I am a 74 year old “newbie” I just earned my technician’s license 3/24/21. I LOVE your videos Dave. Not only do they teach me what I need to know, I have to learn a whole new language just to glean the the tremendous information you impart.
My DX Commander with 30 radials of 2.5m and 19.5m of wire as an inverted L has a sweep of SWR < 1.5 from 3.6MHz to 3.85MHz. It is a truly broadband antenna.
Just make a doublet. Follow Dave's advice about the angle and wood. Cut insulated wire slightly longer than normal resonance at the lowest part of the band. Feed in the center with ladder line. Just before that enters your home install a balun. Run off that with a short pice of good coax into the house to a normal external tuner. Will tune all bands 80-10. That was my first antenna over 30 years ago and it was great. In the years I was active I made 100s of contacts on all bands except 15. For what ever reason it would tune up but had awful performance on 15m. Keep in mind I was 13 when i put this up and had no one to help me so construction and installation was shoddy Like Dave's suggestion of the loop. I am putting one up myself cut for 160. If you make it square keep in mind each side is only 1/4 the length of a normal dipole for the lowest band you want to work and will work for the lowest band through 10 meters. You will need a tuner and feed it with.ladder line through a balun like the doublet.
Here is what I found on the 75 / 80 meter band antenna situation. A full wave loop is one of the better choices if you have the room. I have one and it ranks as a great antenna. I also made an off center fed 75 meter dipole antenna that has an SWR of less than 1.5 from 3.700 to 3.999. Using #10 gage stranded wire really makes the antenna very broad banded. I also use a DX Engineering 4:1 balun. Being fed off center, it does work pretty good on 40 meters and 20 meters. I do use a tuner (Dentron MT2000A) on 40, 20, 17, 15, 12 and 10 and it all works well. I'm up about 70 feet in a tree. Wire thickness is often ignored by many and that I believe is a mistake. I used to use 14 gage wire thinking that it really did not matter.....after using 10 gage wire, I found it really does make for a way better antenna. Don't cheap out on wire. And if using a balun, get a high quality one not the ones sold on E-bay or Amazon for around $20.
Dave, the answer is under the snow in your backyard. The DX Commander actually does pretty well on 80m (a slice anyways on the phone segment) if you set it up as an inverted L as Callum describes in his "instructions" and videos. Mine is 1.40 near the center of the phone band (the General Part) and is never higher than 4.5 SWR anywhere and usable with a tuner. Obviously, he'd need some radials but the thing is really easy for one person to handle. Way easier than climbing a tower. NK5J.
Agreed. I have a homemade vertical with not nearly enough radials, and with an old icon AT-500 tuner I can work the entire band. I’m sure I am not doing as well as I would with other antennas, but I am getting out and having fun, which is really what matters. OP, Don’t give up. I would try the ladder line and a 4:1 balun (which would make it a doublet) then you also can tune it for use in most (if not all) higher HF frequencies.
Given the materials used I suggest it is OK for shorter term installations but eventually the wind and elements will take a toll so not the best solution for long term installations.
@@RobB_VK6ES I have it setup on the South Texas Gulf Coast where we get more than a little wind and a lot of sun (and recently a little cold) and it has held up great. In higher winds (think north of 25-30 mph) the SWR can start jumping a bit but generally it performs really well. My biggest issue is finding enough space for radials on a lot that a post stamp could easily cover.
@Rob B VK6ES Hello, fellow ES. I'm curious what parts you figure will deteriorate. Most antennas use aluminum. Many use wire. Many use fiberglass radomes or poles. The spreader material I'm not sure of. All the antennas made with these materials last many years. My 12.4m DXC has already been through multiple tropical storms, ice rain storms, mini flooding, and hot weather so far. It isn't even a year old yet! So far, other than falling over because the front-end loader doing snow removal snapped the guy peg, it has shrugged it all off. (No damage from the fall that I could find, and that was in winter, so around freezing.) I guess we will see how it lasts.
@Thomas Standley How is it lasting now that it has been another year? Mine isn't a year yet, but see the reply I made to the fellow you replied to about the storms etc mine has already been through.
Not mentioned here are some of the practical issues. Check the feed line for DC continuity and shorting with a multimeter. Check the feed line with RF into a dummy load at far end. Can the instrumentation be trusted and verified? Cross test the analyser with a conventional VSWR bridge to a known good antenna for example. What material is the radiating elements made from? Wires with a high DC resistivity like various steels a will not tune unless quite thick. Insulated wire will resonate at a shorter length than bare copper. Try to conduct testing and tuning close to the feed point using a minimal length feed line.
When I was in the UKI couldn't put up HF antennas, except for a 20 metre dipole under the gutter, fine except when it rained. Only had it a few months before I came to Portugal. At last I'm starting to get set up here. I'm watching all your videos for hf advice.
I’m in the minority as my 80m single band center fed dipole covers over 300kHz with a 3.0 or better SWR and over 200kHz with a 2.0 or better Swr. In other words from 3.650 to 3.950 with a 3.0 SWR or better. Or 3.700 to 3.900 2.0 SWR or better. And I’ve used this antenna at different heights and different configurations and the results were always the same.
I believe you can make a dipole covering the entire 80-meter band if you build it with three parallel wires instead of one. One wire is cut to the lower end of the band, one for the center, and one for the upper end. The three wires all run parallel, held about two inches apart by insulators. Another possibility is a "cage dipole" which consists of 6 or 8 parallel wires held apart by insulating rings to make the antenna appear at radio frequencies to be electrically larger in diameter.
A 274 feet (or 83,0m) loopantenna You c a n use at abt 10feet (3.0m) high then it is a s c NVIS antenna. Feed with 76 feet (23m) 450Ohm windowline and DC Earth on opposite side of the loop! It requires a 2:1 or a 4:1 balun (f ex MFJ969/962)
I've run an 80M dipole for many years with a 1/1 baking at the feedpoint. Feedpoint is at about 25', ends at about 10'. Never has an issue getting a good swr and bandwidth. Excellent NVIS performance. I now use an full size folded Dipole with a 4/1 baking at the feedpoint. Again, no issue getting good swr and bandwidth. Slightly broader than the dipole. Also a bit quieter. Seems like he has something else going on.
My mobile 80 meter antenna is very narrow banded! Like mentioned in the video I have it tuned for the center frequency between the two nets I frequent. With the internal tuner I might get about 40 khz of movement around the band.
I use a doublet antenna with 58 feet of wire on each leg fed with 450 ohm window line. I have a 4:1 balun hooked to the window line and rg 213 going to the tuner. I can use it on every part of 75 and 80 meters on down to 6. It will not tune on 160. The only drawback is that you have to have it high above ground for good performance. Mine is 70 feet on one end sloping down to 30 on the other. I use a pulley to raise it up and down the tower.
There is an antenna that will cover all of 80m, well 160-10 really. It's a compromise antenna. The Icom AH-710 folded dipole at 80ft. long. (doesn't preform well at 160 though it matches within 3:1) :D
I recently got a Tune-A-Tenna, which allows me to change the length of the inverted vee from inside the shack. I still need to work on positioning things to get more apex height, better orientation, and less interference/coupling problems... but it’s looking very promising for allowing me to get it resonant anywhere in 75-80m that I want to operate. I’ll keep you apprised of my progress. Should be very interesting.
Overall a good video. To get the feedpoint impedance from 20 ohms or 30 or 40 to 50 ohms use a match. I only use the hairpin method. It goes by other names as well. It is easy, effective easy to adjust and cheap with the advantage that its value does not change ever and both legs are connected together to make a DC conection. It get rid of a lot of static. Read Beam antenna handbook. It explain it the best. And off course a balun. I prefer a air wound one. 1:1 ZS6ABR
Good discussion, and timely for me. I am assembling a 135 foot inverted V Doublet to deploy on my trailer mounted tip up, jack up, mast, with 45 feet of elevation. It will be used with a manual Palomar 200W tuner, and my Icom 7100. 80M is a definite main target of this system. I am also building a Vertical loop on my city lot, but that project is a couple months off, it will not be at ideal height, but fits my property where a horizontal loop will not. WS7PB
Oggy, he can make a fan dipole just for for 80m tune one element for bottom one for middle and one for top. You will still need a tuner but a lot more manageable. If he's got problems on 80 try 160 my oh my.
Great video, dead on (and I didn't fall off my tower lol) Just put an old G5RV today for 75. Have issues with my MFJ-1785 rotatable di-pole. I read the instructions after I tuned it near the ground and didn't add the 500kc that it shifted when raised. You're right on and I understand the other guy. My mid point is at the top of my tower (43 feet), raised by dac cord and a pulley I installed. At 2.5mhz swr is 1.3, 3.1mhz =4:1 & 4.0mhz it's 9:1 (via my Nano VNA, best tool I ever bought) From 2.4mhz to 2.75mhz the swr is 1.8:1 350kc, with a dip in the middle. I got lucky my LDG tuner can handle it. I called for a signal report 3.966 and had a couple of guy sayI was booming in Ohio. I'm in northern Indiana and made a 5-9 contact to Kentucky tonight. Very informative video and it all made sense. I know what to fine tune. I spaced my ladder line away from the tower with a couple of 5ft fiberglass rod driveway markers you see at the hardware store so you can find it in the snow.
I do very well on 75m with an OCFD, the center is only 30-35 feet high and the ends are 20feet. On 3.855 several times when my amp was not working, I from Indiana, contacted net controls in Kansas, Missouri and Florida on 20 watts.
How ‘bout an Off Center Fed with a 4:1 Balun & a decent tuner to make the radios happy. Not saying it’s efficient but mine at 35 ft. allows me to work from 80 to 10 meters. Of course the odd frequencies are harder on my tuner.
SWR 9.9 in the case of your analyzer means that it is beyond the measuring range. Your antenna's feed point impedance must be either below 5 Ohms or above 500 Ohms. That should not be the case even when a (resonant) dipole is much lower over ground. My first guess would be that the center of your dipole is too close to the (probably conductive) tower. If this is the case, feedpoint impedance can go wild, because you send almost all radiated energy of your dipole into the tower instead of the air. If you can elevate the feedpoint about 2 meters over the tower with a non conductive pole or apply a rope to get it farther away from the tower sideways, try that. But before you do that, check the antenna system (antenna+feedline) for simple electrical errors. Take the balun out of the system an connect the dipole directly to the feedline. Measure the feedline for internal short (inner/outer must be open). If ok, measure the inner and outer conductor of the feedline against the corresponding ends of the dipole.(one short per side, no more, no less) If you want more tips on how to go on with a differential diagnosis of your problem, just comment back. 73
I got a 10 foot 1.5 inch PVC. That gives me 2 ends that are 4.5 feet from the tower. Put I polt at each end with a pulley at the ends so I can lower it to make repairs.
I found out early on that a dipole is narrow in band coverage. I changed to a OCF inverted V, a 4 to 1 Balun and a 1 to 1. The radio easily tunes it. The only problem was a huge null in one direction. We messed with it and could not make it better. Finally out of desperation we add an ugly Balun and it fixed the null. Can not figure out why and there is no way that would help. But it did. Can’t argue with success I guess.
Dave... Very good explanation. I’ve heard about many of the things you mentioned but you bring it all together and tied the ribbons on it. Many thanks.. de... KE0EF. Fred
I'm discovering just what you describe about 75/80m. I found the 12.4m wire vertical too noisy on 80m, so I also have a 131 issue foot efhw in an L due to lot issues. Much better RX on the efhw, better TX on the vertical. I have been considering a low full wavelength loop. Higher bands are a very different experience.
Great video David... I have a Fritzel FD-4 OCFD only about 24' off the ground at the moment. At 3.5mhz I have 4.9 swr at 4.0mhz it is at 3 swr. I am going to get a telescoping fiberglass pole to raise the feed point up over 40' and hopefully lower the swr on 80m and 160m. Other than 160m and 80m a built in tuner will allow you to work all the way to 10m. My first "real" antenna but so far so good. But what do I know I did not stay at a Holiday Inn last night.....
i'm going to get away from inverted vee' just for a moment i have to eighty meeter ham sticks and a mounting brackets ? will cover all of eighty meeter band
Can I make a Fan Dipole antenna for 2 or 3 parts of the 80 M to have something that will cover more of the band. I have a 58 foot tower and can use top rail to get the end up 20 feet. I was thinking of one in the digital part, another in the middle and the third near the top end. I know the thicker wire will make it more broadband. Thinking about 3 sets of 12 gage wire. Does this sound like it may help cover more of the 80M band?
I have seen wire antennas that are 3 wires with something spacing the 3 wires apart. Is that to give it a wider bandwidth? Or is it for something elce? If it is for bandwidth how much will it help and how far apart should the wires be. I didn't get a good look at it but I think they were around 4 to 6 inches apart. I may be way off on the spacing apart. What would be the best spacing? I had been thinking about using 450 ohm window line for the long wires. I think that may give a wider bandwidth. But then I may just have it all wrong.
I have a G-5 rv and I cover most of the eighty meter band. with just a general class licence I don't need to cover the whole band. My g-5 rv is run in a straight out between two trees and a pipe in the middle I get out pretty good on it. a tuner is used for part of the band. it's and auto tuner.
In 30 years of living here I've never been on my roof to do anything with aerials or fix a loose slate. I pay some other idiot to go up there. I haven't aerials on my roof because if anything goes wrong I'd have to pay for someone to go up and fix it. I've no room for 80m but did put up a 40m inverted vee with a narrow angle at the top, maybe 75°, and the ends dropping to about 5 feet above ground, it got out. I used about 6 foot of pvc water pipe to extend the centre above my aluminium mast pole to lessen the effect of it coupling into it. I added loading coils on the ends to get it on 80m, not perfect but you have to do whatever you can. G4GHB.
On a dipole or inverted V why use balanced feedline into a balun instead of simply running the center of the 50 ohm coax to end end and the shield to type other end and then sealing it off?
K6SDW: The MFJ-17758 80/40 meter trap dipole was, for me, the perfect solution for an 80 and 40 meter antenna. With the trap inductance the antenna only needs about 85 feet to cover both CW bands. I worked the world on CW/FT8 with this antenna. I would also suggest a 9:1 balun endfed antenna, which I've used as well, again on 80 meters I've worked the other side of the "flat" earth running FT8.....I couldn't resist the "flat" earth comment, what a joke!! 73/ed
John , I’ll save you 23 minutes of confusion. Buy or build a 80m double bazooka. It will be under a 2:1 from 3.6-4.0. It was made to throw on metal and not throw off the swr. Best antenna you’ll ever have for 80. Take it from someone that’s tried it all. Just do it. It’ll work. And make sure that mfjunk meter hasn’t junked out. Which is common for mfjunk. 73
I have the MfJ 10-80 ha!f wave end fed. My MfJ 998 tuner can tune it to about 1.1 to 1.3.. at 3.800. At 3.963 where my net runs the tuner can do no better than 1.5 to 1.8. If I shorten the antenna to bring the swr down on 3.963 am I right that the swr will be lower on the 40 & 20 meter band higher up on both bands than it is now? I could live with that if I could get a lower swr on 3.963.
Hi Dave. I wonder if he has loaded the antenna with his rig and its swr meter or an external swr meter and if so what did it read as the swr? Since he said he used an antenna analyzer for his measurements this may be what is going on. If he lives near to an AM broadcast station its RF may be picked up by the very low power analyzer with a very sensitive swr meter and the incoming RF makes the instrument look like it's seeing a high swr. I live a mile from KGRE 1450 and using an MFJ antenna analyzer I saw 2.5 to 1 at its lowest point but flat using the rig and a Drake W-4. While looking at the MFJ's meter I saw the meter fluctuating minutely with their music and deduced what was going on. As I went to 40m it was much less and 20m flat with the respective antennas. KGRE is 1KW omni 24/7 with a 343 ft tower with 120 400 ft radials. I hope with the rig and a regular swr meter he saw a good match. My antenna is an 80/40 inverted vee and 20/15/10m a 4 el beam. KØOJ
I have one tuned for the cw portion and the upper part of the band and can transmit anywhere in the band at 2.5:1 swr or lower. It covers the general portions at 2:1 or less. I built a single element at first that covered the whole band at 3.2:1 and lower when tuned for 3.7 mhz. If my radio had an internal tuner I could have stuck with that, but not having a tuner at all forced me to add the other element. I used 10 gauge wire and that gives me far more bandwidth than the usual 14 gauge that is used. My voice element is about 59’ per leg and the cw element is at about 65’ per leg. The two elements are spaced apart 13” from each other and it is currently a sloper that is only about 15’ off the ground on the high end. I’ll raise it once I trim a few hard to reach branches out of the way.
@@ST1300Jim I made a single band fan dipole. It had equal length legs (1 meter apart at the ends with 6mm² copper electrical wire) to shorten the overall length of the antenna. The band width was a bit over the 100kc but little to boast about. It did performe slightly better than the standard dipole and the receive was noticeabley better. Unfortunately I don't have the 3.7-4.0 mhz portion of the band so I wasnt able to do a 75/80 length with it.
Dave a guy said you was his mentor. well you taught me what all the om's and other thing are. I watch one of your vidos ever day and sometime more than one you told him to find a club. well there is one here but my sweet heart did not get along with the wives there. so I don't go there any more.
Hi Dave, Great channel I have considered this: Using the Chameleon CHA-Quadone hamstick dipole, have one pair of hamsticks tuned in the 75 m band and the other pair tuned in the 80 meter band. I live on Guam Island and need to get antennas down with some regularity because we get Typhoons here (Western Pacific Hurricanes). This setup would be subject to rapid deployment and take down by myself. What do you think. Rick, WH2O
@@aurtisanminer2827 never heard that before. Since it's only a nighttime contender. Everyone I know with NVIS setups is using 20m during the day and 40m at night...
@@Justin-bd2dg it could be our location differences. I live in Alaska where we have some different atmospheric effects. Being near the poles gives us a lot of aurora activity to deal with for one. We dont usually get good nvis on 40 m and basically none on 20 m. The 20 m band is great for hitting california or japan pretty regularly from here. 40 meters does best for people who are at least a few hundred miles away. I think it will get better for nvis as the solar cycle becomes more active, though. Since there are so many tall mountain ranges here 80 meter nvis is the best for hitting people during the day who are just a mile or two away but on the opposite side of some tall terrain or a few hundred miles away. At night it goes long and we hit the us west coast pretty regularly and start gettin AM broadcast stations from european countries. Over this last winter the band would go completely dead for nvis once the sun set. I dont know how normal that is, but since our days have grown longer it’s been working much better at night.
@@Justin-bd2dg one of the best examples I had of 80 m nvis characteristics was in my car last summer while in a steep canyon. I made it up over the canyon walls and contacted people all over a couple hundred mile radius. That was with a vertical mobile antenna. A dipole does even better with nvis.
Question, there are "Fan" dipoles right, so would a fan dipole with 3-4 wires cut to different 80m trequencies work? The multi band fan dipole picks the right wire for the frequency desired, would it do the same within the same within a particular band? Just a thought.
10:02 what about loop dipole? ith has parallel lines but it is an antenna that works. I have a small garden and to achieve the longest radiator to me it means less than 90 degrees. @David you said higher SWR but SWR is just a number which means to many things to be specific. What will happen to impedance? maybe a simple transformer with a proper ratio will work.
I read or saw a youtube of a Brit guy using a weather balloon to deploy an antenna for 160 M, transmit and receive. I don't , know anything about drones but a similar concept. RWood WH2O
My MFJ-259B says that my home brew OCF dipole has SWR from 1.5 to 1.8 from 3.5 to 4.0 MHz without a tuner. Is that possible or is something wrong with the analyzer?
Rich? Sean? We dont care. John might care but is anyone actually nammed Johnny? Or just in old movies? Original Gangster movies. Citation. ( The man with the golden arm) starring Frank Sinatra. A great watch.
Getting a nanoVNA to perform as an SWR meter takes you a couple levels down into the menu. I almost did a video about it, but then "they" changed the nanoVNA menu!
I am a 74 year old “newbie”
I just earned my technician’s license 3/24/21. I LOVE your videos Dave. Not only do they teach me what I need to know, I have to learn a whole new language just to glean the the tremendous information you impart.
My DX Commander with 30 radials of 2.5m and 19.5m of wire as an inverted L has a sweep of SWR < 1.5 from 3.6MHz to 3.85MHz. It is a truly broadband antenna.
If you make radials longer 4 to 5 mts longer, you will find your swr and band better
73 de KQ4CD Paul
You have taught me more about antennas in a day than I have learnt in 20 years
Just make a doublet. Follow Dave's advice about the angle and wood. Cut insulated wire slightly longer than normal resonance at the lowest part of the band. Feed in the center with ladder line. Just before that enters your home install a balun. Run off that with a short pice of good coax into the house to a normal external tuner. Will tune all bands 80-10. That was my first antenna over 30 years ago and it was great. In the years I was active I made 100s of contacts on all bands except 15. For what ever reason it would tune up but had awful performance on 15m. Keep in mind I was 13 when i put this up and had no one to help me so construction and installation was shoddy
Like Dave's suggestion of the loop. I am putting one up myself cut for 160. If you make it square keep in mind each side is only 1/4 the length of a normal dipole for the lowest band you want to work and will work for the lowest band through 10 meters. You will need a tuner and feed it with.ladder line through a balun like the doublet.
Here is what I found on the 75 / 80 meter band antenna situation. A full wave loop is one of the better choices if you have the room. I have one and it ranks as a great antenna. I also made an off center fed 75 meter dipole antenna that has an SWR of less than 1.5 from 3.700 to 3.999. Using #10 gage stranded wire really makes the antenna very broad banded. I also use a DX Engineering 4:1 balun. Being fed off center, it does work pretty good on 40 meters and 20 meters. I do use a tuner (Dentron MT2000A) on 40, 20, 17, 15, 12 and 10 and it all works well. I'm up about 70 feet in a tree.
Wire thickness is often ignored by many and that I believe is a mistake. I used to use 14 gage wire thinking that it really did not matter.....after using 10 gage wire, I found it really does make for a way better antenna. Don't cheap out on wire. And if using a balun, get a high quality one not the ones sold on E-bay or Amazon for around $20.
Nice to see an older FT-101 in your collection,That was my first 101!
Dave, the answer is under the snow in your backyard. The DX Commander actually does pretty well on 80m (a slice anyways on the phone segment) if you set it up as an inverted L as Callum describes in his "instructions" and videos. Mine is 1.40 near the center of the phone band (the General Part) and is never higher than 4.5 SWR anywhere and usable with a tuner. Obviously, he'd need some radials but the thing is really easy for one person to handle. Way easier than climbing a tower. NK5J.
Agreed. I have a homemade vertical with not nearly enough radials, and with an old icon AT-500 tuner I can work the entire band. I’m sure I am not doing as well as I would with other antennas, but I am getting out and having fun, which is really what matters.
OP, Don’t give up. I would try the ladder line and a 4:1 balun (which would make it a doublet) then you also can tune it for use in most (if not all) higher HF frequencies.
Given the materials used I suggest it is OK for shorter term installations but eventually the wind and elements will take a toll so not the best solution for long term installations.
@@RobB_VK6ES I have it setup on the South Texas Gulf Coast where we get more than a little wind and a lot of sun (and recently a little cold) and it has held up great. In higher winds (think north of 25-30 mph) the SWR can start jumping a bit but generally it performs really well. My biggest issue is finding enough space for radials on a lot that a post stamp could easily cover.
@Rob B VK6ES Hello, fellow ES. I'm curious what parts you figure will deteriorate. Most antennas use aluminum. Many use wire. Many use fiberglass radomes or poles. The spreader material I'm not sure of. All the antennas made with these materials last many years.
My 12.4m DXC has already been through multiple tropical storms, ice rain storms, mini flooding, and hot weather so far. It isn't even a year old yet! So far, other than falling over because the front-end loader doing snow removal snapped the guy peg, it has shrugged it all off. (No damage from the fall that I could find, and that was in winter, so around freezing.)
I guess we will see how it lasts.
@Thomas Standley How is it lasting now that it has been another year?
Mine isn't a year yet, but see the reply I made to the fellow you replied to about the storms etc mine has already been through.
Not mentioned here are some of the practical issues. Check the feed line for DC continuity and shorting with a multimeter. Check the feed line with RF into a dummy load at far end. Can the instrumentation be trusted and verified? Cross test the analyser with a conventional VSWR bridge to a known good antenna for example. What material is the radiating elements made from? Wires with a high DC resistivity like various steels a will not tune unless quite thick. Insulated wire will resonate at a shorter length than bare copper. Try to conduct testing and tuning close to the feed point using a minimal length feed line.
What a great presentation on 80 meter dipoles. Thanks!
Great explanation on 80m. Very true about tuning a vertical antenna to the band width one wants to use. One day I’ll get it-one day.
Dave, you should also make sure to tell John KB5GGO to renew his Advanced Ham License it's due on June 5th, 2021
I did send him an email David, he emailed me back he just sent in his renewal today!.
I've been trying to build an antenna for 75 meters and I'm telling you it is tough! So I really needed to view this video again.
When I was in the UKI couldn't put up HF antennas, except for a 20 metre dipole under the gutter, fine except when it rained. Only had it a few months before I came to Portugal. At last I'm starting to get set up here. I'm watching all your videos for hf advice.
I’m in the minority as my 80m single band center fed dipole covers over 300kHz with a 3.0 or better SWR and over 200kHz with a 2.0 or better Swr.
In other words from 3.650 to 3.950 with a 3.0 SWR or better. Or 3.700 to 3.900 2.0 SWR or better. And I’ve used this antenna at different heights and different configurations and the results were always the same.
I believe you can make a dipole covering the entire 80-meter band if you build it with three parallel wires instead of one. One wire is cut to the lower end of the band, one for the center, and one for the upper end. The three wires all run parallel, held about two inches apart by insulators.
Another possibility is a "cage dipole" which consists of 6 or 8 parallel wires held apart by insulating rings to make the antenna appear at radio frequencies to be electrically larger in diameter.
Yes, a fan dipole
Doublet 90 feet or longer will get you on 75/80m and up
A 274 feet (or 83,0m) loopantenna You c a n use at abt 10feet (3.0m) high then it is a s c NVIS antenna. Feed with 76 feet (23m)
450Ohm windowline and DC Earth on opposite side of the loop! It requires a 2:1 or a 4:1 balun (f ex MFJ969/962)
I've run an 80M dipole for many years with a 1/1 baking at the feedpoint. Feedpoint is at about 25', ends at about 10'. Never has an issue getting a good swr and bandwidth. Excellent NVIS performance.
I now use an full size folded Dipole with a 4/1 baking at the feedpoint. Again, no issue getting good swr and bandwidth. Slightly broader than the dipole. Also a bit quieter. Seems like he has something else going on.
Balun, not baking.
My mobile 80 meter antenna is very narrow banded! Like mentioned in the video I have it tuned for the center frequency between the two nets I frequent. With the internal tuner I might get about 40 khz of movement around the band.
I use a doublet antenna with 58 feet of wire on each leg fed with 450 ohm window line. I have a 4:1 balun hooked to the window line and rg 213 going to the tuner. I can use it on every part of 75 and 80 meters on down to 6. It will not tune on 160. The only drawback is that you have to have it high above ground for good performance. Mine is 70 feet on one end sloping down to 30 on the other. I use a pulley to raise it up and down the tower.
80 meter antennas are something of the deep subject!
Good stuff, but something to look into for sure. Thank you Dave!
73 de N2NLQ
There is an antenna that will cover all of 80m, well 160-10 really. It's a compromise antenna. The Icom AH-710 folded dipole at 80ft. long. (doesn't preform well at 160 though it matches within 3:1) :D
I recently got a Tune-A-Tenna, which allows me to change the length of the inverted vee from inside the shack. I still need to work on positioning things to get more apex height, better orientation, and less interference/coupling problems... but it’s looking very promising for allowing me to get it resonant anywhere in 75-80m that I want to operate.
I’ll keep you apprised of my progress. Should be very interesting.
Awesome Dave, you answered a lot of questions on the subject .Great videos Dave cheers
Very Helpful information. Thank you Dave!
The full wave loop fed with window line is your best bet,.
Good video, I need to watch it again and take some notes.
Overall a good video. To get the feedpoint impedance from 20 ohms or 30 or 40 to 50 ohms use a match. I only use the hairpin method. It goes by other names as well. It is easy, effective easy to adjust and cheap with the advantage that its value does not change ever and both legs are connected together to make a DC conection. It get rid of a lot of static. Read Beam antenna handbook. It explain it the best. And off course a balun. I prefer a air wound one. 1:1 ZS6ABR
Good discussion, and timely for me. I am assembling a 135 foot inverted V Doublet to deploy on my trailer mounted tip up, jack up, mast, with 45 feet of elevation. It will be used with a manual Palomar 200W tuner, and my Icom 7100. 80M is a definite main target of this system. I am also building a Vertical loop on my city lot, but that project is a couple months off, it will not be at ideal height, but fits my property where a horizontal loop will not. WS7PB
Oggy, he can make a fan dipole just for for 80m tune one element for bottom one for middle and one for top. You will still need a tuner but a lot more manageable. If he's got problems on 80 try 160 my oh my.
Great video, dead on (and I didn't fall off my tower lol)
Just put an old G5RV today for 75. Have issues with my MFJ-1785 rotatable di-pole. I read the instructions after I tuned it near the ground and didn't add the 500kc that it shifted when raised.
You're right on and I understand the other guy. My mid point is at the top of my tower (43 feet), raised by dac cord and a pulley I installed. At 2.5mhz swr is 1.3, 3.1mhz =4:1 & 4.0mhz it's 9:1 (via my Nano VNA, best tool I ever bought)
From 2.4mhz to 2.75mhz the swr is 1.8:1 350kc, with a dip in the middle. I got lucky my LDG tuner can handle it.
I called for a signal report 3.966 and had a couple of guy sayI was booming in Ohio. I'm in northern Indiana and made a 5-9 contact to Kentucky tonight.
Very informative video and it all made sense. I know what to fine tune. I spaced my ladder line away from the tower with a couple of 5ft fiberglass rod driveway markers you see at the hardware store so you can find it in the snow.
I do very well on 75m with an OCFD, the center is only 30-35 feet high and the ends are 20feet. On 3.855 several times when my amp was not working, I from Indiana, contacted net controls in Kansas, Missouri and Florida on 20 watts.
would love to be able to talk on local nets around 2963.00 but have such a small back yard with no trees that it seems impossible to do.
Would adding capacitive loading at the ends of the radiating elements open up the Q and make it more broadbanded?
G5RV is an obsolete antenna. It was a compromise in its day. The ZS6BKW version is much better but still a compromise.
How ‘bout an Off Center Fed with a 4:1 Balun & a decent tuner to make the radios happy. Not saying it’s efficient but mine at 35 ft. allows me to work from 80 to 10 meters. Of course the odd frequencies are harder on my tuner.
same ant, same results - can "tune" it wherever I need it, great on 40!
SWR 9.9 in the case of your analyzer means that it is beyond the measuring range. Your antenna's feed point impedance must be either below 5 Ohms or above 500 Ohms. That should not be the case even when a (resonant) dipole is much lower over ground. My first guess would be that the center of your dipole is too close to the (probably conductive) tower. If this is the case, feedpoint impedance can go wild, because you send almost all radiated energy of your dipole into the tower instead of the air. If you can elevate the feedpoint about 2 meters over the tower with a non conductive pole or apply a rope to get it farther away from the tower sideways, try that. But before you do that, check the antenna system (antenna+feedline) for simple electrical errors. Take the balun out of the system an connect the dipole directly to the feedline. Measure the feedline for internal short (inner/outer must be open). If ok, measure the inner and outer conductor of the feedline against the corresponding ends of the dipole.(one short per side, no more, no less)
If you want more tips on how to go on with a differential diagnosis of your problem, just comment back.
73
I got a 10 foot 1.5 inch PVC. That gives me 2 ends that are 4.5 feet from the tower. Put I polt at each end with a pulley at the ends so I can lower it to make repairs.
I found out early on that a dipole is narrow in band coverage. I changed to a OCF inverted V, a 4 to 1 Balun and a 1 to 1. The radio easily tunes it.
The only problem was a huge null in one direction. We messed with it and could not make it better. Finally out of desperation we add an ugly Balun and it fixed the null. Can not figure out why and there is no way that would help. But it did. Can’t argue with success I guess.
Dave...
Very good explanation. I’ve heard about many of the things you mentioned but you bring it all together and tied the ribbons on it. Many thanks..
de... KE0EF. Fred
I'm discovering just what you describe about 75/80m. I found the 12.4m wire vertical too noisy on 80m, so I also have a 131 issue foot efhw in an L due to lot issues. Much better RX on the efhw, better TX on the vertical. I have been considering a low full wavelength loop.
Higher bands are a very different experience.
Thanks Dave, you're a damn good teacher!
Im an Oggy and im in eastern Europe.
Have your wife there to either call 911 or the corner... Got a chuckle out of that!
My wife even laughed at that one!
Great video David... I have a Fritzel FD-4 OCFD only about 24' off the ground at the moment. At 3.5mhz I have 4.9 swr at 4.0mhz it is at 3 swr. I am going to get a telescoping fiberglass pole to raise the feed point up over 40' and hopefully lower the swr on 80m and 160m. Other than 160m and 80m a built in tuner will allow you to work all the way to 10m. My first "real" antenna but so far so good. But what do I know I did not stay at a Holiday Inn last night.....
i'm going to get away from inverted vee' just for a moment i have to eighty meeter ham sticks and a mounting brackets ? will cover all of eighty meeter band
Can I make a Fan Dipole antenna for 2 or 3 parts of the 80 M to have something that will cover more of the band. I have a 58 foot tower and can use top rail to get the end up 20 feet. I was thinking of one in the digital part, another in the middle and the third near the top end. I know the thicker wire will make it more broadband. Thinking about 3 sets of 12 gage wire. Does this sound like it may help cover more of the 80M band?
Sure you can. A lot of wire, but sure.
Great explanation, thank you!
Need to look at at DX COMMANDER all band vertical
I have seen wire antennas that are 3 wires with something spacing the 3 wires apart. Is that to give it a wider bandwidth? Or is it for something elce? If it is for bandwidth how much will it help and how far apart should the wires be. I didn't get a good look at it but I think they were around 4 to 6 inches apart. I may be way off on the spacing apart. What would be the best spacing? I had been thinking about using 450 ohm window line for the long wires. I think that may give a wider bandwidth. But then I may just have it all wrong.
I have a G-5 rv and I cover most of the eighty meter band. with just a general class licence I don't need to cover the whole band. My g-5 rv is run in a straight out between two trees and a pipe in the middle I get out pretty good on it. a tuner is used for part of the band. it's and auto tuner.
In 30 years of living here I've never been on my roof to do anything with aerials or fix a loose slate. I pay some other idiot to go up there. I haven't aerials on my roof because if anything goes wrong I'd have to pay for someone to go up and fix it.
I've no room for 80m but did put up a 40m inverted vee with a narrow angle at the top, maybe 75°, and the ends dropping to about 5 feet above ground, it got out. I used about 6 foot of pvc water pipe to extend the centre above my aluminium mast pole to lessen the effect of it coupling into it. I added loading coils on the ends to get it on 80m, not perfect but you have to do whatever you can.
G4GHB.
On a dipole or inverted V why use balanced feedline into a balun instead of simply running the center of the 50 ohm coax to end end and the shield to type other end and then sealing it off?
maybe a vertical with a coil to tune it will be more easy... not so great as a dipole but usable
K6SDW: The MFJ-17758 80/40 meter trap dipole was, for me, the perfect solution for an 80 and 40 meter antenna. With the trap inductance the antenna only needs about 85 feet to cover both CW bands. I worked the world on CW/FT8 with this antenna. I would also suggest a 9:1 balun endfed antenna, which I've used as well, again on 80 meters I've worked the other side of the "flat" earth running FT8.....I couldn't resist the "flat" earth comment, what a joke!! 73/ed
Good advice about climbing towers. Lol.
Great stuff as always.
when u run a wire for a dipole should it be stranded or a solid wire?:??
Thanks Dave for another great video that sheds some light on my nemsess the 80 meter bandwidth of antennas. 73 Jeff KE0KRO
I have an aerial51 OCF dipole that covers the whole 80m band
Can a fan dipole select portions of the 80M band?
Horizontal loop?
John , I’ll save you 23 minutes of confusion. Buy or build a 80m double bazooka. It will be under a 2:1 from 3.6-4.0. It was made to throw on metal and not throw off the swr. Best antenna you’ll ever have for 80. Take it from someone that’s tried it all. Just do it. It’ll work. And make sure that mfjunk meter hasn’t junked out. Which is common for mfjunk. 73
question. what if you have a full 160 loop ? what would that do to tuning 80 m?
I have the MfJ 10-80 ha!f wave end fed. My MfJ 998 tuner can tune it to about 1.1 to 1.3.. at 3.800. At 3.963 where my net runs the tuner can do no better than 1.5 to 1.8. If I shorten the antenna to bring the swr down on 3.963 am I right that the swr will be lower on the 40 & 20 meter band higher up on both bands than it is now? I could live with that if I could get a lower swr on 3.963.
Hi Dave. I wonder if he has loaded the antenna with his rig and its swr meter or an external swr meter and if so what did it read as the swr? Since he said he used an antenna analyzer for his measurements this may be what is going on. If he lives near to an AM broadcast station its RF may be picked up by the very low power analyzer with a very sensitive swr meter and the incoming RF makes the instrument look like it's seeing a high swr. I live a mile from KGRE 1450 and using an MFJ antenna analyzer I saw 2.5 to 1 at its lowest point but flat using the rig and a Drake W-4. While looking at the MFJ's meter I saw the meter fluctuating minutely with their music and deduced what was going on. As I went to 40m it was much less and 20m flat with the respective antennas. KGRE is 1KW omni 24/7 with a 343 ft tower with 120 400 ft radials. I hope with the rig and a regular swr meter he saw a good match. My antenna is an 80/40 inverted vee and 20/15/10m a 4 el beam. KØOJ
Curious if one could use a fan dipole to cover more of the whole band.
I think KB9RLW tried this, and it didn’t work well.
I’ve been told that when the elements are somewhat close in frequency they couple, and you end up with a mediocre antenna in between frequencies.
I have one tuned for the cw portion and the upper part of the band and can transmit anywhere in the band at 2.5:1 swr or lower. It covers the general portions at 2:1 or less. I built a single element at first that covered the whole band at 3.2:1 and lower when tuned for 3.7 mhz. If my radio had an internal tuner I could have stuck with that, but not having a tuner at all forced me to add the other element. I used 10 gauge wire and that gives me far more bandwidth than the usual 14 gauge that is used. My voice element is about 59’ per leg and the cw element is at about 65’ per leg. The two elements are spaced apart 13” from each other and it is currently a sloper that is only about 15’ off the ground on the high end. I’ll raise it once I trim a few hard to reach branches out of the way.
@@ST1300Jim I made a single band fan dipole. It had equal length legs (1 meter apart at the ends with 6mm² copper electrical wire) to shorten the overall length of the antenna. The band width was a bit over the 100kc but little to boast about. It did performe slightly better than the standard dipole and the receive was noticeabley better.
Unfortunately I don't have the 3.7-4.0 mhz portion of the band so I wasnt able to do a 75/80 length with it.
Great lesson!
Dave a guy said you was his mentor. well you taught me what all the om's and other thing are. I watch one of your vidos ever day and sometime more than one you told him to find a club. well there is one here but my sweet heart did not get along with the wives there. so I don't go there any more.
Hi Dave, Great channel
I have considered this: Using the Chameleon CHA-Quadone hamstick dipole, have one pair of hamsticks tuned in the 75 m band and the other pair tuned in the 80 meter band. I live on Guam Island and need to get antennas down with some regularity because we get Typhoons here (Western Pacific Hurricanes). This setup would be subject to rapid deployment and take down by myself. What do you think.
Rick, WH2O
A simple 80M Dipole trapped for 75M would cover all of the band, or perhaps an inverted L set mid band will also cover all the band.
Kinda tells ya WHY my buddy from VA has an 80 M loop at 40 ft. ROFL KQ2E
balance fed it is one of the best ants around - trying to figure out how to install on my small lot
80m sure does make you work for it but it's worth it for the best band in the spectrum (imo)
Why is it the best?
It’s my favorite for talking to people located nearby due to it’s NVIS characteristics. I use it exclusively at the moment at home and in my car.
@@aurtisanminer2827 never heard that before. Since it's only a nighttime contender. Everyone I know with NVIS setups is using 20m during the day and 40m at night...
@@Justin-bd2dg it could be our location differences. I live in Alaska where we have some different atmospheric effects. Being near the poles gives us a lot of aurora activity to deal with for one. We dont usually get good nvis on 40 m and basically none on 20 m. The 20 m band is great for hitting california or japan pretty regularly from here. 40 meters does best for people who are at least a few hundred miles away. I think it will get better for nvis as the solar cycle becomes more active, though. Since there are so many tall mountain ranges here 80 meter nvis is the best for hitting people during the day who are just a mile or two away but on the opposite side of some tall terrain or a few hundred miles away. At night it goes long and we hit the us west coast pretty regularly and start gettin AM broadcast stations from european countries. Over this last winter the band would go completely dead for nvis once the sun set. I dont know how normal that is, but since our days have grown longer it’s been working much better at night.
@@Justin-bd2dg one of the best examples I had of 80 m nvis characteristics was in my car last summer while in a steep canyon. I made it up over the canyon walls and contacted people all over a couple hundred mile radius. That was with a vertical mobile antenna. A dipole does even better with nvis.
Question, there are "Fan" dipoles right, so would a fan dipole with 3-4 wires cut to different 80m trequencies work? The multi band fan dipole picks the right wire for the frequency desired, would it do the same within the same within a particular band? Just a thought.
Yes you can do that
Cage dipole is calling my name for experimentation
It's so odd that you posted this video right now because I am just putting up my 80 meter antenna, it blew down several years ago. WN9DGV
I use an inverted V and not that high but works well on 80m.
that is what I was wonding about the twenty and thirty R value. a tuner would make it all right.
10:02 what about loop dipole? ith has parallel lines but it is an antenna that works. I have a small garden and to achieve the longest radiator to me it means less than 90 degrees. @David you said higher SWR but SWR is just a number which means to many things to be specific. What will happen to impedance? maybe a simple transformer with a proper ratio will work.
A local experienced ham told me that a properly set up inverted V antenna will have close to 50 ohms feed-point impedance.
Q: has anyone tried using drones to "fly" antenna wires for best reception?
I read or saw a youtube of a Brit guy using a weather balloon to deploy an antenna for 160 M, transmit and receive. I don't , know anything about drones but a similar concept.
RWood WH2O
My MFJ-259B says that my home brew OCF dipole has SWR from 1.5 to 1.8 from 3.5 to 4.0 MHz without a tuner. Is that possible or is something wrong with the analyzer?
It is possible you may have a lossy feedline or balun or something. Losses can masquerade as low SWR.
why not a non inverted v?
The coroner! LOL - Bahahaha !!!
Rich? Sean? We dont care. John might care but is anyone actually nammed Johnny? Or just in old movies? Original Gangster movies. Citation. ( The man with the golden arm) starring Frank Sinatra. A great watch.
Build an end fed half wave 132' and call it a day lol
Swat i done, works great.
Well darni, need to get my antenna away from my tower amd clothesline post.
for me the idea tower climber is those electric climber.
2:39 frustrated and scared. Not doing the rest of the world any favours.
2nd suggestion is one of these, ZS6BKW 160 - 10m:-
www.wireantennas.co.uk/hf/80m/hf-zs6bkw-160-10m-multi-band-antenna
I use a Double Bazooka works great wide band dipole configuration. I heard inverted v works better.
Why would anyone buy a swr meter now that a nanoVNA is only $50
Getting a nanoVNA to perform as an SWR meter takes you a couple levels down into the menu. I almost did a video about it, but then "they" changed the nanoVNA menu!
NICE PRESENTATION "OG
K7AER
Heya! New sub ☘️
73
HA! HA! You pulled a "BIDEN" at the end!
A G5RV with an ICOM AH-4 tuner works reasonably well
thanks Dave, this helps a great deal. KB1GYS