3 element beam
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has anyone read the article at ARRL on qrp, recommendations to use a 3
element beam for milliwatt transmission instead of vertical _______________________________________________ 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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Yes I have found that my three element 80 meter beam at 190 feet seems to
slightly outperform my 30 foot vertical run with a four foot ground stake as a radial. I can easily hear signals that have a signal strength of one milliwatt. However I am experimenting with a full wavelength 80 meter vertical with 1.3 million pennies as the ground-plane. You have to use the old pennies, as the new ones are copper plated zinc, and will make galvanic noise. For the same reason, the pennies should be spot welded, not soldered, as the dissimilar metals in the solder also cause noise. Also feed line losses become a problem at these low power levels. I want every microwatt of my milliwatt. My tower is located seven miles away from the shack, so I use two parallel twelve inch copper pipes, spaced four feet apart to prevent arcing, and suspended sixty-three feet above the ground by Kevlar ropes to telephone poles every fifty feet. I circulate a mixture of 50/50 distilled water and ethylene glycol through the pipes for heat dissipation, and to prevent freezing. Are you actually a licensed Radio Amateur? You don't sign with your call, and your posted questions are getting progressively more bizarre. Paul N8NOV -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of mc Sent: Sunday, October 09, 2005 1:17 PM To: [hidden email] Subject: [Elecraft] 3 element beam has anyone read the article at ARRL on qrp, recommendations to use a 3 element beam for milliwatt transmission instead of vertical _______________________________________________ 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 |
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In reply to this post by mc-20
On Oct 9, 2005, at 2:16 PM, mc wrote: > has anyone read the article at ARRL on qrp, recommendations to use > a 3 element beam for milliwatt transmission instead of vertical For QRP, you want to use the best antenna possible, to make the maximum use of every watt. A beam certainly has a lot more gain than a vertical. Bill Coleman, AA4LR, PP-ASEL Mail: [hidden email] Quote: "Not within a thousand years will man ever fly!" -- Wilbur Wright, 1901 _______________________________________________ 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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In reply to this post by mc-20
That goes for ANY power level, not just milliwatting. The gain of a beam can
often (not always) squirt more power where you need it to go than a vertical. Sometimes the low take-off angle of a GOOD vertical can trump a beam, though. I have only one problem using a beam...one I can live with. Hi. Many QRP receivers are very hot with low noise. That coupled with my TH7DX at 60' means I can hear a lot of stations that would never be able to hear me. A beam gives you gain on both receive and transmit, but a 100 mW output signal effectively doubled or even quadrupled with a beam is still a pretty puny signal for the guy at the other end. But you never know. I have two rules: 1. Never tell them up front you are QRP. It's an ancient Black Magic incantation that makes people deaf. 2. Call every station you want to talk to regardless of the S-meter. The worst that can happen is they won't come back to you. I can't tell you how many QSOs I've had with 100 watters who were S3 to me and (because of Rule 1) I was S5 or greater to them with 5 watts or less. I might add a 3rd rule, but at the risk of stepping on some toes: 3. Stay away from QRP frequencies unless you are rock-bound. You will find a lot more activity and hams willing to dig deep for weak signals on the FISTS frequencies and the low end of the band of choice. FISTS guys even seem to be immune to the QRP Deafness Curse. Anyway, a beam is a great QRP accessory. Any time you have an opportunity to throw more metal higher in the sky, it can be worthwhile. BTW, I hope you are going to report back with your ham experiences aboard the boat. I was thinking that many of the recommendations you received for antennas ignore the fact that you are actually at sea. Many of the recommendations are going to fold right up in those conditions, though they would work fine in most portable conditions. Eric KE6US www.ke6us.com -----Original Message----- From: [hidden email] [mailto:[hidden email]] On Behalf Of mc Sent: Sunday, October 09, 2005 11:17 AM To: [hidden email] Subject: [Elecraft] 3 element beam has anyone read the article at ARRL on qrp, recommendations to use a 3 element beam for milliwatt transmission instead of vertical _______________________________________________ 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 |
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Well said Eric. Lots to think about for everyone.
73s john-n3drk ----- Original Message ----- From: "EricJ" <[hidden email]> To: "'mc'" <[hidden email]>; <[hidden email]> Sent: Sunday, October 09, 2005 5:55 PM Subject: RE: [Elecraft] 3 element beam > That goes for ANY power level, not just milliwatting. The gain of a beam > can > often (not always) squirt more power where you need it to go than a > vertical. Sometimes the low take-off angle of a GOOD vertical can trump a > beam, though. > > I have only one problem using a beam...one I can live with. Hi. Many QRP > receivers are very hot with low noise. That coupled with my TH7DX at 60' > means I can hear a lot of stations that would never be able to hear me. A > beam gives you gain on both receive and transmit, but a 100 mW output > signal > effectively doubled or even quadrupled with a beam is still a pretty puny > signal for the guy at the other end. > > But you never know. I have two rules: > > 1. Never tell them up front you are QRP. It's an ancient Black Magic > incantation that makes people deaf. > > 2. Call every station you want to talk to regardless of the S-meter. The > worst that can happen is they won't come back to you. I can't tell you how > many QSOs I've had with 100 watters who were S3 to me and (because of Rule > 1) I was S5 or greater to them with 5 watts or less. > > I might add a 3rd rule, but at the risk of stepping on some toes: > 3. Stay away from QRP frequencies unless you are rock-bound. You will find > a > lot more activity and hams willing to dig deep for weak signals on the > FISTS > frequencies and the low end of the band of choice. FISTS guys even seem to > be immune to the QRP Deafness Curse. > > Anyway, a beam is a great QRP accessory. Any time you have an opportunity > to > throw more metal higher in the sky, it can be worthwhile. > > BTW, I hope you are going to report back with your ham experiences aboard > the boat. I was thinking that many of the recommendations you received for > antennas ignore the fact that you are actually at sea. Many of the > recommendations are going to fold right up in those conditions, though > they > would work fine in most portable conditions. > > Eric > KE6US > www.ke6us.com > > > > > > > -----Original Message----- > From: [hidden email] > [mailto:[hidden email]] On Behalf Of mc > Sent: Sunday, October 09, 2005 11:17 AM > To: [hidden email] > Subject: [Elecraft] 3 element beam > > has anyone read the article at ARRL on qrp, recommendations to use a 3 > element beam for milliwatt transmission instead of vertical > > > _______________________________________________ > 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 > _______________________________________________ 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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