Switcher and it is susceptible to rf on 20m. I saw a post where someone has loose screws in theirs so maybe I should open mine up and poke around. Why would Elecraft not offer a ps kit for the K3? Mike W0MU CC Packet Cluster W0MU-1 W0MU.NET or 67.40.148.194 "A slip of the foot you may soon recover, but a slip of the tongue you may never get over." Ben Franklin -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of K4ia Sent: Sunday, May 23, 2010 8:48 AM To: N1JM Cc: [hidden email] Subject: Re: [Elecraft] Samelex Power Supplies with a K3 I have used one at Field Day for years. Works great no issues. If you have a problem with fan noise, put the box on the floor. You don't need it on the operating table anyway and moving it away from the radio can't hurt the rfi issues. Craig Buck k4ia On May 23, 2010, at 10:18 AM, N1JM <[hidden email]> wrote: > > > Phil & Debbie Salas wrote: >> >> "Anyone using a SEC1235 with there K3? Much RF hash? John N1JM" >> >> I do. No hash at all. I did make a few mods to my unit. I enabled >> the fan so it runs at low speed all the time (it can still go to full >> speed if necessary), and I added a pair of PowerPoles to the back. >> Info in the "Reviews" section of my website at www.ad5x.com. >> >> Phil - AD5X >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> > Phil: > > Some are complaing about loud fan noise. Do you have that with > yours? I > don't think your review mentioned fan noise as I recall. > > 73, John N1JM > -- > View this message in context: 932p5090818.html > Sent from the [K3] mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by John_N1JM
I have one I bought a few months ago to go with my new K3. Works great. I
do not notice any hash, and the fan noise hasn't bothered me yet (but then again I'm usually running 2 rigs, 2 power supplies and 2 amps, all at the same time. The PS fan is NOT the loudest thing in my shack by any means. 73 de Al, KE1FO K3 #3055 K3 #4094 ----- Check out my Amateur Radio Contesting blog at ke1fo.wordpress.com. On Sun, May 23, 2010 at 12:17 AM, N1JM <[hidden email]> wrote: > > Anyone using a SEC1235 with there K3? Much RF hash? > > John N1JM > -- > View this message in context: > http://elecraft.365791.n2.nabble.com/Samelex-Power-Supplies-with-a-K3-tp5089932p5089932.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by Steve Ellington
I agree! I would rather have a larger, more expensive box with a big
heatsink than a fan. The only fan I have ever heard that was silent was one with the blades and motor removed and destroyed. :-) Most people don't seem to notice the noise so I guess we just have to endure it as we seem to be very much the minority and manufacturers just won't spend the extra money to eliminate the fan. I have a Yaesu FT-8900R in my truck mounted enclosed in the centre console. Even with road noise at freeway speeds, I notice when its fan cuts in. Most people do not find the fan in this radio offensive and consider it quiet. I suppose I just have a high sensitivity to fan noise. From my work in the audio industry I have come to the conclusion that sound is very subjective. Each person seems to have their own idea of what sounds good and bad. I think that people get used to a certain colouration or lack of colouration and that becomes the standard to which they judge. That is why some people will praise a particular loudspeaker and others will find it offensive. My work with broadcast radio stations in parts of South America, found that the norm was to overmodulate the signals to get the loudest signal on the band. The distorted sound became the norm and people expected other sources like CD's to sound the same. The same phenomena is happening with the new flat screen TV's. They are put in stretch mode to fill the screen and people just don't seem to notice the distorted picture. I was very disappointed to see the big fan on the new KPA500. I have a KPA100 that is still not finished because I keep looking at the fan and wondering why I bought something with a fan. Eric and Wayne, would you consider a larger heatsink as an option to have a fanless KPA500? Darrell VA7TO On 2010.05.23 7:08 AM, Steve Ellington wrote: > Paul....It makes me wonder if they couldn't just put a decent heat sink on > those switchers and virtually eliminate the fan or at least make it very > rare to ever turn on. I realize they want to keep them small and lightweight > and I guess fans are cheap and light but I sure do hate the racket they > make! > > Steve > N4LQ -- Darrell Bellerive Amateur Radio Station VA7TO Grand Forks BC Canada ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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I have never heard the K3 fans. Two fans at very low speed make no
noise. Craig Buck On May 23, 2010, at 11:34 AM, Darrell Bellerive <[hidden email] > wrote: > I agree! I would rather have a larger, more expensive box with a big > heatsink than a fan. The only fan I have ever heard that was silent > was > one with the blades and motor removed and destroyed. :-) > > Most people don't seem to notice the noise so I guess we just have to > endure it as we seem to be very much the minority and manufacturers > just > won't spend the extra money to eliminate the fan. > > I have a Yaesu FT-8900R in my truck mounted enclosed in the centre > console. Even with road noise at freeway speeds, I notice when its fan > cuts in. Most people do not find the fan in this radio offensive and > consider it quiet. I suppose I just have a high sensitivity to fan > noise. > > From my work in the audio industry I have come to the conclusion that > sound is very subjective. Each person seems to have their own idea of > what sounds good and bad. I think that people get used to a certain > colouration or lack of colouration and that becomes the standard to > which they judge. > > That is why some people will praise a particular loudspeaker and > others > will find it offensive. My work with broadcast radio stations in parts > of South America, found that the norm was to overmodulate the > signals to > get the loudest signal on the band. The distorted sound became the > norm > and people expected other sources like CD's to sound the same. > > The same phenomena is happening with the new flat screen TV's. They > are > put in stretch mode to fill the screen and people just don't seem to > notice the distorted picture. > > I was very disappointed to see the big fan on the new KPA500. I have a > KPA100 that is still not finished because I keep looking at the fan > and > wondering why I bought something with a fan. > > Eric and Wayne, would you consider a larger heatsink as an option to > have a fanless KPA500? > > Darrell > VA7TO > > On 2010.05.23 7:08 AM, Steve Ellington wrote: >> Paul....It makes me wonder if they couldn't just put a decent heat >> sink on >> those switchers and virtually eliminate the fan or at least make it >> very >> rare to ever turn on. I realize they want to keep them small and >> lightweight >> and I guess fans are cheap and light but I sure do hate the racket >> they >> make! >> >> Steve >> N4LQ > > -- > Darrell Bellerive > Amateur Radio Station VA7TO > Grand Forks BC Canada > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by P.B. Christensen
On Sun, 23 May 2010 08:40:53 -0400, Paul Christensen wrote:
>Recently, I've added fan speed control with a PWM controller. I trust that you've carefully designed to minimize the RF noise usually associated with this sort of circuit. :) 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by Buck - k4ia
Oh, I too remember now, my K3/100 has fans, I remember putting them in. But, I think they are broken because I NEVER hear them.
PEH's FIVE solutions to fan noise... (1) Use headphones. (2) Turn the sound up on your K3 speakers. (3) Use digital interfaces and play background music while you operate with your computer. (4) Put a wind-chime behind your K3 and listen to the sweet tinkling notes instead of the fan. (5) Receive on your K3 (fan not needed), transmit on your KX1 (no fan). On May 23, 2010, at 8:52 AM, K4ia wrote: > I have never heard the K3 fans. Two fans at very low speed make no > noise. > > Craig Buck > > On May 23, 2010, at 11:34 AM, Darrell Bellerive <[hidden email] >> wrote: > >> I agree! I would rather have a larger, more expensive box with a big >> heatsink than a fan. The only fan I have ever heard that was silent >> was >> one with the blades and motor removed and destroyed. :-) >> >> Most people don't seem to notice the noise so I guess we just have to >> endure it as we seem to be very much the minority and manufacturers >> just >> won't spend the extra money to eliminate the fan. >> >> I have a Yaesu FT-8900R in my truck mounted enclosed in the centre >> console. Even with road noise at freeway speeds, I notice when its fan >> cuts in. Most people do not find the fan in this radio offensive and >> consider it quiet. I suppose I just have a high sensitivity to fan >> noise. >> >> From my work in the audio industry I have come to the conclusion that >> sound is very subjective. Each person seems to have their own idea of >> what sounds good and bad. I think that people get used to a certain >> colouration or lack of colouration and that becomes the standard to >> which they judge. >> >> That is why some people will praise a particular loudspeaker and >> others >> will find it offensive. My work with broadcast radio stations in parts >> of South America, found that the norm was to overmodulate the >> signals to >> get the loudest signal on the band. The distorted sound became the >> norm >> and people expected other sources like CD's to sound the same. >> >> The same phenomena is happening with the new flat screen TV's. They >> are >> put in stretch mode to fill the screen and people just don't seem to >> notice the distorted picture. >> >> I was very disappointed to see the big fan on the new KPA500. I have a >> KPA100 that is still not finished because I keep looking at the fan >> and >> wondering why I bought something with a fan. >> >> Eric and Wayne, would you consider a larger heatsink as an option to >> have a fanless KPA500? >> >> Darrell >> VA7TO >> >> On 2010.05.23 7:08 AM, Steve Ellington wrote: >>> Paul....It makes me wonder if they couldn't just put a decent heat >>> sink on >>> those switchers and virtually eliminate the fan or at least make it >>> very >>> rare to ever turn on. I realize they want to keep them small and >>> lightweight >>> and I guess fans are cheap and light but I sure do hate the racket >>> they >>> make! >>> >>> Steve >>> N4LQ >> >> -- >> Darrell Bellerive >> Amateur Radio Station VA7TO >> Grand Forks BC Canada >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by Buck - k4ia
From: "K4ia" <[hidden email]>
> I have never heard the K3 fans. Two fans at very low speed make > no > noise. I guess you don't operate RTTY! Dave Hachadorian, K6LL Yuma, AZ . ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Steve Ellington
I have a JetStream JTPS-35 switcher. It has a humongous heat sink inside the box and has a fan that makes some noise when the transceiver is turned on. However, I can't hear it when my Dentron Clipperton L is turned on. The Dentron has an aftermarket Radio Shack fan. The original fan was replaced before 1990 when I bought the amp second hand. It seems that a big enough heatsink for the switching transistors might be counterproductive to the light weight.
I did reduce the fan noise quite a bit by tying the wires that were touching the fan blades to the heat sink with a twistie from a cord that I got with something. Willis 'Cookie' Cooke K5EWJ ________________________________ From: Steve Ellington <[hidden email]> To: Paul Christensen <[hidden email]>; [hidden email] Sent: Sun, May 23, 2010 9:08:25 AM Subject: Re: [Elecraft] Samelex Power Supplies with a K3 Paul....It makes me wonder if they couldn't just put a decent heat sink on those switchers and virtually eliminate the fan or at least make it very rare to ever turn on. I realize they want to keep them small and lightweight and I guess fans are cheap and light but I sure do hate the racket they make! Steve N4LQ ----- Original Message ----- From: "Paul Christensen" <[hidden email]> ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by John_N1JM
"Some are complaing about loud fan noise. Do you have that with yours? I
don't think your review mentioned fan noise as I recall." I said that you'll know when the fan comes on. That's the reason I modified the unit to keep the fan turning at low speed. That keeps the PS cool and so the fan almost never goes to full speed. It never goes to full speed when just powering the K3. But when I also power other rigs (I have an IC-706MKII and an IC-706MKIIG that I sometimes also have on) along with operating the K3, sometimes it will switch to full speed. But this is very rare. Phil - AD5X ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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In reply to this post by Jim Brown-10
Jim,
I should have mentioned that. From the beginning, I wrapped about twelve turns onto a #31 core from the DC input, fan output, and speed pot leads onto a #31 core. In fact, all leads are done with IDC ribbon cable and grouped/wrapped together on one core. Paul, W9AC ----- Original Message ----- From: "Jim Brown" <[hidden email]> To: <[hidden email]> Sent: Sunday, May 23, 2010 11:52 AM Subject: Re: [Elecraft] Samelex Power Supplies with a K3 > On Sun, 23 May 2010 08:40:53 -0400, Paul Christensen wrote: > >>Recently, I've added fan speed control with a PWM controller. > > I trust that you've carefully designed to minimize the RF noise usually > associated with this sort of circuit. :) > > 73, > > Jim K9YC > > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
Re: Samelex Power Supplies with a K3
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On Sun, 23 May 2010 15:04:30 -0400, Paul Christensen wrote:
>In fact, all leads are done with IDC ribbon cable and >grouped/wrapped together on one core. Thats good. Whats even better is to use twisted pair for the entire length of any current loop carrying pulsed current. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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