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Log-Periodic Antenna Design
My current UHF antenna is a 14" Radio Shack clip lead clipped from the
center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich |
Log-Periodic Antenna Design
"Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Before you get too far, be sure you know what you need. This is based on post 2/09 channel assignments. You will need to cover either a) CH2 - CH51 b)CH7 - CH51 c) CH14 - CH51 Tam |
Log-Periodic Antenna Design
In article ,
Rich Grise wrote: Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Most of the wideband TV antennas I've seen, seem to be log-periodic in the VHF range, but to use a reflector and a bunch of auxiliary elements (which don't appear to stick to the L-P taper schedule) for the UHF. You might want to consider a different approach - have you seen this one? http://www.digitalhome.ca/ota/superantenna/index.htm -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Log-Periodic Antenna Design
On Nov 20, 9:45 am, Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap:http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? Are you seriously THAT hard up for cash? :- So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Try this - go to your local hardware or whatever store that sells a suitable log-periodic antenna with camera and tape measure in hand. Record it all and then go home and duplicate. Or easier still, buy it, take home, duplicate, then return for a refund. Dave. |
Log-Periodic Antenna Design
It's not log periodic but it looks cheap to toss together and they claim
great performance: http://www.digitalhome.ca/ota/superantenna/index.htm ----- Regards, Carl Ijames "Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich |
Log-Periodic Antenna Design
David L. Jones wrote:
On Nov 20, 9:45 am, Rich Grise wrote: My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap:http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? Are you seriously THAT hard up for cash? :- So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Try this - go to your local hardware or whatever store that sells a suitable log-periodic antenna with camera and tape measure in hand. Record it all and then go home and duplicate. Or easier still, buy it, take home, duplicate, then return for a refund. Dave. You don't really need a new antenna. If your current antenna is working such that you get a good picture then it should work as a digital tv antenna. Another Dave |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 22:45:19 GMT, Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Reminds me of the famous, very expensive Dick Smith Electronics Coa-Thanger antenna. John |
Log-Periodic Antenna Design
Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? Interlibrary loan is your answer. Your library may not have it, but someone else's does. So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Looking for a cookbook design, or the theory to do it yourself? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich |
Log-Periodic Antenna Design
"Rich Grise" wrote in message ...
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Upisi najnizju radnu frekvenciju : enter lowest frequency Upisi najvisju radnu frekvenciju : enter highest frequency Duzina antene: length of antena Broj elemenata: number of elements Pritisni taster za proracun antene: press a key to calculate antenna Duzina 1. elem. length of first element Pritisni taster za nastavak Press any key to continue Duzina zavrsnog kratkospojenog odsecka: length of final shorted section Upisi precnik dipola: enter diameter of the dipole Upisi ulaznu otpornost (ohm): Entry resistance (weird in original) Impedanca napojnog voda: feeder impedance (not sure what this is) Upisi precnik napojnih provodnika: diameter of feeding leeds (my guess these are two bars that hold elements) razmak izmedju napojnih provodnika: distance between feeder leeds (and distance between two bard holding elements) You owe me a beer. BTW, its Croatian or Serbian. I kind of understand some 90%. M |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 18:14:27 -0500, Tam wrote:
"Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Before you get too far, be sure you know what you need. This is based on post 2/09 channel assignments. You will need to cover either a) CH2 - CH51 b)CH7 - CH51 c) CH14 - CH51 This won't do at all! Two of my favorite stations are ch. 56 & ch. 58. =:-O I've got 2-13 covered by my external VHF folded dipole. (It's an RV). Are the channel frequencies going to be all changed around? I suppose I should email those two stations. I don't know much about DTV, other than I have to buy a damn box and I need a "better" antenna. Thanks, Rich |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 15:20:13 -0800, Dave Platt wrote:
In article , Rich Grise wrote: Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Most of the wideband TV antennas I've seen, seem to be log-periodic in the VHF range, but to use a reflector and a bunch of auxiliary elements (which don't appear to stick to the L-P taper schedule) for the UHF. You might want to consider a different approach - have you seen this one? http://www.digitalhome.ca/ota/superantenna/index.htm Thanks, but that thing's HUGE! I was thinking something more along the lines of 1' square. (or a 1' cube) Thanks, Rich |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 17:52:01 -0600, David G. Nagel wrote:
You don't really need a new antenna. If your current antenna is working such that you get a good picture then it should work as a digital tv antenna. I've heard that there's no "signal strength" meter or anything - it's either there, or not. With my analog, I can zero in on the proper tuning (I just futz around with the clip lead until it's "good enough") so I need something I don't have to screw around with. Thanks, Rich |
Log-Periodic Antenna Design
"Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich You probably don't need a program, just a decent text book that covers the topic adequately, which, undoubtedly is what the program writers worked from, and they might not have got it right! 'Antennas' by John Kraus contains enough detail to make a start and it's probably more general than someone's program which might involve specific choices of some parameter values. So my recommendation would be to find a technical library that offers access to non-members and send yourself to Log-Periodic School as you put it. The IET library in London does this, for free. Do you have an equivalent institution (e.g. IEEE), or a local university that covers electronic engineering? You might be surprised how much access you can gain to libraries to which you have contributed through taxes, or which need to maintain an 'altruistic' public appearance. The pyramidal form has greater aperture in the vertical plane for all but the highest frequencies. It behaves like a vertically-stacked pair of Log-Periodic Dipole Arrays and achieves a bit more gain. Its pattern in the vertical plane is consistently sharper over a range of frequencies because of the vertical taper, but it is a bit more difficult to design. Not all 'wideband' UHF antennas are based on the LPDA - some are Yagi-Uda arrays designed using NEC and its derivatives, achieving a useful compromise between bandwidth, gain, and pattern shapes. But if you want to include channels below 21 as well as the UHF band, with consistent directivity, then LPDA is probably the only way to go. Chris |
Log-Periodic Antenna Design
This won't do at all! Two of my favorite stations are ch. 56 & ch. 58.
=:-O Not after The Big Day. Their frequencies will be changing. Channels which are broadcasting NTSC in channels 52 and above will be moving down to a lower frequency. I've got 2-13 covered by my external VHF folded dipole. (It's an RV). Are the channel frequencies going to be all changed around? I suppose I should email those two stations. I don't know much about DTV, other than I have to buy a damn box and I need a "better" antenna. A lot of them will be. Take a look at: http://hraunfoss.fcc.gov/edocs_publi...C-06-150A1.pdf I don't think it's the latest set of assignments but it's pretty well up to date. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Log-Periodic Antenna Design
On Nov 20, 12:03 pm, Rich Grise wrote:
On Wed, 19 Nov 2008 17:52:01 -0600, David G. Nagel wrote: You don't really need a new antenna. If your current antenna is working such that you get a good picture then it should work as a digital tv antenna. I've heard that there's no "signal strength" meter or anything Most digital STB's have a "signal strength" indicator on screen for each channel. it's either there, or not. That's true of the displayed picture, but not the signal. Poor (or even too much) signal strength can lead to "drop outs" or "freezing" of the video image. Dave. |
Log-Periodic Antenna Design
On Nov 20, 11:55 am, Rich Grise wrote:
On Wed, 19 Nov 2008 18:14:27 -0500, Tam wrote: "Rich Grise" wrote in message .. . My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Before you get too far, be sure you know what you need. This is based on post 2/09 channel assignments. You will need to cover either a) CH2 - CH51 b)CH7 - CH51 c) CH14 - CH51 This won't do at all! Two of my favorite stations are ch. 56 & ch. 58. =:-O I've got 2-13 covered by my external VHF folded dipole. (It's an RV). Are the channel frequencies going to be all changed around? Yes. Channels will vary depending upon your country and location. You should have some sort of official digital TV website for your country that lists and explains all this stuff. Australia for instance is: http://www.dba.org.au/ (server down?) Dave. |
Log-Periodic Antenna Design
On Nov 19, 6:14�pm, "Tam" wrote:
"Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Before you get too far, be sure you know what you need. This is based on post 2/09 channel assignments. You will need to cover either a) CH2 - CH51 b)CH7 - CH51 c) CH14 - CH51 Tam- Hide quoted text - - Show quoted text - I agree. How much can a coat hanger cost? If you are really rubbing pennies together, I would ditch the log- periodic approach and go with something simpler, like a monopole or folded unipole antenna. (All you need is wire.) I just want to mention (again) here that: Hopefully, we'll be able to knock out Ch-5 and Ch-6 from this antenna scenario very soon (and move them to the FM Band, as the FCC is presently considering. I'm a huge proponent of this possibility! I will try to find the Comments link at the FCC web site so those of you who agree can chime in.... This idea has been floated before, of course. This time it seems to have "legs". I don't know how much you can read into it, but... the FCC has yet to explain how Non-Commercial Educational (NCE) vertical only stations can obtain authorization for horiz/vertical operation once this DTV transition occurs - which is now less than 90 days away. There are many pending Construction Permits (CP's) and NCE facilities that proposed Vertical-Only operation in order to protect local ANALOG TV-6 stations. These new NCE facilities will undoubtedly delay construction until a decision is made how to obtain dual polarization licensing. (Due to increased transmitter power requirements and/or RF Safety exposure issues, tower height requirements, etc..) To date, the FCC has yet to adopt ANY relaxed TV-6 digital protection criteria for NCE FM stations. Instead, these stations must use the old Analog standard - which is MUCH stricter than is necessary to fully protect a Digital TV operation! And of course, there are only (8) full service TV's on digital channel 6. (Which is a really, really good reason to move TV-6, and possibly TV-5 to the FM band!! -- What a huge waste of spectrum!!) Yes, there are some low-power DTV 6's out there (translators, boosters, LPTV's). Not very many, and all of which are in locations where other spectrum is, or will be, avaialble after the DTV transition... Anyway, any NCE or CP not near a digital-6 would obviously qualify for dual-polarization. It remains to be seen what the FCC will do about this. Hopefully, they will grow a brain and shift this "un-used" spectrum to alleviate the very crowded FM band. I don't know if I should hold my breath or not.? -mpm |
Log-Periodic Antenna Design
On Nov 19, 9:13*pm, mpm wrote:
I don't know if I should hold my breath or not.? Oops. that post was directed at Rich. My apologies for responding at the wrong thread entry point... |
Log-Periodic Antenna Design
Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. LOL ... talk about trolls! That HAS TO BE THE BEST TROLL OPENING LINE I HAVE EVER SEEN! Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. Well, that is the second best ... But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif hmmm .... Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Ever heard of amplifed rabbit ears? Regards, JS |
Log-Periodic Antenna Design
Try a bowtie (like the one that came with sets) 5 inches in front of a piece
of hardware cloth. Most of the boxes (which are almost free after the FCC rebate) have a signal strength bar (although with a 3-5 sec. delay) Years ago they used to make one as a magazine rack that you could pick up and move around. "Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich |
Log-Periodic Antenna Design
Hi John.
On Nov 19, 6:31 pm, John Smith wrote: Rich Grise wrote: My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. LOL ... talk about trolls! That HAS TO BE THE BEST TROLL OPENING LINE I HAVE EVER SEEN! Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. Well, that is the second best ... But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif hmmm .... Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Ever heard of amplifed rabbit ears? Regards, JS It's not a troll. I bought a fair good UHF-VHF antenna, assembled it and sat it on a saw horse in the driveway for test, and it tested perfect for 3 channels + ch.34 . So I set her up using a roof mount and LOST ch.34, and no amount of rotating got it back. (I was a pro antenna/tower installer as a kid). Next I'm going to tape wire on 1/8" panelling and do experiments ... ugh, I hate trial and error. Ken |
Log-Periodic Antenna Design
Ken S. Tucker wrote:
... It's not a troll. I bought a fair good UHF-VHF antenna, assembled it and sat it on a saw horse in the driveway for test, and it tested perfect for 3 channels + ch.34 . So I set her up using a roof mount and LOST ch.34, and no amount of rotating got it back. (I was a pro antenna/tower installer as a kid). Next I'm going to tape wire on 1/8" panelling and do experiments ... ugh, I hate trial and error. Ken OK brother, you may not be what I accuse you of ... But darn, the antenna you bought was designed with certain parameters in mind ... I would seriously doubt you are going to vastly increase performance with the route(s) you have described here ... Sorry if I made a joke. But, my advise to you would be, if you saved your receipt, take it back! DON'T HACK THE ANTENNA! Chat with buddies or someone who has had better experience(s) (or, varied experiences) with a better antenna, one which would serve you better. Without expensive instrumentation and experience of years of experimenting, it is hard to accomplish what I perceive your goals to be ... I would never say anything is impossible, just what I feel is the best advise I can provide you with in hoping for your best success. Wish you the best, JS |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 22:45:19 GMT, Rich Grise wrote:
But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? Hi Rich, Someone else has already provided the translation, so that will take care of some of the wholes in data entry and reading. There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. Tau is related to the shape of what you call the pyramid, or more actually to the angle of the taper. This defines the smoothness of matching across the span of frequencies you entered into the program. As you can see, it also relates to the available gain. Another correlative is it also relates to its length. All of these things are trade-offs that lend to the rule of choosing what you want most and giving up on the rest. I note elsewhere that you wanted something about 1 foot long. There is a Tau that will give you this boom length, and you got it on the first guess. So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? You should start building what your screen shot gave you IF that is the span of frequency you need (already questioned by other correspondents). 73's Richard Clark, KB7QHC |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 22:45:19 GMT, Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Why don't you sell your house and move to a place next to the TV transmitter station. You will only need a piece of wire then. Or the bare finger. Must be wet, of course. w. |
Log-Periodic Antenna Design
Rich Grise wrote:
Are the channel frequencies going to be all changed around? Here in the Tyler, TX area, the TV stations are continuing their analog broadcasts on their previous channels. Their digital signals are on different channels. When the switch- over comes, they plan to switch their digital channels over to their previous analog channels. -- 73, Cecil http://www.w5dxp.com |
Log-Periodic Antenna Design
Rich Grise wrote:
I've heard that there's no "signal strength" meter or anything - it's either there, or not. Some of the converter boxes have a signal strength indication. My "Insignia" box does. It allowed me to find a sweet spot for channel 10 DTV reception using RS rabbit ears. -- 73, Cecil http://www.w5dxp.com |
Log-Periodic Antenna Design
John Smith wrote:
Ever heard of amplifed rabbit ears? I bought one, a Phillips MANT310/MNT310F - didn't work as well as the non-amplified RS one I already had. -- 73, Cecil http://www.w5dxp.com |
Log-Periodic Antenna Design
Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Log periodics are not necessary for sub-octave operation. http://www.youtube.com/watch?v=EWQhlmJTMzw |
Log-Periodic Antenna Design
In article , Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. I did the same thing and I was surprised how many digital chanels I got. I was at a dollar store and saw the RCA UHF/VHF loop/ears for $5 and that gave me considerable better reception. greg |
Log-Periodic Antenna Design
In article , Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich Ever hear of the BOW TIE. Its a sort of Fractal antenna. Having a wide band. It could be improved by making it a full fractal. greg |
Log-Periodic Antenna Design
Cecil Moore wrote:
John Smith wrote: Ever heard of amplifed rabbit ears? I bought one, a Phillips MANT310/MNT310F - didn't work as well as the non-amplified RS one I already had. Actually, I had to construct my own with a broadband MMIC device, to get decent functionality ... however, my mother has an el-cheapo unit she purchased from some yard sale, it/they work surprisingly well! Location, reflections, etc. can vary ones experience greatly--but hey, they usually beat a wire coat hanger! :-) Regards, JS |
Log-Periodic Antenna Design
On 19 Nov, 22:45, Rich Grise wrote:
My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Well, with this new Fascist "No More Free TV" crap, I'm gonna need a real UHF antenna. My budget is exceedingly limited, but I have a supply of materials (GTAW filler rod, with some coppery-colored coating, so it solders like a dream, and is as stiff as piano wire) to build an antenna with. But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap:http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. My local library has no ARRL Antenna Book (!), and did I mention I have a seriously limited budget? So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Thanks, Rich I have used the procedure in the following paper: http://www.urel.feec.vutbr.cz/ra2008...tracts/116.pdf I slightly modified the design (e.g. I used several different diameters for the elements), but basically I used the same formulae. I did not use their formula for deciding the right spacing between the support tubes to get the right characteristic impedance, because I suspect that maybe it is only valid over a limited range of spacing. Instead, I measured the characteristic impedance of just the tubes with no elements attached on a VNA that could plot impedance vs distance in a sort of TDR mode, and I adjusted the spacing until it was right. I epoxied some very small (roughly 1mm cube) spacers between the support tubes to keep the distance right, once it was adjusted properly. It is important that the space between the support tubes is mostly filled with air, not epoxy or any other dielectric, because the wave needs to propagate at the right speed between the tubes so that the elements are fed in the right relative phase, and this won't happen if there is something with a higher dielectric constant in there. I used those brass tubes that you can get in hobby shops, but unfortunately brass is fairly resistive and I did not silver plate it. I would have used aluminium if it were easier to solder in a reliable way. The finished antenna had a good return loss over the desired frequency range (sorry, can't remember the numbers) and it did the job for which it was intended although I don't have a measured gain value etc. because I don't have an antenna range. I have a spreadsheet for calculating the element lengths (in Openoffice.org format) if you are interested. Chris |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 16:49:03 -0800, Jim Lux wrote:
Rich Grise wrote: .... myself to Log-Periodic School, where should I start? Looking for a cookbook design, or the theory to do it yourself? Cookbook, if at all possible. Like, element lengths and spacing, and the angle between the booms - which brings up a question - what effect does it have when you take a flat L-P and "open it up", like to a pyramid shape - I was doing a thought experiment with this and when it's completely "flattened out", (180 degrees between the booms), it looks like a drum roll please Bow Tie! Thanks, Rich |
Log-Periodic Antenna Design
On Thu, 20 Nov 2008 01:53:33 +0100, TheM wrote:
"Rich Grise" wrote in message ... My current UHF antenna is a 14" Radio Shack clip lead clipped from the .... myself to Log-Periodic School, where should I start? Or, does anyone have a UHF-TV log-periodic design that they'd share? :-) Upisi najnizju radnu frekvenciju : enter lowest frequency Upisi najvisju radnu frekvenciju : enter highest frequency Duzina antene: length of antena Broj elemenata: number of elements Pritisni taster za proracun antene: press a key to calculate antenna Duzina 1. elem. length of first element Pritisni taster za nastavak Press any key to continue Duzina zavrsnog kratkospojenog odsecka: length of final shorted section Upisi precnik dipola: enter diameter of the dipole Upisi ulaznu otpornost (ohm): Entry resistance (weird in original) Impedanca napojnog voda: feeder impedance (not sure what this is) Upisi precnik napojnih provodnika: diameter of feeding leeds (my guess these are two bars that hold elements) razmak izmedju napojnih provodnika: distance between feeder leeds (and distance between two bard holding elements) You owe me a beer. BTW, its Croatian or Serbian. I kind of understand some 90%. Thanks! Rich |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 18:31:05 -0800, John Smith wrote:
Rich Grise wrote: My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. LOL ... talk about trolls! That HAS TO BE THE BEST TROLL OPENING LINE I HAVE EVER SEEN! Hey, "John Smith", why don't you go outside and play hide-and-go-****-yourself? Cheers! Rich |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 22:53:28 -0800, Richard Clark wrote:
On Wed, 19 Nov 2008 22:45:19 GMT, Rich Grise wrote: But I've been searching the web for some weeks now, and I can't seem to find any kind of formula, except there was this program I downloaded - LPDA.EXE, which runs on DOS. Unfortunately, it's in Russian or Polish or Uzbekistani - one of those East Yurp languages. Here's a screen snap: http://mysite.verizon.net/richgrise/...rog-Output.gif Which I went through pretty much by-guess-and-by-gosh - can anybody read that stuff? Someone else has already provided the translation, so that will take care of some of the wholes in data entry and reading. There are a lot of factors I don't know about, like "Tau", and all of the specific designs on the web are flat - something is telling me I want one of those pyramid-shaped ones, but I really don't know the difference (between that and flat) - it's probably something to do with bandwidth or F/B ratio or whatever. Tau is related to the shape of what you call the pyramid, or more actually to the angle of the taper. This defines the smoothness of matching across the span of frequencies you entered into the program. As you can see, it also relates to the available gain. Another correlative is it also relates to its length. All of these things are trade-offs that lend to the rule of choosing what you want most and giving up on the rest. I note elsewhere that you wanted something about 1 foot long. There is a Tau that will give you this boom length, and you got it on the first guess. So, how do I pursue this? It'd be nice to have a program that will calculate the whole thing for me, but am I dreaming? If I want to send myself to Log-Periodic School, where should I start? You should start building what your screen shot gave you IF that is the span of frequency you need (already questioned by other correspondents). 73's "Best Regardses"? ;-) Anyway, thanks for this - I'm feeling a lot better about this project now thanks to your help and that guy that translated it for me (forgot the name, but he knows who he is - Thanks Again!); I might even start cutting wire[1] and soldering this weekend! ;-) Thanks! Rich [1] GTAW (Gas Tungsten Arc Welding) filler rod, with some coppery- colored coating that solders even better than copper, about .030 dia., and as stiff as piano wire. |
Log-Periodic Antenna Design
On Wed, 19 Nov 2008 22:53:28 -0800, Richard Clark wrote:
You should start building what your screen shot gave you IF that is the span of frequency you need (already questioned by other correspondents). Apparently I'll only need up to ch. 52; have to look up the carrier freq. on that. Ch. 14 = 470-476 MHz Ch. 83 = 884-890 MHz I think. Now all I need to do is the algebra. ;-) 52 - 14 = 38 38 * 6 = 228 228 + 470 = 698 698 + 6 = 704 Cheers! Rich |
Log-Periodic Antenna Design
On Thu, 20 Nov 2008 13:50:57 +0000, Dave wrote:
Log periodics are not necessary for sub-octave operation. http://www.youtube.com/watch?v=EWQhlmJTMzw Dude! Awesome! And this one doesn't even have a reflector!. I wonder how far I should hang it in front of the venetian blind. ;-) Thanks! Rich |
Log-Periodic Antenna Design
In article ,
Rich Grise wrote: My current UHF antenna is a 14" Radio Shack clip lead clipped from the center of my coax to the venetian blind. I have to hand-adjust it for the channel, weather conditions, phase of the moon, etc. I can do this because I can _see_ an indication of signal strength. Your clip lead is too long. Try 1/4 wave. I got good reception using a 4 1/2 inch length of 24 gauge solid poked into the F connector for a (line of sight) 45 kW station, 20 miles away. (Most of the local stations run in the 500-1000 kW range). Mark Zenier Googleproofaddress(account:mzenier provider:eskimo domain:com) |
Log-Periodic Antenna Design
On Thu, 20 Nov 2008 14:18:47 +0000, GregS wrote:
Ever hear of the BOW TIE. Its a sort of Fractal antenna. Having a wide band. It could be improved by making it a full fractal. Yes - somebody just pointed to a youtube of somebody making one out of coathangers. I think I'm gonna do that. Cheers! Rich |
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