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Message |
    
Wire_saber
Junior Member
Username: Wire_saber
Post Number: 14
Registered: 4-2015
| | Posted on Friday, August 21, 2015 - 1:53 pm: | 
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I'm compelled to share an experience that may benefit others. Recently lowered my Sirio GM for its first PMI in 3 years. Its feed point is at 54' from the soil. Everything was good. While the GM had whipped and gracefully sustained 40 to 50 MPH winds without problems, I began to worry about some 'bad reviews' that appear to be based solely on its perceived fragility. So, before re-installation, I tied 3 strings, 120 degrees apart, from the middle of the GM to the anchors that support the tower. Two days ago, my area was hit by rain & wind gusts of 60 to 80 MPH. After witnessing the wind fury from a small window in the basement, and helping to clear numerous trees fallen all around, I'm convinced that the parachute cord saved the antenna. The flexibility of the cord allowed the antenna to whip, but its reinforcing hold definitely precluded damage. Wet or dry, the cords do not affect the exceptional characteristics of the GM. I recommend the use of non-conductive cord to reinforce GM's in areas where wind gusts may present a hazard. |
Keithinatlanta
Senior Member
Username: Keithinatlanta
Post Number: 1037
Registered: 3-2003
| | Posted on Wednesday, September 02, 2015 - 8:26 pm: |
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Wire Saber, that is a great idea. Where do you find the parachute cord? Thanks.
Keith in Atlanta
CEF 150 |
Wire_saber
Junior Member
Username: Wire_saber
Post Number: 17
Registered: 4-2015
| | Posted on Thursday, September 03, 2015 - 10:42 pm: |
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Hello Keithinatlanta: Bought it at the sports/ camping section of a nearby Army Exchange Store. The same product can be obtained at Wallmart or thru Amazzon. I used the parachute cord nylon 550 in olive-green color, for its subdued appearance. $6 each bag of 100'. |
Rumblefish
Junior Member
Username: Rumblefish
Post Number: 49
Registered: 12-2002
| | Posted on Wednesday, February 10, 2016 - 11:34 am: |
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Unfortunately I didn't have the same luck with the GainMaster. Originally I had the gpe 27 5/8's wave up on the side of the house. It was a very good antenna. It started to have SWR problems when it would rain. It finally gave up the ghost when Sandy came through in 2012. I cant blame the antenna for that. I decided to give the GM a try. I couldn't have secured the antenna with guy lines because of where it's mounted. We recently had a big snow storm come through the area. 45 to 50 mph winds. It broke just above the clamp closest to base of the antenna. This seems to be a problem spot for these antennas. I didn't notice any difference in performance to the gpe. I just don't feel the antenna was worth 200 dollars. It's been replaced with the Imax 2000. We had some wind gusts in the 40 mph range and it did whip around quite a bit. so far no problems. I'm hoping the Imax will last longer than the GM. Again I saw no difference in performance from the other antennas. I don't have the ground plane kit on the Imax. I'm not sure if I will get one. 60 dollars for the kit seems a bit much. I hope you have a better experience with the GM than I did. 73's. |
Wire_saber
Junior Member
Username: Wire_saber
Post Number: 39
Registered: 4-2015
| | Posted on Monday, February 15, 2016 - 10:31 pm: |
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K: Your disappointment is not isolated. That is why I shared my notes about reinforcing the GM. There may not be as many anecdotes of I-2Ks snapping against strong winds, but if the need arose, I would not be inclined to replace the GM with an I2K just for the lesser incidence of mishaps. I've become too used to making wide frequency excursions at less than 1:1.5 vswr, without having to retune the antenna, or using an external matcher/ tunning device. The reassurance of the built-in bottom coil against any EMI, is just an added plus to the purported advantage of a lower angle of radiation. I'm aware that guying a GM with nonconductive cord may not be an option for all hobbyists, but it may work for many as it has for me. |
Wire_saber
Junior Member
Username: Wire_saber
Post Number: 40
Registered: 4-2015
| | Posted on Monday, February 15, 2016 - 10:42 pm: |
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Hi Rumblefish: I mistakenly started my last post with K. It is admirable that you have persisted with the hobby after the loss of two antennas. This third time will be the charm. 73 |
Rumblefish
Member
Username: Rumblefish
Post Number: 50
Registered: 12-2002
| | Posted on Saturday, March 12, 2016 - 2:19 pm: |
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Hi Wire Saber, I got an email response back from a sirio rep. I may have over tightened the bottom clamp causing the failure, oh well live and learn. I would have gotten another aluminum 5/8ths, but living this close to the ocean they corrode quickly. Seeing that the gainmaster was a fiberglass antenna I wanted to try it out. It performed as well as the gpe. The only other 5/8ths fiberglass antenna was the I2K. So far the 2000 is performing flawlessly. I hope You're GM gives you years of trouble free service. 73 |
Dale
Senior Member
Username: Dale
Post Number: 2271
Registered: 12-2002
| | Posted on Thursday, March 17, 2016 - 7:59 pm: |
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rumblefish should have gotten a sirio 827. there the most robust antenna by sirio. local here has used ons since 2013 and loves it .has seen ice storms ,high winds no issues what so ever.
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
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