Author Topic: Small area,BIG ANTENNA...The "M" vertical  (Read 2021 times)

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Small area,BIG ANTENNA...The "M" vertical
« on: January 27, 2018, 06:58:11 AM »
  I am developing the "M" tenna  to aid a lot of ills for portable,fast setup antenna...designed for 6 thru 80 meters with low angle radiation for DX with a small footprint so it works in small lots or clearings. I often use a 20 foot or so expanding squid pole or fishing pole as an antenna support and often suffer as the coax and balun weight the support too much.

 Enter the "M"Tenna.. with a 3 to 5 foot rope attached at the top of the fish pole to form a "T" ,I mount the balun at the base of the pole and the two antenna elements (light weight wire) go up with one 'leg' going to each rope (mono filament or twine will do) and thus a sharp "V" is formed...THEN the wires are pulled out so insulated pegs or bushes/rocks to form a wire antenna in the shape of an "M". You have a light weight,small footprint VERTICAL antenna that ,with a 4 to 1 balun and 51 feet of wire one each side,will tune and perform well on 6 through 80 meters and can be quickly set up by just one man.

 Due to the vertical radiation angle,this antenna favors long distance and even though I prefer an NVIS antenna for it's capability to work closer in (50 to 600 miles) and over mountains ,into valleys that normally prevent HF from working,this is a good ,long distance ,option and excellent short wave listening antenna.

  I have had little 'hands on' use ,but thought I would as if anyone else wants to test drive this simple,yet effective,antenna..With an antenna tuner (matcher) and a 4 to 1 balun,you have the start of many exciting antenna options.

Offline Greekman

  • Survival Demonstrator
  • *******
  • Posts: 3621
  • Karma: 190
  • New TSP Forum member
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #1 on: January 27, 2018, 04:05:16 PM »
wow! this is a clever way to "cheat" on height.
Do take pics Carl when you set it up!

Offline Canadian Prepper

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 54
  • New TSP Forum member
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #2 on: January 27, 2018, 04:49:33 PM »
Hmmm, I just got a 40 foot Spiderbeam for which this might be just the ticket, though I might be looking at something closer to 80m resonance with that much beam. I will try out the zip-zepp soon in a near vertical sloper configuration, but this might be just the ticket for my QTH. Thanks for sharing!

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #3 on: January 27, 2018, 06:18:04 PM »
Hmmm, I just got a 40 foot Spiderbeam for which this might be just the ticket, though I might be looking at something closer to 80m resonance with that much beam. I will try out the zip-zepp soon in a near vertical sloper configuration, but this might be just the ticket for my QTH. Thanks for sharing!

The W3EDP and ZIPP-ZEPP are great for all band quick deploy but the 4 to 1 balun with 51  (or even just 50 ) feet of wire on each leg of a 'dipole' or inverted "V" configureation will net a good 5 to 8 plus DB of increased capability and my currently in us 51 foot by 84 foot off center fed will cover 6 to 160 meters well with a good antenna matcher/tuner. I still like and use the various ZEP antennas as they are fast and easy...like my first wife . BUT for performance when you have time and or help to put it up the dipole.inverted "V" with more wire do impress.

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #4 on: January 28, 2018, 07:10:17 PM »
MTenna tested

My local student/antenna helper came by today and we set up a 51 foot per side DOUBLIT (a non resonant dipole or inverted "V" antenna) in the experimental VERTICAL format for small lots . We set it up low enough to earth to get reasonable fotos as this antenna is a bit different as to take advantage of lightweight fishing poles of 20 feet long without overloading them with weight. I would use a speaker tripod and 20 foot tall ,NON CONDUCTING fiberglass pole with the 4 to 1 balun mounted at the base of the pole so balun and coax do not weigh down the support. This test antenna was set to about 15 feet total height above the ground and took less than 15 minutes for ONE MAN ,who only had an idea of what I wanted to do. The 6 foot of rope with pass through loops on each end gave about 36 inches spread of the antenna elements as it was set up a bit shorter than idea.

  With the balun at about 4 feet high and coax connected the 'legs' of the 51 foot antenna were passed through a loop of rope on each side  of the pole and then the pole was expanded to height and the ends pulled to tie points on each direction and the antenna was complete. When compared to the ZIPP ZEPP of 17 and 51 feet length...it made the ZEPP look and sound anemic.as there was a good 5 DB improvement with the M'Tenna...WOW. I link to a few photos of the antenna and the resulting contacts from this afternoon and HF was fairly poor though many stations were heard and contacted.

only 102 feet of wire (actually 51 feet of low cost speaker wire ) and a 4 to 1 LDG balun made an impressive vertical antenna in a small space.


https://drive.google.com/open?id=1Br1h_E-je2wUN0PDPP3t0JArCs4jV2LS

Offline Smurf Hunter

  • Survival Veteran
  • ********
  • Posts: 7024
  • Karma: 329
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #5 on: January 28, 2018, 07:17:40 PM »
I did something similar during winter field day.  Bought a cheap spool of thin gauge speaker wire, (50 feet) and used the 4:1 LDG balun.  It worked.  Made over a dozen contacts in a couple hours.

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #6 on: January 28, 2018, 07:43:29 PM »
I did something similar during winter field day.  Bought a cheap spool of thin gauge speaker wire, (50 feet) and used the 4:1 LDG balun.  It worked.  Made over a dozen contacts in a couple hours.

A good antenna matcher makes all the difference!

Offline Canadian Prepper

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 54
  • New TSP Forum member
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #7 on: January 29, 2018, 04:57:31 AM »
Looks great! I haven't cut up the wire for the Zipp Zepp yet and think that I'll go with this option instead. I will probably have to forego the crappie rod option and use the Spiderbeam, as I don't think I'd have the space to comfortably spread out the remaining 70 feet or so of wire that was probably left over in your set up. I will try about 30-36 feet high and see how that works.

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #8 on: January 29, 2018, 05:28:13 AM »
  As a dipole,inverted"V",sloper,or "M" antenna...the 51 foot doublet (non-resonant balanced antenna) is a winner when used with a good tuner as a 6 through 80 meter antenna that is cheap and easy. I do want to mention that a slight modification is the 51 foot by 84 foot ,off center antenna that will tune 6 to 160 meters and provides good gain on 6 to 80 meters with very acceptable performance on 160 meters.I have used it to add frequency agility at my home station for several weeks now and find it very capable as many of my repeat contacts on nets I check into have commented with such as "Did you get an amplifier?" and noted while much of the propagation is poor ,I sound better. The yard I have is about 50 by 50 feet and has power lines on two side with a huge tree on the third side and my house on the fourth side,less than ideal. The antenna wraps around as it can fit  in a lopsided diamond configuration and radiation pattern is the least of my thoughts.

  Put some wire in the air and operate,all the equations ,math,and charts can be done after you see this bumble-bee can fly.

  The "M"tenna was placed in the middle of all of this wire and junk and still performed on a day that the band was pretty poor.

Offline Greekman

  • Survival Demonstrator
  • *******
  • Posts: 3621
  • Karma: 190
  • New TSP Forum member
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #9 on: January 29, 2018, 06:12:25 AM »
Carl, from the pics i see that the M's outer legs are on a shallower angle. (obvious since yuo use only a 6m pole)

So if you were to go higher and form a perfect M (actually an inverted W)- with wire ends almost touching the ground)- how would this perform/act in theory?
Cos that would be like half the legs of an inverted V were moved sideways

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #10 on: January 29, 2018, 06:43:37 AM »
Carl, from the pics i see that the M's outer legs are on a shallower angle. (obvious since yuo use only a 6m pole)

So if you were to go higher and form a perfect M (actually an inverted W)- with wire ends almost touching the ground)- how would this perform/act in theory?
Cos that would be like half the legs of an inverted V were moved sideways

A taller support and more vertical "M" will make a smaller footprint antenna and I suggest 4 to 5 feet as a minimum separation at the wide areas between wires this should work well ,though the antenna tuning will change a bit....this is why an antenna matcher/tuner is the heart of non-resonant antennas working though any wire will radiate RF (being longer than 1/4 wave on bands used helps efficiency) the radio of today needs a 50 ohm match (25 to 100 OHM) to load it's power properly and not be damaged. We tune antennas so the radio is 'happy' ,not to get better RF as any wire will work as long as the radio sees it's expected load.

While I prefer a horizontal antenna that is low to earth for NVIS as it provides better ,close in 50 to 500 mile capability for emergency...the vertical still has a place for it's greater distance capability as smart operators can RELAY a message back into your area easily and accomplish success. Antennas are the most simple and easy to make part of radio and design can effect your capability far more than amplifiers and such...I have over TEN antennas in my 50 by 50 foot yard to do my radio work with and have great success with wire bought cheap or found in the trash.

  I often see artists of great fame making treasures from junk and so I feel I am in good company with my wire farm.

Ham is a skill,the more active you are ,the greater success and satisfaction you will have.

Offline Canadian Prepper

  • Survivalist Mentor
  • *****
  • Posts: 674
  • Karma: 54
  • New TSP Forum member
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #11 on: February 03, 2018, 10:25:46 PM »
I finally put together a 102 ft doublet today in the "M" configuration and tried her out in the back yard. I used a Spiderbeam fibreglass pole extended to about 36 feet (max length is 40ft) and with the LDG 4:1 Balun about 3-4 feet off the ground had just enough space to fit everything in the space available. The pole did collapse upon itself a few times, but given the wind, cold and lack additional guying I won't complain about it given the hastiness of my setup. The company does sell clamps for permanent installations and I probably could have avoided the collapsing issue had I been more careful to tighten each section as I extended it.

I only did three check ins to some local 80m nets but heard a fair bit of traffic and rather clearly on 160, 80, 40 and 20m. The SWR was relatively low (2-4) on the 20m band and above, and went up to about 6-10 SWR on 40-160m, but it was still tunable on those bands. I have enough speaker wire left to put together another leg for a 6-160m Windom but will have to wait at least until I have access to parts of the yard where I could hook up that extra length of wire to fit within the available space or will keep that for portable operations in the future.

I seemed to miss out a bit on more local traffic due to the configuration, but the nets I checked into had people further away who were able to provide good signal reports and relay back to closer net control stations. The vertical sections of wire were closer than in Carl's experiments and came back down at a fairly sharp angle, but I was pleasantly surprised that the noise level was actually lower than with my W3EPD end fed, that by necessity paralleled three power lined and was lower/ closer to potential sources of interference. To be fair to the latter antenna, I since picked up a Common Mode Choke RF choke, isolator and noise suppressor from MyAntennas.com and wasn't able to test it's potential effects on the noise floor of the W3EPD for comparison.

I will have to try to install the antenna in a more robust manner, and perhaps even trim some branches, but I was very impressed with my initial experiments. My schedule won't allow much daytime testing in the coming weeks on the higher bands, but I hope to do so after that. This may very well be the best, and reasonably cost effective setup for my given space, and suspect that I'll do a fair bit more hamming in the coming months than if I hadn't tried this option.

Thanks Carl!

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #12 on: February 04, 2018, 05:21:28 AM »
 Thanks Canadian Prepper on your report. My local antenna helper JEFF has also ordered the same spider pole and is going to test his soon also. The vertical orientation does tend to have less capability than a horizontal (NVIS) configuration but the antenna can be oriented many ways to favor the need and I notice about six DB difference when the antenna is operating outside of it's favored range as in an NVIS used for distance (beyond 500 miles) and a vertical used for local or (under 500 miles) though blockage from terrain may cause more as when operation within a valley will do much better with NVIS to get more signal out.

  I have not studied the noise factor of the "M" antenna yet and appreciate your noting the noise as it will prompt another 'antenna day with Jeff and myself in the future.

Offline Greekman

  • Survival Demonstrator
  • *******
  • Posts: 3621
  • Karma: 190
  • New TSP Forum member
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #13 on: February 05, 2018, 05:38:44 AM »
Carl, i have 2 novice questions.
1- What would the groundwave be with the M?
2- if you were to move the outer (half) elements almost horizontally, what would that make? A disaster or a dual use antenna? (I mean vertical + NVIS function)

Offline Carl

  • Mr HamTastic!
  • Forum Veteran
  • *********
  • Posts: 13112
  • Karma: 712
  • COW?...No ,I haven't seen your cow.
Re: Small area,BIG ANTENNA...The "M" vertical
« Reply #14 on: February 05, 2018, 06:15:48 AM »
Carl, i have 2 novice questions.
1- What would the groundwave be with the M?
2- if you were to move the outer (half) elements almost horizontally, what would that make? A disaster or a dual use antenna? (I mean vertical + NVIS function)

1Ground wave is due to curvature of the earth,hills and terrain,and height above terrain...HF will work just better (a few percentage points) than VHF/UHF and so ,depending on the other operators antenna...about 15 miles with a 30 foot tall M tenna

2You can have a combined polarity and DX/NVIS antenna though I much prefer to make either a

 Vertical (for distance transmit with higher man made noise)
Or NVIS with a 10 to 12 foot high dipole or inverted "V" for better NVIS and lower noise on receive

Most any configuration will 'WORK' though a purposely configured antenna can get better desired results.

I have an antenna that is BURIED below the surface To keep my BOL more hidden, and while it should not work...I get good results as it is low noise and soil conductivity is poor so the antenna acts more like it is a few feet ABOVE earth...a 4 to 1 balun with 250 feet of wire buried a few inches below the surface  on a HILL TOP and it works great ,even when many can hear only noise on the bands.

Many times we must compromise an antenna due to trees and terrain as most any antenna is a compromise. A VERTICAL works better at a distance (400 to 1600 plus miles),though it misses at closer range...A NVIS works better at close range (1 to 600 miles) BUT performs well from within a valley or behind a hill or to get into other valleys  as it bounces well and yet still can be heard well at a distance.
« Last Edit: February 05, 2018, 06:21:49 AM by Carl »