Final Review and Installation of the M2 40M4LLDD

Hi.  This is my experience and an expansion of a review I posted on regarding the M2 40M4LLDD 4 Element 40 meter Linear Loaded Yagi.

Purchase: The purchase and shipping experience with M2 was FB. The cost of the antenna was roughly just under $2400 US, delivered. The antenna arrived in good shape within the time stated. The parts arrived in a rather large, heavy box, with the three boom sections all wrapped together in plastic wrap.

Manual, Parts, Assembly and Installation: The manual for the antenna could be significantly improved. A few detailed photos of a completed antenna assembly, could answer a lot of questions someone may have during the assembly process. The manual only gives drawings, that are not always clear, and only shows one half of the antenna. I had a question about the linear loading lines on both sides of the antenna, whether they mirror each other or does it matter? Nevertheless, I contacted M2 for assistance and found them to be very helpful.

The antenna contains a large amount of small parts and hardware, some that was missing from my order. The parts count given in the manual for a few of the smaller #8 screws, indicated that I should have received more than was actually delivered, and I was given extra longer screws that I did not need.  I was able to replace the missing hardware at the local big box store. I am sure M2 Inc. would have provided the missing screws, but I was on a time schedule and did not want to delay the assembly waiting for generic parts. Other than noted below, most of the antenna components seem to be very good quality and up to the task.

During assembly and installation, I was concerned about several key components that were provided with the antenna. My first concern, the locking nuts on the turnbuckles. The way the turnbuckles are supposed to be installed on the antenna for the elements, the standard thread locking nut is not on the side of the turnbuckle that attaches to the metal center support. Rather, the locking nut is on the side of the turnbuckle that holds the support rope or Phillystran.  I did not like that arrangement at all. I thought it would be better to have a locking nut on the side of the antenna that could not rotate due to vibration or wind. Therefore, I added left hand threaded nuts to the other end of each turnbuckle as well, thus locking both sides.

The antenna comes with just enough cable clamps to use two per end on the Phillystran support guys. Another amateur I know that has previous experience with a M2 full size 40 meter beam, indicated that with two cable clamps, the Phillystran support for those elements had slipped. To prevent that from happening, I added a third clamp to each end of the Phillystran support guys.

Another concern of mine was the boom support.  M2 provides a section of Dacron rope to support the boom. IMO, with a 42 foot boom, rope may not last very long.  At first, I contemplated using aircraft grade cable for the boom support, but I wanted to avoid any interaction from using a metal support.  Therefore, I changed from rope to 2100 pound rated Phillystran.  

Moreover, the last two components that really concerned me was the rather small boom to mast plate, and the 4 muffler style clamps provided to secure the antenna to the mast. They appeared inadequate to me, and my suspicions were realized during the installation, because the clamps failed.

I own a tilt-over, crank up tower. To install the antenna from the ground, I planned to install the center section of the antenna. Add the front boom section, director, and support. Rotate the antenna 180 degrees. Then install the rear boom section, reflector and support. During assembly, things went as planned, until I attempted to crank the tower back over to install the rear boom section after I had rotated the antenna.

The unbalanced weight of the antenna literally warped the boom plate and two of the four mast clamps, causing the antenna to rotate freely out of control on the mast. Luckily, no permanent damage occurred, because the elements flexed, rather than bent, when they made contact with the ground.  To remedy that issue, I purchased a much larger boom plate and solid cast aluminum clamps with stainless bolts from DX Engineering.  In my opinion, a must for this large antenna. The new plate and clamps are working excellent to support this large antenna.

Tuning and On the Air: The advantage to the M2 dual driven linear loaded design, is the increased usable bandwidth and near full size antenna performance in a smaller size footprint. Using the "Full Band" settings provided in the manual, the antenna covers the entire 40 meter band with an SWR below the advertised max SWR of 2:1. This has been confirmed on my installation. The measured SWR is 1.7 on the lower band edge at 7.000, 1.2 at the upper band edge of 7.300, and exhibits a nice smooth curve bottoming out around 1.1 on 7.180.  No additional adjustments were necessary, but it was necessary to retune a six meter beam that is mounted four feet above this one (now resonance is 49.850), so there is some minor interaction to that antenna.  Based on other's experience, the center antenna always suffers the most on a single mast multi-antenna installation.

At this time, I don’t have my rotator control lines installed, so the antenna is fixed at 45 degrees East of North towards Europe. So far, the gain seem so be on par as advertised. I’ve worked a few stations and have received “Big Signal” reports from stations on the other end, when I am just running 200 watts, at 1.5 KW, I've been told, I am the loudest station heard!

I notice the bulk of U.S. stations usually given "5/9", while I am consistently given 5-20+ over S-9 signal reports. I am copying stations easily as well.  As expected, the antenna works just as well on receive too. In comparison to a ladder line fed 120 foot inverted V at 70 feet, the beam has much better receive on DX in the direction it is pointed.  I’ve seen as much as 7 S units in difference.

Based on performance, I am very pleased with the antenna.  I hope to be more active on 40 meters, a band that I haven't used much in the past.  73 and Good DXing.

Failed Mast Clamps

Warped Boom Plate

TH-11DX, 40M4LLDD,  + 5 Elements on 6 Meters

Improved Boom to Mast Plate 40M4LLDD

The M2 40M4LLDD

The final Yagi antenna that I plan to soon install on my tower is a M2 40M4LLDD.  The antenna is quite large, but not near as heavy as I expected.  When assisted by another person, we can easily move this antenna around as I prepare for installation.  I hope the performance of the antenna is as impressive as its physical appearance. Overall, I would say the quality of the antenna is good, but there is room for improvement in regard to the instructions contained within the assembly manual, and with some of the hardware items.

First, there is a problem with the turnbuckles supplied to adjust the Phillystran lines that support each of the elements and linear loading lines.  The installation instructions show the element turnbuckles installed with the jam nut facing the center support bracket.  However, the end of the turnbuckle that has the jam nut is a closed loop, so it cannot be installed on the center support as shown.  Installing the turnbuckle in reverse, would allow the turnbuckle to loosen because the Phillystran line is not stiff enough to prevent the turnbuckle from turning.  To fix that issue, I had to also install a second jam nut on the opposite end of the turnbuckle. The nuts are left hand threaded and after checking multiple big box stores without success.  I was lucky enough to find them at one of the local True Value hardware stores.   

Another item that really concerns me is the boom support. M2 supplies a piece of UF rated rope, a mast bracket, and two turnbuckles to support the 42 foot boom.  I can see the rope not lasting very long and failing under stress if there is a significant freezing rain event.  If the center support fails under extreme load, it would not take much to destroy the antenna. To strengthen the support system, rather than using the supplied rope, I am installing aircraft grade cable in its place.

Another source of contention with me, the antenna is not supplied with any type of caps to close off the boom and elements. Left open, wasps and other insects will make my new antenna their home.  To resolve that issue, I obtained a set of vinyl caps from DX Engineering to close up the open elements and boom.  

Additionally, the manual could use clarification and revision.  Some of the written instructions contradict the illustrations, are unclear, or don't seem to match the parts count.  I kept referring to the same set of instructions multiple times to get a clear understanding of the correct assembly.  Another issue is the lay out of the illustrations, logically they should be next to the written instruction for the part of the antenna you are assembling.  However, it is necessary to flip back and forth between multiple pages to find the illustration that is applicable to the written text.

The assembled 40M4LLDD without the final element ends....   

The Hy-Gain TH11-DX

Over the past several days, I installed two of three Yagi-Uda style antennas on my ham radio tower. The antennas I installed are a M2 6M5XHP, five element beam for the six meter band, and a Hy-Gain TH 11-DX, 5 band HF beam for 20, 17, 15, 12, 10 meter bands. The next antenna to go up on the tower, will be the M2 40M4LLDD, a shortened linear loaded 4 element antenna for the 40 meter band.  Unlike other  smaller antennas that can be assembled on the ground, and then moved to the tower for installation.  I believe, it may be easier to install the elements on the boom, once it has been mounted on the mast.

TH 11-DX on the tower...


Amateur Radio Interference

Hi.  While casually surfing the net, I occasionally run across incorrect information regarding Amateur Radio, especially in relation to interference complaints by consumers, who allege that a ham radio station is interfering with their home entertainment equipment.

These self-appointed experts about interference matters, really say some incorrect things.  Below are a few examples from a message board that I recently read Ham Radio Interference. That thread contains quite a bit of incorrect information...which I will debunk with fact.

"A few years ago the FCC started imposing new restrictions on hams including scanning their emissions for unintended directionality and the like. I believe every ham was required to scan the area for their particular modes of operation."

The FCC has never imposed broad restrictions on ham radio operators, beyond the rules and regulations published in Part 97. Unless there has been some level of enforcement action, operating restrictions are rarely imposed. The rules state, the FCC can impose quiet hours on hams (47 CFR 97.121).  However, in my experience, I have never heard of anyone being restricted by the FCC for causing interference to their neighbor's TV set or Stereo.  Long ago the FCC realized, 99.9% of interference to home entertainment equipment is usually caused by the poorly designed receiving equipment being sold in the U.S. from China and Southeast Asia.  Even well known name brand products from companies based in Japan, many times do not have adequate shielding and filtering.

To maximize profits, manufacturers of home entertainment products take a chance to save a few dollars on each unit by not properly shielding and filtering that equipment.  They count on the fact, that most of the equipment will never be co-located near an RF transmitter.  Combining that equipment with the poor installation usually performed by most consumers, it's a recipe for interference.  When consumers use cheap poorly shielded wires from the local big box stores or Wal-Mart, to interconnect that equipment, and then leave a rats nest of wire behind the TV or Stereo, they've also built themselves a great antenna to increase their vulnerability for interference.

Not withstanding that posters comments, the FCC does not randomly scan ham radio emissions for "unintended directionality".  I don't even know what that term implies. The expectation from the FCC is we self-police our own.  If a station is out of compliance, and is experiencing technical issues, that condition is usually immediately noticed by other hams. The offending station is usually informed there is an issue that requires their attention.   

Another post in that thread reads...

"It is not legal for a ham operator to interfere with his neighbors' electronic devices. There are laws to protect the citizens from invasive radio frequencies."

There are no federal laws that "protect the citizen from invasive radio frequencies." There are no laws against something that does not exist.  There is no such thing as an "invasive radio frequency." I believe the poster was trying to say "invasive radio frequency signals" a fact of life in our modern society.  We are all subjected to it, and our bodies are invaded by it each day without our consent. Radio frequency energy is used by our cars, cell phones, broadcast radio and TV transmitters, radar systems for aircraft and weather, public service communications fire/police, home entertainment devices, even using an IPod/IPad or computer subjects us to small amounts of RF energy at various frequencies, it's everywhere.

There are some state and local nuisance laws in the U.S. that various localities try to enforce. However, those laws are only applicable to interference caused by non-licensed stations, such as CB radio operators using illegal non-type excepted equipment and high power external amplifiers.  Since amateur radio is a licensed service regulated by the FCC, local and state law enforcement has no jurisdiction over the operation of a amateur radio station. The courts have repeatedly stated, the FCC has sole jurisdiction in the United States over all matters relating to any station licensed under the radio services regulated by the FCC.

In closing, one poster actually provided factual information....

"More than likely the fault is due to lack of/or inadequate filtering inside the TV or a break in the cable system. FCC Part 15 specifically states that the TV user must accept any unintentional interference from transmitters operating within specification. Check your user's manual."

That is a true statement. 47 CFR 15.5b, states that "Operation of an intentional, unintentional, or incidental radiator is subject to the conditions that no harmful interference is caused and that interference must be accepted that may be caused by the operation of an authorized radio station, by another intentional or unintentional radiator, by industrial, scientific and medical (ISM) equipment, or by an incidental radiator."  In laymen terms, if you own and operate any device that is regulated under Part 15 of the Commission's rules (which most home electronic entertainment devices full under those rules), it must accept any interference that may be caused by the operation of an authorized radio stations (i.e. a licensed amateur radio station; emphasis added), and may not cause interference to any licensed radio station.

When the marketplace became flooded in the 1980's with cheap electronics and home entertainment devices, the FCC revised Part 15 (54 FR 17714, Apr. 25, 1989, as amended at 75 FR 63031, Oct. 13, 2010), to state that Part 15 devices must accept interference from licensed stations FCC Part 15.

If you are a consumer, and are experiencing Radio Frequency Interference, do not jump to the conclusion that the source of the interference is from "that ham down the street."  Interference that affects the operation of a device can come from many sources, sometimes even within your own home. Do not demand that he or she cease all operation. It is an unreasonable request, and can set a tone for non-cooperation.  Unless the station is being operated not in accordance with good engineering and good amateur practice as determined by the FCC, amateur radio operators are under no obligation to help you solve the interference condition you are experiencing.  Rather, if you suspect an amateur radio station is interfering with your equipment, politely tell him or her what you are experiencing and ask if they can help.  Most amateur radio operators will be happy to help you track down the source of the interference, even if they are the source. Many times they can provide the technical assistance needed to help you correct the situation. 

The M2 6M5XHP

Today, I was able to assemble the first of three Yagi style antennas that I plan to soon install on my tower.  The antenna is an M2 6M5XHP, a five element beam for the six meter band.  The antenna seems to be designed OK, but the elements and boom could be a little more robust.

In the past, I owned a 5 element six meter beam from Cushcraft.  On that antenna, the elements are made from larger tubing and the elements are attached to the boom by heavy stainless steel saddle clamps.  The M2 antenna uses smaller tubing for the elements, and they are attached to an aluminum block with a single screw, and the block is attached to the boom by another single screw.

The antenna should survive, but I will certainlly keep an eye on this one during any severe weather or ice storms.



Antennas for the Tower...

During the past year, AB4D has been off the air while expanding the QTH.  Now that construction is complete and the dust has settled.  I am again focusing my attention to expanding my capabilities on the HF bands, and to build a satisfactory antenna system for my amateur radio station.

HF 40/75/80 meters:  The antenna selection for those particular bands was fairly easy.  I previously used a horizontal dipole strung between two fixed points, fed with 600 ohm ladder line. It worked well for those bands. However, this time I wanted the antenna center supported by my tower.  Therefore, I installed another wire dipole fed with 600 ohm ladder line, but in an inverted "V" configuration.  The feed point is at 70 feet with the ends situated at around 25 feet from the ground.  It's working well at this time, and I have received good signal reports from other stations.   Although, I do note that I now have a small bit of measurable RF at the operating position.  I will work on that antenna to reduce the amount of stray RF.

To further enhance my operating capabilities on 40 meters, I plan to install a M2 40M4LLDD 4 element 40 meter Yagi on the tower.  Comments and reviews about the 40M4LLDD have been favorable.  Although not the biggest gun out there.  It fits both within my budget and the specifications of my tower, along with the other antennas and hardware I plan to add.   
Multi-band HF Antenna 20-10 meters:  I found, trying to choose an antenna for HF multi-band operation can be a daunting task.  There are many choices available, ranging in price from several hundred dollars to well over $8,000 dollars.  They come in all types of designs; linear loaded, shortened elements;  trapped; mechanically adjusted; and log cell; all with claimed specifications that sometimes make it hard to perform an apples to apples comparison.  I performed considerable research, and read a lot of reviews about the many antennas available on the market from various manufacturers.  Basically, all multi-band antennas present some type of compromise or issues.  Finding out the compromises, and determining if you can live with them can help you make an educated decision.

My initial goal, if possible, was to cover the bands from 40 to 6 meters with one large directional antenna.  However, I found many antennas that would accomplish that feat, and have good specifications while being compatible with my tower, were antennas that had as I would say, "other issues".  The first antenna design I considered was the Steppir. A lot of hams who own Steppir antennas like them.  However, there have been some spotty reliability and mechanical strength issues. The Steppir antennas are complex, heavy, and seem to be one of the most expensive antennas on the market.  I priced out their newest beast, the Dream Beam 42.  With options, the antenna was priced at well over $8,000 dollars before delivery, and they did not recommend placing one on my HDX tower.  I also reviewed one of their more moderately priced antennas, a 4 element Yagi.  That antenna approaches $3000 in cost, but the gain specifications were not all that much better than conventional 5 band beams costing significantly less, usually within one db or less.  The one db difference of gain probably would go unnoticed by most operators.  IMO band conditions and propagation path play a more important role.  Based on the reviews I've read regarding reliability, and some opinions that question Steppir's performance claims,  I decided to stay away from the Steppir.  Mostly, because I just didn't believe the antenna design can survive long term (10-20 years) without major component failures.  There are way too many moving parts involved in the Steppir for my liking.

The second line of antennas I considered, was the Optibeam antennas.  Optibeam antennas have been getting very good reviews from the amateur community.  However, like the Steppir these antennas are somewhat expensive, and unlike the Steppir, they are not readily available to U.S. amateurs.  The Optibeam antennas are made in Germany, and that equals to very inflated shipping costs, plus Customs fees for any individual in the U.S. who wishes to import an Optibeam.  If there was a stocking dealer in the U.S., I certainly would give an Optibeam serious consideration, but I find it hard to part with nearly an extra $1000+ dollars in shipping and Customs fees to obtain that antenna.  For some it's worth it, for me it's not.  Array Solutions is the only U.S. dealer for Optibeam, but sadly they do not stock them.  I believe Optibeam is missing out on a significant number of sales by limiting themselves to only one manufacturing facility.  IMO, a smart business decision would be to partner with someone in the U.S. to start manufacturing their antenna designs here as well.

I've also considered antennas from Cushcraft, Mosley, M2, Force 12, Tennadyne, and Hy-Gain.  Cushcraft offers what I consider are value priced antennas with moderate performance, they are good entry level antennas.  However, they publish what I believe are questionable performance claims for some of their antenna line.  Based on past experience with Cushcraft, the quality is sometimes lacking.  The only exception is the Cushcraft X-7, that was designed by Danny Horvat E73M.  I found the X-7 performed well, and the boom and element components are exceptionally strong.  I wish many antenna manufacturers would supply such heavy duty boom brackets.  Nevertheless, even the X-7 arrived with a non-functional Balun that required replacement.  Cushcraft is now part of MFJ Enterprises, Inc.  Unfortunately, I suspect the quality has not improved with the change in ownership.  

Mosley is another brand of antenna I considered.  However, I read a significant number of complaints about Mosley antennas.  Many of the complaints are in regard to poor quality, and the relatively short life of their plastic components, traps, and trap forms.  Moreover, back in the late 90's, H. Ward Silver, N0AX and Steve Morris, K7LXC, performed extensive testing of multiple tri-band antenna, and published the results in a booklet titled, HF-TRIBANDER-PERFORMANCE-TEST-METHODS-RESULTS.  Based on what I've read from hams who purchased that report, their testing actually showed negative gain figures on some band segments for the Mosley antenna under test.

All of the above narrowed my available choices to antennas from M2, Force 12, Tennadyne, and Hygain.  All four of these companies seem to make quality products. I consistently read mostly favorable reviews about their products.  In regard to Force 12, they seem to make good products, but there were a few reviews that noted long term problems with their use of pop rivets for assembly.  I was considering the Force 12 5BA, but one commenter noted the longer elements can sometimes whip around in the wind, and touch other elements to the point that it caused his amplifier to "trip out".

Tennadyne offers log periodic antennas, that seem to be first rate. Their specifications and the reviews of their longer boom log periodic antenna are impressive.  If I had a second tower,  I would certainly consider one of their antennas as a second HF antenna.   However, I could not get the band coverage I am seeking using one of their antenna along with the other antennas and hardware I plan to install, without exceeding the specification of the HDX-572 tower 50 mph ratings.

Hy-gain and M2 are the two remaining manufacturers I considered.  I found that both had compatible antennas to fit all of my criteria, (cost to benefit ratio, band coverage, proven reputation of strength, acceptable specifications, and combination of weight and wind loading did not exceed the ratings of my tower).

Trying to find an antenna that covers 40 through 6 meters without sacrificing too much is problematic. Rather, I found it was better in my situation to run two monobanders and one 5 band antenna. As mentioned above, I am installing a M2 40M4LLDD 4 element 40 meter antenna.  The antenna has received favorable reviews, and M2 antenna are known to handle severe weather with ease. At least one well know installer of ham radio towers and antenna systems in the Northeast commented, that M2 antennas are the only ones that can survive the harsh New England winters. 

In relation to 6 meters, I also chose an M2 antenna, model 6M5XHP.  The antenna is a 5 element monobander that covers the bottom 300khz of the SSB portion of the band. The antenna offers reasonable gain and rejection.  I've previously used a similar antenna on that band.  When 6 meters is open, it is a fun band that requires very little power to make a lot of long distance contacts.

To cover the 10 through 20 meter bands, I chose a Hy-Gain TH-11DX 5 band antenna. Although the design may be considered dated by some, I was hard pressed to find any negative reviews about that particular antenna.  Rather, I found many favorable reviews and comments about the TH-11DX.
I understand testing by N0AX and K7LXC revealed accurate published specifications from Hy-gain.


Photos of the feed line, static discharge unit, and inverted V antenna on the tower.

AB4D is now QRV...


The mobile station is now partially functional.  I have the VHF and UHF bands working, along with the mobile APRS (AB4D-9).  Since the vehicle is mostly used on the weekends and when I am not working, if mobile, I will show up on the maps at  Track AB4D-9

I am still working on the HF side of the station.  I acquired a Tokyo Hy-Power HL450B and a Scorpion HF Screwdriver antenna to interface into the mobile station. I will post more info about the mobile installation as it develops.

Mobile Install: