Topband: Vacuum variable capacitors.
Steve, you can purchase excellent quality vac variable caps from Dr Alex Gavva UR4LL for a very reasonable price Bob..VK3ZL.. _ Topband Reflector
Topband: Light fiber question
I am now using twisted pair on my receiving Delta antenna and is less noise than the coax. Question: Any one ever tried using light fibers as a near ultimate transmission line from their receiving antennas? 73 Bruce-K1FZ www.qsl.net/k1fz/beveragenotes.html _ Topband Reflector
Re: Topband: Idiom Press
Why doesn't Rob do us all a favor and sell Idiom Press to a company that seems to have its act together, such as DX Engineering, Array Solutions or W4PA (Vibroplex/Spiderbeam USA) ? He's certainly not going to make any money the way he currently runs the company. 73, Steve, N2IC On 10/23/2013 09:40 PM, Doug Renwick wrote: I checked my email records and see the same story back in year 2008. Some things never change. I hope this time Rob gets his act together for good. Doug Think of all the ways you can hurt yourself laughing. -Original Message- This is Rob Locher W7GH. Idiom Press was started by my father Bob Locher W9KNI. A few years ago he brought me on board, and then later retired, leaving me in charge. I'd had no business experience before running Idiom Press. Recently I've had several unanticipated challenges that I've had to deal with. The challenges have led to an order backlog, which has multiplied my workload. I've dropped the ball in keeping up with emails and phone calls. My father, and also friends and other concerned people, have reminded me that the most important thing to any business is contact with the customer. To the people I've inconvenienced, I'm sorry, and I apologize. I am learning as I go. I have a plan to get caught up with orders as quickly as possible. Most importantly, I've personally refocused on customer contact. I'll be contacting everyone with an outstanding order. I must, however, ask customers for a little patience for the next month or so. 73, - Rob Locher W7GH Idiom Press _ Topband Reflector _ Topband Reflector _ Topband Reflector
Topband: Light fiber question
Tim, Good information, but I was thinking of a way for Mr. Average DXer to get a connection, that is not adding noise, from his on site receiving antenna. 73 Bruce - Original Message - From: Shoppa, Tim tsho...@wmata.com To: Bruce k...@myfairpoint.net Sent: Thursday, October 24, 2013 5:50 AM Subject: RE: Topband: Light fiber question I think that is called a remote receiver connected by optical fiber networking. Several folks use this technology on topband. Sometimes the remote receiver is the other side of the world. Tim. -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bruce Sent: Thursday, October 24, 2013 11:48 AM To: topband@contesting.com Subject: Topband: Light fiber question I am now using twisted pair on my receiving Delta antenna and is less noise than the coax. Question: Any one ever tried using light fibers as a near ultimate transmission line from their receiving antennas? 73 Bruce-K1FZ www.qsl.net/k1fz/beveragenotes.html _ Topband Reflector _ Topband Reflector
Re: Topband: Light fiber question
I do not know of any analog optical coupling technology that has nearly the dynamic range of copper. 50dB is considered quite good HF dynamic range for completely sealed analog optocouplers. Start putting cables and junctions in there and it has to only get worse. Tim N3QE -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bruce Sent: Thursday, October 24, 2013 12:06 PM To: topband@contesting.com Subject: Topband: Light fiber question Tim, Good information, but I was thinking of a way for Mr. Average DXer to get a connection, that is not adding noise, from his on site receiving antenna. 73 Bruce - Original Message - From: Shoppa, Tim tsho...@wmata.com To: Bruce k...@myfairpoint.net Sent: Thursday, October 24, 2013 5:50 AM Subject: RE: Topband: Light fiber question I think that is called a remote receiver connected by optical fiber networking. Several folks use this technology on topband. Sometimes the remote receiver is the other side of the world. Tim. -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bruce Sent: Thursday, October 24, 2013 11:48 AM To: topband@contesting.com Subject: Topband: Light fiber question I am now using twisted pair on my receiving Delta antenna and is less noise than the coax. Question: Any one ever tried using light fibers as a near ultimate transmission line from their receiving antennas? 73 Bruce-K1FZ www.qsl.net/k1fz/beveragenotes.html _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: Beverage Woes
I use ladder line from the Wireman and from Davis RF. I think the conductors are copper plated solid steel. I bought 1/4 thick 2 wide strips of acrylic from McMaster Carr and made a pair of clamps of 6 long pieces by cutting grooves for the wire thickness, two holes for ss bolts and one for a rope. These clamp the ends tightly and the acrylic is useable outdoors. The ladder line is supported every 50 -75 feet by a 3-4 piece of pvc wide enough to easily pass the ladder line and with a large and small hole in it. The small hole is for a screw into a convenient tree and the large is to pass the screwhead. Where there were no trees, mainly a swampy area, I used metal fence posts with a piece of pvc over the post with a bolt through limit how far down it slides on the post and a T on the top end. The ladder line passes through the T. The supports are at the end only. The ladder line has a twist every 3 or 4 feet and rides easily through the pvc supports. This has been up for at least three years and has survived tree limbs, frost, snow and people with no problems to date. I think I have pictures of the clamps if anyone is interested. Les W2LK On 10/23/2013 5:46 PM, Mike Waters wrote: Whatever you use for wire, it needs to float at the supports. Anchor it at only one end and tension it tightly at the other end. I use my own ladder line, made from .061 diameter plated steel electric fence wire and spacers made from 1/4 dia. plastic coat hangers. Supports are 10' high and 100' apart. It's taken a lot of abuse, including large tree branches falling on it and a porch roof hurled against it by a small tornado. Some supports broke during the flying porch roof incident, but the wires never broke either time. WD-1A military telephone wire works well, if you have the right impedance matching transformers. Having said all this, I know that a lot of Topbanders use that brown plastic window line for their Beverage antennas. Which kind lasts? 73, Mike http://www.w0btu.com/Beverage_antennas.html _ Topband Reflector _ Topband Reflector
Re: Topband: Beverage Woes
I use twinlead (DX-wire or Wireman) 300 Ohm, less attenuation compaired to RG58 and small. not much windload. Doing its job for over 5 years now. Only fixed at the ends. Kees, PE5T -- From: Les Kalmus w...@bk-lk.com Sent: Thursday, October 24, 2013 4:21 PM To: topband@contesting.com Subject: Re: Topband: Beverage Woes I use ladder line from the Wireman and from Davis RF. I think the conductors are copper plated solid steel. I bought 1/4 thick 2 wide strips of acrylic from McMaster Carr and made a pair of clamps of 6 long pieces by cutting grooves for the wire thickness, two holes for ss bolts and one for a rope. These clamp the ends tightly and the acrylic is useable outdoors. The ladder line is supported every 50 -75 feet by a 3-4 piece of pvc wide enough to easily pass the ladder line and with a large and small hole in it. The small hole is for a screw into a convenient tree and the large is to pass the screwhead. Where there were no trees, mainly a swampy area, I used metal fence posts with a piece of pvc over the post with a bolt through limit how far down it slides on the post and a T on the top end. The ladder line passes through the T. The supports are at the end only. The ladder line has a twist every 3 or 4 feet and rides easily through the pvc supports. This has been up for at least three years and has survived tree limbs, frost, snow and people with no problems to date. I think I have pictures of the clamps if anyone is interested. Les W2LK On 10/23/2013 5:46 PM, Mike Waters wrote: Whatever you use for wire, it needs to float at the supports. Anchor it at only one end and tension it tightly at the other end. I use my own ladder line, made from .061 diameter plated steel electric fence wire and spacers made from 1/4 dia. plastic coat hangers. Supports are 10' high and 100' apart. It's taken a lot of abuse, including large tree branches falling on it and a porch roof hurled against it by a small tornado. Some supports broke during the flying porch roof incident, but the wires never broke either time. WD-1A military telephone wire works well, if you have the right impedance matching transformers. Having said all this, I know that a lot of Topbanders use that brown plastic window line for their Beverage antennas. Which kind lasts? 73, Mike http://www.w0btu.com/Beverage_antennas.html _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: Beverage Woes
How long it lasts really depends on how mechanically intuitive we are when we install the antenna. Key things are to let the wire float in everything but the end supports, and make sure things don't cut, flex, or rip the wire apart. Spreading the end load, if you grip the insulation, is a good idea. It is better to strip back the insulation and egg insulator the ends with a rope that floats and allows tensions to equalize between both conductors. The wire also has to be supported to make short spans, so tension is not too great. Mine traditionally lasted for several years, although I'm not sure about quality of new wire. I had some stranded window line where wires just rusted apart in a few years. - Original Message - From: Les Kalmus w...@bk-lk.com To: topband@contesting.com Sent: Thursday, October 24, 2013 10:21 AM Subject: Re: Topband: Beverage Woes I use ladder line from the Wireman and from Davis RF. I think the conductors are copper plated solid steel. I bought 1/4 thick 2 wide strips of acrylic from McMaster Carr and made a pair of clamps of 6 long pieces by cutting grooves for the wire thickness, two holes for ss bolts and one for a rope. These clamp the ends tightly and the acrylic is useable outdoors. The ladder line is supported every 50 -75 feet by a 3-4 piece of pvc wide enough to easily pass the ladder line and with a large and small hole in it. The small hole is for a screw into a convenient tree and the large is to pass the screwhead. Where there were no trees, mainly a swampy area, I used metal fence posts with a piece of pvc over the post with a bolt through limit how far down it slides on the post and a T on the top end. The ladder line passes through the T. The supports are at the end only. The ladder line has a twist every 3 or 4 feet and rides easily through the pvc supports. This has been up for at least three years and has survived tree limbs, frost, snow and people with no problems to date. I think I have pictures of the clamps if anyone is interested. Les W2LK On 10/23/2013 5:46 PM, Mike Waters wrote: Whatever you use for wire, it needs to float at the supports. Anchor it at only one end and tension it tightly at the other end. I use my own ladder line, made from .061 diameter plated steel electric fence wire and spacers made from 1/4 dia. plastic coat hangers. Supports are 10' high and 100' apart. It's taken a lot of abuse, including large tree branches falling on it and a porch roof hurled against it by a small tornado. Some supports broke during the flying porch roof incident, but the wires never broke either time. WD-1A military telephone wire works well, if you have the right impedance matching transformers. Having said all this, I know that a lot of Topbanders use that brown plastic window line for their Beverage antennas. Which kind lasts? 73, Mike http://www.w0btu.com/Beverage_antennas.html _ Topband Reflector _ Topband Reflector - No virus found in this message. Checked by AVG - www.avg.com Version: 2014.0.4158 / Virus Database: 3614/6767 - Release Date: 10/20/13 _ Topband Reflector
Re: Topband: Light fiber question
I am now using twisted pair on my receiving Delta antenna and is less noise than the coax. If you now have less noise with a twisted pair, it only means you had a significant design or installation issue with your coax someplace in the system. 73 Tom _ Topband Reflector
Re: Topband: Beverage Woes
While I have tried this myself, you could try black UHMW for your supports on the middle posts between the ones taking tension. UHMW is Ultra High Molecular Weight polyethylene. The black stuff holds up outside pretty well. It wouldn't be hard to make a small support with a bottom and top piece and a spacer on either side so that the ladder line could slide a bit inside. The UHMW won't wear through the insulation of the wire as much as a harder material would, and it should hold up in the weather well itself. UHMW is cheap and easy to get. There is some on Ebay now, otherwise any plastics supply house should have it. It's commonly used as a wear material industrially. -Bill I have two bidirectional 720 ft beverages that use 450 ohm ladder line, oriented NE-SW and NW-SE. The ladder line is supported by 4x4 wood posts, about 7 ft above ground, spaced every 60 ft. The antenna works well, but has turned out to be a maintenance nightmare. My first mistake was to anchor the ladder line to the top of each 4x4 post using little plastic clamps (DX Engineering). Those lasted about a week before being pulled apart by the wind. I replaced them with wood pressure plates screwed down over the ladder line with 2 lag screws into the top of the posts. Those lasted about a year before cracking and splitting. The ladder line turned out to be very fragile. The plastic material gets brittle and cracks, and the wind causes metal fatigue and eventual failure of the strands. I've spent the past three afternoons patching up the beverages for the winter DX season and am only about half done.Yesterday, I thought I had everything fixed and only needed to phase the ladder line properly. I left one wire open and grounded the other wire at one end, and then used a DMM to identify the grounded wire. To my dismay I found an open circuit on both wires. A spent a couple of hours with a toner trying to find the break, but to no avail. Then, it occurred to me that my Fluke 87-V DMM may be giving me erroneous readings. I replaced the Fluke with my trusty Simpson 260 and discovered the wire was actually intact. Evidently, the Fluke's sensitive solid state ohmmeter circuit had been overloaded by the inductance/capacitance of the ladderline or possibly RF pickup. I should have known better from the get-go. So now, I've got one of my beverages working and will start repairs on the 2nd one. I've decided ladder line is a terrible choice for a beverage antenna, at least in New Mexico, where there is intense UV sunlight and windy Springtimes. My plan is to replace the ladder line with parallel strands of 12 AWG copperweld wire, with pass-through insulators on each 4x4 post, and the wire anchored at each end. I'll use turnbuckles to adjust the tension. I'm really tired of repairing the damn antennas, and my feet hurt from hiking back and forth to each end. 73, Jim W8ZR _ Topband Reflector _ Topband Reflector
Re: Topband: Light fiber question
Um, no... Not really -- you do NOT need modulators and demodulators to use fiber for *analog* applications. If you want to run your signal over a commercial transport network you will (to digitize the signal and deal with framing for SONET, Ethernet etc.). Cable TV systems run their RF over fiber with very wide frequency ranges (50-700+MHz). I don't know dynamic range off hand since that's not a parameter that comes up with the digital systems I work with (we use extinction ratio instead). The downside is that the equipment to do that is not cheap. This is what I do all day at work (well, digital only, but optical) :-) Anyway, if you only want to run a topband signal it shouldn't be difficult to run the entire band over fiber. You'd need to use a small laser (although an LED would probably work fine since 2MHz is very slow compared to the data rates used on most digital transport systems these days). The important part would be that you'd need to run a feedback loop with the laser/LED and a photodiode monitoring the output. The combined system would be your fiber driver. The receiver would be simpler -- just a photodiode and an amplifier. If you used a decent laser in the 1310nm band and singlemode fiber (the most common kind) you should be able to send your signal at least 5 miles or so without really doing anything special. If I was to build a system like this, I'd use a small 1310nm laser driving an optical splitter. One output from the splitter would be the output, the other would go to a photodiode that would be part of a feedback loop with the laser. The receiver would be a photodiode and an amplifier to convert the optical signal back into an electrical signal. Note that optical splitters are specified in percentages, not decibels, so a 50/50 is 3dB down on both outputs, a 90/10 is 10dB down on one output, etc. It would be an interesting project, although I think it would be a lot simpler to just use low-loss coax unless you run is REALLY long or you have some very special requirements. Fiber is lightning proof though -- just plastic and glass :-) -Bill People forget, or don't know, fiber cables require modulators and demodulators. The modulators and demodulators are not simple, and have horrible dynamic range compared to a simple piece of coax. I can't think of a good Ham shack application using fiberoptics for coupling RF signals. First, the dynamic range stinks compared to coax. Second, common mode is very easily completely cured with extreme measures. _ Topband Reflector
Re: Topband: Light fiber question
CATV analog modulation video over fiber has a typical 50dB dynamic range. See e.g. http://www.emcore.com/wp-content/uploads/Medallion-6000-Series.pdf Tim N3QE -Original Message- From: Bill Wichers [mailto:bi...@waveform.net] Sent: Thursday, October 24, 2013 12:10 PM To: Tom W8JI; Shoppa, Tim; Bruce; topband@contesting.com Subject: RE: Topband: Light fiber question Um, no... Not really -- you do NOT need modulators and demodulators to use fiber for *analog* applications. If you want to run your signal over a commercial transport network you will (to digitize the signal and deal with framing for SONET, Ethernet etc.). Cable TV systems run their RF over fiber with very wide frequency ranges (50-700+MHz). I don't know dynamic range off hand since that's not a parameter that comes up with the digital systems I work with (we use extinction ratio instead). The downside is that the equipment to do that is not cheap. This is what I do all day at work (well, digital only, but optical) :-) Anyway, if you only want to run a topband signal it shouldn't be difficult to run the entire band over fiber. You'd need to use a small laser (although an LED would probably work fine since 2MHz is very slow compared to the data rates used on most digital transport systems these days). The important part would be that you'd need to run a feedback loop with the laser/LED and a photodiode monitoring the output. The combined system would be your fiber driver. The receiver would be simpler -- just a photodiode and an amplifier. If you used a decent laser in the 1310nm band and singlemode fiber (the most common kind) you should be able to send your signal at least 5 miles or so without really doing anything special. If I was to build a system like this, I'd use a small 1310nm laser driving an optical splitter. One output from the splitter would be the output, the other would go to a photodiode that would be part of a feedback loop with the laser. The receiver would be a photodiode and an amplifier to convert the optical signal back into an electrical signal. Note that optical splitters are specified in percentages, not decibels, so a 50/50 is 3dB down on both outputs, a 90/10 is 10dB down on one output, etc. It would be an interesting project, although I think it would be a lot simpler to just use low-loss coax unless you run is REALLY long or you have some very special requirements. Fiber is lightning proof though -- just plastic and glass :-) -Bill People forget, or don't know, fiber cables require modulators and demodulators. The modulators and demodulators are not simple, and have horrible dynamic range compared to a simple piece of coax. I can't think of a good Ham shack application using fiberoptics for coupling RF signals. First, the dynamic range stinks compared to coax. Second, common mode is very easily completely cured with extreme measures. _ Topband Reflector
Re: Topband: Light fiber question
- Original Message - From: Bill Wichers bi...@waveform.net To: Tom W8JI w...@w8ji.com; Shoppa, Tim tsho...@wmata.com; Bruce k...@myfairpoint.net; topband@contesting.com Sent: Thursday, October 24, 2013 12:10 PM Subject: Re: Topband: Light fiber question Um, no... Not really -- you do NOT need modulators and demodulators to use fiber for *analog* applications. If you want to run your signal over a commercial transport network you will (to digitize the signal and deal with framing for SONET, Ethernet etc.). Cable TV systems run their RF over fiber with very wide frequency ranges (50-700+MHz). I don't know dynamic range off hand since that's not a parameter that comes up with the digital systems I work with (we use extinction ratio instead). The downside is that the equipment to do that is not cheap. This is what I do all day at work (well, digital only, but optical) :-) Sorry, but by definition that is a modulator and demodulator. You have to convert the radio signal to light, and that involves modulating a light beam of some type. At the other end, you have to demodulate the light into the original baseband. You may not recognize it as a modulator/demodulator system, but that's what it is. You cannot just hook the coax to the fiber optic cable at each end. 73 Tom _ Topband Reflector
Re: Topband: Light fiber question
I see your point, since the signal is undergoing a conversion. My thinking was modulator = baseband to some kind of RF or digital signal, i.e. something very different from the original signal in terms of content of the waveform. I wasn't thinking of using a band-limited section of spectrum being converted to an amplitude-modulated light source as a modulator in this case. What I had meant was that the electrical-optical conversion doesn't have to be a particularly fancy system when you're only trying to run about 200kHz of spectrum over the fiber in the 2(ish)MHz range. The basics I mentioned before and some op amps are all that are needed. The op amps will likely be the limiting factor for dynamic range. I do agree with you that a simple run of decent coax is likely to be the better option though. -Bill Sorry, but by definition that is a modulator and demodulator. You have to convert the radio signal to light, and that involves modulating a light beam of some type. At the other end, you have to demodulate the light into the original baseband. You may not recognize it as a modulator/demodulator system, but that's what it is. You cannot just hook the coax to the fiber optic cable at each end. 73 Tom _ Topband Reflector
Re: Topband: Light fiber question
I see your point, since the signal is undergoing a conversion. My thinking was modulator = baseband to some kind of RF or digital signal, i.e. something very different from the original signal in terms of content of the waveform. I wasn't thinking of using a band-limited section of spectrum being converted to an amplitude-modulated light source as a modulator in this case. What I had meant was that the electrical-optical conversion doesn't have to be a particularly fancy system when you're only trying to run about 200kHz of spectrum over the fiber in the 2(ish)MHz range. The basics I mentioned before and some op amps are all that are needed. The op amps will likely be the limiting factor for dynamic range. It isn't the small bandwidth that matters, it is the dynamic range. The most important part is people seem to think all noise comes from common mode, and that suppressing common mode to non-harmful levels requires extremes in isolation. That just isn't factual at all. If someone has noise that is cured by going to a balanced line or extremes in cable shielding or choking, they have something else wrong with their system. Some antennas and feed systems are just troublesome or nearly impossible to design correctly, and some systems are designed incorrectly. _ Topband Reflector
Re: Topband: Light fiber question
BTW, Bill, amplitude modulation and mixing are the same process mathematically. In a mixer we just select one of the sidebands -depending on whether we are doing up-conversion or down-conversion mixing. So, in an optical fiber, passing 2 MHz 160m RF, there would be two sidebands at 2 MHz above and below the optical carrier frequency. The photo-diode would see the optical carrier and the +/- 2 MHz sidebands as an amptltude modulate optical carrier and we would select the lower sideband to recover the 2 MHz baseband signal. 73, Charlie, K4OTV 73. Charlie Cunningham -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Bill Wichers Sent: Thursday, October 24, 2013 1:39 PM To: Tom W8JI; Shoppa, Tim; Bruce; topband@contesting.com Subject: Re: Topband: Light fiber question I see your point, since the signal is undergoing a conversion. My thinking was modulator = baseband to some kind of RF or digital signal, i.e. something very different from the original signal in terms of content of the waveform. I wasn't thinking of using a band-limited section of spectrum being converted to an amplitude-modulated light source as a modulator in this case. What I had meant was that the electrical-optical conversion doesn't have to be a particularly fancy system when you're only trying to run about 200kHz of spectrum over the fiber in the 2(ish)MHz range. The basics I mentioned before and some op amps are all that are needed. The op amps will likely be the limiting factor for dynamic range. I do agree with you that a simple run of decent coax is likely to be the better option though. -Bill Sorry, but by definition that is a modulator and demodulator. You have to convert the radio signal to light, and that involves modulating a light beam of some type. At the other end, you have to demodulate the light into the original baseband. You may not recognize it as a modulator/demodulator system, but that's what it is. You cannot just hook the coax to the fiber optic cable at each end. 73 Tom _ Topband Reflector _ Topband Reflector
Topband: Light fiber question
From Tom People forget, or don't know, fiber cables require modulators and demodulators. The modulators and demodulators are not simple, and have horrible dynamic range compared to a simple piece of coax. From Bill The important part would be that you'd need to run a feedback loop with the laser/LED and a photodiode monitoring the output. The combined system would be your fiber driver. The receiver would be simpler -- just a photodiode and an amplifier. I see your point, since the signal is undergoing a conversion. My thinking was modulator = baseband to some kind of RF or digital signal, i.e. something very different from the original signal in terms of content of the waveform. I wasn't thinking of using a band-limited section of spectrum being converted to an amplitude-modulated light source as a modulator in this case. What I had meant was that the electrical-optical conversion doesn't have to be a particularly fancy system when you're only trying to run about 200kHz of spectrum over the fiber in the 2(ish)MHz range. The basics I mentioned before and some op amps are all that are needed. The op amps will likely be the limiting factor for dynamic range. Comment: Improvements are very evident as we look back in time. When I was about 13 years old and interested in radio, I would spend time in the Belfast Library. Radio books were in the basement and most dated into the 1920's, some early 1930's. These books were lost to hurricane flooding years later. I remember a 1920's publication where the author talked about germanium diodes and cat whiskers, He concluded that better diodes/rectifiers could come from other sources like silicon. Well silicon did not come for about 30 years, think about the late 1950's but it came with an avalanche. Think of the wire recorders in the 1940's to todays improved advanced digital recordings. New Your city lost all its phone connections through the subways in hurricane Sandy. Now replaced with light fibers that are not sensitive to salt water, NYC has taken another step up. It was not that many years ago when LED's were invented. With further advances in LED's, types of lighting, and better forms of fiber optics, large signal connection efficiency should be possible. With each improvement we have to somehow look beyond what we now know. 73 Bruce-K1FZ www.qsl.net/pennantnotes.html _ Topband Reflector
Re: Topband: Balun question
Well, might work. Another idea though, check with Fair-Rite - I believe that they have some cores that wil fit over .405 RG-8, and I know they have lots that sill fit over RG-58 or RG-8X. If you don't mind removing the connector, you can just slip a bunch of them over the end of the cable and use wire ties to keep them from sliding up and down the cable. I've left them out in the weather for years with no adverse effects. They also have snap-ons if you don't' want to remove the connector. About the only thing that the PVC tube around that W2AU balun does is hold the connectors ( and maybe trap moisture). You didn't say what kind of cable, but winding RG-8 around a 1 form can be sort of a pain! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Gary Smith Sent: Thursday, October 24, 2013 7:25 PM To: topband@contesting.com Subject: Topband: Balun question Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
Check this link out. It works flawlessly. audiosystemsgroup.com/*RFI*-Ham.pdf On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector _ Topband Reflector -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
What works flawlessly, Randy? The link? J 73, Charlie, K4OTV From: Randy Lake [mailto:randyn1...@gmail.com] Sent: Thursday, October 24, 2013 7:51 PM To: Charlie Cunningham Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question Check this link out. It works flawlessly. audiosystemsgroup.com/RFI-Ham.pdf On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector _ Topband Reflector -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
I am sorry! That was not very clear. The info on chokes worked wonderfully for me on 80m and 160m using the Big 31 snap-ons. Not only that but lots of good info other than chokes. Randy On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: What “works flawlessly”, Randy? The link? J ** ** 73, Charlie, K4OTV ** ** *From:* Randy Lake [mailto:randyn1...@gmail.com] *Sent:* Thursday, October 24, 2013 7:51 PM *To:* Charlie Cunningham *Cc:* Jim Bennett; g...@ka1j.com; topband@contesting.com *Subject:* Re: Topband: Balun question ** ** Check this link out. It works flawlessly. audiosystemsgroup.com/*RFI*-Ham.pdf ** ** On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector _ Topband Reflector ** ** -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
Just teasin' you, Randy! J I think the snap-ons would be quick, simple and very effective and should outlast the antenna, I expect! From: Randy Lake [mailto:randyn1...@gmail.com] Sent: Thursday, October 24, 2013 7:58 PM To: Charlie Cunningham Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question I am sorry! That was not very clear. The info on chokes worked wonderfully for me on 80m and 160m using the Big 31 snap-ons. Not only that but lots of good info other than chokes. Randy On Thu, Oct 24, 2013 at 7:55 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: What works flawlessly, Randy? The link? J 73, Charlie, K4OTV From: Randy Lake [mailto:randyn1...@gmail.com] Sent: Thursday, October 24, 2013 7:51 PM To: Charlie Cunningham Cc: Jim Bennett; g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question Check this link out. It works flawlessly. audiosystemsgroup.com/RFI-Ham.pdf On Thu, Oct 24, 2013 at 7:47 PM, Charlie Cunningham charlie-cunning...@nc.rr.com wrote: That would work as well. I used something similar, but with less turns to precede the 4:1 current balun feeding the drivers on my home brew 5-band quad. Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Jim Bennett Sent: Thursday, October 24, 2013 7:41 PM To: g...@ka1j.com Cc: topband@contesting.com Subject: Re: Topband: Balun question I was just looking through the ARRL Antenna Book - if it's RG-8, then 8 turns would work if wound on an 8 inch PVC tube. However, that size PVC may be difficult to find, and certainly wouldn't be to spiffy hung way up the air. But then again, you were thinking about 10 turns on a 12 inch diameter form...? I assume you were going to place it at the apex of the Inverted Vee, right? An alternative would be to get 5 mix 31 ferrite cores, 2.4 inch OD and pass the coax through it six times. That ought to get about 5,000 ohm impedance at 3.5 MHz and would do the trick. I'm using exactly that on my 80 meter Inverted L and it does a fine job. Mouser has those cores for $6-$7 each. Jim / W6JHB On Thursday, Oct 24, 2013, at Thursday, 4:25 PM, Gary Smith wrote: Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Thanks, Gary KA1J _ Topband Reflector _ Topband Reflector _ Topband Reflector -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH -- Randy Lake N1KWF 73 Gunn Rd. Keene,NH _ Topband Reflector
Re: Topband: Balun question
Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Gary, The W2AU balun he was happy with isn't a balun at all...it basically has NO common mode suppression. The impedance of a few turns of coax is also next to nothing on 80 meters, but almost everyone is happy with them. As a matter of fact, if the feedline from the antenna to the ground point of the coax is 30-45 feet long, it would need no balun at all for good common mode suppression. This illustrates some of the ridiculous overkill we are all caught up in. Since he was happy with his non-suppression balun, just use anything he thinks is a balun. He will be just as happy. A sting of beads of any impedance, a few turns of coax, a big coil of coax, if he didn't notice the W2AU balun causing a problem anything you put there will make him happy. :) 73 Tom 73 Tom _ Topband Reflector
Re: Topband: Balun question
True! -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Thursday, October 24, 2013 8:41 PM To: g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Gary, The W2AU balun he was happy with isn't a balun at all...it basically has NO common mode suppression. The impedance of a few turns of coax is also next to nothing on 80 meters, but almost everyone is happy with them. As a matter of fact, if the feedline from the antenna to the ground point of the coax is 30-45 feet long, it would need no balun at all for good common mode suppression. This illustrates some of the ridiculous overkill we are all caught up in. Since he was happy with his non-suppression balun, just use anything he thinks is a balun. He will be just as happy. A sting of beads of any impedance, a few turns of coax, a big coil of coax, if he didn't notice the W2AU balun causing a problem anything you put there will make him happy. :) 73 Tom 73 Tom _ Topband Reflector _ Topband Reflector
Re: Topband: Balun question
A W2DU balun, however is another story! Walt knew what he was doing! 73, Charlie, K4OTV -Original Message- From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of Tom W8JI Sent: Thursday, October 24, 2013 8:41 PM To: g...@ka1j.com; topband@contesting.com Subject: Re: Topband: Balun question Though this reflector is for 160M I have an 80M question that might be best asked here. My father W1BML is on an 80 meter net nightly. His antenna in an inv-V with 40 80 elements though he never uses 40 any more. I needed to fell a couple of trees to remove branches that were touching his copperweld and the W2AU balun he had broke in two during the process. (Don't ask, your imagination is probably correct) :) And he would like it put back the way it was, with a balun. He's 96 so I try to keep him happy. I'm thinking 10 or so rolls of coax around 1' in diameter ought to be fine for a choke on 80. Any better suggestions? Gary, The W2AU balun he was happy with isn't a balun at all...it basically has NO common mode suppression. The impedance of a few turns of coax is also next to nothing on 80 meters, but almost everyone is happy with them. As a matter of fact, if the feedline from the antenna to the ground point of the coax is 30-45 feet long, it would need no balun at all for good common mode suppression. This illustrates some of the ridiculous overkill we are all caught up in. Since he was happy with his non-suppression balun, just use anything he thinks is a balun. He will be just as happy. A sting of beads of any impedance, a few turns of coax, a big coil of coax, if he didn't notice the W2AU balun causing a problem anything you put there will make him happy. :) 73 Tom 73 Tom _ Topband Reflector _ Topband Reflector
Re: Topband: Light fiber question
There are niche applications, called antenna remoting, where photonic and fiberoptic technologies are used to transmit RF signals from an antenna to a remote receiver. You can buy commercial systems to do this. I once designed such a system for a government application to send RF signals from microwave antennas to receivers that were up to 10 km away. These applications exploit the advantages of optical fiber, namely (1) extremely low loss compared to conventional RF methods that use coax or other copper media, and (2) the extremely wide bandwidths (thousands of GHz) that can be supported in fiber. That's why the telecom industry now uses fiberoptics for commercial networks, particularly for WAN applications. However, optical fiber solutions make sense only when the application pushes the limitations of conventional RF transmission techniques like coax or twisted pair. I honestly can't imagine any lowband amateur need where this would be the case. And optical solutions come at a cost. High performance optical transmitters and receivers that provide low noise and high dynamic range do exist but they are not cheap by amateur radio standards. It's much easier and far less expensive to make coax (or twisted pair, if you prefer) work properly. 73, John W1FV _ Topband Reflector
