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One way shingles
Not that it maters but another ham and myself have been licensed for 40
years. We ran across somethng the other day that we had not seen before. We live about 10 to 15 air miles apart. I have a vertical dipole at 35 feet on a tower. He has 2 differant FM rigs and vertical dipole wire antenas in his attic about 50 feet apart. I can work him direct on 6 meters with him mobile in his drive way. A couple of days ago we could work with his attic antenna. He built another antenna , so he has two antennas and rigs. A Midland and GE comercial unit that puts out 40 watts each. I check the sensitivity on a HP 8924C and they both seemed to be as good as a Midland I was using. It rained and now he can not hear me, but I can hear him fine on either rig and antenna of his. I switched to an Icom 706 at 100 watts out and and checked the reflected power is about 2 watts. At this time, he could tell when I was transmitting ,but not understand me. We were co-ordinating over 2 meters. I also switched to an OCD antenna at 50 feet and could hear him. The internal tuner on a 746 pro tuned it,but he could not hear me on that either and he was about S-5 on the meter. Do you think we have discovered one way shingles ??? Anyone else seen anything like this ? KU4PT |
One way shingles
On Wed, 19 Sep 2012 10:12:09 -0400, "Ralph Mowery"
wrote: Not that it maters but another ham and myself have been licensed for 40 years. We ran across somethng the other day that we had not seen before. We live about 10 to 15 air miles apart. I have a vertical dipole at 35 feet on a tower. He has 2 differant FM rigs and vertical dipole wire antenas in his attic about 50 feet apart. I can work him direct on 6 meters with him mobile in his drive way. A couple of days ago we could work with his attic antenna. He built another antenna , so he has two antennas and rigs. A Midland and GE comercial unit that puts out 40 watts each. I check the sensitivity on a HP 8924C and they both seemed to be as good as a Midland I was using. It rained and now he can not hear me, but I can hear him fine on either rig and antenna of his. I switched to an Icom 706 at 100 watts out and and checked the reflected power is about 2 watts. At this time, he could tell when I was transmitting ,but not understand me. We were co-ordinating over 2 meters. I also switched to an OCD antenna at 50 feet and could hear him. The internal tuner on a 746 pro tuned it,but he could not hear me on that either and he was about S-5 on the meter. Do you think we have discovered one way shingles ??? Anyone else seen anything like this ? KU4PT His antenna pre-amplifier has died. w. |
One way shingles
On Wed, 19 Sep 2012 10:12:09 -0400, Ralph Mowery wrote:
Not that it maters but another ham and myself have been licensed for 40 years. We ran across somethng the other day that we had not seen before. We live about 10 to 15 air miles apart. I have a vertical dipole at 35 feet on a tower. He has 2 differant FM rigs and vertical dipole wire antenas in his attic about 50 feet apart. I can work him direct on 6 meters with him mobile in his drive way. A couple of days ago we could work with his attic antenna. He built another antenna , so he has two antennas and rigs. A Midland and GE comercial unit that puts out 40 watts each. I check the sensitivity on a HP 8924C and they both seemed to be as good as a Midland I was using. It rained and now he can not hear me, but I can hear him fine on either rig and antenna of his. I switched to an Icom 706 at 100 watts out and and checked the reflected power is about 2 watts. At this time, he could tell when I was transmitting ,but not understand me. We were co-ordinating over 2 meters. I also switched to an OCD antenna at 50 feet and could hear him. The internal tuner on a 746 pro tuned it,but he could not hear me on that either and he was about S-5 on the meter. Do you think we have discovered one way shingles ??? More likely you've discovered a nearby lightning strike and now his RCVR front end is blown. |
One way shingles
"Helmut Wabnig" [email protected] --- -.dotat wrote in message His antenna pre-amplifier has died. There are no antenna preamps. All our rigs just go from the output up some coax and to the antennas. The rigs are just older comercial Midland XTR and GE MLS. They have been reprogrammed to 6 meters. He has two seperate antennas and rigs. I had just checked all rigs involved in the last two weeks with an HP 8924c test set and all were putting out 30 to 40 watts and the receivers would open the squelch at under .3 uV. I don't recall the exect valuse, but they met the origional specs. I know the rigs are on frequency to less than 100 hz. Also all were verified that the receive and tramsmitt matched what we have the chanels set for. The midlands were all programmed off the same programming file and computer. |
One way shingles
"Allodoxaphobia" wrote in message More likely you've discovered a nearby lightning strike and now his RCVR front end is blown. I do not recall any thunder storms in the area. If it blew the front end, it would have had to do it to two rigs and the antennas are in the attic. We will check out the sensitivity again at the first chance. |
One way shingles
On Wednesday, September 19, 2012 9:12:14 AM UTC-5, Ralph Mowery wrote:
Do you think we have discovered one way shingles ??? My doctor gave me Acyclovir for shingles. |
One way shingles
On 9/19/2012 1:42 PM, W5DXP wrote:
On Wednesday, September 19, 2012 9:12:14 AM UTC-5, Ralph Mowery wrote: Do you think we have discovered one way shingles ??? My doctor gave me Acyclovir for shingles. Then you must be omnidirectional again. Good for you. |
One way shingles
"Ralph Mowery" wrote in message m... It rained and now he can not hear me, but I can hear him fine on either rig Hi Either his receiver is dead or it is suffering interference. --- news://freenews.netfront.net/ - complaints: --- |
One way shingles
Ralph Mowery skrev 2012-09-19 16:12:
Not that it maters but another ham and myself have been licensed for 40 years. We ran across somethng the other day that we had not seen before. We live about 10 to 15 air miles apart. I have a vertical dipole at 35 feet on a tower. He has 2 differant FM rigs and vertical dipole wire antenas in his attic about 50 feet apart. I can work him direct on 6 meters with him mobile in his drive way. A couple of days ago we could work with his attic antenna. He built another antenna , so he has two antennas and rigs. A Midland and GE comercial unit that puts out 40 watts each. I check the sensitivity on a HP 8924C and they both seemed to be as good as a Midland I was using. It rained and now he can not hear me, but I can hear him fine on either rig and antenna of his. I switched to an Icom 706 at 100 watts out and and checked the reflected power is about 2 watts. At this time, he could tell when I was transmitting ,but not understand me. We were co-ordinating over 2 meters. I also switched to an OCD antenna at 50 feet and could hear him. The internal tuner on a 746 pro tuned it,but he could not hear me on that either and he was about S-5 on the meter. Do you think we have discovered one way shingles ??? Anyone else seen anything like this ? KU4PT The usual cause when this happens to me is an frequency offset in either my in rig or the other operators. Are you sure that your rig isn't set accidently to some type of TX shift. There are two rigs at the other end and none of them can hear you. 73 Ben / SM0KBW |
One way shingles
"Ben" wrote in message ... The usual cause when this happens to me is an frequency offset in either my in rig or the other operators. Are you sure that your rig isn't set accidently to some type of TX shift. There are two rigs at the other end and none of them can hear you. 73 Ben / SM0KBW It is doubtful the frequency has been changed in any way. The rigs are comercial FM units and the only way to program them is with a computer connection. Once set, all you can do is change the chanels on it. I know the other ham did not change his as I have the programming cable. All the Midland units were programmed using the same program file at the same time. They worked fine before the rain. The frequencies were even verified with a service monitor after they were programmed. I also used an Icom 746pro and can read the frequency on that, and I did not see the display change frequencies. At 100 watts, he could just hear me in the noise where before the rain we were full quieting with the 40 watt units. |
One way shingles
"bilou" wrote in message ... "Ralph Mowery" wrote in message m... It rained and now he can not hear me, but I can hear him fine on either rig Hi Either his receiver is dead or it is suffering interference. Now that is an idea I have not explored. A six meter repeater was just put on the air about 5 miles from him and sometimes there is a power pole that generates enough noise at the repeater site it desenses the repeater receiver. We are working with the power people now. We do not hear it on the repeater, but an AM receiver pickes it up very well. I am sure it is not this noise as it is too far away, but he may have a local source that is causing a problem. |
One way shingles
"Ben" wrote in message ... The usual cause when this happens to me is an frequency offset in either my in rig or the other operators. Are you sure that your rig isn't set accidently to some type of TX shift. There are two rigs at the other end and none of them can hear you. Now the shingles have dried out we can hear each other on all the radios and antennas. I know nothing has changed as the radios need to be programmed by computer and I have the cable. The distance is just under 10 miles so we should be almost radio line of sight. The land between us is rolling hils. Going from about 600 feet at the lowest to 900 feet at the highest. |
One way shingles
"Ralph Mowery" napisał w wiadomości m... Not that it maters but another ham and myself have been licensed for 40 years. He built another antenna , so he has two antennas and rigs. A Midland and GE comercial unit that puts out 40 watts each. I check the sensitivity on a HP 8924C and they both seemed to be as good as a Midland I was using. It rained and now he can not hear me, but I can hear him fine on either rig and antenna of his Do you think we have discovered one way shingles ??? Yes. Water is able to damp completly the weak yours waves. His waves are emitted close to the wet shingles and are damped a little only. S* |
One way shingles
On 10/8/2012 8:56 PM, J. C. Mc Laughlin wrote:
Back when the Michigan State Police used 40 MHz, at some posts static levels would become so high as to reduce range to almost nothing. Some say it was precipitation noise (as is common with aircraft) and some people believe it had another cause. It seemed to be weather related. On 6 meters, with an AM circuit I had for years with my father, I have heard discharge noise that starts with a sequence of pops and progresses to a steady roar that occasionally would abruptly stop. (about 100 km path with yagi antennas at both ends) My guess is it was due to local, enhanced noise. Effects may have been suppressed due to the nature of FM and its mode of squelching. 73, Mac N8TT That noise sequence is exactly what I hear when I see a corn snow squall come through my property in the winter. I have actually watched the wind blown snow come closer and closer while the HF radio noise increases until all signals are wiped out, then when the back edge of the squall passes the antenna, all is quiet, again. I live at 2800 ft in the Central Oregon desert. The antenna is either a ground mounted 5BTV with 40 radials, or a 160 meter horizontal loop at 35 ft. Paul, KD7HB |
One way shingles
On Wed, 19 Sep 2012 10:12:09 -0400, "Ralph Mowery"
wrote: Do you think we have discovered one way shingles ??? Nope. You've discovered Fresnel zone diffraction, multipath cancellation, and frequency selective fading. Congratulations. Anyone else seen anything like this ? Not on 6 meters, put plenty at 900MHz and up. Basically, if you have more than one path between endpoints, and the path lengths differ by 1/2 wavelength, you'll get cancellation. It's easy enough to detect the problem by simply moving 1/2 wavelength toward or away from the other endpoint and see if the signal levels change significantly. If you can't do that, change frequency by the largest amount possible. Also, if you live 15 miles apart, with antennas at about 15ft off the ground, you're below the horizon. That means you're relying on knife edge diffraction to communicate. That works, but is not reliable as almost any metal object near the knife edge can send the signal off into the wrong direction. At 6 meters, things like swaying wet trees can do that. If the signals are NOT stable and tend to move around in the wind, this might be the problem. One way paths are possible. It's not the path. It's the antennas. The basic assumption is that the antenna pattern is the same in xmit and receive. That's a fair working assumption but not always true. Different side lobes of an antenna can have a slightly different phase shifts. If the two multipath signals arrive via the main lobe and a side lobe in receive, and the side lobe moves slightly in transmit, it's possible to achieve cancellation only in one direction. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
One way shingles
On Thu, 20 Sep 2012 11:45:52 -0400, "Ralph Mowery"
wrote: I am sure it is not this noise as it is too far away, but he may have a local source that is causing a problem. If the 6 meter receiver has a noise blanker, he could be hearing so much noise that the receiver acts like there's nothing to hear. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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