Loop antenna's
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I read the two posts about the MFJ loop antenna and thought I would add my own personal comments on my experience’s with loops.
Years ago, I bought a MFJ 36” loop with the remote tuner and while it worked from indoors from 30m to 10m, it wasn’t earth shaking. I was always the weakest signal in a round table. That was when MFJ was still recommending using the loop in a horizontal position rather than vertical as they do now. Now, I had been reading some reviews on the MFJ loop antenna tuners and decided to get one and try it out. I got the MFJ-935B tuner that comes complete with the tuning cap and matching cap plus a RF current meter for tuning, so all you need to add is a loop to make it work. 3’ dia. loops are fine for the higher HF bands, and if you are going portable with it, then it might be the right antenna for you, but if you are living in a antenna restricted home as I am, and have to use indoor antennas let me tell you that I have used many different configurations of antennas and find that the loop is working the best for me, so far. I have used a Super Antenna MP-1 coil loaded vertical like a mobile whip, I have used homebrew Buddipole, and various indoor doublets so I have some data to compare them to. I use the Reverse Beacon Net for getting accurate reports back on my signal with the various antennas. As I said above, the 3’ dia. loop is fine for the higher bands, and OK for 20m and 30m but if you want to really get out as good as you can, then the homebrew loop that is bigger, is the way to go. MFJ says that a 7 foot wire or copper tube will make a loop to go with their series of loop tuners that will cover 20m, 17m and 15, and it does, but, if you want to maximize your signal on 20m the way to go is to use a 13 ft. wire or tube which doesn’t make that big of a loop and gets out a lot better on 20m.. My 7 ft. loop got a 12 dB SNR from K7EG RBN and the 13 ft. loop got a 18 dB SNR from him just a few minutes later and at the same power input from my K3. On 40m MFJ says a 20 ft. wire will tune 40m and 30m and it does, but a 28 ft. wire will give you maximum output (for a mag loop) and it does. I think I got about 8-10 dB more out of the 28 ft. loop than the 20 ft. one on 40m. MFJ says you can hang these larger loops form a curtain rod or draped over a bookcase and that’s what I do, it’s not critical but you do have to be very careful and not touch the loop when transmitting as there is a lot of RF in that loop. I made two PVC standards that sit on top of my bookcase/desk where I operate from and have the 28 ft. wire forming a square shape hanging from the top of the standards, coming down to a shelf just about eye level and I have the tuner there so I can adjust it as needed. With this loop and the K3 at 5 watts I contact my buddy Dale, K6PJV up in Sacramento just about anytime I want to, just fine from Marina Del Rey, CA and remember this loop is indoors on the second floor of my home. That’s almost 400 miles. On 20m with the 13 ft. wire in a diamond shape on a cross piece made out of PVC that sits on the tuner, I work AL7V up in Juneau Alaska with 50-100 watts on a pretty regular basis in the mornings. So if you are restricted to indoor antennas you might find the loop antenna is the way to for you. Usual disclaimer, I don’t work for or have any financial attachment to MFJ, just a happy customer. 73, Bill k6mgo ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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Let me throw some stuff out. Electrically small loops can work out very well if they are constructed correctly. I was impressed with the Alexloop that one of our Field Day operators brought to the site. It was used for an unrelated station on site that the operator was using to demo his new KX3 using PSK-31 on 20 meters. He had the loop because he wanted a portable antenna that might work. The Alex fit his needs nicely. However, there are much more effective antennas that can be used in a fixed location.
One of those antennas is a 1/2 wave dipole up in an attic, fed with open wire to a point below the ceiling where there is a transition to coax using a balun and a tuner. The 1/2 wave length is dependent on room available in the attic, and it doesn't need to be in a totally straight line. The antenna can have some bend at the end. The antenna tuner will work out the impedance issues. I put one of these up for a friend who has a two story house with a very high pitched roof and enough room to install 66' of wire. He has been happy working 40-10 meters. My friend lives in an antenna restricted development just as the initiator of this thread. And lastly, A loop antenna made of wire the traces the outside roof periphery using insulated wire colored to match the roofing will also work well. It can be fed just like a loop sky wire ( shown in ARRL pubs). Your neighbors won't see it and it can work out pretty well. I would get too anal about total wire length as open wire is pretty low loss stuff, even at very high SWR, and a balun and tuner will take care of the issue with coax. Just make sure that the tuner is as close to the open wire as possible. Antennas are fun. Every ham has his own idea about what is best. I make no claim as to how close to best these are, but they do work. Best of luck. 73, Barry K3NDM ----- Original Message ----- From: "Bill Ross" <[hidden email]> To: [hidden email] Sent: Monday, August 12, 2013 3:50:17 PM Subject: [Elecraft] Loop antenna's I read the two posts about the MFJ loop antenna and thought I would add my own personal comments on my experience’s with loops. Years ago, I bought a MFJ 36” loop with the remote tuner and while it worked from indoors from 30m to 10m, it wasn’t earth shaking. I was always the weakest signal in a round table. That was when MFJ was still recommending using the loop in a horizontal position rather than vertical as they do now. Now, I had been reading some reviews on the MFJ loop antenna tuners and decided to get one and try it out. I got the MFJ-935B tuner that comes complete with the tuning cap and matching cap plus a RF current meter for tuning, so all you need to add is a loop to make it work. 3’ dia. loops are fine for the higher HF bands, and if you are going portable with it, then it might be the right antenna for you, but if you are living in a antenna restricted home as I am, and have to use indoor antennas let me tell you that I have used many different configurations of antennas and find that the loop is working the best for me, so far. I have used a Super Antenna MP-1 coil loaded vertical like a mobile whip, I have used homebrew Buddipole, and various indoor doublets so I have some data to compare them to. I use the Reverse Beacon Net for getting accurate reports back on my signal with the various antennas. As I said above, the 3’ dia. loop is fine for the higher bands, and OK for 20m and 30m but if you want to really get out as good as you can, then the homebrew loop that is bigger, is the way to go. MFJ says that a 7 foot wire or copper tube will make a loop to go with their series of loop tuners that will cover 20m, 17m and 15, and it does, but, if you want to maximize your signal on 20m the way to go is to use a 13 ft. wire or tube which doesn’t make that big of a loop and gets out a lot better on 20m.. My 7 ft. loop got a 12 dB SNR from K7EG RBN and the 13 ft. loop got a 18 dB SNR from him just a few minutes later and at the same power input from my K3. On 40m MFJ says a 20 ft. wire will tune 40m and 30m and it does, but a 28 ft. wire will give you maximum output (for a mag loop) and it does. I think I got about 8-10 dB more out of the 28 ft. loop than the 20 ft. one on 40m. MFJ says you can hang these larger loops form a curtain rod or draped over a bookcase and that’s what I do, it’s not critical but you do have to be very careful and not touch the loop when transmitting as there is a lot of RF in that loop. I made two PVC standards that sit on top of my bookcase/desk where I operate from and have the 28 ft. wire forming a square shape hanging from the top of the standards, coming down to a shelf just about eye level and I have the tuner there so I can adjust it as needed. With this loop and the K3 at 5 watts I contact my buddy Dale, K6PJV up in Sacramento just about anytime I want to, just fine from Marina Del Rey, CA and remember this loop is indoors on the second floor of my home. That’s almost 400 miles. On 20m with the 13 ft. wire in a diamond shape on a cross piece made out of PVC that sits on the tuner, I work AL7V up in Juneau Alaska with 50-100 watts on a pretty regular basis in the mornings. So if you are restricted to indoor antennas you might find the loop antenna is the way to for you. Usual disclaimer, I don’t work for or have any financial attachment to MFJ, just a happy customer. 73, Bill k6mgo ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I have a nonresonant-in-any-ham-band 44' doublet in my attic peak at 31'
above ground. Only 26' is actually "flat top" while the rest droops down at the ends. I have 16' of 450 ohm ladder line coming through a slit in the ceiling just above a linen closet. In that linen closet, on a shelf right below the ceiling is an SG237 auto coupler. From that point onward to my "shack", the coax feed line is nice and clean and length no longer matters. I've had this antenna up there for four years now and have yet to find a more effective solution for my antenna restricted QTH. I've experimented with other attic solutions, including various full, random and partial wave loops. Outside, I've experimented with "temporary" end fed wires in different configurations, random "stealth" wires, and vertical antennas. They've all worked but so far nothing has consistently outperformed my attic doublet, day in and day out, for effortless frequency agility between 40 meters and 6 meters, inclusive of all bands. It loads on 80 meters also, well enough to provide me with some winter time entertainment. Without "bragging", this doublet has earned me QRP WAC, WAS, and a QSL album with a host of impressive QSO not only with KW stations and large antennas but with some very modest stations using simple wire antennas in some remote locations around the world. "Attic success" requires, in my opinion and experience, two conditions: 1) an "RF Friendly" attic and 2) Enough height. An "RF Friendly" attic includes no metal foil building insulation and shingles that do not absorb RF, no HVAC, and "luck". "Enough height" suggests that a two story (or higher) attic trumps a low ranch style home. The antenna is looking for height above ground, not height above the attic floor! There is much talk of distorted patterns, RF absorption, and other consequences. At HF frequencies, there is very little RF absorption in wood. And who cares about pattern distortion as long as the antenna works well ;) With 53 years of ham radio behind me, I've yet to find any simple wire antenna --overall-- that beats a resonant dipole for single band work or a parallel line fed doublet and a coupler for frequency agility. P.S. - the autocoupler is in the closet below the attic to keep it out of the intense summer heat and winter cold. Attics are not the greatest environment for electronic equipment. My two cents, Stan WB2LQF On Mon, Aug 12, 2013 at 10:54 PM, [hidden email] wrote: > Let me throw some stuff out. Electrically small loops can work out very well if they are constructed correctly. I was impressed with the Alexloop that one of our Field Day operators brought to the site. It was used for an unrelated station on site that the operator was using to demo his new KX3 using PSK-31 on 20 meters. He had the loop because he wanted a portable antenna that might work. The Alex fit his needs nicely. However, there are much more effective antennas that can be used in a fixed location. > > One of those antennas is a 1/2 wave dipole up in an attic, fed with > open wire to a point below the ceiling where there is a transition to > coax using a balun and a tuner. The 1/2 wave length is dependent on > room available in the attic, and it doesn't need to be in a totally > straight line. The antenna can have some bend at the end. The antenna > tuner will work out the impedance issues. I put one of these up for a > friend who has a two story house with a very high pitched roof and > enough room to install 66' of wire. He has been happy working 40-10 > meters. My friend lives in an antenna restricted development just as > the initiator of this thread. > And lastly, A loop antenna made of wire the traces the outside roof > periphery using insulated wire colored to match the roofing will also > work well. It can be fed just like a loop sky wire ( shown in ARRL > pubs). Your neighbors won't see it and it can work out pretty well. I > would get too anal about total wire length as open wire is pretty low > loss stuff, even at very high SWR, and a balun and tuner will take > care of the issue with coax. Just make sure that the tuner is as close > to the open wire as possible. > Antennas are fun. Every ham has his own idea about what is best. I > make no claim as to how close to best these are, but they do work. > Best of luck. > 73, Barry K3NDM > > ----- Original Message ----- > > From: "Bill Ross" To: [hidden email] Sent: Monday, August > 12, 2013 3:50:17 PM Subject: [Elecraft] Loop antenna's > I read the two posts about the MFJ loop antenna and thought I would > add my own personal comments on my experience’s with loops. > Years ago, I bought a MFJ 36” loop with the remote tuner and while it > worked from indoors from 30m to 10m, it wasn’t earth shaking. I was > always the weakest signal in a round table. That was when MFJ was > still recommending using the loop in a horizontal position rather than > vertical as they do now. > Now, I had been reading some reviews on the MFJ loop antenna tuners > and decided to get one and try it out. I got the MFJ-935B tuner that > comes complete with the tuning cap and matching cap plus a RF current > meter for tuning, so all you need to add is a loop to make it work. > 3’ dia. loops are fine for the higher HF bands, and if you are going > portable with it, then it might be the right antenna for you, but if > you are living in a antenna restricted home as I am, and have to use > indoor antennas let me tell you that I have used many different > configurations of antennas and find that the loop is working the best > for me, so far. I have used a Super Antenna MP-1 coil loaded vertical > like a mobile whip, I have used homebrew Buddipole, and various indoor > doublets so I have some data to compare them to. I use the Reverse > Beacon Net for getting accurate reports back on my signal with the > various antennas. > As I said above, the 3’ dia. loop is fine for the higher bands, and OK > for 20m and 30m but if you want to really get out as good as you can, > then the homebrew loop that is bigger, is the way to go. MFJ says that > a 7 foot wire or copper tube will make a loop to go with their series > of loop tuners that will cover 20m, 17m and 15, and it does, but, if > you want to maximize your signal on 20m the way to go is to use a 13 > ft. wire or tube which doesn’t make that big of a loop and gets out a > lot better on 20m.. My 7 ft. loop got a 12 dB SNR from K7EG RBN and > the 13 ft. loop got a 18 dB SNR from him just a few minutes later and > at the same power input from my K3. > On 40m MFJ says a 20 ft. wire will tune 40m and 30m and it does, but a > 28 ft. wire will give you maximum output (for a mag loop) and it does. > I think I got about 8-10 dB more out of the 28 ft. loop than the 20 > ft. one on 40m. MFJ says you can hang these larger loops form a > curtain rod or draped over a bookcase and that’s what I do, it’s not > critical but you do have to be very careful and not touch the loop > when transmitting as there is a lot of RF in that loop. I made two PVC > standards that sit on top of my bookcase/desk where I operate from and > have the 28 ft. wire forming a square shape hanging from the top of > the standards, coming down to a shelf just about eye level and I have > the tuner there so I can adjust it as needed. With this loop and the > K3 at 5 watts I contact my buddy Dale, K6PJV up in Sacramento just > about anytime I want to, just fine from Marina Del Rey, CA and > remember this loop is indoors on the second floor of my home. That’s > almost 400 miles. > On 20m with the 13 ft. wire in a diamond shape on a cross piece made > out of PVC that sits on the tuner, I work AL7V up in Juneau Alaska > with 50-100 watts on a pretty regular basis in the mornings. So if you > are restricted to indoor antennas you might find the loop antenna is > the way to for you. > Usual disclaimer, I don’t work for or have any financial attachment to > MFJ, just a happy customer. > 73, Bill k6mgo > > ______________________________________________________________ > Elecraft mailing list Home: > http://mailman.qth.net/mailman/listinfo/elecraft Help: > http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] > This list hosted by: http://www.qsl.net Please help support this email > list: http://www.qsl.net/donate.html > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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you should join the magloop list....
-- R.Neese KB3VGW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by stan levandowski
Stan,
Right on. The idea of using a 40 meter length allows the operation as described in the books as a "classical" multiband antenna. Few hams have enough space for the 80 meter version. Don't discount using an attic that has HVAC equipment in it. The installation I described had HVAC and some power distribution in the attic. The attic was a standup attic meaning we could run the antenna wires a semi-reasonable distance from all of it. But you are correct this is not the best. Unless you have a metal roof, I can't think of any roofing material that will give you a problem, fiberglass and asphalt shouldn't. It's only been in very recent years that home owners have gotten the idea of using aluminum foil as a heat reflecting material in the attic; most fiberglass batts use a paper backing. I agree height does make a difference. It would be better to place your attic antenna in a second floor attic vice a rancher's first floor attic. But, loops around the roof periphery seem to work also. That was used by another friend who decided to get his ticket a few years after he moved into the community that wouldn't allow antennas. His attic just was too difficult to get into and his rancher was ell shaped. The loop was the only alternative. I would never have guess that it would work as well as it did, but it did. Was it the best antenna around? No it wasn't, but it got him on the air effectively enough so that he was reasonably content. I guess the best advice is find an old community with no antenna restrictions. If that is not possible, pick your house carefully. 73, Barry K3NDM On 8/13/2013 7:54 AM, stan levandowski wrote: > I have a nonresonant-in-any-ham-band 44' doublet in my attic peak at > 31' above ground. Only 26' is actually "flat top" while the rest > droops down at the ends. I have 16' of 450 ohm ladder line coming > through a slit in the ceiling just above a linen closet. In that > linen closet, on a shelf right below the ceiling is an SG237 auto > coupler. From that point onward to my "shack", the coax feed line is > nice and clean and length no longer matters. > > I've had this antenna up there for four years now and have yet to find > a more effective solution for my antenna restricted QTH. I've > experimented with other attic solutions, including various full, > random and partial wave loops. Outside, I've experimented with > "temporary" end fed wires in different configurations, random > "stealth" wires, and vertical antennas. They've all worked but so far > nothing has consistently outperformed my attic doublet, day in and day > out, for effortless frequency agility between 40 meters and 6 meters, > inclusive of all bands. It loads on 80 meters also, well enough to > provide me with some winter time entertainment. Without "bragging", > this doublet has earned me QRP WAC, WAS, and a QSL album with a host > of impressive QSO not only with KW stations and large antennas but > with some very modest stations using simple wire antennas in some > remote locations around the world. > > "Attic success" requires, in my opinion and experience, two > conditions: 1) an "RF Friendly" attic and 2) Enough height. An "RF > Friendly" attic includes no metal foil building insulation and > shingles that do not absorb RF, no HVAC, and "luck". "Enough height" > suggests that a two story (or higher) attic trumps a low ranch style > home. The antenna is looking for height above ground, not height > above the attic floor! There is much talk of distorted patterns, RF > absorption, and other consequences. At HF frequencies, there is very > little RF absorption in wood. And who cares about pattern distortion > as long as the antenna works well ;) > > With 53 years of ham radio behind me, I've yet to find any simple > wire antenna --overall-- that beats a resonant dipole for single band > work or a parallel line fed doublet and a coupler for frequency agility. > > P.S. - the autocoupler is in the closet below the attic to keep it out > of the intense summer heat and winter cold. Attics are not the > greatest environment for electronic equipment. > > My two cents, > > Stan WB2LQF > > > > > > On Mon, Aug 12, 2013 at 10:54 PM, [hidden email] wrote: > > > Let me throw some stuff out. Electrically small loops can work out > very well if they are constructed correctly. I was impressed with the > Alexloop that one of our Field Day operators brought to the site. It > was used for an unrelated station on site that the operator was using > to demo his new KX3 using PSK-31 on 20 meters. He had the loop because > he wanted a portable antenna that might work. The Alex fit his needs > nicely. However, there are much more effective antennas that can be > used in a fixed location. >> >> One of those antennas is a 1/2 wave dipole up in an attic, fed with >> open wire to a point below the ceiling where there is a transition to >> coax using a balun and a tuner. The 1/2 wave length is dependent on >> room available in the attic, and it doesn't need to be in a totally >> straight line. The antenna can have some bend at the end. The antenna >> tuner will work out the impedance issues. I put one of these up for a >> friend who has a two story house with a very high pitched roof and >> enough room to install 66' of wire. He has been happy working 40-10 >> meters. My friend lives in an antenna restricted development just as >> the initiator of this thread. >> And lastly, A loop antenna made of wire the traces the outside roof >> periphery using insulated wire colored to match the roofing will also >> work well. It can be fed just like a loop sky wire ( shown in ARRL >> pubs). Your neighbors won't see it and it can work out pretty well. I >> would get too anal about total wire length as open wire is pretty low >> loss stuff, even at very high SWR, and a balun and tuner will take >> care of the issue with coax. Just make sure that the tuner is as >> close to the open wire as possible. >> Antennas are fun. Every ham has his own idea about what is best. I >> make no claim as to how close to best these are, but they do work. >> Best of luck. >> 73, Barry K3NDM >> >> ----- Original Message ----- >> >> From: "Bill Ross" To: [hidden email] Sent: Monday, August >> 12, 2013 3:50:17 PM Subject: [Elecraft] Loop antenna's >> I read the two posts about the MFJ loop antenna and thought I would >> add my own personal comments on my experience’s with loops. >> Years ago, I bought a MFJ 36” loop with the remote tuner and while it >> worked from indoors from 30m to 10m, it wasn’t earth shaking. I was >> always the weakest signal in a round table. That was when MFJ was >> still recommending using the loop in a horizontal position rather >> than vertical as they do now. >> Now, I had been reading some reviews on the MFJ loop antenna tuners >> and decided to get one and try it out. I got the MFJ-935B tuner that >> comes complete with the tuning cap and matching cap plus a RF current >> meter for tuning, so all you need to add is a loop to make it work. >> 3’ dia. loops are fine for the higher HF bands, and if you are going >> portable with it, then it might be the right antenna for you, but if >> you are living in a antenna restricted home as I am, and have to use >> indoor antennas let me tell you that I have used many different >> configurations of antennas and find that the loop is working the best >> for me, so far. I have used a Super Antenna MP-1 coil loaded vertical >> like a mobile whip, I have used homebrew Buddipole, and various >> indoor doublets so I have some data to compare them to. I use the >> Reverse Beacon Net for getting accurate reports back on my signal >> with the various antennas. >> As I said above, the 3’ dia. loop is fine for the higher bands, and >> OK for 20m and 30m but if you want to really get out as good as you >> can, then the homebrew loop that is bigger, is the way to go. MFJ >> says that a 7 foot wire or copper tube will make a loop to go with >> their series of loop tuners that will cover 20m, 17m and 15, and it >> does, but, if you want to maximize your signal on 20m the way to go >> is to use a 13 ft. wire or tube which doesn’t make that big of a loop >> and gets out a lot better on 20m.. My 7 ft. loop got a 12 dB SNR from >> K7EG RBN and the 13 ft. loop got a 18 dB SNR from him just a few >> minutes later and at the same power input from my K3. >> On 40m MFJ says a 20 ft. wire will tune 40m and 30m and it does, but >> a 28 ft. wire will give you maximum output (for a mag loop) and it >> does. I think I got about 8-10 dB more out of the 28 ft. loop than >> the 20 ft. one on 40m. MFJ says you can hang these larger loops form >> a curtain rod or draped over a bookcase and that’s what I do, it’s >> not critical but you do have to be very careful and not touch the >> loop when transmitting as there is a lot of RF in that loop. I made >> two PVC standards that sit on top of my bookcase/desk where I operate >> from and have the 28 ft. wire forming a square shape hanging from the >> top of the standards, coming down to a shelf just about eye level and >> I have the tuner there so I can adjust it as needed. With this loop >> and the K3 at 5 watts I contact my buddy Dale, K6PJV up in Sacramento >> just about anytime I want to, just fine from Marina Del Rey, CA and >> remember this loop is indoors on the second floor of my home. That’s >> almost 400 miles. >> On 20m with the 13 ft. wire in a diamond shape on a cross piece made >> out of PVC that sits on the tuner, I work AL7V up in Juneau Alaska >> with 50-100 watts on a pretty regular basis in the mornings. So if >> you are restricted to indoor antennas you might find the loop antenna >> is the way to for you. >> Usual disclaimer, I don’t work for or have any financial attachment >> to MFJ, just a happy customer. >> 73, Bill k6mgo >> >> ______________________________________________________________ >> Elecraft mailing list Home: >> http://mailman.qth.net/mailman/listinfo/elecraft Help: >> http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] >> This list hosted by: http://www.qsl.net Please help support this >> email list: http://www.qsl.net/donate.html >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I wish to make a comment on the loop antenna situation from a different
angle. Pardon my being a novice to posting to this list. So here goes: There are a lot of hams that face difficulties with putting up sizeable antennas. Where does the remote operation of a K3 fit into this situation? Is there a casual group of K3 operators that let other K3 owners Use their station so the advantage of the large antenna is a shared commodity ? Or does this aspect of remote operation have so many obstacles that prevent casual operation? Actually the main reason I would own a K3 would be so I could loan it out to others thru the remote operation. 'That' would make it worth my while. My last antenna was a 160m loop and It was a nice all band antenna. Not perfect , just nice. nels nelsen NE7LS ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Barry K3NDM
Howdy to all,
I don't think anyone will question the fact that a good antenna system is one of the most important factors in a ham station being able to communicate efficiently particularly when using qrp power levels. While I would agree that a full length dipole antenna, or beam antenna would be preferable to a smaller 3' loop antenna, in my case that is not only impractical but impossible at my home qth since I live in a high rise building that has steel supports throughout the building instead of wooden studs. This effectively makes the interior of my high rise apartment inside of a faraday rf shield and prevents most radio signals from radiating or receiving when using an antenna inside of my apartment. This means an antenna has to be mounted outside of the apartment, and the balcony is the only area available to install an antenna. With such a limited area to install an amateur antenna, I find the MFJ 3' loop to be one of the better alternatives to be able to operate my ham station on the hf bands, and still be able to change bands and tune the antenna remotely with the MFJ Remote Control Unit. With the myriad of various CC&R's and antenna restrictions around the USA, many hams are forced to utilize compromise antenna systems to operate from their home qth, and finding the best alternative antenna configuration for an individual ham's location can be challenging. Therefore, I am very pleased with the various Loop antennas available from various ham vendor sources, since it allows many hams the capability to get on the air, when they might not be able to do so without the smaller loop antennas. Before deciding that hf ham radio operation is not feasible from an antenna restricted location, I would encourage a person facing such restrictions to seriously consider trying a loop antenna. 73, --Bill - K6IH- ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by k6mgo
Well said, Bill. I used to sign /QRP but stopped doing that routinely and increased my CQ return rate. Nowadays I do not mention my attic doublet unless the subject comes up. Why shoot myself in the foot...
I have nothing against small loops. I built a simple 40 meter STL from about 8 feet of hardline and used inductive coupling and it was very, very impressive. Then I built the mother of all loops from Home Depot 2 inch copper tubing, an Edmunds Scientific 1 rpm motor, and a Jennings vacuum variable. Cost me over $500 ! It was for 20 meters only. It worked amazingly well, including a QRPp contact with UA1CE not once, but twice. The reason I abandoned small loops was a practical one -- frequency agility. Because I had the option, I installed my remotely coupled multiband attic doublet. My advice to those dealing with antenna restrictions is to consider small loops along with other solutions if the opportunity is there but not to view a small loop as something magical and mystical. My QRPp QSO with Gene could have occurred with a wet noodle if the conditions were right. 73, Stan WB2LQF Sent from Samsung tabletBill - K6IH <[hidden email]> wrote:Howdy to all, I don't think anyone will question the fact that a good antenna system is one of the most important factors in a ham station being able to communicate efficiently particularly when using qrp power levels. While I would agree that a full length dipole antenna, or beam antenna would be preferable to a smaller 3' loop antenna, in my case that is not only impractical but impossible at my home qth since I live in a high rise building that has steel supports throughout the building instead of wooden studs. This effectively makes the interior of my high rise apartment inside of a faraday rf shield and prevents most radio signals from radiating or receiving when using an antenna inside of my apartment. This means an antenna has to be mounted outside of the apartment, and the balcony is the only area available to install an antenna. With such a limited area to install an amateur antenna, I find the MFJ 3' loop to be one of the better alternatives to be able to operate my ham station on the hf bands, and still be able to change bands and tune the antenna remotely with the MFJ Remote Control Unit. With the myriad of various CC&R's and antenna restrictions around the USA, many hams are forced to utilize compromise antenna systems to operate from their home qth, and finding the best alternative antenna configuration for an individual ham's location can be challenging. Therefore, I am very pleased with the various Loop antennas available from various ham vendor sources, since it allows many hams the capability to get on the air, when they might not be able to do so without the smaller loop antennas. Before deciding that hf ham radio operation is not feasible from an antenna restricted location, I would encourage a person facing such restrictions to seriously consider trying a loop antenna. 73, --Bill - K6IH- ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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I used to have a mag loop too. It is ideal when it can be transported in nearly original condition, when no tuner is available, and when tall structures are unavailable. With a loop, one can be in the air in seconds. However, the loop weighs a couple of pounds and it needs to be adjusted very often.
Inside, loop's performance depends on the type of siding and roof +obstructions. With vinyl siding and no outside obstructions, very good. With metal siding, hard luck. An extra advantage of the loop is the ability to null noises. If one has a good tuner, a thin long wire weighs ounces and can be matched automatically in no time. But setting time is higher and lots of space is needed. Once I had a business at a FL mountain (300ft!) during the time of a CQ 160 SSB contest. 2 x 150 ft gauge 30 wire from a window directly to nearest trees. Good for 10 QSOs with K2/10. The wire + fishing line weighed a few ounces. No size fits it all. Ignacy, NO9E |
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Administrator
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Folks - We are exceeding the single list posting topic limit for the subjects on
loops and attic antennas. Let's close the thread at this time in the interest of keeping list noise level under control. 73, Eric Elecraft List Moderator elecraft.com On 8/14/2013 8:44 AM, Ignacy wrote: > I used to have a mag loop too. It is ideal when it can be transported in > nearly original condition, when no tuner is available, and when tall > structures are unavailable. With a loop, one can be in the air in seconds. > However, the loop weighs a couple of pounds and it needs to be adjusted very > often. > > Inside, loop's performance depends on the type of siding and roof > +obstructions. With vinyl siding and no outside obstructions, very good. > With metal siding, hard luck. An extra advantage of the loop is the ability > to null noises. > > If one has a good tuner, a thin long wire weighs ounces and can be matched > automatically in no time. But setting time is higher and lots of space is > needed. > > Once I had a business at a FL mountain (300ft!) during the time of a CQ 160 > SSB contest. 2 x 150 ft gauge 30 wire from a window directly to nearest > trees. Good for 10 QSOs with K2/10. The wire + fishing line weighed a few > ounces. > > No size fits it all. > > Ignacy, NO9E > > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/Loop-antenna-s-tp7577664p7577722.html > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by Ignacy
Can you guys join the yahoo magloop group and move the discussion there.
where it should be held. this is really off topic of the elecraft thread. -- R.Neese KB3VGW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by stan levandowski
Hello,
I have built a 21' loop for 30 and 40m, which I use inside the house on the second floor. No problem reaching Russia on 40m with 5W, CW... See: http://radiopreppers.com/index.php/topic,180.0.html Gil. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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In reply to this post by stan levandowski
Here is a good antennae discussion reflector email address, which is
more appropriate than the Elecraft list: [hidden email]. Try it you'll like it. 73, Tom Amateur Radio Operator N5GE Licensed since 1976 ARRL Lifetime Member QCWA Lifetime Member On Wed, 14 Aug 2013 08:44:33 -0400, Stan <[hidden email]> wrote: >Well said, Bill. I used to sign /QRP but stopped doing that routinely and increased my CQ return rate. Nowadays I do not mention my attic doublet unless the subject comes up. Why shoot myself in the foot... > >I have nothing against small loops. I built a simple 40 meter STL from about 8 feet of hardline and used inductive coupling and it was very, very impressive. Then I built the mother of all loops from Home Depot 2 inch copper tubing, an Edmunds Scientific 1 rpm motor, and a Jennings vacuum variable. Cost me over $500 ! It was for 20 meters only. It worked amazingly well, including a QRPp contact with UA1CE not once, but twice. > >The reason I abandoned small loops was a practical one -- frequency agility. Because I had the option, I installed my remotely coupled multiband attic doublet. My advice to those dealing with antenna restrictions is to consider small loops along with other solutions if the opportunity is there but not to view a small loop as something magical and mystical. > >My QRPp QSO with Gene could have occurred with a wet noodle if the conditions were right. > >73, Stan WB2LQF > >Sent from Samsung tabletBill - K6IH <[hidden email]> wrote:Howdy to all, > >I don't think anyone will question the fact that a good antenna system >is one of the most important factors in a ham station being able to >communicate efficiently particularly when using qrp power levels. > >While I would agree that a full length dipole antenna, or beam antenna >would be preferable to a smaller 3' loop antenna, in my case that is not >only impractical but impossible at my home qth since I live in a high >rise building that has steel supports throughout the building instead of >wooden studs. This effectively makes the interior of my high rise >apartment inside of a faraday rf shield and prevents most radio signals >from radiating or receiving when using an antenna inside of my >apartment. This means an antenna has to be mounted outside of the >apartment, and the balcony is the only area available to install an >antenna. With such a limited area to install an amateur antenna, I find >the MFJ 3' loop to be one of the better alternatives to be able to >operate my ham station on the hf bands, and still be able to change >bands and tune the antenna remotely with the MFJ Remote Control Unit. > >With the myriad of various CC&R's and antenna restrictions around the >USA, many hams are forced to utilize compromise antenna systems to >operate from their home qth, and finding the best alternative antenna >configuration for an individual ham's location can be challenging. >Therefore, I am very pleased with the various Loop antennas available >from various ham vendor sources, since it allows many hams the >capability to get on the air, when they might not be able to do so >without the smaller loop antennas. Before deciding that hf ham radio >operation is not feasible from an antenna restricted location, I would >encourage a person facing such restrictions to seriously consider trying >a loop antenna. > >73, > >--Bill - K6IH- >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[hidden email] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html >______________________________________________________________ >Elecraft mailing list >Home: http://mailman.qth.net/mailman/listinfo/elecraft >Help: http://mailman.qth.net/mmfaq.htm >Post: mailto:[hidden email] > >This list hosted by: http://www.qsl.net >Please help support this email list: http://www.qsl.net/donate.html ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Amateur Radio Operator N5GE
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Good discussions. No silver bullet.
I am trying to decide what to do when travling, often by bike and overseas. My current strategy is close to half wave vertical. But shooting with a slingshot takes time. A small fiberglass pole (2 .5 folded', 22' unfolded) may help when trees are not around. Also, sometimes the performance is not that good because of poor soil conductivity or lack of higher angle of radiation.
I am tempted to have a dipole with TV line but it is an extra hassle. Also good performance is not be there until half a wave high. I had best luck with long wire, which can also be described as a form of inv L. But it needs a second support.
73, Ignacy, NO9E
On Thu, Aug 15, 2013 at 12:10 PM, N5GE [via Elecraft] <[hidden email]> wrote: Here is a good antennae discussion reflector email address, which is |
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Loop at a opec multi ban vertical . I have oped for 1 for hf backpack
... and I just add a trailing ground radial. you can set it up on a tripod also ... -- R.Neese KB3VGW ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html |
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