Re: [Elecraft] KPA100 Issue
Thanks for your reply Geoff. I think that the reason the screws loosen isn't because of twisting out, but because the heat sink material that is placed between the power transistors and the heat sink is cold flowing. Many plastics will, under pressure, actually flow a bit and change it's shape ( in this case becoming thinner). After a period of time the plastic assumes it's final new shape. Using locktite (especially the permanent type) will make it very challenging to remove the screws when needed. Another idea would be using heat sink compound (a form of heat conducting paste) instead of the pads provided by Elecraft. The mounting bracket of the power transistors is insulated from the transistor itself by a heat conducting oxide so no insulating material is needed for mounting. Just mounting the transistor to the heat sink will not provide enough thermo conductivity between the transistor and heat sink. That is why Elecraft provided the thermo conductive pads. If heat sink compound is used the screws will remain tight because there is no lingering cold flow properties in the compound. 73 Dave KD1NA - Original Message - From: [EMAIL PROTECTED] To: David Robertson [EMAIL PROTECTED]; Elecraft elecraft@mailman.qth.net Sent: Thursday, January 25, 2007 11:11 AM Subject: Re: [Elecraft] KPA100 Issue Hi David; I can confirm your experience - and add a bit more. I too had occasion to remove the KPA100 shield, and found he PA and driver fixing screws I had tightened (but not overtightened!) quite loose. I re-tightened them, but this time overdid it with one of the studs tightened with an octagonal wrench, which twisted off. Fortunately a spare had been included with the kit, and it was not too difficult to remove and replace it. I wonder if a spot of 'Locktite' (cyanoacrylite 'superglue') applied during construction would be a good idea? Geoff G3NAQ (ex AE4PI) - Original Message - From: David Robertson [EMAIL PROTECTED] To: Elecraft elecraft@mailman.qth.net Sent: Thursday, January 25, 2007 1:31 PM Subject: [Elecraft] KPA100 Issue To All, Though there is some mention about tightening the screws that mount the final power transistors in the manual, it can be easily missed. When I first built the KPA100 I made sure the transistor hear sink mounting screws were tight. After operating the rig for about a week (and heat cycling the heat sink) I had an opportunity to open up the K2 to show a friend. At that time something in my mind reminded me to recheck the final transistor heat sink mounting screws (please remember the screws were carefully tightened upon assembly) and to my surprise I could easily tighten the screws 1/2 turn or more! It seems the heat conducting material cold flows a bit between the final transistors and the heat sink. So for those who have a KPA100 it would be prudent to check those final transistor heat sink mounting screws every so often. If you don't you could lose your finals. 73 Dave KD1NA ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com -- This email has been verified as Virus free Virus Protection and more available at http://www.plus.net -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.10/651 - Release Date: 24/01/2007 18:48 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] C227
Mike After looking at your picture I think I would only replace C227, Clean up the board around it, then test it out (in a dummy load). Don't think the relay is gone but those type of capacitors do sometimes fail. In your case you were trying to couple good VSWR into the rig but haven't succeeded yet and that capacitor took a voltage spike. Those capacitors do emit a lot of smoke when they fail. 73 Dave KD1NA ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] KPA100 Issue
Folks - Please do not replace the thermal pads with heatsink compound on the KPA100. As designed, the material on the pads flows slightly as they are heated up during transmit for the first several times, filling in the small gaps between the transistors and the heatsink surface. That is why we note that your should tighten the screws after your first several hours transmitting. Once the initial flow has occurred and you have tightened the screws there should be no need to tighten them significantly in the future. 73, Eric WA6HHQ Elecraft Dave Jeanne Robertson wrote: Thanks for your reply Geoff. I think that the reason the screws loosen isn't because of twisting out, but because the heat sink material that is placed between the power transistors and the heat sink is cold flowing. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
RE: [Elecraft] build time for KPA100
I found the KPA to go pretty quickly after I got the proper wheel for my Dremel. You're supposed to take the anodizing off the heat sink in specific places, and going at hard anodizing with a piece of emery cloth made me go nuts. The dremel attachment (a tiny wire brush) was great for taking the paint off of the case where grounding was needed as well. On Thu, 25 Jan 2007, Don Wilhelm wrote: J, You will likely find the KPA100 build time about 1/2 ot that required for the K2. 73, Don W3FPR -Original Message- Hey Folks, what's the approximate build time on a KPA100 compared to a K2? I just finished K2 #5945 and am antsy to get the KPA100 on the air ;) Also, wondering about the KDSP2 (looks quick) and KNB2 (also looks quick). Thanks, -J -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.432 / Virus Database: 268.17.10/651 - Release Date: 1/24/2007 6:48 PM ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com -- Hisashi T Fujinaka - [EMAIL PROTECTED] BSEE(6/86) + BSChem(3/95) + BAEnglish(8/95) + MSCS(8/03) + $2.50 = latte ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] 160m alignment quesion
I noticed today that my K2 is peaked for 1.900 mHz, or at least the background noise gets loudest when I tune there. I would like to peak the noise for 1840. Is it worthwhile to do this peaking? ( I use the CW end of the band most often.) Should I go through the complete p. 77 alignment for all bands if I realign this way for the 160m band only? Thanks, Bob VA3RKM ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] KPA100 Trouble
Fellow Elecrafters-- This morning I tested a few things with my dead K2/100. K2/100 configuration: no response at power-on, power supplied via KPA100 J3. KPA100 heat sink warms. All power pole connections checked. 13.9V from the Samlex 1223 power supply. 2V or so detected were detected at the interior J3 leads. Basic K2 test: all functions are normal, receive and transmit, all menu items are normal. E = 13.6, i = .38. All internal accessories work (160m, SSB, noise blanker). K2 with KPA100 connected, power supplied through K2 J3: rig turns on, all functions are normal. KPA100 fan runs for a minute or so. Normal receive and QRP transmit, internal SWR bridge works. All primary and secondary menu items appear normal. PA E message is normal, 12. E = 13.6, i = .38. No scorching or shorts detected. I'll only remove the KPA100 heat sink if I have to, but no visible signs of a problem after exploring underneath it with a miniature LED. The KPA100 has been in use for a little more than a year without problems. The trouble began yesterday afternoon as I was testing a receive antenna. I switched power supplies from my regular Samlex to a regulated supply I've used with the K2/100 in the past. All connections were carefully checked. One thing I failed to check was the power supply output -- it worked the last time I used it so I didn't bother (an important lesson learned). I've checked the regulated power supply output voltage after the KPA100 failure and it's only 1 - 2 volts. Something happened somewhere. All was well with the regulated-supply K2/100 as I checked out a receive antenna for about 30 minutes. I never transmitted while the regulated supply was connected. I turned the rig off while working on an outdoor antenna. When I returned to the shack, the rig wouldn't turn on and I noticed the heat sink was slightly warm. Here's where I am: the basic K2 checks out fine. Some functions of the KPA100 work when it's attached to the basic K2 (fan, SWR meter). No visible damage is apparent inside the KPA100. I don't have a clue where to start. My K2/100 technical skills have diminished in the time since I completed the rig. I'll have a chance to work on the rig again this evening. Any suggestions where to start would be appreciated. Are there any specific component failures I should look for after a problem somewhere in the DC input path caused by a faulty power supply? 73, John, N7ON K2/100 #5023 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
re: [Elecraft] K2 vs. FT817 on 160m
I've had the same conclusion with my FT-897 vs. KX1 on 80M. I too love the Yaesu as my amazing shack-in-a-box, but have found the kx1 beats it hands down when trying to dig that elusive fox out its den. Once I work my way through a pile of small qrp kits awaiting me, I intend on tackling the K2. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Missing diode
I was getting ready to fire up my K2 for the first alignment session today! Only had a couple more parts to go. Then I realized I am missing D36. Looks like a special diode, although I have not found out where it is in the schematic yet. My question is - is there any workaround (skip it, short it, use some other diode I might have in my kit...) that will let me do any of the alignment without it? Any chance this diode is also used in other modules (I have several sitting here). Thanks and 73, Tom KG3V ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
re: [Elecraft] K2 vs. FT817 on 160m
Hi Paul, I was once a user of FT817 about 4 years ago. FT817 has the merit of getting everything in a little box. However, the problem of FT817 is that it does receive everything no matter you want it or not. The performance of K2 under field condition is way way above FT817 and I eventually sold my F817 and stick to K2. However, it is not without price: 1. FT817ND is now very cheap in price; 2. K2 is not all mode; 3. If I feel bore, I can listen to broadcast with FT817 4. If the band is dead, I can do some local V/U activities with FT817 Having said that, my decision is still going for K2. 73 Johnny VR2XMC From: Paul Neuman [EMAIL PROTECTED] To: elecraft@mailman.qth.net Subject: re: [Elecraft] K2 vs. FT817 on 160m Date: Fri, 26 Jan 2007 16:14:50 -0500 I've had the same conclusion with my FT-897 vs. KX1 on 80M. I too love the Yaesu as my amazing shack-in-a-box, but have found the kx1 beats it hands down when trying to dig that elusive fox out its den. Once I work my way through a pile of small qrp kits awaiting me, I intend on tackling the K2. _ 与世界各地的朋友进行交流，免费下载 Live Messenger; http://get.live.com/messenger/overview ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Boy, it's *quiet* here!
Ok, so no one is talking... I just finished my K2 #5945 last week, and love it so much that I decided to give myself some early Christmas presents, so I dropped by Elecraft this morning (they're about 5 minutes down the highway from my house) and picked up a KPA100 and KDSP2. I was going to get the KNB2 also but they're out of those until Monday. Well, by Monday I hope to have the KPA100 and KDSP2 done (the KDSP2 is done already, short of soldering/testing). Love this stuff. See you on the bands. 73, Jeff KA6LAF ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] OT: Need FET for Yaseu Musen FRG-7
Buddy needs NTE-454 FET for Yaesu Musen FRG-7. The original is a 3SK40M. Please respond offline if you can help. 73 Gil NN4CW K2 #3104, KX1 #53 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] FS: K2/100 SN 5297, Many Extras
FS: K2/100, SN 5297, with KSB2, KNB2, KAF2, and Heil iCM microphone. Very nicely built, full 100 watts out on all bands. $900 delivered to your doorstep. If interested please contact me off list at [EMAIL PROTECTED] Thanks. Paul, K5HKX Paul Webb [EMAIL PROTECTED] ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] build time for KPA100
On Jan 25, 2007, at 8:45 PM, Jeff Kinzli wrote: Hey Folks, what's the approximate build time on a KPA100 compared to a K2? I just finished K2 #5945 and am antsy to get the KPA100 on the air ;) My build time for the basic K2 was about 45 hours. Build time for the KPA100 was about 8. I remember being surprised at how quickly it went together, and that it worked perfectly the first time. Also, wondering about the KDSP2 (looks quick) and KNB2 (also looks quick). A couple of hours each. Bill Coleman, AA4LR, PP-ASELMail: [EMAIL PROTECTED] Quote: Not within a thousand years will man ever fly! -- Wilbur Wright, 1901 ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] OT - W9C Special Event Stn Needs a little help tomorrow (Saturday)
Greetings: You may have read my posting (yesterday) regarding the Special Event Station (W9C) which will be in operation to commemorate the 90th Anniversary of the first transcontinental passing of a formal message via radio. More info available at: http://www.newstribune.com/articles/2007/01/23/community/342com01.prt Our station will start operating at 2000Z, 27 JAN 2007, on 14.040 MHz (+/- QRM), using the callsign W9C. We will have relatives of the 18 year old operator (9ABD) who was the middle leg of this historic event present at our station and one of them will initiate out first CQ from W9C. I'd really like to ensure that this initial CQ is met with a response from another station... and I'm asking for some help to ensure that this wish comes true. If you have the time and inclination to help us out, please be listen for us on (or near) 14.040 MHz at 2000Z tomorrow (Saturday) and respond to your CQ. Obviously, there's a chance that several stations may respond... we will probably come back to the strongest caller, because that will be the best 'show' for those present and observing the operation, BUT we will make every effort to respond to ALL CALLERS, regardless of how long it takes. Thanks for your time and I hope we will be able to work you this weekend from W9C. 73, Tom N0SS for The Mid-MO ARC 9ABD 90th Anniv Celebration ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] K2 on 160m
I had lots of fun on various 160m contests last year but so far this year haven't had time to do any. At least until now. I'm just getting things in shape to get going on the CQ 160m contest. Just gotta grab a Coke to keep me awake for a couple more hours as I get going here. Was at a Peter Frampton concert tonight. Talk about great high fidelity audio! Don, W3LR, and fellow Elecraft builder went along with me and we both enjoyed the show. Now on to the contest. Oh, my KX1 is nearly done. Just have to finish final alignment and test, hopefully tomorrow sometime. I want to get it out on the trail next weekend for the Polar Bear event, and maybe FYBO. 73, Mark, NK8Q ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
