| AB4D |
Rating:  |
2012-12-18 | |
| Very Good, but hardware could be improved. |
Time Owned: 0 to 3 months. |
Hi. I recently installed a M2 40M4LLDD 4 Element 40 meter Linear Loaded Yagi at my QTH. This is my experience with M2 and the antenna thus far.
Purchase: The purchase and shipping experience with M2 was fine, the cost was roughly just under $2400 delivered. The antenna arrived in good shape within the time stated. The parts arrived in a rather large, heavy box, with the boom sections all wrapped together in plastic wrap. If you are not getting door to door service, I suggest you bring along a helper for loading at the depot and unloading once you get home. This one is quite heavy.
Assembly, Manual, Parts, and installation: The manual could be significantly improved. A few detailed photos of a completed antenna assembly, could answer a lot of questions one may have during the assembly of the antenna. The manual only gives drawings that are not always clear, and only shows one side 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? I called M2 for that information and found them to be very helpful.
The antenna contains a large amount of small parts and hardware, some which was missing from my order. The count given in the manual for a few of the smaller #8 screws was less than I received, 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 the M2 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, I was concerned about several key components that were provided with the antenna. My first concern was the locking nuts on the turnbuckles. The way the turnbuckles have to be installed on the antenna, 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 loosen due to vibration or wind. Therefore, I added left hand threaded nuts to the other end of the each turnbuckle as well, thus locking both sides.
The antenna comes with enough cable clamps to use two per end on the Phillystran support guy. Another amateur I talk to with previous M2 40 meter antenna experience, indicated that with two clamps, the Phillystran had slipped on another friends antenna, and that required them to take down the antenna for repairs. To prevent that, I added a third clamp to each end.
Another concern of mine, was the boom support. M2 provides a section of Dacron rope to support the boom. IMO, on a 42 foot boom, that component would not last very long. I changed that 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 looked totally inadequate to me, and my suspicions were realized during installation when they failed.
I own a tilt-over, crank up tower. To install the antenna, my plan was 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.
The weight of the antenna literally bent the boom plate and the four clamps, causing the antenna to spin free on the mast. To remedy that, 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 antenna. The new plate and clamps are working excellent to support this large antenna.
Tuning and On the Air: Using the settings given in the manual, the antenna covers the entire 40 meter band. The SWR is around 1.7 on the band edges, with a nice smooth curve bottoming out around 1.1 on 7.180. No adjustments are necessary, but I now need to retune a six meter beam that is four feet above this one (now resonance is 49.850), so there is some minor interaction.
At this time, I don’t have my rotator control lines installed, so the antenna is fixed at 45 degrees East of North. 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, while I am running just 200 watts.
I notice the bulk of U.S. stations are given S-9, while I am given 10-20 over S-9 signal reports. I am copying stations easily, I worked a UK station last night and also heard Israel come in for a contact behind me, both were 20 over S-9 on an Icom IC7700, with the preamps turned off.
On receive, 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. Once I get the rotor system fully operational, I will start hunting the weak ones, and that will be the real test for this antenna. I am rating the antenna a 4, because of the inadequate boom to mast plate and clamps, a critical component in my opinion.
73
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| W3UA |
Rating: |
2005-08-15 | |
| Can't imagine anything better for the task |
Time Owned: 6 to 12 months. |
When I moved from Texas to New Hampshire, I got a 6.5 acres in antenna friendly town (no height limit and setback limitations, since "amateur radio is considered an important part of the US Civil Defence system"). So a little antenna farm became a reality.
KC1XX (who actually built my antenna systems) suggested M2 as the only vendor which makes antennas strong enough for NH winter storms and icing. I decided for stacks of 2x5 element for 20, 2x6 element for 15 and 3x7 element yagies for 10. As for 40, I picked 40M4LLDD. It shares the 80' tower with 10 meter stack, and rotates with top 10 meter beam (lower beams on all towers are fixed to Europe). So far, antenna works excellent. I can work everyone I hear, and if propagation permits, I can hear anyone spotted on the cluster. F/B and F/S are phenomenal -- stations pop from nowhere to S9. SWR is less than 1:2 within 300 KHz, and my Alpha 87A has no problem to tune the antenna anywhere on the band. It is also very stable, despite high winds, icing, rain, etc.
I have home built 3 ele 40 meter yagi in my Moscow QTH (similar to Force 12 linear loaded), which helps... to be on the par with tens of other average Russian stations; but the M2 makes me really feel good. I know, RA3-land is different, and the comparison may be unfair, but still...
The bottom line: if you have at least 70' tower and decent rotator -- this beam may be the best bet. |
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