++++++++++++++++++++ Date: Tue, 16 Apr 2002 20:11:31 -0700 From: Phil Wheeler Organization: Outstanding To: Steve & Anne Ray Cc: Elecraft Subject: Re: [Elecraft] Power Supply K2 100 Steve & Anne Ray wrote: >I am looking at the Astron Power supplies for when I order my K2 100. >Should I look for a RS-20A which is 16 A continuous and 20 A ICS or go with >the RS-35A which is 25 A continuous and 35 A ICS. I am hoping to find one >or something similar at Dayton this year, when hopefully I can order the K2 >100. > I use the Astron switcher, which runs around 20 ICS and continuous. Before that I used the RS-35 for my 100 W rigs. I would not try the 16 A supply -- assuming the K2/100 has a 100% duty cycle at 100 W (some rigs do). MIght be a bit marginal Phil +++++++++++++++++++ Date: Mon, 29 Jul 2002 21:09:39 -0400 (EDT) From: kc4kgu at ENTERZONE.NET To: james h edwards Cc: Elecraft at mailman.qth.net Subject: Re: [Elecraft] k2-100?? On Tue, 9 Jul 2002, james h edwards wrote: > yes i hav e current rf meter. Forgot how to fig..power useing current. Also > i have 55 to 60 watts out on all bands,could the bias if not set just right > be the prob.Every thing else is ok no other prob thanks n5tog k2 1587 James, I can't answer the rf current to power question off the top of my head but, the low power out symptoms could be caused by several things. If you have the FWD/REF power trimmers improperly calibrated, the KPA100 may THINK it's delivering 100w. If your power supply is unable to deliver the required current at 13.8v, you won't be able to develope full power from the KPA100. What does your POWER SUPPLY tell you about current when you request 100w from the K2/100 in CW mode and TX? Your dummy load, swr bridge, coax connector (pick any or all) may be bad, causing excessive SWR and the KPA100 may be backing off to protect itself. Your wattmeter may be showing you AVERAGE power and not peak power. In CW, this will be the same but in SSB, it is quite different. If you have a true peak-reading meter (MFJ doesn't count in my book, no matter what their ads say!), you'll get a much better idea of what the rig is doing. When you select 50w on the K2/100, does it deliver 50w according to your meter? 73 de John - KC4KGU K2/100 #2490 ++++++++++++++++++ Date: Fri, 30 Aug 2002 16:22:00 -0400 From: JimWMiller at aol.com To: elecraft at mailman.qth.net Subject: [Elecraft] K2 and MFJ-4125 Switch Power Supply ? Greetings, Now that my K2 is working I considering getting the 100 watt PA. This will of course require a new power supply. I like the MFJ-4125 Switching Power Supply. MFJ claims that it generates no RFI hash. The ARRL review agrees and suprisingly rates the MFJ-4125 as the best in its class. Is anyone using the MFJ-4125 and could you comment on the level of (or lack of) RFI ??? Please also comment on any configuration issues such as antenna, ground or relative positioning that have contributed to its performance. 73 and thanks in advance, Jim WA2UMP K2:2679 --__--__-- From: "Alan J. Price" To: , Subject: RE: [Elecraft] K2 and MFJ-4125 Switch Power Supply ? Date: Fri, 30 Aug 2002 18:13:25 -0400 I have one that I use to test K2's. So far no problems, handles the load of the radio and amp with flying colors. 73 Alan ++++++++++++++++ From: "George Winship" To: Cc: Date: Fri, 30 Aug 2002 19:20:35 +0100 Subject: [Elecraft] K2 and MFJ-4125 Switch Power Supply My MFJ-4125 has some hash on it. Sounds like someone with an open mic tuning his vfo knob. Sometimes it it is loud enough to disturb the signal I am trying to copy. Usually it travels through and but will return periodically. Also have an Alinco DM-330MVT power supply. It is very quite and if any hash happens to come along you can tune it out. Both supplies have posed no problems on transmit and will more than handle the power requirements of the K2-100. 73, George, NC5G K2-2217 ++++++++++++++++++ From: w7qhd at webtv.net (Kurt Cramer) Date: Fri, 30 Aug 2002 18:29:06 -0700 (MST) To: JimWMiller at aol.com Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] Re: K2 and MFJ-4125 Switch Power Supply My MFJ 4125 is quite! No noise. I tried it in a motel room with a piece of wire on the floor for an antenna and heard some hash, but I'm not sure it was from the ps. Here at home with a 80/40 dipole and a triband beam NO noise. 73, Kurt W7QHD (since 1951) web page: http://W7QHD.tripod.com ++++++++++++++++++ To: JimWMiller at aol.com, elecraft at mailman.qth.net Date: Fri, 30 Aug 2002 18:44:32 -0700 Subject: Re: [Elecraft] Re: K2 and MFJ-4125 Switch Power Supply From: k6se at juno.com Jim, WA2UMP wrote: "Do you prefer a linear PS over the switching PS ?" ========== When you're trying to dig that weak signal out of the noise, you don't want to have to contend with even the slighest bit of hash. I bought a new MFJ-4322 linear 22-amp power supply from AES for $69 a while back that I'm completely satisfied with. It's more than ample to power my K2/100 (and hopefully my new Ten-Tec Orion when I get it). I don't know if AES has any of them left at that price. 73, de Earl, K6SE +++++++++++++++++ Reply-To: From: "Ron D'Eau Claire" To: Subject: RE: [Elecraft] Re: K2 and MFJ-4125 Switch Power Supply Date: Fri, 30 Aug 2002 20:27:26 -0700 For low-current applications like the K2 (up to 15 amps or so) I stick with linear supplies too. I do not need the light weight for portability and I like the inherently quiet operation. The only critical issue, where the K2 (and maybe some other rigs) is concerned with a linear supply is to keep the rig AWAY from the power supply. When I first fired up my K2, I plopped the K2 on top of the supply. That's a very common practice in the commercial world, and my power supply is almost the same size as the K2. My first QSO's reported hum on my signal. Hooked up a dummy load and listened on an aux receiver and it was clean. Back on the air and there was another hum report. It too a couple of iterations before I realized that I was pulling the K2 off of the power supply to hook up the dummy load and testing with it sitting on the desk. Put it back on the power supply and there was the hum. The big 60 Hz field around the transformer was modulating one of the VCO's in the K2. Ron AC7AC K2 # 1289 +++++++++++++++++++++ Date: Sun, 06 Oct 2002 16:42:39 -0700 From: Jerry Hancock To: elecraft at mailman.qth.net Reply-To: jehancoc at pacbell.net Subject: [Elecraft] Power supply alternative I was looking for a 25 to 30 amp bench supply to run my k2/100 (when the I get around to building the KPA) and checked out the usual Astron, MFJ and others. I wanted linear regulation being wary of switching hash. I decided to build my own and while I was at the local surplus dealer scrounging for parts, I stumbled across an old HP 6261B lab grade supply. These supplies listed for around $3,800 but they can be found for well under $500. Mine was $150. It is 0-20V at 0 to 50amps in both constant voltage and constant current regulation. The 6261b is regulated to .01%. I love the current limiting and over voltage protection. This supply will well out perform standard ham types for about the same money. I looked around on the web and you can find other HP supplies like a 6269b for very reasonable prices. +++++++++++++++++ From: "Lyle Johnson" To: Date: Sat, 26 Oct 2002 22:29:11 -0700 Subject: [Elecraft] ELPAC Power Supply Hello! A couple years ago there was a lot of discussion on this reflector about a surplus ELPAC power supply, suitable for operating the K2 and keeping the optional KBT2 battery properly charged. For under $20, it was a great deal. I have had one for two years and have been very happy with it - until today :-( I ran into a problem when doing some testing of the KAT100. The ELPAC was the culprit. Details are at http://www.fidalgo.net/~wa7gxd/k2kpa100.html. The short version is that the ELPAC seems fine for use with a K2, but not an external device attached to the K2. I mention this not because you might want to run a KAT100 with one (although you might), but if Elecraft ever comes out with any sort of other external accessories for the K2 system, you might have difficulties if you don't understand your power supply's characteristics. I am sure ELPAC is not alone in their supply's reaction to idling with no load, then suddenly having a load applied. Caveat emptor. 72/73, Lyle KK7P ++++++++++++++++ Date: Sun, 27 Oct 2002 00:52:19 -0700 From: Wayne Burdick Organization: Elecraft To: Lyle Johnson Cc: elecraft at mailman.qth.net Subject: [Elecraft] Re: ELPAC Power Supply Lyle Johnson wrote: > > I ran into a problem when doing some testing of the KAT100. > > The short version is that the ELPAC seems fine for use with a K2, but not an > external device attached to the K2.... Lyle, We're going to study the power-supply turn-on issue more carefully. As of right now your particular ELPAC supply is the only we we know of that exhibits such a dip in voltage when the load is applied. But if there are others like it, we'll try to find a solution in firmware rather than make such supplies obsolete. I should point out that this came up during KAT100 field testing, which is exactly why we do it! 73, Wayne N6KR ++++++++++++++++++ From: "Lyle Johnson" To: Subject: RE: [Elecraft] ELPAC Power Supply Date: Sun, 27 Oct 2002 17:25:43 -0800 Hello Ron! > When faced with firing off all of those big relays in the KAT100, it > allows the voltage to droop about 4 volts below normal for about 1/2 > second. That causes problems for the K2 controller. That right? Long answer: It allows the +12V to droop to about +4 volts for about 450 mSec. The brownout detector in the KAT100 MCU sees that its Vcc is below +5V nominal, so it stops working. During this time, the K2 CPU can't handshake with the now-silent KAT100 CPU, so it fails to detect its presence. Short answer: Yes :-) > It looks like the regulator wasn't designed to respond to such large > transients quickly enough for this application... It appears that my supply doesn't respond well at all. Even a 60 Hz switcher (using an SCR on the priomary) would respond in 16.7 mSec. To take 450 mSec to figure it out is really, really bad. I frankly suspect I may have a bad supply. But it seems to works OK when it runs the K2, although I haven't fully characterized it under that condition since I have the KBT2 installed and always ON. The *real* question becomes: Is KK7P's ELPAC supply typical, or is it a defective supply? > ..That may well be a > problem with many supplies that do not have a large capacitor at the > output. Indeed, putting a BIG capacitor across the output may take care > of the problem, provided the regulator can supply the current to charge > it up when the supply is first turned on without damage. Yes, the supply could be modifed (if it is a design problem) or repaired (if it is a defect in my particular supply). With no schematics, and at under $20 to buy it in the first place, it's not worth much time or trouble. But I would be interested to know if other ELPAC supplies have this problem, or if I am just lucky :-/ *** In normal operation, my KAT100 runs on the supply that also runs the KPA100, and has no problems at all. As Wayne pointed out, this is just something uncovered during testing, and it may or may not be typical of the ELPAC supplies. Worst case, a note in the troubleshooting section of the KAT100 manual could say "If the K2 doesn't recognize the KAT100, be sure the power supply voltage doesn't droop when the K2 is turned on." 73, Lyle KK7P +++++++++++++++++++ Reply-To: From: "Ron D'Eau Claire" To: "'S Johns'" , "'Elecraft mailing list'" Subject: RE: [Elecraft] Need _quiet_ power supply recommendations for k2-100 Date: Tue, 4 Mar 2003 19:30:47 -0800 I use an Astron RS20 amp linear supply. No fans, no noise - electrical or mechanical. Coasts along powering the K2/100 combo at 100 watts with current capacity to spare. Ron AC7AC K2 # 1289 -----Original Message----- Hi everyone, I've been using an mfj-4065mv ps with the k2-100. Unfortunately, the ps has a fan that comes on (and runs a while) after transmitting. It's loud enough to make cw copy difficult for signals near the noise floor. Any suggestions for a silent, high quality power supply appreciated. 73, Scott W3TX ++++++++++++++++++ Date: Tue, 04 Mar 2003 19:41:03 -0800 To: "S Johns" , "Elecraft mailing list" From: Jeff Stai WK6I Subject: Re: [Elecraft] Need _quiet_ power supply recommendations for k2-100 At 07:17 PM 3/4/2003, S Johns wrote: >Hi everyone, > >I've been using an mfj-4065mv ps with the k2-100. Unfortunately, the ps >has a fan that comes on (and runs a while) after transmitting. It's >loud enough to make cw copy difficult for signals near the noise floor. > >Any suggestions for a silent, high quality power supply appreciated. > >73, Scott W3TX I use an Astron RS-35M - plenty of current to spare to run accessories as well as the K2, and it has meters on the front panel, which is at least cool and sometimes useful... 73 - jeff wk6i Jeff Stai jds at twistedoak.com Twisted Oak Winery http://www.twistedoak.com/ Rocketry Org. of CA http://www.rocstock.org/ Amateur Radio WK6I +++++++++++++++++++ From: "David Walker" To: Date: Wed, 5 Mar 2003 16:37:54 +1100 Subject: [Elecraft] Re Quiet Pwr Supply I use the ALINCO DM-330MV. It's doesn't generate HF noise, and the fan = is completely silent. ++++++++++++++++++++ From: "Don Brown" To: "Jibeji" , Subject: Re: [Elecraft] KPA100 Power question Date: Sat, 15 Mar 2003 09:04:46 -0600 Hi No. You do not have R26 set right. Assuming your Bird is accurate you need to make the K2 wattmeter read the same as the Bird. Adjust the K2 power for 50 watts as indicated on the bird then adjust R26 until the K2 display reads 50 watts. Readjust the power pot slightly after each change of R26 so the MPU will reread the power out. If everything looks good check at 100 watts and readjust R26 a little to bring the meters into agreement. Make very tiny adjustments of R26 on the order of only 1 or 2 degrees. Once R26 is set, adjust R27 to about 20% more clockwise than R26. Just eyeball it or, with the power off, measure R26 with an ohmmeter and set R27 to 20% higher resistance. Don Brown KD5NDB ----- Original Message ----- From: "Jibeji" To: Sent: Saturday, March 15, 2003 8:47 AM Subject: [Elecraft] KPA100 Power question > Hi. > I have just finished to build the KPA100 option. All tests were succesfully > passed but, at full power range, my Bird indicates only 75 W instead of the > 110 W shown by the internal Powermeter. > Is it normal ? > Thanks, 73 > -- > F8DQL - UFT 1116 > K2/100 #3249 ++++++++++++++++++ To: andrew.m.moore at verizon.net Cc: Elecraft at mailman.qth.net Date: Wed, 7 May 2003 19:56:28 -0700 Subject: Re: [Elecraft] max current drain for K2/100? From: k6se at juno.com Andrew Moore wrote: What's the max current drain for a K2/100 at 100 watts?" ========== At 100 watts output, my K2/100 draws from 13 to 16 amps (depending on the band) from my 13.8 VDC power supply. 73, de EArl, K6SE ++++++++++++++++++