Good Day everybody!
Please note that the BUBBA contest was inadvertently scheduled in a manner that conflicted with the 2005 running of the SK Memorial Contest. The organizers of the BUBBA event have apologized and modified their contest exchange to match the exchange of the SK Memorial Contest. A Contest TWOFER so to speak. The sending of the temperatures that is the basis of the BUBBA contest has been made optional, but please be courteous and comply with any requests for temperatures from BUBBA operators. Thanks Everybody. 73/72 Jeff - VA3JFF QRP-ARCI Contest Manager 2005 SILENT KEY MEMORIAL CONTEST ANNOUNCEMENT This contest celebrates and honors the QRP luminaries who no longer answer CQ's. Those generous people who graciously donated to the QRP community their time, effort and knowledge to advance the premise that more fun could be had using less than 5 watts. Some were irascible and some were even considered curmudgeons but when you took a keen look at their accomplishments and listened to those who knew them well you discovered truly wonderful people who would give you their last diode. The people we are celebrating are well known among the QRP Community. Some passed recently and some have enjoyed their reward many years. They are not forgotten for their accomplishments live on either on the bands, the internet, through published works or organizations that benefited from their largess. This contest celebrates ALL SK's who now call CQ from above, where all sigs are 599 and all contacts QSL 100%. Celebrate the many SKs that we have known and loved in years past. Date/Time: 20 August 2005, 1500Z to 1800Z. Mode: CW Only Exchange: Members send: RST, State/Province/Country, ARCI member number Non-Members send: RST, State/Province/Country, Power Out QSO Points: Member = 5 points Non-Member, Different Continent = 4 points Non-Member, Same Continent = 2 points Multiplier: SPC (State/Province/Country) total for all bands. The same station may be worked on multiple bands for QSO points and SPC credit. Power Multiplier: >5 Watts = x1 >1 - 5 Watts = x7 >250 mW - 1 Watt = x10 >55 mW - 250 mW = x15 <55 mW = x20 Suggested Frequencies: 160m 1810 kHz 80m 3560 kHz 40m 7040 kHz 20m 14060 kHz 15m 21060 kHz 10m 28060 kHz Score: Final Score = Points (total for all bands) x SPCs (total for all bands) x Power Multiplier + Bonus Points. Bonus Points: If you are operating PORTABLE using battery power AND a temporary antenna, add 5000 points to your final score. (You can NOT be at your shack operating from battery power using your home station antenna to qualify for this bonus.) This is to help level the playing field for contesters who work from the field against contest stations with 5 element yagis at 70 ft. Categories: Entry may be All-Band, Single Band, High Bands (10m-15m-20m) or Low Bands (40m-80m-160m) How to Participate: Get on any of the HF bands except the WARC bands and hang out near the QRP frequencies. Work as many stations calling CQ QRP or CQ TEST as possible, or call CQ QRP or CQ TEST yourself! You can work a station for credit once on each band. Email Log Submission: Submit Logs in plain text format along with a summary stating your Callsign, Entry Category, Actual Power and Station Description along with score calculation to [hidden email] on or before 20 September 2005. Snail mail Log Submission: Submit Logs along with a summary stating your Callsign, Entry Category, Actual Power and Station Description along with score calculation to: Silent Key Memorial Sprint c/o Jeff Hetherington, VA3JFF 139 Elizabeth St. W. Welland, Ontario Canada L3C 4M3 Entries must be postmarked on or before 20 September 2005. Results: Will be published in QRP Quarterly and shown on the QRP-ARCI website. Certificates: Will be awarded to the top scoring entrant in each category. Certificates may be awarded for 2nd and 3rd place if entries are sufficient in a category. -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.338 / Virus Database: 267.10.12/75 - Release Date: 8/17/05 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Hi all,
I'm considering putting up a 40 meter dipole fed with a 450 ladder line. I have a K2 which I run at about 5 to watts (I do not have the 100 watt amp). The K2 also has the internal ATU. I have always used 50 ohm coax up until now. Is there anything I should know about using the K2 with 450 ohm feedline? (Will I need a balun, or can I just feed the ladderline directly to the K2's ATU and that will take care of the match. Thanks for your help. Tom, WB2QDG K2 1103 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
Hi Tom - I don't think you mentioned what bands you intend to use the
antenna for. If just 40M, then you may do as well with coax and not need the tuner. If you use it for an all band doublet, the tuner may have difficulty on some bands depending on the impedence and the lenght of the feedline. Without the balun, you may have radiation from the feedline, which may not be a problem or it may cause problems in the shack with RF getting into equipment or noise on receive if the source is near the rig. I use a doublet but I increased the lenght to 88 ft and the k2 handles it well on most bands. I plan to increase the lenght to 100 ft to get better efficiency on 80 meters. I use a 1 to 1 balun. A 4 to 1 balun may work better on some frequencies but would likely give less efficiency on 80 meters due to low radiation resistance. Finally, changing the lenght of the feed line can improve the match on some bands with a possible worse match on others. Multiband antennas are always a compromise and experimenting may be required. Rick - K7MW Original Message ----- From: "Tom McCulloch" <[hidden email]> To: <[hidden email]> Sent: Saturday, August 20, 2005 6:57 PM Subject: [Elecraft] Antenna question > Hi all, > I'm considering putting up a 40 meter dipole fed with a 450 ladder line. > I have a K2 which I run at about 5 to watts (I do not have the 100 watt > amp). The K2 also has the internal ATU. > > I have always used 50 ohm coax up until now. Is there anything I should > know about using the K2 with 450 ohm feedline? (Will I need a balun, or can > I just feed the ladderline directly to the K2's ATU and that will take care > of the match. > > Thanks for your help. > > Tom, WB2QDG > > K2 1103 > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > 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 mailing list Post to: [hidden email] 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 |
In reply to this post by Tom McCulloch
Tom,
While you can run the ladder line right to the shack and connect directly to the K2, a balun mounted outside and a coax run to the rig works well and you avoid having to run the ladder line inside which sometimes can be problematic. There are several low cost 4:1 baluns on the market including the Elecraft one, or you can use a BA-58 or BA-8 kit of ferrite beads over the coax from Palomar. As my late friend George used to say, a 1:1 balun works as well in this application as a 4:1. You need to avoid a length of feed line such that the sum of the length of the feed line times its velocity factor plus 1/2 the length of the dipole is 1/2 wave length. Then keep the length of coax times its velocity factor unequal to a 1/2 wave length too. Best to keep the coax run short. That is to avoid a current node either at the position of the balun or at the K2. 73, Chas, W1CG At 09:57 PM 8/20/2005, Tom McCulloch wrote: >Hi all, > I'm considering putting up a 40 meter dipole fed with a 450 ladder line. > I have a K2 which I run at about 5 to watts (I do not have the 100 watt > amp). The K2 also has the internal ATU. > > I have always used 50 ohm coax up until now. Is there anything I should > know about using the K2 with 450 ohm feedline? (Will I need a balun, or > can I just feed the ladderline directly to the K2's ATU and that will > take care of the match. > >Thanks for your help. > >Tom, WB2QDG > >K2 1103 >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >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 mailing list Post to: [hidden email] 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 |
In reply to this post by Tom McCulloch
Hello Tom
I'm using a similar setup here for my K2. The dipole is just 60 ft long, a bit under a true half wavelength. However, with the 450 ohm tuned feeders, I use the antenna on 80, 40, 30 and 20 meters. Works very well at a height of 42 ft in center and 35 feet at ends. Two things will make matching easier. Get two baluns, 1:1 and 4:1. Put them on the two antenna ports of the ATU. Now, when you change bands, put the feeder on the balun that gives you the lowest swr while the ATU is in CAL S. This is effectively bypassing the ATU. Then switch in the ATU and match. From then on, the ATU memory will remember the settings, so you will just have to remember which balun goes with which band or bands. Works very well. Good luck and 73 Bob N6WG -----Original Message----- From: [hidden email] [mailto:[hidden email]]On Behalf Of Tom McCulloch Sent: Saturday, August 20, 2005 6:58 PM To: [hidden email] Subject: [Elecraft] Antenna question Hi all, I'm considering putting up a 40 meter dipole fed with a 450 ladder line. I have a K2 which I run at about 5 to watts (I do not have the 100 watt amp). The K2 also has the internal ATU. I have always used 50 ohm coax up until now. Is there anything I should know about using the K2 with 450 ohm feedline? (Will I need a balun, or can I just feed the ladderline directly to the K2's ATU and that will take care of the match. Thanks for your help. Tom, WB2QDG K2 1103 _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 mailing list Post to: [hidden email] 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 |
On 21 Aug 2005 at 8:40, Robert Tellefsen wrote: > Two things will make matching easier. Get two > baluns, 1:1 and 4:1. Put them on the two > antenna ports of the ATU Looking at the two versions of the BL1 for 1:1 and 4:1 Can you not use a 2pco ( dpdt ) switch or relay to change between the two ?. Commons to the two inner windings ( see BL1.pdf ). Short them for interconnect on the NO connections for 4:1 Parallel them on the NC connections for 1:1. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
You can. Somewhere on the web I saw one set up with a little DPDT slide
switch, but I can't find it now that I want it. Hi. Anyway, it's not that difficult as you have already discovered. Eric KE6US www.ke6us.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of Mike W Sent: Sunday, August 21, 2005 4:03 PM To: Robert Tellefsen; [hidden email] Subject: RE: [Elecraft] Antenna question - Balun On 21 Aug 2005 at 8:40, Robert Tellefsen wrote: > Two things will make matching easier. Get two baluns, 1:1 and 4:1. > Put them on the two antenna ports of the ATU Looking at the two versions of the BL1 for 1:1 and 4:1 Can you not use a 2pco ( dpdt ) switch or relay to change between the two ?. Commons to the two inner windings ( see BL1.pdf ). Short them for interconnect on the NO connections for 4:1 Parallel them on the NC connections for 1:1. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 mailing list Post to: [hidden email] 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 |
In reply to this post by Mike W-13
Yes, it can be done, Mike.
Remember that the 4:1 balun will be happiest seeing an impedance around 200-300 ohms, though. The 4:1 ratio really only holds when the impedances are correct. Once you throw in a mixed load that is well away from this value, plus an unknown amount of reactance, the ratio changes and losses can mount. Not a serious concern at QRP power levels, but at 100w it could cook a balun that is seriusly mismatched. The best way to use baluns is to adjust your balanced feedline length on a given band to give very little reactance, regardless of the resistive part of the load impedance. The ATU will have an easier time matching a resistive load than one with combined reactance and resistance. The baluns will work best when the loads are resistive, even if the wrong value. When you mix in reactance, the balun will have unpredictable ratios and losses. Good luck and 73 Bob N6WG The Little Station with Attitude -----Original Message----- From: Mike W [mailto:[hidden email]] Sent: Sunday, August 21, 2005 4:03 PM To: Robert Tellefsen; [hidden email] Subject: RE: [Elecraft] Antenna question - Balun On 21 Aug 2005 at 8:40, Robert Tellefsen wrote: > Two things will make matching easier. Get two > baluns, 1:1 and 4:1. Put them on the two > antenna ports of the ATU Looking at the two versions of the BL1 for 1:1 and 4:1 Can you not use a 2pco ( dpdt ) switch or relay to change between the two ?. Commons to the two inner windings ( see BL1.pdf ). Short them for interconnect on the NO connections for 4:1 Parallel them on the NC connections for 1:1. _______________________________________________ Elecraft mailing list Post to: [hidden email] 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 |
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