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Do receiver antennas need matching or not?
Paul Hovnanian P.E. wrote:
AI4QJ wrote: [snip] Over the air HDTV is superior to cable and satellite HDTV. They may sell more outdoor antennas as soon as it becomes clear that, from the 1996 telecommunications, not only did the FCC ruling on small satellite dishes overrule the homeowner association covents restricting dsmall satellite antennas, they ALSO overruled covenants restricting outdoor TV (i.e.yagi type) antennas...this was done to promote fair competition for cable, satellite and broadcast TV. I did put up a regular radio shack yagi style outdoor TV antenna back then and the HOA did contact their lawyer and found they could do nothing about it. If I ever splurge and buy my 1080p, I will do it again because the OTA picture is absolutely the best. AI4QJ Put up one of these: http://www.digitalhome.ca/ota/superantenna A home brewed double Gray-Hoverman. Apparently, they work pretty well and if you build a really impressive one, the HOA will really get their panties in a bunch. And the best thing is that there's no size limit in the OTARD rules for these antennas. the 1 meter limit is ONLY for satellite antennas. OTA terrestrial has no size limit. Build that 20 bay curtain array. |
Do receiver antennas need matching or not?
Jeff Liebermann wrote:
On Mon, 17 Mar 2008 22:13:35 -0800, "Paul Hovnanian P.E." wrote: AI4QJ wrote: [snip] Over the air HDTV is superior to cable and satellite HDTV. They may sell more outdoor antennas as soon as it becomes clear that, from the 1996 telecommunications, not only did the FCC ruling on small satellite dishes overrule the homeowner association covents restricting dsmall satellite antennas, they ALSO overruled covenants restricting outdoor TV (i.e.yagi type) antennas...this was done to promote fair competition for cable, satellite and broadcast TV. I did put up a regular radio shack yagi style outdoor TV antenna back then and the HOA did contact their lawyer and found they could do nothing about it. If I ever splurge and buy my 1080p, I will do it again because the OTA picture is absolutely the best. AI4QJ Put up one of these: http://www.digitalhome.ca/ota/superantenna Nice. Too bad it only goes from about 400-800MHz, which covers the UHF channels. It doesn't work for the VHF channels. Looking at the 4NEC2 plots, it's not very good on VSWR, has reasonable gain, but only on the lower UHF channels (no problem because the higher channels are being auctioned off by the FCC). http://www.qsl.net/va3rr/hdtv/hoverman.htm A home brewed double Gray-Hoverman. Apparently, they work pretty well and if you build a really impressive one, the HOA will really get their panties in a bunch. The local OTA digital TV is on Channel 8 (KSBW) at roughly 87MHz. The reflector of a suitable Gray-Hoverman antenna should be about 1.5 meters wide. I think the aesthetics committee will be banging on the front door rather quickly. What's that giant fly swatter doing on the roof? The OTARD rules say, "tough beans" to the HOA. No size limit. I wonder if a TV antenna can legitimize a solar cell array if the array is mounted on the TV antenna? There are other laws in many states that prohibit a HOA from restricting alternative energy sources (like solar panels for hot water or electricity, wind generators) |
Do receiver antennas need matching or not?
In article ,
Jim Lux wrote: A home brewed double Gray-Hoverman. Apparently, they work pretty well and if you build a really impressive one, the HOA will really get their panties in a bunch. And the best thing is that there's no size limit in the OTARD rules for these antennas. the 1 meter limit is ONLY for satellite antennas. OTA terrestrial has no size limit. Build that 20 bay curtain array. There's no explicit size limit stated for the antennas. However, it could be argued that building an antenna which is larger than necessary for good reception is not protected... prohibited restrictions include those which "preclude(s) a person from receiving or transmitting an acceptable quality signal from an antenna covered under the rule." Hence, if you can receive an acceptable-quality signal on all channels with a 1-bay antenna, the FCC *might* consider as reasonable a restriction against putting up a 20-bay antenna. The rules also say "Masts higher than 12 feet above the roofline may be subject to local permitting" and that the rules do not preempt "legitimate safety restrictions". It's clear that a blanket "no on-the-roof TV antennas" restriction by HOR rules or CCRs is generally unenforceable. -- 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! |
Do receiver antennas need matching or not?
On 3月15日, 下午7时11分, billcalley wrote:
Hi All, I always hear that antennas have to be matched to their radio, but in receivers (such as FM and shortwave radios) I see mostly long random length antennas used, and these antennas -- be they a telescoping whip or a long wire out a window -- are used over some really wide bandwidths. How is this possible if an impedance match must always be maintained for radios? And since there cannot be a good match over such wide bandwidths with any (typical) wire antenna, what is the downside to using these completely unmatched long antennas for receivers? (Poor gain patterns with lots of nulls? Lower sensitivity due to bad noise figure or gain match for any LNA or frontend amp? Degraded overall antenna gain)? Thanks; I'm very confused on this subject! -Bill Do you want access to China's massive pool of electronic manufacturers... but lack the time to contact suppliers, negotiate contracts, arrange shipping or monitor product quality? Don't worry - Let seriouswholesale deal with all that for you. *Check out the huge range of Gadgets, MP3 / MP4 Players, Car DVD / Audio, and Computer Accessories now by visiting the online wholesale catalog at seriouswholesale. com You'll have peace of mind thanks to the seriouswholesale Quality Control, 12-month Warranty on all products, and easy secure payment by credit card through Paypal. Selling on eBay or your own online store? Send products direct from our warehouse to your customers using our unique drop-shipping service. You can profit by selling hundreds of different products, without holding any of your own inventory! Any questions you have will be answered by the seriouswholesale English-speaking customer support team... Their aim is to make your China electronics importing business easier to run than ever before. Welcome to http://www.seriouswholesale.com. seriouswholesale - Buy from the source, profit without the hassle. - 12 Months Warranty - No minimum order restrictions - Drop-shipping with no additional fee - Pay by safely by PayPal seriouswholesale Wholesale Co., Ltd.: Chinas original and best online electronics wholesaler & drop-shipper: seriouswholesale. com |
Do receiver antennas need matching or not?
On 3月15日, 下午7时11分, billcalley wrote:
Hi All, I always hear that antennas have to be matched to their radio, but in receivers (such as FM and shortwave radios) I see mostly long random length antennas used, and these antennas -- be they a telescoping whip or a long wire out a window -- are used over some really wide bandwidths. How is this possible if an impedance match must always be maintained for radios? And since there cannot be a good match over such wide bandwidths with any (typical) wire antenna, what is the downside to using these completely unmatched long antennas for receivers? (Poor gain patterns with lots of nulls? Lower sensitivity due to bad noise figure or gain match for any LNA or frontend amp? Degraded overall antenna gain)? Thanks; I'm very confused on this subject! -Bill Do you want access to China's massive pool of electronic manufacturers... but lack the time to contact suppliers, negotiate contracts, arrange shipping or monitor product quality? Don't worry - Let seriouswholesale deal with all that for you. *Check out the huge range of Gadgets, MP3 / MP4 Players, Car DVD / Audio, and Computer Accessories now by visiting the online wholesale catalog at seriouswholesale. com You'll have peace of mind thanks to the seriouswholesale Quality Control, 12-month Warranty on all products, and easy secure payment by credit card through Paypal. Selling on eBay or your own online store? Send products direct from our warehouse to your customers using our unique drop-shipping service. You can profit by selling hundreds of different products, without holding any of your own inventory! Any questions you have will be answered by the seriouswholesale English-speaking customer support team... Their aim is to make your China electronics importing business easier to run than ever before. Welcome to http://www.seriouswholesale.com. seriouswholesale - Buy from the source, profit without the hassle. - 12 Months Warranty - No minimum order restrictions - Drop-shipping with no additional fee - Pay by safely by PayPal seriouswholesale Wholesale Co., Ltd.: Chinas original and best online electronics wholesaler & drop-shipper: seriouswholesale. com |
Do receiver antennas need matching or not?
Dave Platt wrote:
In article , Jim Lux wrote: A home brewed double Gray-Hoverman. Apparently, they work pretty well and if you build a really impressive one, the HOA will really get their panties in a bunch. And the best thing is that there's no size limit in the OTARD rules for these antennas. the 1 meter limit is ONLY for satellite antennas. OTA terrestrial has no size limit. Build that 20 bay curtain array. There's no explicit size limit stated for the antennas. However, it could be argued that building an antenna which is larger than necessary for good reception is not protected... prohibited restrictions include those which "preclude(s) a person from receiving or transmitting an acceptable quality signal from an antenna covered under the rule." Hence, if you can receive an acceptable-quality signal on all channels with a 1-bay antenna, the FCC *might* consider as reasonable a restriction against putting up a 20-bay antenna. And the FCC has carefully stayed away from defining "acceptable" . In fact, in one case, they've said that it's in the judgement of the person receiving the signal (The HOA wanted to make the homeowner put the antenna inside the attic, claiming that since they were close to the transmitter site, that an acceptable signal was available). (I can't find the reference off hand.. it's in Maryland or Virginia, as I recall) One might also want to look up the very interesting case of Stanley and Vera Holliday (5 masts, 30 ft high, 3 dishes, etc.) http://www.fcc.gov/Bureaus/Cable/Ord...9/da992132.txt I spent a while trying to hunt down what "acceptable" might be in FCC rules terms (e.g. what's a minimum performance standard for a Cable TV).. It's pretty tough to find a numerical standard. There are standard service contours which relate to RF field strength, but they're also statistical. For digital receivers, in fact, on 21 Jan 2001, the FCC: "Denied requests to set performance standards for digital receivers, expressing concern that the effect of setting such standards at this point would be to stifle innovation and limit performance to current capabilities. The Commission said it would continue to monitor receiver issues;" As recently as June, 2007, an article in CED Magazine said:"The FCC has never before adopted receiver performance specifications or interference rejection requirements. It has the authority to do since Senator Goldwater introduced a bill that became Public Law 97-259 in 1982, which added the italicized language below to the Communications Act:..." ATSC has a document A/74 which defines a recommended practice for receiver performance, but it's kind of a clunky document, based on technology that was available in 2003-2004, and not really intended for this sort of thing. FWIW, the FCC assumes you need 7dB SNR for UHF and 10dB for VHF, with an assumed 7dB NF. So, one could claim you need that 20x20 bay antenna to get enough signal to compensate for your horrid transmission line and terrible receiver. The rules also say "Masts higher than 12 feet above the roofline may be subject to local permitting" and that the rules do not preempt "legitimate safety restrictions". The FCC has set a pretty high bar on safety restrictions. They have to be clearly articulated and justified in the rules (i.e. no "in the opinion of the architectural review board, that's unsafe"). The 12 foot thing is a building code issue. The city or jurisdiction would have to have a fairly specifically articulated justification. It's clear that a blanket "no on-the-roof TV antennas" restriction by HOR rules or CCRs is generally unenforceable. Yep.. In fact, can't even have a "must put antenna in position X" or "must plant or paint" rule, unless the cost of compliance is trivially small (as in $5, see the Meade,KS case) and has ZERO effect on reception |
Do receiver antennas need matching or not?
On Tue, 18 Mar 2008 10:54:25 -0700, "Paul Hovnanian P.E."
wrote: Does your HOA forbid solar arrays? Some of them can be pretty anal retentive. Mine won't let me put up my thermonuclear clothes dryer. :-( No home owners association in my neighborhood. (However, I am the self-appointed chair person and bill collector for the private road committee). If we had an HOA, I would be the first to be lynched as I have 2 dead cars in front of the house, a huge mess ready for recycling, and an antenna farm on the roof. However, I have friends that bought into the "planned community" philosophy and are stuck with CC&R's from hell. Basically, anything that can be seen from ground level is unacceptable. In the CC&R's I've read, solar arrays are certainly not allowed, especially on the roof. http://www.renewableenergyworld.com/rea/news/ate/story?id=45648 I've found the local cities and county bureaucracy on behalf of various homeowners. Batting average is about 50%. Ghosts are a big problem where I live. Or multipath and the resulting dropouts the case of DTV broadcasts. That's why I like highly directional designs (both horizontally as well as vertically). Other than that, I can get all of our local stations with rabbit ears and a UHF loop. I live too far away from the local digital TV xmitters to get reliable reception. My rule of thumb is that if OTA analog TV reception is marginal, digital TV will be worse. Highly directional antennas are the right way to eliminate ghosts (reflections). However, I keep running into problems with f/b (front to back) ratio problems, where the ghosts are reflected from behind the antenna. That's where the lower gain, but higher f/b ratio antennas, such as a barbeque grill backed bowtie array, makes more sense. My preference is to use single channel narrowband yagi's for maximum gain, but that gets really ugly as one per channel is required. All of our DTV stations broadcast on UHF as the VHF band in the Seattle area is pretty much filled up with the legacy analog stuff. We have Channel's digital 10 (KSBW) and digital Channel 12 (KNTV) http://en.wikipedia.org/wiki/KNTV http://en.wikipedia.org/wiki/KSBW I once did a paper design for a trapped yagi, designed solely for channels 8 and 11 (the analog channels) and no others. It probably would work, but nobody was interested in buying one. I'm not certain what the stations plan on doing once the digital cut over is complete. All of them. The station owners would need to be insane not do do digital. It's a free extra channel with the oportunity to sell additional services (i.e. data broadcasting). They might move their digital signal down onto their analog slot or abandon the analog slot altogether. That will be a factor in what kind of antenna I put up. Duh... I never thought to ask the local broadcast engineers what the channel lineup is going to be after the Feb 17, 2009 fire drill. I'll ask. Every day, I go on an extended exercise constitutional. One day, I decided to count outdoor TV antennas in my mountain neighborhood. My guess is that I passed about 100 houses and only saw three outdoor antennas (which looked ancient and inoperative). I'm wondering if anyone watches OTA TV in my area. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
Do receiver antennas need matching or not?
On Tue, 18 Mar 2008 16:25:02 -0700, Jeff Liebermann
wrote: On Tue, 18 Mar 2008 10:54:25 -0700, "Paul Hovnanian P.E." wrote: [snip] However, I have friends that bought into the "planned community" philosophy and are stuck with CC&R's from hell. Basically, anything that can be seen from ground level is unacceptable. In the CC&R's I've read, solar arrays are certainly not allowed, especially on the roof. http://www.renewableenergyworld.com/rea/news/ate/story?id=45648 I've found the local cities and county bureaucracy on behalf of various homeowners. Batting average is about 50%. [snip] Check your state laws, solar is allowed, period, here in AZ... irrespective of HOA regulations. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave |
Do receiver antennas need matching or not?
On Tue, 18 Mar 2008 17:06:21 -0700, Jim Thompson
wrote: On Tue, 18 Mar 2008 16:25:02 -0700, Jeff Liebermann wrote: On Tue, 18 Mar 2008 10:54:25 -0700, "Paul Hovnanian P.E." wrote: [snip] However, I have friends that bought into the "planned community" philosophy and are stuck with CC&R's from hell. Basically, anything that can be seen from ground level is unacceptable. In the CC&R's I've read, solar arrays are certainly not allowed, especially on the roof. http://www.renewableenergyworld.com/rea/news/ate/story?id=45648 I've found the local cities and county bureaucracy on behalf of various homeowners. Batting average is about 50%. [snip] Check your state laws, solar is allowed, period, here in AZ... irrespective of HOA regulations. ...Jim Thompson The State of Schwarzenegger has had a "Solar Right Act" since 1978. See: http://www.sandiego.edu/epic/publications/documents/070123_RightsActPaperFINAL.pdf The Calif Civil Code Section 714 limits the power of HOA's and governments to restrict solar installations. http://www.akeena.net/cm/About_Solar_Power/California_Civil_Code_714.html The problem is that term there seems to be some variations in what constitutes "reasonable restrictions" which are allowed by the law. If the purpose of the CC&R's is to maintain some semblance of aesthetic integrity, the local courts have ruled it "reasonable" for them to block the installation of just about anything with a visual impact. The interpretation of "reasonable" varies in different jurisdictions but locally, it seems almost random. Incidentally, I've read CC&R's that were apparently written perhaps 50 years ago. They're full of restrictions based on race, color, ethnicity, and such, which are obviously unenforceable. The buyers were told that that the old contract is good enough because anything that's illegal won't be enforced. These contracts tend to also have very broad clauses blocking "anything with an aesthetic impact" and such, which is where the solar prohibition originated. One contract I've read itemized examples of prohibited installations, which included all forms of antennas and mentioned solar panels. Locally, one planning department imposed some siting and support structure restrictions that effectively prevented installing of any solar panels. That apparently was accidental, but it took a year and an expensive legal action to get them to admit that they goofed. One homeowner wanted a variance to install the solar panels very close to the property line. No CC&R's. The variance was denied because of neighbors protests. It went to court and he lost. Another tried to get his radio tower approved on the basis of it providing supports for his tower mounted solar panels. That also was denied. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
Do receiver antennas need matching or not?
On Mon, 17 Mar 2008 18:51:33 GMT in rec.radio.amateur.antenna, Cecil
Moore wrote, Does Walmart honor the $40 coupon Duh. |
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