Topband: 160m Band Utilization Chart updated: 15 November 2012
The 160m Band Utilization Chart has been updated. It now shows the JT9 dial frequency at 1.8395 MHz. The chart is at: http://homepage.ntlworld.com/wadei/160m_band_utilization.htm The chart is still sparse on detail, so if you have anything to add to it, please let me know: mailto: g3nrw-ra...@ntlworld.com -- 73 Ian, G3NRW The 30m Band Utilization Chart: http://homepage.ntlworld.com/wadei/30m_band_utilization.htm The UK 60m Band Utilization Chart: http://homepage.ntlworld.com/wadei/UK_60m_band_utilization.htm The 160m Band Utilization Chart: http://homepage.ntlworld.com/wadei/160m_band_utilization.htm The Top Band Digital Group (TBD160): http://groups.yahoo.com/group/TBD160 ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
CU on the 525 foot band, Carl? Seriously, I suspect that the reason why many of us work in meters when modeling is simply that some of the most useful software products default to that. 73, Pete N4ZR Check out the Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com. For spots, please go to your favorite ARC V6 or VE7CC DX cluster node. On 11/14/2012 3:48 PM, ZR wrote: I cant find the button to convert that metric stuff to good old USA measurements when posted from this country(-: Subject: Re: Topband: Vertical Array Over Uneven Ground I never found a way to model an an antenna over anything but flat, level ground. Not in EZNEC+ 5.0, anyway. 73, Mike www.w0btu.com On Tue, Nov 13, 2012 at 7:41 PM, Ken Claerbout k...@verizon.net wrote: Has anyone modeled or have experience with a transmit vertical array, say a 4-square, over uneven ground? By uneven I mean a variance of up to 2 - 3 meters over the footprint of the array elements. ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5394 - Release Date: 11/14/12 ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: 8877 Tube
The Alpha 77-SX is a great amplifier with plenty of reserve. The plate voltage runs just under 4KV on the Hi-Power position. If you go to the larger transformers you are asking for trouble. The filter capacitor has to be changed to one with a 5 KV rating. When you do this you will push circuit components to their HV limit. There have been too many problems out there with those who have done this... 73, John, W4NU On 11/14/2012 9:56 PM, ZR wrote: The only problem with pushing an 8877 or the 3CPX to or over the 4KV limit is that it enhances the chance of instability. Carl KM1H - Original Message - From: Paul Christensen w...@arrl.net To: topband@contesting.com Sent: Wednesday, November 14, 2012 7:23 PM Subject: Re: Topband: 8877 Tube Bob, A non-issue. Many of us have been running 8877s with Ep of 4KV. For example, the typical no-load Ep of an Alpha 77Dx/Sx amp is right at the specified limit of 4KV. Some owners have been converting their 8877 amps over to the 3CPX1500A7 which has a much higher rated Ep since it was designed for pulsed service. Unless someone has access to a supply of pulse-rated tubes, I think it's waste of time unless the plate supply voltage is also increased. Paul, W9AC - Original Message - From: Chortek, Robert L robert.chor...@berliner.com To: topband@contesting.com Sent: Wednesday, November 14, 2012 6:56 PM Subject: Topband: 8877 Tube Wonder if someone can help with a technical question with the amp I use on 160 meters. The Spec Sheet for the 8877 tube lists the Absolute Maximum Plate Voltage of 4000 Volts for the tube, and also says in typical operation the plate voltage is between 2700 and 3500 volts. In my amp (Ameritron AL-1500), the plate voltage is 3750. My question is - should I be concerned (it's clearly below the maximum but above the range that is considered typical? I just want to be sure I'm not adversely affecting the useful life of the tube. Any help would be appreciated. 73, Bob/AA6VB ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5395 - Release Date: 11/14/12 ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
GM Pete et al: That metric stuff is widely used around the globe. Cu on 459 ft. 73 Len SM7BIC On 11/14/2012 3:48 PM, ZR wrote: I cant find the button to convert that metric stuff to good old USA measurements when posted from this country(-: ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
Pošiljalac: Lennart M lennart.michaels...@telia.com That metric stuff is widely used around the globe. It's fun to learn that Dr. Maxwell, the inventor of electromagnetic waves, had used metric units exclusively 200 years ago. So, why we cannot do the same today? 73, Sinisa YT1NT, VE3EA ___ Topband reflector - topband@contesting.com
Re: Topband: TX/ RX Antenna Switching
If something goes wrong in the RX antenna switch, you don't have to worry about the rig transmitting into its own receiver. That can't happen. The only thing that can happen is that you could damage the antenna or its preamp. The reed relay is just like the one in your radio, so it shouldn't be unreliable. I've never heard of one of those failing. Reed relays, and on rare occasions other relays or relay systems, come in two variations. Some use a single contact bar that moves between NO and NC positions. These are OK, because they can never do two connections at once if something fails. The contact carrier is either one way or the other. These are potentially good as transfer relays. Some use dual reeds or dual contact carriers that are mechanically independent. If something goes wrong, they can make two connections at the same time. They also can have sequence issues where they make two connections at once. Some vacuum reed relays have two glass tubes inside the coil with independent NC and NO reeds. These relays are questionable for anything. They can lock in two contact positions at once, tying all three terminals of a DPST together. As a matter of fact, they actually do this for a millisecond or so when transferring. These are bad relays for many applications. By the way, some popular radios transmit RF even after telling the external relay line to release, and some transmit at the very same time as they tell an external relay to transfer. Most radios are good, but not all radios are good at timing. Some hot switch on the leading edge, and some on the tailing edge. 73 Tom ___ Topband reflector - topband@contesting.com
Topband: Covered /bare antennn wire
Dry blowing snow or high wind can cause quite some voltage build up on a antenna, especially a long one. It is possible to draw quite an arc to ground. There have been reports of high voltage electrocutions from antenna static build up in Short Wave Broadcast stations. A short stick was mandatory for maintenance periods. And yes, I did work at a shortwave station with 500 KW transmitter output. So receiving antenna wire insulation could have some benefit if the voltage on a bare wire is leaking to a tree limb or across an insulator. Beyond some point all insulators can fail. Indoor antennas do hear static, but I have never seen any evidence of voltage build up. ( The building may provide adequate insulation.) Out of curiosity, has anyone ever really done testing of voltage buildup on a insulated antenna wire, VS a non-insulated wire ? Indoor antennas VS outdoor antennas of equal size? 73 Bruce-K1FZ ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
Why not prevent the static buildup in the first place? I use 33K resistors from each wire to ground. Schematic is at http://www.w0btu.com/Beverage_antennas.html . The components in parallel with the 33K resistors are 90 volt gas discharge tubes, and the resistors are to prolong the life of those GDTs. 73, Mike www.w0btu.com ___ Topband reflector - topband@contesting.com
Topband: V84SMD
Hello all, looks like V84SMD is not very active on 160 ! Do we know why ? thank you Jacques F6BKI ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
On 2012-11-15, at 3:42 PM, Bruce wrote: Dry blowing snow or high wind can cause quite some voltage build up on a antenna, especially a long one. It is possible to draw quite an arc to ground. There have been reports of high voltage electrocutions from antenna static build up in Short Wave Broadcast stations. A short stick was mandatory for maintenance periods. And yes, I did work at a shortwave station with 500 KW transmitter output. So receiving antenna wire insulation could have some benefit if the voltage on a bare wire is leaking to a tree limb or across an insulator. Beyond some point all insulators can fail. Indoor antennas do hear static, but I have never seen any evidence of voltage build up. ( The building may provide adequate insulation.) Out of curiosity, has anyone ever really done testing of voltage buildup on a insulated antenna wire, VS a non-insulated wire ? Indoor antennas VS outdoor antennas of equal size? Hi Bruce, I am not so sure that the notion of insulated vs. uninsulated wire holds true in long wire spans... Case in point: years ago when I first erected my 1500' long Beverage antenna here, I was specific in using insulated wire though its entire course because it runs through a grove of trees at one point. Well, one day, in the advance of an approaching storm front, I decided to ground the end of the Beverage in my shack. I could feel a tingling sensation as I man-handled the wire, negotiating my way to the common ground pipe that I have running the length of the back of my operating table...imagine my complete utter shock as I neared the wire to this same pipe, and managed to induce 1/8 long blue arcs from the pipe to the wire! Since that time---FWIW---I have always had a rugged 2.5 mh. RF choke clipped between the wire's end where it attaches to the matching transformer, and ground. In theory this acts as a static drain, I guess, but does not induce signals to ground. I've heard that a multi-megohm resistor will do the same thing at this point... ~73~ de Eddy VE3CUI - VE3XZ ___ Topband reflector - topband@contesting.com
Topband: Covered /bare antennn wire
Good point Mike, but I am hoping someone has done definitive testing between insulated and un-insulated wire concerning voltage build up. If the voltage is lower with insulated wire there is less to bleed off, and possibly lower noise activity. http://www.qsl.net/k1fz/beveragenotes.html 73 Bruce-K1FZ - Original Message - From: Mike Waters mikew...@gmail.com To: topband topband@contesting.com Sent: Thursday, November 15, 2012 9:56 AM Subject: Re: Topband: Covered /bare antennn wire Why not prevent the static buildup in the first place? I use 33K resistors from each wire to ground. Schematic is at http://www.w0btu.com/Beverage_antennas.html . The components in parallel with the 33K resistors are 90 volt gas discharge tubes, and the resistors are to prolong the life of those GDTs. 73, Mike www.w0btu.com ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Topband: Pennant Transformer
Many tnx to all who replied offline with advice and help. I am on the right track and hope to complete the project today. 73 Frank VO1HP --- I am in the process of building a pennant. I'm stuck on the right way to wind the transformer. I have Type 73 binocular cores but am not clear on how to do it. I am feeding the loop with RG6 and my terminating resistor is 910 Ohm 2%. The transformer will go at the point of the pennant and should be 12:1 ratio ? For 75 Ohm cable K6SE info sez - 2 turn primary and 7 turns secondary. I see on W7IUV website he sez - wind the primary on first. --- so for two turns I do this: one turn is: - up through one side and down through the other side. another turn is - continue up one side and down through the other --- that makes two turns...is that correct? Winding 7 turns would follow same procedure winding the wire over the primary wire and have the leads out the opposite end of the core from the primary? I hope you can follow my primitive description. Am I on the right track? 73 Frank VO1HP ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
On 2012-11-15, at 4:35 PM, Bruce wrote: Good point Mike, but I am hoping someone has done definitive testing between insulated and un-insulated wire concerning voltage build up. If the voltage is lower with insulated wire there is less to bleed off, and possibly lower noise activity. Hi Bruce, I am a tad confused by your reasoning, so please excuse me...! Are you implying that some amount of voltage build-up is OK somehow? I don't get the logic in that---to me, it's all or nothing. What's to be gained by having less voltage to bleed off, s. more? An RF choke to ground doesn't care if it's a lot, or a little: it just does its job, end of story... I'm no expert by any means, but please enlighten me as I think I've obviously missed something. Thanks! ~73~ de Eddy VE3CUI - VE3XZ PS: FWIW, I always endeavour here to use insulated wire in ALL of my antenna projects---even radials laid atop the ground. I guess in the case of wire up in the air, I still subscribe to the belief (urban myth...?) that rain snow discharge themselves on bare wire, static electrically speaking. For the minimal extra expense of insulated vs. bare wire, it's one less thing that I have to worry about, rightly or wrongly! Hi Hi ___ Topband reflector - topband@contesting.com
Topband: Covered /bare antennn wire
Hi Eddy, Yes, above some voltage all insulators let high voltage through. Most common wire insulation is only good for about 600 volts. Take care not to become a bleeder resistor. Your idea of the RF choke is better than resistors to ground as there should be lower signal loss. GUD DX OM. See you in the pile ups, 73 Bruce - Original Message - From: Eddy Swynar To: Bruce Cc: topband@contesting.com Sent: Thursday, November 15, 2012 10:31 AM Subject: Re: Topband: Covered /bare antennn wire Hi Bruce, I am not so sure that the notion of insulated vs. uninsulated wire holds true in long wire spans... Case in point: years ago when I first erected my 1500' long Beverage antenna here, I was specific in using insulated wire though its entire course because it runs through a grove of trees at one point. Well, one day, in the advance of an approaching storm front, I decided to ground the end of the Beverage in my shack. I could feel a tingling sensation as I man-handled the wire, negotiating my way to the common ground pipe that I have running the length of the back of my operating table...imagine my complete utter shock as I neared the wire to this same pipe, and managed to induce 1/8 long blue arcs from the pipe to the wire! Since that time---FWIW---I have always had a rugged 2.5 mh. RF choke clipped between the wire's end where it attaches to the matching transformer, and ground. In theory this acts as a static drain, I guess, but does not induce signals to ground. I've heard that a multi-megohm resistor will do the same thing at this point... ~73~ de Eddy VE3CUI - VE3XZ ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
Hi Bruce, Sure, and I'd be interested in knowing that, too. :-) I should add that the GDTs were added after a lighting hit in the vicinity caused windings to open up on the transformers. The GDTs were to prevent that, and the resistors were to minimize the number of times that the GDTs conducted (each time they fire, their life is shortened just a little). You have a good page about Beverages there. I think I may have used some of those ideas when I built the ones I have. 73, Mike On Thu, Nov 15, 2012 at 3:33 PM, Bruce k...@myfairpoint.net wrote: Good point Mike, but I am hoping someone has done definitive testing between insulated and un-insulated wire concerning voltage build up. If the voltage is lower with insulated wire there is less to bleed off, and possibly lower noise activity. http://www.qsl.net/k1fz/**beveragenotes.htmlhttp://www.qsl.net/k1fz/beveragenotes.html ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
Out of curiosity, has anyone ever really done testing of voltage buildup on a insulated antenna wire, VS a non-insulated wire ? Indoor antennas VS outdoor antennas of equal size? I tested this extensively years ago, and there was no difference at all except if the insulation was in an area of corona discharge. All of the noise appeared related to corona, which was a function of exposed sharp points, and all of the charge for a floating wire was the same insulated or not. I discussed this with KB8MU (just recently a SK) from NASA, because he dealt with ion propulsion and electromagnetics, and what he found on spacecraft and aircraft agreed with my earth-based experiments. I used an electrostatic paint gun with water, and a modified garden hose, as the charged water source. I also noticed no difference on real antennas. My higher antennas with sharp points get p-static, the low antennas or antennas with blunt ends do not. Grounding and static drains make no difference except for the popping when a dielectric charges and arcs. 73 Tom ___ Topband reflector - topband@contesting.com
Topband: Limiters - not T/R Relays
I'm more interested in the 'limiters' aspect of the other thread. Back-to-back diodes == bad, but am looking for something to better tame RF coming in on my beverages, or whatever leaks by the bandpass filters on the 'other' station antenna in a multi-multi. Some sort of saturable transformer design, like http://www.arraysolutions.com/Products/as_rxfep.htm ? PIN diode attenuator? What are some good references to learn about the tradeoffs and techniques? -Brian N9ADG ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
Hi Tom, Thank you for the information, It sounds very convincing. As you have said it is difficult to get a A-B test unless instant switching or direct observation is available. I was hoping for a test something like, side by side identical wires, one insulated, and one un-insulated with voltage measuring devices at the ends. Also separated enough not to get Beverage coupling, and using real stormy weather measuring. Over the insulation breakdown voltage, one would expect them to be equal anyway. 73 Bruce-K1FZ - Original Message - From: Tom W8JI w...@w8ji.com To: Bruce k...@myfairpoint.net; topband@contesting.com Sent: Thursday, November 15, 2012 11:14 AM Subject: Re: Topband: Covered /bare antennn wire Out of curiosity, has anyone ever really done testing of voltage buildup on a insulated antenna wire, VS a non-insulated wire ? Indoor antennas VS outdoor antennas of equal size? I tested this extensively years ago, and there was no difference at all except if the insulation was in an area of corona discharge. All of the noise appeared related to corona, which was a function of exposed sharp points, and all of the charge for a floating wire was the same insulated or not. I discussed this with KB8MU (just recently a SK) from NASA, because he dealt with ion propulsion and electromagnetics, and what he found on spacecraft and aircraft agreed with my earth-based experiments. I used an electrostatic paint gun with water, and a modified garden hose, as the charged water source. I also noticed no difference on real antennas. My higher antennas with sharp points get p-static, the low antennas or antennas with blunt ends do not. Grounding and static drains make no difference except for the popping when a dielectric charges and arcs. 73 Tom ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Limiters - not T/R Relays
Brian Moran wrote: Some sort of saturable transformer design, like http://www.arraysolutions.com/Products/as_rxfep.htm ? What is interesting about this is that it uses T1-6 transformers, which I have been using and recommending for years for RX antenna use. I have repeatedly been told that these are no good because they will saturate at too low of a level and cause intermods, etc. The design cited is an existence proof that these transformers will work just fine in most situations. I'm only 6 miles from a 50 kW AM BC station and I have never had any trouble with T1-6 transformers generating spurs. I will note that the T1-6 has an especially large core, so it may be that the T1-1, for example, is not up to the job. FWIW, I accidentally transmitted into a beverage using a T1-6 transformer with 100 watts, and it did not burn out the transformer. Rick N6RK ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
As you have said it is difficult to get a A-B test unless instant switching or direct observation is available. The purpose of my test was to see if p-static was caused by individual charged particles as they hit the wire, or some other mechanism like corona discharge into the charged air or charged cloud of particles. My thought was if it was charged particles each making noise, the pitch or frequency distribution would be at the rate of particle contact, and that insulation should mute the effect by slowing rise time of charge transfer from particles to the wire. Clearly the noise was all from corona at sharp points. This also agrees with the effects people with multiple antennas see, or even two-way antenna on tall buildings or towers. The highest and most protruding antenna has the first and worse noise. Grounded elements, fiberglass housings, and other tricks make no difference at all. The only thing that matters is streamers from the exact point of corona leakage. We saw this when a repeater moved from side mount on a tower to a building roof peak. The fiberglass Station Master was swapped for a grounded folded dipole antenna, and both were equally useless in bad weather. The only thing that improved p-static noise was using an antenna well below the height of other sticks on the roof, but that didn't work out because of severe pattern nulls. We could raise the antenna and watch the noise increase, and at the same time actually hear the same sizzling acoustically through our ears and see it at night from antenna tips. Everyone with stacked monoband identical Yagis sees this on the top antenna. The top antenna is always terrible in inclement weather, even though the same precipitation strikes all antennas equally and the antennas are all on the same tower. This all, since it all always agrees, clearly means the noise has nothing to do with static drain or insulated or bare conductors. It is all about where the highest voltage gradient to space around the antenna is, and how easy that point can leak (generate corona). I was hoping for a test something like, side by side identical wires, one insulated, and one un-insulated with voltage measuring devices at the ends. Also separated enough not to get Beverage coupling, and using real stormy weather measuring. Over the insulation breakdown voltage, one would expect them to be equal anyway. Leakage current to earth was identical in my spray tests. It has nothing to do with insulation breakdown. It is more like the effect of a charged plastic comb. The charge obviously distributed right through the insulation. I suppose if the insulation was really thick the charge migration would be pretty slow, but charging of the wire is not what makes the noise we are concerned with. The noise comes from corona. I've had insulated wire Beverages and bare wire Beverages since the 1960's or 1970's, often at the same time as mixtures of wire. Neither is any quieter for me for local storm static. My bare wire Beverages here are dead quiet even while Yagi's are useless in foul weather, unless the Beverage points at the towers or are near tall trees. 73 Tom ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
Tom, Thank you for your research and information. You have me convinced My much lower BOG Beverage has a better signal to noise than my taller Beverages in storm events. This aligns to your research. 73 Bruce-K1FZ - Original Message - From: Tom W8JI w...@w8ji.com To: Bruce k...@myfairpoint.net; topband@contesting.com Sent: Thursday, November 15, 2012 12:25 PM Subject: Re: Topband: Covered /bare antennn wire As you have said it is difficult to get a A-B test unless instant switching or direct observation is available. The purpose of my test was to see if p-static was caused by individual charged particles as they hit the wire, or some other mechanism like corona discharge into the charged air or charged cloud of particles. My thought was if it was charged particles each making noise, the pitch or frequency distribution would be at the rate of particle contact, and that insulation should mute the effect by slowing rise time of charge transfer from particles to the wire. Clearly the noise was all from corona at sharp points. This also agrees with the effects people with multiple antennas see, or even two-way antenna on tall buildings or towers. The highest and most protruding antenna has the first and worse noise. Grounded elements, fiberglass housings, and other tricks make no difference at all. The only thing that matters is streamers from the exact point of corona leakage. We saw this when a repeater moved from side mount on a tower to a building roof peak. The fiberglass Station Master was swapped for a grounded folded dipole antenna, and both were equally useless in bad weather. The only thing that improved p-static noise was using an antenna well below the height of other sticks on the roof, but that didn't work out because of severe pattern nulls. We could raise the antenna and watch the noise increase, and at the same time actually hear the same sizzling acoustically through our ears and see it at night from antenna tips. Everyone with stacked monoband identical Yagis sees this on the top antenna. The top antenna is always terrible in inclement weather, even though the same precipitation strikes all antennas equally and the antennas are all on the same tower. This all, since it all always agrees, clearly means the noise has nothing to do with static drain or insulated or bare conductors. It is all about where the highest voltage gradient to space around the antenna is, and how easy that point can leak (generate corona). I was hoping for a test something like, side by side identical wires, one insulated, and one un-insulated with voltage measuring devices at the ends. Also separated enough not to get Beverage coupling, and using real stormy weather measuring. Over the insulation breakdown voltage, one would expect them to be equal anyway. Leakage current to earth was identical in my spray tests. It has nothing to do with insulation breakdown. It is more like the effect of a charged plastic comb. The charge obviously distributed right through the insulation. I suppose if the insulation was really thick the charge migration would be pretty slow, but charging of the wire is not what makes the noise we are concerned with. The noise comes from corona. I've had insulated wire Beverages and bare wire Beverages since the 1960's or 1970's, often at the same time as mixtures of wire. Neither is any quieter for me for local storm static. My bare wire Beverages here are dead quiet even while Yagi's are useless in foul weather, unless the Beverage points at the towers or are near tall trees. 73 Tom ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
I used to have an ICE model 303 lightning protector which I believe was a gas discharge tube with a toroidal choke in parallel to ground. I recall the toroidal choke was to continually bleed the electrons from the antenna so there would not be a buildup sufficient to cause damage and to not create a focus for a lightning strike. I may still have it in one of my boxes of Ham Gear still back in the midwest. I also remember my father running a not too terribly long wire outside with a Rf ammeter in series indoors watching the movement increase as a storm approached. Gary KA1J On 2012-11-15, at 3:42 PM, Bruce wrote: Dry blowing snow or high wind can cause quite some voltage build up on a antenna, especially a long one. It is possible to draw quite an arc to ground. There have been reports of high voltage electrocutions from antenna static build up in Short Wave Broadcast stations. A short stick was mandatory for maintenance periods. And yes, I did work at a shortwave station with 500 KW transmitter output. So receiving antenna wire insulation could have some benefit if the voltage on a bare wire is leaking to a tree limb or across an insulator. Beyond some point all insulators can fail. Indoor antennas do hear static, but I have never seen any evidence of voltage build up. ( The building may provide adequate insulation.) Out of curiosity, has anyone ever really done testing of voltage buildup on a insulated antenna wire, VS a non-insulated wire ? Indoor antennas VS outdoor antennas of equal size? Hi Bruce, I am not so sure that the notion of insulated vs. uninsulated wire holds true in long wire spans... Case in point: years ago when I first erected my 1500' long Beverage antenna here, I was specific in using insulated wire though its entire course because it runs through a grove of trees at one point. Well, one day, in the advance of an approaching storm front, I decided to ground the end of the Beverage in my shack. I could feel a tingling sensation as I man-handled the wire, negotiating my way to the common ground pipe that I have running the length of the back of my operating table...imagine my complete utter shock as I neared the wire to this same pipe, and managed to induce 1/8 long blue arcs from the pipe to the wire! Since that time---FWIW---I have always had a rugged 2.5 mh. RF choke clipped between the wire's end where it attaches to the matching transformer, and ground. In theory this acts as a static drain, I guess, but does not induce signals to ground. I've heard that a multi-megohm resistor will do the same thing at this point... ~73~ de Eddy VE3CUI - VE3XZ ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
Not that Ive noticed. I suspect most Americans are more comfortable with our own measuring system plus our ham bands where antenna formulas are still published in feet and inches. Carl KM1H - Original Message - From: Pete Smith N4ZR n...@contesting.com To: topband@contesting.com Sent: Thursday, November 15, 2012 6:14 AM Subject: Re: Topband: Vertical Array Over Uneven Ground CU on the 525 foot band, Carl? Seriously, I suspect that the reason why many of us work in meters when modeling is simply that some of the most useful software products default to that. 73, Pete N4ZR Check out the Reverse Beacon Network at http://reversebeacon.net, blog at reversebeacon.blogspot.com. For spots, please go to your favorite ARC V6 or VE7CC DX cluster node. On 11/14/2012 3:48 PM, ZR wrote: I cant find the button to convert that metric stuff to good old USA measurements when posted from this country(-: Subject: Re: Topband: Vertical Array Over Uneven Ground I never found a way to model an an antenna over anything but flat, level ground. Not in EZNEC+ 5.0, anyway. 73, Mike www.w0btu.com On Tue, Nov 13, 2012 at 7:41 PM, Ken Claerbout k...@verizon.net wrote: Has anyone modeled or have experience with a transmit vertical array, say a 4-square, over uneven ground? By uneven I mean a variance of up to 2 - 3 meters over the footprint of the array elements. ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5394 - Release Date: 11/14/12 ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5396 - Release Date: 11/15/12 ___ Topband reflector - topband@contesting.com
Re: Topband: 230+ QSLs On LOW Dipole - There's Hope!
I did a search for K2UO here and didn't see anything recent, so I thought I would post the article again for those with Low Dipoles or tight spaces. Mentioned in ON4UN's book. http://vss.pl/lf/14.pdf K2UO was #61 for North America (2009) with an antenna that is 12-30ft high on flat land was using 100W for the first 75 Countries. Then added Amp and Beverage. 2009 Data (anyone have the link to current data?) http://www.qsl.net/160/ [CONFIDENTIALITY AND PRIVACY NOTICE] Information transmitted by this email is proprietary to Mr. Mrs. B and is intended for use only by the individual or entity to which it is addressed, or where ever the hell it ends up, and will almost certainly contain information that will offend a large portion of the population, which isn't our concern. If you are not the intended lucky recipient, or it appears that this mail has been forwarded to you without the proper authority of the Wizard of Email or Al Gore, you are notified that any thought, use, or consumption of this email is entirely your choice. In such case, Bon AppetitNote: A $.02 Internet Tax was charged for receiving this email and all funds were given to some family somewhere in America or the U.N Have a nice day. ___ Topband reflector - topband@contesting.com
Re: Topband: Limiters - not T/R Relays
Ive made several contacts up to about 2500 miles (West from NH) running 100W into a single 750' #12 copperweld Beverage up about 8' using a FT114-43 autotransformer back in the 80's at a prior home. These were mostly on CW during contests; the terminator was a 600 Ohm 100W NI resistor and the #24 transformer wire still looked as new. Carl KM1H - Original Message - From: Rick Karlquist rich...@karlquist.com To: Brian Moran bria...@yahoo.com Cc: topband@contesting.com Sent: Thursday, November 15, 2012 3:16 PM Subject: Re: Topband: Limiters - not T/R Relays Brian Moran wrote: Some sort of saturable transformer design, like http://www.arraysolutions.com/Products/as_rxfep.htm ? What is interesting about this is that it uses T1-6 transformers, which I have been using and recommending for years for RX antenna use. I have repeatedly been told that these are no good because they will saturate at too low of a level and cause intermods, etc. The design cited is an existence proof that these transformers will work just fine in most situations. I'm only 6 miles from a 50 kW AM BC station and I have never had any trouble with T1-6 transformers generating spurs. I will note that the T1-6 has an especially large core, so it may be that the T1-1, for example, is not up to the job. FWIW, I accidentally transmitted into a beverage using a T1-6 transformer with 100 watts, and it did not burn out the transformer. Rick N6RK ___ Topband reflector - topband@contesting.com - No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1427 / Virus Database: 2441/5396 - Release Date: 11/15/12 ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
I suspect most Americans are more comfortable with our own measuring system plus our ham bands where antenna formulas are still published in feet and inches. I suspect most (or at least many) Americans are resistant to change and unwilling to give anything different than what they are used to a fair try before dismissing it. When I don't have to deal too extensively with materials made to specific sizes for the U.S. market, I do much of my measuring and work using the metric system. Why? Because once I got used to it, I find it much easier to work with. My notes on projects going back over 20 years usually give dimensions in metric (eg. plate line dimensions for a VHF amplifier in millimeters). I have grown somewhat weary of converting to another system just so that other Americans won't grumble about my choice of units. I may stop that practice. If other Americans don't understand the measurements and can't be bothered to do the conversion, they probably don't really want/need the information. Paul ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
Gosh, Paul.why don't you simply keep measuring in our system and avoid the obvious mental wedgie you keep forming PLUS you won't be so weary?!?!?! 72, Jim Rodenkirch K9JWV Date: Thu, 15 Nov 2012 18:58:48 -0500 From: p...@n1bug.com To: z...@jeremy.mv.com CC: topband@contesting.com Subject: Re: Topband: Vertical Array Over Uneven Ground I suspect most Americans are more comfortable with our own measuring system plus our ham bands where antenna formulas are still published in feet and inches. I suspect most (or at least many) Americans are resistant to change and unwilling to give anything different than what they are used to a fair try before dismissing it. When I don't have to deal too extensively with materials made to specific sizes for the U.S. market, I do much of my measuring and work using the metric system. Why? Because once I got used to it, I find it much easier to work with. My notes on projects going back over 20 years usually give dimensions in metric (eg. plate line dimensions for a VHF amplifier in millimeters). I have grown somewhat weary of converting to another system just so that other Americans won't grumble about my choice of units. I may stop that practice. If other Americans don't understand the measurements and can't be bothered to do the conversion, they probably don't really want/need the information. Paul ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
All, This argument has been going on ever since I got out of Engineering school, and frankly, it's not going to stop until my generation is gone. I'm an EE and I work in my own machine shop in my (new) retirement. I work in Imperial units because I THINK in Imperial units - it's what I learned as a wee bairn. I KNOW what an inch and a foot are, instinctively, and although I have no problem working in metric, I prefer not to because the units are non-instinctive - to ME. I care not a whit if metric calculations are faster or somehow superior; I don't think in metric - period. Now, two of my kids are 1990's vintage EEs, and they grew up on metric. I was taken aback when one of them - in high school - described a dimension to me by holding his fingers THIS far apart and stating: oh, it's about 10 cm. When his generation largely displaces mine in the workforce, metric will have won. It won't be better or worse than Imperial measurement - it will just BE. Me, I'll continue working - and thinking - in inches, feet, mils, and turning out good work to precise dimensions, while ignoring snobs that presume that I just don't get it. 73, geo - n4ua On Thu, Nov 15, 2012 at 7:05 PM, James Rodenkirch rodenkirch_...@msn.comwrote: Gosh, Paul.why don't you simply keep measuring in our system and avoid the obvious mental wedgie you keep forming PLUS you won't be so weary?!?!?! 72, Jim Rodenkirch K9JWV Date: Thu, 15 Nov 2012 18:58:48 -0500 From: p...@n1bug.com To: z...@jeremy.mv.com CC: topband@contesting.com Subject: Re: Topband: Vertical Array Over Uneven Ground I suspect most Americans are more comfortable with our own measuring system plus our ham bands where antenna formulas are still published in feet and inches. I suspect most (or at least many) Americans are resistant to change and unwilling to give anything different than what they are used to a fair try before dismissing it. When I don't have to deal too extensively with materials made to specific sizes for the U.S. market, I do much of my measuring and work using the metric system. Why? Because once I got used to it, I find it much easier to work with. My notes on projects going back over 20 years usually give dimensions in metric (eg. plate line dimensions for a VHF amplifier in millimeters). I have grown somewhat weary of converting to another system just so that other Americans won't grumble about my choice of units. I may stop that practice. If other Americans don't understand the measurements and can't be bothered to do the conversion, they probably don't really want/need the information. Paul ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com ___ Topband reflector - topband@contesting.com
Re: Topband: Covered /bare antennn wire
Subject: Re: Topband: Covered /bare antennn wire As you have said it is difficult to get a A-B test unless instant switching or direct observation is available. The purpose of my test was to see if p-static was caused by individual charged particles as they hit the wire, or some other mechanism like corona discharge into the charged air or charged cloud of particles. My thought was if it was charged particles each making noise, the pitch or frequency distribution would be at the rate of particle contact, and that insulation should mute the effect by slowing rise time of charge transfer from particles to the wire. Clearly the noise was all from corona at sharp points. This also agrees with the effects people with multiple antennas see, or even two-way antenna on tall buildings or towers. The highest and most protruding antenna has the first and worse noise. Grounded elements, fiberglass housings, and other tricks make no difference at all. The only thing that matters is streamers from the exact point of corona leakage. We saw this when a repeater moved from side mount on a tower to a building roof peak. The fiberglass Station Master was swapped for a grounded folded dipole antenna, and both were equally useless in bad weather. The only thing that improved p-static noise was using an antenna well below the height of other sticks on the roof, but that didn't work out because of severe pattern nulls. We could raise the antenna and watch the noise increase, and at the same time actually hear the same sizzling acoustically through our ears and see it at night from antenna tips. Everyone with stacked monoband identical Yagis sees this on the top antenna. The top antenna is always terrible in inclement weather, even though the same precipitation strikes all antennas equally and the antennas are all on the same tower. This all, since it all always agrees, clearly means the noise has nothing to do with static drain or insulated or bare conductors. It is all about where the highest voltage gradient to space around the antenna is, and how easy that point can leak (generate corona). I was hoping for a test something like, side by side identical wires, one insulated, and one un-insulated with voltage measuring devices at the ends. Also separated enough not to get Beverage coupling, and using real stormy weather measuring. Over the insulation breakdown voltage, one would expect them to be equal anyway. Leakage current to earth was identical in my spray tests. It has nothing to do with insulation breakdown. It is more like the effect of a charged plastic comb. The charge obviously distributed right through the insulation. I suppose if the insulation was really thick the charge migration would be pretty slow, but charging of the wire is not what makes the noise we are concerned with. The noise comes from corona. I've had insulated wire Beverages and bare wire Beverages since the 1960's or 1970's, often at the same time as mixtures of wire. Neither is any quieter for me for local storm static. My bare wire Beverages here are dead quiet even while Yagi's are useless in foul weather, unless the Beverage points at the towers or are near tall trees. 73 Tom ___ Topband reflector - topband@contesting.com Before I moved here in 89 I had a KLM 4el 40M yagi at 120' that was very noisy during blowing snow and less in the rain. All elements were insulated from the boom. When I moved here (same town, 500' higher) the tower was initally 160'. I grounded the reflector and director centers to the boom using wide AL strap per KLM's suggestion. The dual driven elements then had low inductance heavy wire, very low DC resistance, chokes added (my own idea based upon what the USN did for receiver static) to each phasing line at the feed end and to the boom. There was nothing above it most of the time and those were a short experiment with a 20' boom 4el 10M (too high based upon 2 contests compared to the switchable 4 high stack) and a 34' boom 6el 6M (about 6 months) during the tail end of a sun spot cycle that did wonders on weak F2 openings. Another thing I did with that KLM at the new QTH was to toss their 4:1 voltage balun (it started acting up just before I moved) and build one from a 1/2 wave of coax and then added a big coax choke at the feed connector. All the changes were done at the same time so Ive no idea if any particular step did the trick or if it was cumulative. No more P-static as shown in the 40M scores in various all band contests. The 4 stacked 20M monobanders on the same tower below the 40 were silent as were the 10 and 15M stacks on other towers that had various VHF/UHF long yagis above them. Ive no idea if they helped or not. I would suggest trying various methods on 160 or other bands as the jury is still out on what works, when, where, and how. Carl KM1H
Re: Topband: Covered /bare antennn wire
Subject: Re: Topband: Covered /bare antennn wire Tom, Thank you for your research and information. You have me convinced My much lower BOG Beverage has a better signal to noise than my taller Beverages in storm events. This aligns to your research. 73 Bruce-K1FZ That has nothing to do with the P-static itself. The BOG is coupled closely to ground and the elevation angle signal lobe increases. I use elevated and BOG Beverages and see no correlation to P-static but the BOG's have much less local neighborhood crud which is vertically polarized; they always have a better SNR but do not hear the long haul pee weak DX at all most of the time. Both have their purpose in any weather. OTOH all my runs are thru deep woods and not wide open fields so maybe that is a factor. Carl KM1H ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
Since I started this thread, hopefully this will end it. I was talking about a difference on the order of 6' - 9', which I think was understood. But there are always those few that like to stir the pot, no matter how petty. Thanks to those who provided useful feedback. I'll follow up directly as I get further into the project. Ken K4ZW ___ Topband reflector - topband@contesting.com
Topband: Fwd: TX/RX Antenna Switching
-- Forwarded message -- From: Herb Schoenbohm he...@vitelcom.net Date: Thu, Nov 15, 2012 at 5:22 PM I used to use at first the MFJ-1026 Noise Canceller/Phaser box in a reverse configuration to bring the RX only antennas in from the Beverage bank. With the RF sense switch there were problems with the leading edge on higher speed CW being cut. This was solved by using the forced 12 available from a small relay box in line with the amp keying line, as my Icom does not provide 12 VDC out on key down only 8VDC at a few mills. About a year later I purchased the RTR-1 by DXE and this is really the way to go. As Tom, W8JI pointed out on an earlier article on his website, there are several improvements that can be made to the MFJ unit to reduce the noise figure on the RX port but I just use them now to phase Beverages primarily for noise cancellation from unwanted directions. This may help in some circumstances but the tuning in the MFJ is very critical and not something you can do well during the heat of a contest during peaking mode. So I just set things up in advance for one path and two Beverages such as Europe but that to can change radically the longest distance signals which can shift here from 20 to 90 degrees at times depending on what is happening at the north pole. Herb, KV4FZ ___ Topband reflector - topband@contesting.com
Re: Topband: Vertical Array Over Uneven Ground
Here in South Africa we always had the imperial system till somewhere in the middle sixties and before that we changed from pounds to decimal Rand and cents. It was met with some resistance but soon everybody got used to it. As I have a British lathe and milling machine in my garage /workshop, and is part time building a model steam train from imperial plans, I can switch between metric and imperial quite easily. Most eletronic callipers and micrometers have a little mode button to measure in both systems. 73 Raoul ZS1REC I'm an EE and I work in my own machine shop in my (new) retirement. I work in Imperial units because I THINK in Imperial units - it's what I learned as a wee bairn. I KNOW what an inch and a foot are, instinctively, and although I have no problem working in metric, I prefer not to because the units are non-instinctive - to ME. I care not a whit if metric calculations are faster or somehow superior; I don't think in metric - period. 73, geo - n4ua ___ Topband reflector - topband@contesting.com
