Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Paul, I doubt that anyone can predict the effect exactly without some very sophisticated modeling software and exact dimensions. I will give a stab at it, but because you are talking about a very wide frequency band and some unknowns about bonding and the conductivity of the roof you will have as an alternate I will have to speak in generalities. Since you are talking 30 feet from the antenna which is about 1/2 wavelength on 20 meters, presumed to be the lowest frequency, the effect should not be too great. The alternate roofing material will also affect radiation somewhat, so I would doubt that the solid metel effect would be much greater than composition shingles. I don't know much about ceramic roofs, but I would guess they would have a little greater effect than composition but less than metal. I would expect more effect on pattern than SWR or other loading indications. The effect, if noticed at all would be a slight signal improvement in the directions away from the room and a slight deterioration in the direction of the roof. I would expect that your situation will be very interesting for observation and discussion during rag chews and increase your enjoyment of your QTH and amateur radio. We hams like to observe and discuss such things at length. I would predict that you are much more likely to make interesting contacts while sitting in a dry hamshack talking on the radio than while replacing shingles standing on the roof. My advice as an Electrical Engineer and after 57 years as a ham radio operator is to buy the roof you want, enjoy the lack of leaks and continue to enjoy radio. I doubt that you will notice much difference in antenna performance, but you will spend many enjoyable hours trying and discussing the difference on the radio and in eyeball QSOs. Willis 'Cookie' Cooke K5EWJ Trustee N5BPS, USS Cavalla, USS Stewart From: Paul Taenzer ptaen...@gmail.com To: elecraft@mailman.qth.net Sent: Thursday, July 4, 2013 11:19 AM Subject: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace? Hello, We live on a very windy Island (with an industrial wind farm) and have been loosing shingles off the roof due to severe wind storms. We've been considering having a metal roof, but I'm wondering about the possible impact of the metal roof on the radiation pattern and efficacy of nearby antennas. There's a SteppIR on a tower about 20 feet from a corner of the roof. The antenna is about 30 feet higher than the highest point of the roof. I'd appreciate learning from anyone with relevant experience or technical expertise related to this. Many thanks. 73s, Paul VA3LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
The original poster did not mention doing anything to his antenna or feed line. He just wondered if putting a new metal roof on his house would screw up his antenna. The answer, I think is probably not enough to notice, so go for it. A leaky roof is not a joy at all! Willis 'Cookie' Cooke K5EWJ Trustee N5BPS, USS Cavalla, USS Stewart From: Jim Bennett w6...@mac.com To: Elecraft Reflector Reflector elecraft@mailman.qth.net Sent: Thursday, July 4, 2013 3:54 PM Subject: Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace? Not sure I'm liking where this conversation is going. I answered the original poster's question as to whether a metal roof has been seen to adversely affect antenna performance, not advocate doing stupid things. My installation worked very well for me w/o running high power. I knew I WOULD be doing QRO after a new roof was installed and subsequently ran my feeder in an appropriate location. Jim / W6JHB On Thursday, Jul 4, 2013, at Thursday, 12:52 PM, John Marvin wrote: I didn't see the original reply, but I just wanted to clear up one misconception. Homeowner's insurance covers stupidity. Unless it can be proved that you put that ladder line on the roof and ran high power through it with the intention of burning the house down, you would be covered. 73, John AC0ZG On 7/4/2013 1:19 PM, Jim Bennett wrote: Yes. Yes I was. :-) On Thursday, Jul 4, 2013, at Thursday, 12:11 PM, Tom H Childers wrote: You must have been running very low power. Laying any kind of ladder-line on a roof, insulated or not, is an excellent way to have a house fire that the insurance company will not pay for. Especialy a shake shingle roof. 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member [snip] 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
A 4 square can be badly affected by metal (towers, masts, metal roofs). The gain is similar but it loses front to back ratio in the affected direction. David G3UNA You forgot the Gain. Forexample you can loose 2 - 3 dB gain on an antenna due to interaction with another antenna or object and see no nothing on the SWR you measure down in the shack. Then you think everything is fine a perfect, well maybe it´s good since what you don´t know you don´t worry about. /SM2EKM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
On 2013-07-05 22:22, Brian Alsop wrote: SWR is a pretty coarse indication of interaction. Interactions can change directional antenna F/B and F/S ratio by 6-10 db easily (assuming you have it in the first place) and hardly affect SWR. At least, this is my experience from antenna modeling. However, we have to live with the hands we're dealt. Without any field strength measurements or calculations, one probably won't detect much. Ignorance is bliss. 73 de Brian/K3KO You forgot the Gain. Forexample you can loose 2 - 3 dB gain on an antenna due to interaction with another antenna or object and see no nothing on the SWR you measure down in the shack. Then you think everything is fine a perfect, well maybe it´s good since what you don´t know you don´t worry about. /SM2EKM __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
I had verticals on concrete, roof shingle and metal roofs. Always radials lying on top. The metal roof was the best by far. One way to find out how much the roof is affecting the performance of a beam is to look at SWR changes as the antenna is rotating. Ignacy, NO9E -- View this message in context: http://elecraft.365791.n2.nabble.com/OT-anyone-have-experience-with-effects-of-metal-roofs-on-antenna-performace-tp7576265p7576322.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
SWR is a pretty coarse indication of interaction. Interactions can change directional antenna F/B and F/S ratio by 6-10 db easily (assuming you have it in the first place) and hardly affect SWR. At least, this is my experience from antenna modeling. However, we have to live with the hands we're dealt. Without any field strength measurements or calculations, one probably won't detect much. Ignorance is bliss. 73 de Brian/K3KO On 7/5/2013 20:13, Ignacy wrote: I had verticals on concrete, roof shingle and metal roofs. Always radials lying on top. The metal roof was the best by far. One way to find out how much the roof is affecting the performance of a beam is to look at SWR changes as the antenna is rotating. Ignacy, NO9E -- View this message in context: http://elecraft.365791.n2.nabble.com/OT-anyone-have-experience-with-effects-of-metal-roofs-on-antenna-performace-tp7576265p7576322.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2242 / Virus Database: 3204/5967 - Release Date: 07/05/13 - No virus found in this message. Checked by AVG - www.avg.com Version: 2012.0.2242 / Virus Database: 3204/5967 - Release Date: 07/05/13 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
I remember the toughest class was antenna theory. As an undergrad EE student, I believed that this class would kill my plan to be an EE. I got a 25 (out of 100)! No bragging, it was the highest grade. They graded on a curve. My prof was a world renown antenna expert. He liked to @#* with us. So if anyone figures out this antenna stuff email me __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Paul, Our home is about 25 miles east of downtown Sacramento, CA. It is a two story home and until May of 2012 had a wood shake roof - very common in this part of the state. It was the original roof, about 21 years old, and was getting pretty nasty. We had it replaced with a metal roof: the Barcelona style of powder coated steel roofing made by Gerard. My primary antenna is an 88 foot long doublet made with #26 wire. It is supported in the center (at 45 feet) by a long fiberglass windsurfing mast. The ends run through some trees to the north and south. The roof is only about 15-20 feet from quite a bit of the antenna. I did not notice ANY differences in performance of this antenna when we had the roof replaced. Note that with the wood shake roof, my feeder was 600-ohm line that I had simply lying on the wood shakes. I knew that was not a good idea with a metal roof, so I replaced the 600-ohm feeder with 450-ohm ladder line and routed that along the side of the house, running about 120 feet from the shack window to the antenna. Other than my K3's internal tuner having to re-learn tuning algorithms for each band/frequency, all was good. I never bothered to mess with my eznec radiation pattern stuff, as (1) the patterns from a doublet are really whacky to begin with, and (2) I had no other options, so I knew it is what it is!. :-) IMHO, you may see some difference, but I doubt it's going to be significant. Jim / W6JHB Folsom, CA (not the prison!) On Thursday, Jul 4, 2013, at Thursday, 9:19 AM, Paul Taenzer wrote: Hello, We live on a very windy Island (with an industrial wind farm) and have been loosing shingles off the roof due to severe wind storms. We've been considering having a metal roof, but I'm wondering about the possible impact of the metal roof on the radiation pattern and efficacy of nearby antennas. There's a SteppIR on a tower about 20 feet from a corner of the roof. The antenna is about 30 feet higher than the highest point of the roof. I'd appreciate learning from anyone with relevant experience or technical expertise related to this. Many thanks. 73s, Paul VA3LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Hello Paul, I have not had any bad experience with metal roof with one exception. I had a garage with a metal roof and while I did not see any pattern or tuning issues, I did notice that on a couple of galvanized panels where the connection was marginal, some discoloration where they touched. I was using a 14AVQ at power near the roof. RF currents? With insulated panels that are screwed together, or galvanized ones with sheet metal screws probably will never give you any problems. On my barn which is 46 x 54 feet I have used a vertical with the Galvanized panel roof as a ground plane. Worked great. Mel, K6KBE From: Jim Bennett w6...@mac.com To: Paul Taenzer ptaen...@gmail.com Cc: elecraft@mailman.qth.net Sent: Thursday, July 4, 2013 10:31 AM Subject: Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace? Paul, Our home is about 25 miles east of downtown Sacramento, CA. It is a two story home and until May of 2012 had a wood shake roof - very common in this part of the state. It was the original roof, about 21 years old, and was getting pretty nasty. We had it replaced with a metal roof: the Barcelona style of powder coated steel roofing made by Gerard. My primary antenna is an 88 foot long doublet made with #26 wire. It is supported in the center (at 45 feet) by a long fiberglass windsurfing mast. The ends run through some trees to the north and south. The roof is only about 15-20 feet from quite a bit of the antenna. I did not notice ANY differences in performance of this antenna when we had the roof replaced. Note that with the wood shake roof, my feeder was 600-ohm line that I had simply lying on the wood shakes. I knew that was not a good idea with a metal roof, so I replaced the 600-ohm feeder with 450-ohm ladder line and routed that along the side of the house, running about 120 feet from the shack window to the antenna. Other than my K3's internal tuner having to re-learn tuning algorithms for each band/frequency, all was good. I never bothered to mess with my eznec radiation pattern stuff, as (1) the patterns from a doublet are really whacky to begin with, and (2) I had no other options, so I knew it is what it is!. :-) IMHO, you may see some difference, but I doubt it's going to be significant. Jim / W6JHB Folsom, CA (not the prison!) On Thursday, Jul 4, 2013, at Thursday, 9:19 AM, Paul Taenzer wrote: Hello, We live on a very windy Island (with an industrial wind farm) and have been loosing shingles off the roof due to severe wind storms. We've been considering having a metal roof, but I'm wondering about the possible impact of the metal roof on the radiation pattern and efficacy of nearby antennas. There's a SteppIR on a tower about 20 feet from a corner of the roof. The antenna is about 30 feet higher than the highest point of the roof. I'd appreciate learning from anyone with relevant experience or technical expertise related to this. Many thanks. 73s, Paul VA3LX __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Yes. Yes I was. :-) On Thursday, Jul 4, 2013, at Thursday, 12:11 PM, Tom H Childers wrote: You must have been running very low power. Laying any kind of ladder-line on a roof, insulated or not, is an excellent way to have a house fire that the insurance company will not pay for. Especialy a shake shingle roof. 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member [snip] 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
I didn't see the original reply, but I just wanted to clear up one misconception. Homeowner's insurance covers stupidity. Unless it can be proved that you put that ladder line on the roof and ran high power through it with the intention of burning the house down, you would be covered. 73, John AC0ZG On 7/4/2013 1:19 PM, Jim Bennett wrote: Yes. Yes I was. :-) On Thursday, Jul 4, 2013, at Thursday, 12:11 PM, Tom H Childers wrote: You must have been running very low power. Laying any kind of ladder-line on a roof, insulated or not, is an excellent way to have a house fire that the insurance company will not pay for. Especialy a shake shingle roof. 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member [snip] 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Not sure I'm liking where this conversation is going. I answered the original poster's question as to whether a metal roof has been seen to adversely affect antenna performance, not advocate doing stupid things. My installation worked very well for me w/o running high power. I knew I WOULD be doing QRO after a new roof was installed and subsequently ran my feeder in an appropriate location. Jim / W6JHB On Thursday, Jul 4, 2013, at Thursday, 12:52 PM, John Marvin wrote: I didn't see the original reply, but I just wanted to clear up one misconception. Homeowner's insurance covers stupidity. Unless it can be proved that you put that ladder line on the roof and ran high power through it with the intention of burning the house down, you would be covered. 73, John AC0ZG On 7/4/2013 1:19 PM, Jim Bennett wrote: Yes. Yes I was. :-) On Thursday, Jul 4, 2013, at Thursday, 12:11 PM, Tom H Childers wrote: You must have been running very low power. Laying any kind of ladder-line on a roof, insulated or not, is an excellent way to have a house fire that the insurance company will not pay for. Especialy a shake shingle roof. 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member [snip] 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
I run an Optibeam OB9-5 at about 42 feet on a tower only 10 feet away from the corner of our single story house with metal roof. It hasn't disadvantaged me any. I see a small change in SWR as the larger elements of 20M and 17M swing over the roof. Regards, Mike VP8NO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
I had a summer Mobile home in Bisbee AZ. It had a large room added that also had a metal roof. A vertical for twenty meters mounted in the middle worked very well. Kurt, W7QHD Date: Thu, 4 Jul 2013 11:06:25 -0700 From: farrerfo...@yahoo.com To: w6...@mac.com; ptaen...@gmail.com CC: elecraft@mailman.qth.net Subject: Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace? __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
I ran some quick models of a tower at the corner of a house with a metal roof in HFTA. The effects of the metal roof were modeled by a plane (sloping) from the tower to the edge of the roof, a drop from eave height to local ground height (set to flat for these purposes) and then flat ground out five miles. While there is some change, the effects are minor and would be lost in the clutter of other terrain effects anyplace other than in the middle of a vast open plain. The biggest effect will be impedance changes as Mike noted - and they should me minimal if the antenna is 10 meters/30 feet or more above the roof level for 20 meters and and above. A low band wire will be a different story as the effective height will be quite low. 73, ... Joe, W4TV On 7/4/2013 5:05 PM, Mike Harris wrote: I run an Optibeam OB9-5 at about 42 feet on a tower only 10 feet away from the corner of our single story house with metal roof. It hasn't disadvantaged me any. I see a small change in SWR as the larger elements of 20M and 17M swing over the roof. Regards, Mike VP8NO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
On Thursday Taenzer used a Straight-Key to send: -Original Comment--- We've been considering having a metal roof, but I'm wondering about the possible impact of the metal roof on the radiation pattern I can tell you that my barn metal roof allows me to make about an hour window to the WNW for 6m EME. I do not have Az/El rotator. The 6M8GJ 8 element is about 30 feet above , and at the apex of, the barn roof. The orientation of the barn is generally also WNW. It's predictable, never fails and I have made a few EME contacts on 6m looking that way towards moonset and an Elevation of about 28 degrees and down. -- Best regards, Bob KD7YZWin7-64bit + K3 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Have used metal as a ground plane it worked great. Metal sections must be well bonded together or rectification will result. The larger the better. John Hendricks K7JLT On Jul 4, 2013, at 16:16, KD7YZ Bob kd...@denstarfarm.us wrote: On Thursday Taenzer used a Straight-Key to send: -Original Comment--- We've been considering having a metal roof, but I'm wondering about the possible impact of the metal roof on the radiation pattern I can tell you that my barn metal roof allows me to make about an hour window to the WNW for 6m EME. I do not have Az/El rotator. The 6M8GJ 8 element is about 30 feet above , and at the apex of, the barn roof. The orientation of the barn is generally also WNW. It's predictable, never fails and I have made a few EME contacts on 6m looking that way towards moonset and an Elevation of about 28 degrees and down. -- Best regards, Bob KD7YZWin7-64bit + K3 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
Re: [Elecraft] OT - anyone have experience with effects of metal roofs on antenna performace?
Sorry, that was not my intention. We all do stupid things. The intention of my post was not to say that what you did was stupid. My illustration particularly mentioned running high power, which you already said you had not done, as an extreme to illustrate the point. Insurance won't cover it if it is proved to be an intentional act, and even intentional acts are covered for kids up to a certain age. The intention was to clear up the misconception that if one of our homes was damaged or destroyed by doing something that in hindsight might not have been the wisest thing, insurance still would cover it. But I can see that this discussion could turn off into a long discussion that has nothing to do with Elecraft or ham radio, so it should probably die right here. 73, John AC0ZG On 7/4/2013 2:54 PM, Jim Bennett wrote: Not sure I'm liking where this conversation is going. I answered the original poster's question as to whether a metal roof has been seen to adversely affect antenna performance, not advocate doing stupid things. My installation worked very well for me w/o running high power. I knew I WOULD be doing QRO after a new roof was installed and subsequently ran my feeder in an appropriate location. Jim / W6JHB On Thursday, Jul 4, 2013, at Thursday, 12:52 PM, John Marvin wrote: I didn't see the original reply, but I just wanted to clear up one misconception. Homeowner's insurance covers stupidity. Unless it can be proved that you put that ladder line on the roof and ran high power through it with the intention of burning the house down, you would be covered. 73, John AC0ZG On 7/4/2013 1:19 PM, Jim Bennett wrote: Yes. Yes I was. :-) On Thursday, Jul 4, 2013, at Thursday, 12:11 PM, Tom H Childers wrote: You must have been running very low power. Laying any kind of ladder-line on a roof, insulated or not, is an excellent way to have a house fire that the insurance company will not pay for. Especialy a shake shingle roof. 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member [snip] 73, Tom Amateur Radio Operator N5GE ARRL Lifetime Member QCWA Lifetime Member __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
