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Rain Static ?
I have recently been plagued by rain static on a new vertical antenna,
this a 42 foot vertical fed at the base through an SG230 auto tuner, and used on all bands. It seems I need a static bleed of some sort, a choke or resistor. What is the best component to use in an outdoor environment? I thought the auto ATU would in itself provide a static bleed path, but apparently not. Any thoughts, how have you solved this? 73, Deni F5VJC |
Rain Static ?
Deni F5VJC wrote:
I have recently been plagued by rain static on a new vertical antenna, this a 42 foot vertical fed at the base through an SG230 auto tuner, and used on all bands. It seems I need a static bleed of some sort, a choke or resistor. What is the best component to use in an outdoor environment? I thought the auto ATU would in itself provide a static bleed path, but apparently not. Any thoughts, how have you solved this? 73, Deni F5VJC Are you sure it's rain static? Most all verticals have higher noise levels than horizontal antennas. Reason, as it is reported, is that man made noise is vertically polarized. |
Rain Static ?
Deni F5VJC wrote:
I have recently been plagued by rain static on a new vertical antenna, this a 42 foot vertical fed at the base through an SG230 auto tuner, and used on all bands. It seems I need a static bleed of some sort, a choke or resistor. What is the best component to use in an outdoor environment? Take a look at page 4 of the schematic. There is already a static bleed through 20 turns on a transformer winding to ground plus about 40K ohms of resistance to ground. You are already bleeding the static charge, just not fast enough to get rid of the RF content. The problem is that the RF content of the precipitation static is finding its way through your receiver along with the desirable RF signals. Question is: Is there something that discriminates against local RF static without discriminating against desirable RF signals? Here's my two cents and others certainly do vehemently disagree with me. A single precipitation static charge transfer is at a localized point. Desirable arriving RF waves/photons are spread out over the entire antenna. That should make them separable. Folding the antenna into a loop is one way to reduce precipitation static. Desirable arriving RF waves are unaffected by folding as they encounter the entire antenna, i.e. it's hard to tell the difference between the performance of a dipole and a folded dipole. Single charges of precipitation static, however, are confined to one point on the antenna. If there is a discharge path to the other side besides through the receiver, the charge will at least partially take the shortest path of reduced resistance. IMO, that's why folded antennas are quieter than open-ended antennas as far as precipitation static is concerned. The way I reduced the problem with open-ended antennas is to use heavily insulated wire. Bare conductors transfer all charges. 600 volt insulation blocks charge transfer. In my experience, 1000v insulation blocks most charge transfer. I use something called "Quietflex" that has 1000v insulation. Most of the precipitation static doesn't transfer to the antenna wire while RF waves/photons flow right through the insulation with little attenuation. I suspect plastic encased antennas are quieter than bare antennas. There is a wealth of information on precipitation static on the web, a lot of it having to do with antennas on airplanes. Folding and insulating are two ways they have solved the problem. Folding or insulating your vertical may or may not be feasible. If you solve your problem, please share it with us here. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Cecil Moore wrote:
600 volt insulation blocks charge transfer. Lest I be nibbled to death by a flock of angry geese, this should be, "600 volt insulation blocks *some* charge transfer." Leaving out the word "some" was a typo. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
On Dec 9, 1:57 pm, Cecil Moore wrote: Cecil Moore wrote: 600 volt insulation blocks charge transfer.Lest I be nibbled to death by a flock of angry geese, this should be, "600 volt insulation blocks *some* charge transfer." Leaving out the word "some" was a typo. -- 73, Cecil http://www.w5dxp.com Interesting Cecil, my vertical antenna is constucted from a 42 foot length of coaxial cable using the outer braid as the radiator (but the inner and outer are shorted together anyway) and this fat vertical "wire" is suspended inside a telescopic fibre glass pole from Spiderbeam ( not the conductive type). So, I guess my verical wire is quite well insulated and certainly not in contact with charged rain. We've had particularly heavy rainstorms lately in France and this is definitely rain or rain induced static., starting and stopping in sympathy with the rain storms very easy to identify. 73, Deni F5VJC |
Rain Static ?
Dave wrote:
... Most all verticals have higher noise levels than horizontal antennas. Reason, as it is reported, is that man made noise is vertically polarized. Dave: Frankly, I think that the statement, "most man made noise is vertical polarized" is a myth. How many power lines do you see running vertically? How many extension cords do you see running vertically? How many phone lines do you see running vertically? Etc, etc. I think this needs looked at in a new light. Now most 160m antennas are easier to construct for horizontal operation--perhaps this is where the myth got started? Regards, JS |
Rain Static ?
Deni F5VJC wrote:
... Any thoughts, how have you solved this? 73, Deni F5VJC Deni: Perhaps a very high resistance hooked to the radiator and gnd would be the quick, cheap fix? Regards, JS |
Rain Static ?
Deni F5VJC wrote:
So, I guess my verical wire is quite well insulated and certainly not in contact with charged rain. We've had particularly heavy rainstorms lately in France and this is definitely rain or rain induced static., starting and stopping in sympathy with the rain storms very easy to identify. Is anything about your antenna in contact with charged rain? Your noise problem might have the same cause as lightning, i.e. the global atmospheric electrical circuit. You might be experiencing simple corona discharge. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
John Smith wrote:
How many power lines do you see running vertically? How many ground wires do you see running vertically from power pole capacitors and transformers? :-) -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
John Smith wrote:
Perhaps a very high resistance hooked to the radiator and gnd would be the quick, cheap fix? Perhaps not. Such is already provided inside the SG-230. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Cecil Moore wrote:
John Smith wrote: Perhaps a very high resistance hooked to the radiator and gnd would be the quick, cheap fix? Perhaps not. Such is already provided inside the SG-230. Cecil: I am slow to fence with you, your logic is impressive; however, perhaps this "safe guard" has failed? It is hard for me to picture static which is able to resist (pun intended) a path to ground ... Regards, JS |
Rain Static ?
Cecil Moore wrote:
John Smith wrote: How many power lines do you see running vertically? How many ground wires do you see running vertically from power pole capacitors and transformers? :-) Cecil: True. But, given the hundred-of-thousands/millions? of miles in conductors, carrying noise generating power in a horizontal plane, those ground wires must only amount to a small percentage of the whole ... Regards, JS |
Rain Static ?
Cecil if a static charge has a time varying field applied by gravity
would it have radiatiatonal properties and if so would it not be vertically polarised? Can't be true as it is not printed in a book ! Cecil Moore wrote: John Smith wrote: Perhaps a very high resistance hooked to the radiator and gnd would be the quick, cheap fix? Perhaps not. Such is already provided inside the SG-230. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
John Smith wrote:
I am slow to fence with you, ... On guard, varlet! :-) your logic is impressive; however, perhaps this "safe guard" has failed? It is hard for me to picture static which is able to resist (pun intended) a path to ground ... If the SG-230 weren't there you would be right. But the SG-230 already has two built-in paths to ground from the main RF line. One is about 40K ohms resistive and the other is 20 turns on a transformer, probably a toroid. Your high-resistance path would probably have negligible effect in this particular situation. Tom, W8JI, explained it as not just a static charge problem but as an RF problem. If the impedance is low enough to discharge RF static, then it is also low enough to discharge desirable RF signals. What a parallel impedance does is prevent arcing due to static DC buildup but it does little to prevent RF noise due to precipitation static which is many small discharges but only one small one at a time. (Someone reported being able to count the charged snowflakes.) In the absence of a parallel impedance as exists in the SG-230, a parallel impedance can certainly eliminate DC arcing along with its associated corona so it's not a bad idea. But precipitation static is a number of small hits each generating a small amount of RF energy. The only way I know of to reduce the amount of that RF energy reaching the receiver is to partially short it out with a loop antenna or insulate the antenna from the physical hits. And in fact, those are the most popular ways of reducing precipitation static on airplane antennas. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
John Smith wrote:
Cecil Moore wrote: How many ground wires do you see running vertically from power pole capacitors and transformers? :-) True. But, given the hundred-of-thousands/millions? of miles in conductors, carrying noise generating power in a horizontal plane, those ground wires must only amount to a small percentage of the whole ... A small percentage of the length of wires - a very large percentage of the vertically polarized noise. Probably two S-units of noise at my QTH that goes away during a power failure. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
"Cecil Moore" wrote in message ... bad idea. But precipitation static is a number of small hits each generating a small amount of RF energy. The ... a loop antenna or insulate the antenna from the physical hits. And in fact, those are the most popular ways of ... 73, Cecil http://www.w5dxp.com Cecil: Stated was: "Interesting Cecil, my vertical antenna is constucted from a 42 foot length of coaxial cable using the outer braid as the radiator (but the inner and outer are shorted together anyway) and this fat vertical "wire" is suspended inside a telescopic fibre glass pole from Spiderbeam ( not the conductive type). So, I guess my verical wire is quite well insulated and certainly not in contact with charged rain." How better could the actual metal radiator (receiving element) be insulated from the physical striking of rain drops, other than in the nonconductive fiberglass casing it already resides in? What am I missing? Warmest regards, JS |
Rain Static ?
art wrote:
Cecil if a static charge has a time varying field applied by gravity would it have radiatiatonal properties and if so would it not be vertically polarised? Can't be true as it is not printed in a book ! Whoa there, Art. There seems to be confusion between two topics. As far as I know, there is no obvious difference between the precipitation static levels on a horizontal Vs vertical antenna. That this particular antenna is vertical is mostly irrelevant to the alleged precipitation static problem. It could just as easily be happening with a horizontal antenna. The fact that the noise might be attributed to something other than precipitation static might involve vertical polarization but I don't think precipitation static has much to do with polarization. A wind-driven charged particle is just as likely to encounter a vertical wire as a horizontal wire. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Cecil:
Undoubtably, in a power failure, "most all" of the noise, both horiz and vert, goes away. How to you differentiate between what is the horiz component and that of the vert component? Regards, JS "Cecil Moore" wrote in message . .. John Smith wrote: Cecil Moore wrote: How many ground wires do you see running vertically from power pole capacitors and transformers? :-) True. But, given the hundred-of-thousands/millions? of miles in conductors, carrying noise generating power in a horizontal plane, those ground wires must only amount to a small percentage of the whole ... A small percentage of the length of wires - a very large percentage of the vertically polarized noise. Probably two S-units of noise at my QTH that goes away during a power failure. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
On Sat, 09 Dec 2006 07:27:39 -0800, John Smith
wrote: Dave wrote: ... Most all verticals have higher noise levels than horizontal antennas. Reason, as it is reported, is that man made noise is vertically polarized. Dave: Frankly, I think that the statement, "most man made noise is vertical polarized" is a myth. How many power lines do you see running Perhaps the explanation for the observation that the vertically polarised component of man made noise is greater at a receiver antenna than the horizontal component lies in the propagation mechanism. Most man made noise is received from nearby and by ground wave, and vertically polarised ground waves are attenuated less than horizontally polarised waves over the same path. This explanation is supported by the observation that the closer one is to a high intensity man made noise source (but still within radiating far field), the less variation in field strength with antenna polarisation. Owen -- |
Rain Static ?
John Smith wrote:
How better could the actual metal radiator (receiving element) be insulated from the physical striking of rain drops, other than in the nonconductive fiberglass casing it already resides in? What am I missing? Netnews is a challenge. Apparently you have read his followup posting without reading mine. Just be patient. My followups will arrive on your server sooner or later. For instance, if he has uninsulated elevated radials, the same thing might be happening. Or maybe it's noise from lightning and not precipitation static at all. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
John Smith wrote:
Undoubtably, in a power failure, "most all" of the noise, both horiz and vert, goes away. How to you differentiate between what is the horiz component and that of the vert component? I continue to operate on backup power during an AC power failure. The change in noise level on my horizontal dipole is not very noticeable. The change in noise level on my vertical is 2+ S-units. It is obvious that the 60 Hz power lines furnish the source of the vertical noise with power. I am still not sure of the source of the vertical noise but I strongly suspect the ground wire on the pole in my front yard that contains a power factor capacitor. If I bring my portable AM radio close to that ground wire, I cannot even hear the local AM radio station. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
John Smith wrote: How better could the actual metal radiator (receiving element) be insulated from the physical striking of rain drops, other than in the nonconductive fiberglass casing it already resides in? What am I missing? It seems to me that static electicity, and hence noise, can be induced through the fibreglass. I used to have horrible wind static on a dipole made with insulated wire. I would suggest that the rain striking the insulated material could also induce a static charge. Irv VE6BP -------------------------------------- Visit my HomePage at http://members.shaw.ca/finkirv/index.html Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm -------------------- Irv Finkleman, Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP Calgary, Alberta, Canada |
Rain Static ?
Cecil:
Yep. EXACTLY, the same problem here. I constructed a wideband fsm with a fet front end amping up the rf, then through a full wave rect and feeding two opamps in a lm324 acting as a VERY high gain dc amp, plug for ferite/"rubber duck"/telescope antennas. This finds the groundwire on a pole adjacent to my yard is a culprit, when brought close it pegs the meter and turns on the led (powered by extra opamps on board the lm324 acting as a comparator and voltage follower) in the output circuit. There is also a large, square, distribution xfmr where there are underground lines, although it appears perfectly shielded, it is yet another culprit on the opposite side of my property and gives a substantial reading on the same meter. Numerous complaints from me has had the power company send out individuals with an am radio, as you describe, they are quite taken with my "noise meter" when I show it to them, and the audio on their am radio confirms my meters reading--however, the noise is still there ... I am happy they like my meter! straight face Warmest regards, JS "Cecil Moore" wrote in message . .. John Smith wrote: Undoubtably, in a power failure, "most all" of the noise, both horiz and vert, goes away. How to you differentiate between what is the horiz component and that of the vert component? I continue to operate on backup power during an AC power failure. The change in noise level on my horizontal dipole is not very noticeable. The change in noise level on my vertical is 2+ S-units. It is obvious that the 60 Hz power lines furnish the source of the vertical noise with power. I am still not sure of the source of the vertical noise but I strongly suspect the ground wire on the pole in my front yard that contains a power factor capacitor. If I bring my portable AM radio close to that ground wire, I cannot even hear the local AM radio station. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Cecil Moore wrote: art wrote: Cecil if a static charge has a time varying field applied by gravity would it have radiatiatonal properties and if so would it not be vertically polarised? Can't be true as it is not printed in a book ! Whoa there, Art. There seems to be confusion between two topics. As far as I know, there is no obvious difference between the precipitation static levels on a horizontal Vs vertical antenna. Cecil I am just putting up something for thought Apparently stacked antennas of the horizontal style can avoid a lot of static noise if they disconect the upper array. Could this possibly mean that the horizontal array will not pick up a vertically phased noise in the near region. I know nothing in this area but just offering something that could be discussed. That this particular antenna is vertical is mostly irrelevant to the alleged precipitation static problem. It could just as easily be happening with a horizontal antenna. The fact that the noise might be attributed to something other than precipitation static might involve vertical polarization but I don't think precipitation static has much to do with polarization. A wind-driven charged particle is just as likely to encounter a vertical wire as a horizontal wire. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Cecil:
Netnews? News server? Newgroups? This ain't google chat? Huh? grin Regards, JS "Cecil Moore" wrote in message . .. John Smith wrote: How better could the actual metal radiator (receiving element) be insulated from the physical striking of rain drops, other than in the nonconductive fiberglass casing it already resides in? What am I missing? Netnews is a challenge. Apparently you have read his followup posting without reading mine. Just be patient. My followups will arrive on your server sooner or later. For instance, if he has uninsulated elevated radials, the same thing might be happening. Or maybe it's noise from lightning and not precipitation static at all. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
he OP mentioned that the static comes and goes with approaching and
receeding rain fronts... Likely he has a significant component of coronal discharge... He may PERHAPS reduce the induced noise a bit with ball on the top of the vertical, a copper float from the toilet works well, or even a nice capacity hat... NOw this is a topic that has been roundly beaten within an inch of it's life on other forums, but perhasps we are bored enough here to go all through it again groan denny / k8do |
Rain Static ?
Correct... Everything is known about antennas in America !
Denny wrote: he OP mentioned that the static comes and goes with approaching and receeding rain fronts... Likely he has a significant component of coronal discharge... He may PERHAPS reduce the induced noise a bit with ball on the top of the vertical, a copper float from the toilet works well, or even a nice capacity hat... NOw this is a topic that has been roundly beaten within an inch of it's life on other forums, but perhasps we are bored enough here to go all through it again groan denny / k8do |
Rain Static ?
This topic tends to be provocative. You have heard/read everyone's
opinions/measurements in the past. What is interesting in F5VJC's account is that the vertical is surrounded by what may be a good insulator. Additional information that will be of interest includes: 1. What is in the vicinity of the antenna? How far from exposed conductors, house, barn, trees, and such. Are objects within ten wavelengths higher than the antenna? 2. Are guy wires used to support the antenna? Some contend that P-noise exists and some contend that it does not exist associated with fixed antennas. F5VJC might be able to add a data point. 73 Mac N8TT -- J. Mc Laughlin; Michigan U.S.A. Home: "Denny" wrote in message ups.com... he OP mentioned that the static comes and goes with approaching and receeding rain fronts... Likely he has a significant component of coronal discharge... He may PERHAPS reduce the induced noise a bit with ball on the top of the vertical, a copper float from the toilet works well, or even a nice capacity hat... NOw this is a topic that has been roundly beaten within an inch of it's life on other forums, but perhasps we are bored enough here to go all through it again groan denny / k8do |
Rain Static ?
John, at 60 Hz a horizontal wire carrying current has a very strong magnetic
field. The 'right hand rule' indicates the magnetic field, a near field effect, is vertically polarized. My 60 meter horizontal is quiet. My 60 meter vertical, about 30 feet from the horizontal, has a good S4 noise level on the same radio at the same time. John Smith wrote: Dave wrote: ... Most all verticals have higher noise levels than horizontal antennas. Reason, as it is reported, is that man made noise is vertically polarized. Dave: Frankly, I think that the statement, "most man made noise is vertical polarized" is a myth. How many power lines do you see running vertically? How many extension cords do you see running vertically? How many phone lines do you see running vertically? Etc, etc. I think this needs looked at in a new light. Now most 160m antennas are easier to construct for horizontal operation--perhaps this is where the myth got started? Regards, JS |
Rain Static ?
Denny wrote:
he OP mentioned that the static comes and goes with approaching and receeding rain fronts... Likely he has a significant component of coronal discharge... He may PERHAPS reduce the induced noise a bit with ball on the top of the vertical, a copper float from the toilet works well, or even a nice capacity hat... NOw this is a topic that has been roundly beaten within an inch of it's life on other forums, but perhasps we are bored enough here to go all through it again groan The heated part of the discussion was because of the assertion that precipitation static does not exist. One only need do a web search for "precipitation static" to see that it is an accepted, well known, well defined physical phenomenon. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
J. Mc Laughlin wrote:
Some contend that P-noise exists and some contend that it does not exist associated with fixed antennas. F5VJC might be able to add a data point. Don't know about his static problems but it seems to me that it doesn't make much difference whether the antenna is moving or the charged particle stream is moving. It's all relative. :-) -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Dave wrote:
... Dave: Krist! Turn off the 60 hz receiver you silly duck! That right hand rotation is, most likely, making you dizzy! JS |
Rain Static ?
Hello Deni:
I have had such problems with rain noise. A ground plane antenna mounted to the side of the house had severe rain static noise. After checking the antenna and coax it was found that a new roof was installed and sheet metal pieces where installed on the roof before the roof paper and roof was installed. After finding this out, the mast was moved away and insulated from the side of the house. This reduced the rain static in the receiver significantly. What I think was happening was the heavy rain static energy was using the mast as a ground rod, inducing the noise into the antenna. I have at times experienced severe rain static, but only two times when the the rain was a complete heavy down poor of rain, that only lasted a few minuets. I think its possible that some, but not all weather brings the rain static and most antenna installations will hear it. Jay in the Mojave Deni F5VJC wrote: I have recently been plagued by rain static on a new vertical antenna, this a 42 foot vertical fed at the base through an SG230 auto tuner, and used on all bands. It seems I need a static bleed of some sort, a choke or resistor. What is the best component to use in an outdoor environment? I thought the auto ATU would in itself provide a static bleed path, but apparently not. Any thoughts, how have you solved this? 73, Deni F5VJC |
Rain Static ?
Jay in the Mojave wrote:
I have at times experienced severe rain static, ... Others have reported experiencing severe snow static. My worst precipitation static problems occurred in the Arizona desert on a dry sunny day with 40 mph winds filled with charged dust particles streaming across the desert. It actually caused a burst of arcing at my coax connector. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Number of things are getting confused and lumped.
There are different types of "Rain Static" and "noise" 1. One that W5DXP experienced in dry winds of Arizona, is charging of metal parts by air mass movement and generated charge by it. Either in immediate vicinity of the antennas or higher up. Insulated wires, loops and balanced antennas and feeders help here. 2. High altitude static buildup during the storms. Is due to buildup of static in higher altitudes, accompanied by lightning discharges. Here the umbrella effect of having higher structure with "capacitance hat" like Yagi helps to drain the charge from the vicinity and static free reception from lower antennas is possible. Stacked beams are example, where lower antenna is dead quiet while top one gets S9+20 frying noise. Insulation or no insulation immaterial here. 3. Discharge from the rain droplets on the antenna elements is like #2. Insulated elements help here to a point. Power line noise. If the source is a bad connection in power lines system (point source) that noise is "everything polarized". Depends how the antenna and structures around it participate in the radiation from it. Argument that it is vertically polarized has more to do with RX antennas and their pattern rather than "pure" polarization. Verticals have major lobe at the horizon and they "see" everything near by. Horizontals at typical height have major lobe at some higher angle, mostly "looking" up and have a null at the horizon, "ignoring" nearby sources of noise. Then there is the propagation mode effect contributing to the noise propagation and affect on receiving systems. Regardless of W8JI claims that small loop antennas don't have electrostatic shield - effect, they can be of great help in discriminating against the near by noise sources by using electrostatic shields. And yes Virginia, in the close proximity there is a separation of E and H fields. One has to be careful and properly identify the type of noise, ways of propagating and means of suppressing it. The best way is to do it at the antennas. For example I had horrible noise situation from HV power lines. The most effective way was to null it out by mutual positioning of the main antenna (Razors) and 3 el. Yagi between them. I could suppress, null out noise of 30dB over S9 down to almost nothing. Then the noise blankers and filtering are put to work. 73 Yuri, K3BU "Owen Duffy" wrote in message ... On Sat, 09 Dec 2006 07:27:39 -0800, John Smith wrote: Dave wrote: ... Most all verticals have higher noise levels than horizontal antennas. Reason, as it is reported, is that man made noise is vertically polarized. Dave: Frankly, I think that the statement, "most man made noise is vertical polarized" is a myth. How many power lines do you see running Perhaps the explanation for the observation that the vertically polarised component of man made noise is greater at a receiver antenna than the horizontal component lies in the propagation mechanism. Most man made noise is received from nearby and by ground wave, and vertically polarised ground waves are attenuated less than horizontally polarised waves over the same path. This explanation is supported by the observation that the closer one is to a high intensity man made noise source (but still within radiating far field), the less variation in field strength with antenna polarisation. Owen -- |
Rain Static ?
"Jay in the Mojave" wrote in message ... Hello Deni: I have had such problems with rain noise. A ground plane antenna mounted to the side of the house had severe rain static noise. After checking the antenna and coax it was found that a new roof was installed and sheet metal pieces where installed on the roof before the roof paper and roof was installed. After finding this out, the mast was moved away and insulated from the side of the house. This reduced the rain static in the receiver significantly. What I think was happening was the heavy rain static energy was using the mast as a ground rod, inducing the noise into the antenna. I have at times experienced severe rain static, but only two times when the the rain was a complete heavy down poor of rain, that only lasted a few minuets. I think its possible that some, but not all weather brings the rain static and most antenna installations will hear it. Jay in the Mojave Deni F5VJC wrote: I have recently been plagued by rain static on a new vertical antenna, this a 42 foot vertical fed at the base through an SG230 auto tuner, and used on all bands. It seems I need a static bleed of some sort, a choke or resistor. What is the best component to use in an outdoor environment? I thought the auto ATU would in itself provide a static bleed path, but apparently not. Any thoughts, how have you solved this? 73, Deni F5VJC The only rain static I have observed is during a sudden downpour. This is on a longwire antenna. If the rain last more than a few minutes the static goes away. I have wondered sometimes if this isnt caused by the rain hitting a dry antenna. No real reason to assume this is fact but it does seem to fit the observation. Perhaps I will run out one day and hose the antenna down and see if this stops the static. |:). This seems to be even more the case when I take my radio down to florida from north carolina. In florida we have afternnon storms that you can almost set your watch by. When they hit the haose I usally get a steady build up of noise then suddenly it dies down. It seems to die down durung the heaviest part of the rain. |
Rain Static ?
Anyone who says you can't revive a dead horse with a good, firm beating has not met this group :) I suspect that there are several points of agreement with the majority of the group, however not everyone will agree, heck I may choose to disagree with something right after I write it...... That dry wind will cause high voltage charging -and arcing- of insulated antennas and static noise, especially on long wires - that this is mostly friction charging, a similar mechanism to rubbing silk on glass, though charged body impact of dust may be relevant... That dry, falling/blowing snow causes extreme levels of static noise on insulated antennas - by mixed phenomenon of friction static and charged body impact... That static noise builds up as a rain front approaches, with or without associated wind... That this static noise is separate from lighting discharge impulses.... That lightning discharges cause noise - inductive noise... That rain causes static noise on insulated antennas - charged body impact primarily, I don't know about friction charge... That heavy rain 'may' lessen associated static noise.... I haven't personally experienced this - is it the magnitude of the rainfall or the fact that the highly charged front has passed on by and the falling drops are now less charged? That a grounded tower with an antenna stack can have the top antenna experience heavy static noise while lower antennas will have significantly less static roar... my opinion is that coronal discharge from the top antenna elements is inducing noise into the top antenna circuit, and that the coronal flow that would have occurred off the lower antenna elements is suppressed and drained to the top antenna by the differential voltage on the higher antenna So, in the end it may be that the charging of the antenna circuit by either friction or charged body impact causes less noise than the subsequent coronal flow back off the highly charged antenna body... We know that the antenna is a "convertor", that is it converts a moving electron departing the antenna into a photon - and vice versa - causing an RF signal in the process... Certainly, this topic of the role that coronal discharge v/s the charging mechanism plays in antenna noise would make a good dissertation subject for a PhD thesis... Doctoral candidates out there, hint, hint!... denny |
Rain Static ?
Yuri Blanarovich wrote:
1. One that W5DXP experienced in dry winds of Arizona, is charging of metal parts by air mass movement and generated charge by it. Incidentally, there was a special on the Discovery Channel about man colonizing the other planets. They said one of the main dangers to life on Mars was the charged iron oxide particles during a Martian dust storm. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
yeah, that would be a bitch... Trudging through a 200mph sand storm at
-200F, dog tired from working12 hours in the mine, hungry, thirsty, and get to the airlock going into the station, reach out for the handle and have a 20,000 volt charge blow a hole through your glove and fingers, and you die from explosive decompression.... denny Cecil Moore wrote: Yuri Blanarovich wrote: 1. One that W5DXP experienced in dry winds of Arizona, is charging of metal parts by air mass movement and generated charge by it. Incidentally, there was a special on the Discovery Channel about man colonizing the other planets. They said one of the main dangers to life on Mars was the charged iron oxide particles during a Martian dust storm. -- 73, Cecil http://www.w5dxp.com |
Rain Static ?
Denny wrote:
Anyone who says you can't revive a dead horse with a good, firm beating has not met this group :) ... Denny: I am one calif born and raised boy who has only been though other states on visits only lasting weeks, or passing through. I find the subject quite interesting and have never had to deal with this on a level which has been aggravating or annoying. Indeed, the worst experience I have ever had is crossing nylon carpets on very dry days in well insulated footwear. However, I have heard horror stories of purplish cornea discharges from antennas which are a sight to behold. Just as in school, each new generation learns, this is one calif boy who is new generation in his 50's! (and I hate faq's!) Regards, JS |
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