Re: [Elecraft] Re: [QRP-L] What antenna should I build?
You need to use a tuner between your antenna and the radio to avoid the radio cutting back power to protect itself from high SWR. You might want to try measurements without the unknown balun. They might be better! Don't get hung up on the need for balun without trying without first. I did not use a balun for my first 18 years as a ham, and worked just as good that way as now with a balun. Stuart K5KVH ___ 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: [QRP-L] What antenna should I build?
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of JT Croteau Here is what I have in the junk box: 75' of RG213 ~30' of solid conductor commercial ladder line ~800' of 14ga stranded insulated THN wire Assortment of dog-bone style insulators Wide assortment of PVC and nuts/bolts What can I do with the above and the internal tuner in my K1 without going out and buying anything? Ideally, I'd like something that will load well on 80/40/30/20/15 but will settle for 40-15. Anyone have any ideas? Most of this will bounce since I am not subscribed to but one of your cross-posted forums... However, There are several things you can do. You didn't tell us how much horizontal space you have so I will just guess. You don't have a balun or an external tuner so this will be fun to work with. You can try some of the following: 1: stretch out a 135 foot dipole (Inverted Vee) and feed it with the RG213 to the rig. Trim the antenna to match as close to the lower end of 80 as possible. 3.525 or so should work. Then see if the rig can handle the antenna on the other bands. It should work harmonically on all bands but 30 meters. If not, calculate the center frequency of the 80 meter band and trim it to one whose multiple will put you closest to those other bands you wish to operate. I am assuming you are wanting to operate CW mostly. Once trimmed, then try to fine-tune it with the internal tuner to those bands it doesn't match. If it matches all but 30, then calculate a 30 meter dipole and add it under the 80 meter dipole. Use the PVC to space the elements about 4-8 inches apart. Trim the lower frequency antenna first, and then the higher frequency antennas. Now, you should be able to operate on all bands. If you don't have the space, you will have to be more creative. Trimming the inverted vee to 7.025 will also give you a multi-band from 40-10 and require less space. You may still need the 30 meter element. If you could make a full sized dipole (flat-top), you can keep adding dipoles under the 80 meter dipole until you have all the bands you desire, each trimmed for your favorite frequency and the tuner will match it on the rest of the band. I don't remember if the G5RV uses the same or less twin feed as you have, but you can look into that. I hope this helps, if nothing else maybe it will stir up some thoughts that bring about your solution. 73 for now Buck N4PGW -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.8.3/361 - Release Date: 6/11/2006 __ QRP-L mailing list Home: http://mailman.qth.net/mailman/listinfo/qrp-l Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[EMAIL PROTECTED]
Re: [QRP-L] What antenna should I build?
I'd like to thank everyone who replied. Here is what I just finished building and installing: I only had 17' feet of ladder line, not the 30' I thought I had so this antenna is probably extremely far from ideal. The overall antenna is roughly 102' long in an inverted vee configuration. The ends are only 8' to 10' off the ground with the center probably around 35' judging by the feedlines I ended up having to use. It is fed in the center with the 17' of ladder line connected to some type of balun I found in the junk box (I think it came with a G5RV kit many moons ago). I then had to use a 20' piece of RG8X to extend it to meet the 75' of RG8U TRIAX into the shack. Here are what the numbers from my MFJ analyzer reads. If someone could translate all this for me into how this antenna will work at QRP levels with my K1 and KAT1, I'd sure appreciate it. 1.810 MHz SWR=7.0 R=6 X=37 3.560 MHz SWR=8.1 R=5 X=21 7.040 MHz SWR=5.2 R=5 X=34 10.100 MHz SWR=4.6 R=101 X=124 14.060 MHz SWR=6.0 R=7 X=15 18.080 MHz SWR=3.7 R=146 X=80 21.060 MHz SWR=4.5 R=118 X=123 24.906 MHz SWR=3.9 R=11 X=10 28.060 MHz SWR=3.9 R=30 X=54 So how bad does this POS look? Thanks -- JT Croteau - W6FO - Canton, GA | K1 #292 ARS #2,147 | NoGA-QRP | SEDXC | ARRL __ QRP-L mailing list Home: http://mailman.qth.net/mailman/listinfo/qrp-l Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[EMAIL PROTECTED]
RE: [Elecraft] Re: [QRP-L] What antenna should I build?
It looks like the KAT1 should be able to match it - have fun. 73, Don W3FPR -Original Message- I only had 17' feet of ladder line, not the 30' I thought I had so this antenna is probably extremely far from ideal. The overall antenna is roughly 102' long in an inverted vee configuration. The ends are only 8' to 10' off the ground with the center probably around 35' judging by the feedlines I ended up having to use. It is fed in the center with the 17' of ladder line connected to some type of balun I found in the junk box (I think it came with a G5RV kit many moons ago). I then had to use a 20' piece of RG8X to extend it to meet the 75' of RG8U TRIAX into the shack. Here are what the numbers from my MFJ analyzer reads. If someone could translate all this for me into how this antenna will work at QRP levels with my K1 and KAT1, I'd sure appreciate it. 1.810 MHz SWR=7.0 R=6 X=37 3.560 MHz SWR=8.1 R=5 X=21 7.040 MHz SWR=5.2 R=5 X=34 10.100 MHz SWR=4.6 R=101 X=124 14.060 MHz SWR=6.0 R=7 X=15 18.080 MHz SWR=3.7 R=146 X=80 21.060 MHz SWR=4.5 R=118 X=123 24.906 MHz SWR=3.9 R=11 X=10 28.060 MHz SWR=3.9 R=30 X=54 So how bad does this POS look? ___ 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: [QRP-L] What antenna should I build?
Your HF2-V will work fine as is on 15 meters. I usually mine rather than my Cushcraft R5 which also covers 15. The ground mounted Butternut does better for dx while the R5 maybe better for the US and South America. By the way you can load your HF2v up on 20 and 17 meters with your tuners if you are using qrp. I wouldnt run high power or you might blow a capacitor. If you add the 30 meter add on kit to the HF2V you use that band as well. By the way you can also use the HF2v to work six meter e-skip. 73 de Dave, N0IT - Original Message - From: JT Croteau [EMAIL PROTECTED] To: QRP-L [EMAIL PROTECTED]; Elecraft elecraft@mailman.qth.net; [EMAIL PROTECTED] Sent: Monday, June 12, 2006 1:25 PM Subject: [QRP-L] What antenna should I build? My only antenna currently here at the home QTH is an HF2V vertical which does great for long haul DX on 40 and 80 but in general is not good for local or regional work. I just launched some monofilament over the only high branch in my yard at 50'. As I only have a single support, I'm looking at some suggestions on constructing a multiband vee wire antenna but have limited materials on hand and even more limited $$ to go out an buy stuff at the moment. Here is what I have in the junk box: 75' of RG213 ~30' of solid conductor commercial ladder line ~800' of 14ga stranded insulated THN wire Assortment of dog-bone style insulators Wide assortment of PVC and nuts/bolts What can I do with the above and the internal tuner in my K1 without going out and buying anything? Ideally, I'd like something that will load well on 80/40/30/20/15 but will settle for 40-15. Anyone have any ideas? Thanks -- JT Croteau - W6FO - Canton, GA | K1 #292 ARS #2,147 | NoGA-QRP | SEDXC | ARRL __ QRP-L mailing list Home: http://mailman.qth.net/mailman/listinfo/qrp-l Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[EMAIL PROTECTED] __ QRP-L mailing list Home: http://mailman.qth.net/mailman/listinfo/qrp-l Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[EMAIL PROTECTED]
