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Is an Antenna Analyzer an FCC violation?
Hi,
I'm trying to determine if using an antenna analyzer is technically a violation of the telecommunications Code of Federal Regulations. Typical antenna analyzers inject a incident CW or sweeping CW to the antenna and measure its return loss (reflection). Very few frequency bands have a CW or sweeping CW as their allowed modulation type. The way I see it is that by using an antenna analyzer you are intentionally radiating an improper modulation type that was allocated for the band and therefore you are in violation of the Code of Federal Regulations. Anyone have any thoughts on this topic? Thomas Magma |
Is an Antenna Analyzer an FCC violation?
Thomas Magma wrote:
I'm trying to determine if using an antenna analyzer is technically a violation of the telecommunications Code of Federal Regulations. Typical antenna analyzers inject a incident CW or sweeping CW to the antenna and measure its return loss (reflection). Very few frequency bands have a CW or sweeping CW as their allowed modulation type. The way I see it is that by using an antenna analyzer you are intentionally radiating an improper modulation type that was allocated for the band and therefore you are in violation of the Code of Federal Regulations. Anyone have any thoughts on this topic? By your logic a noise bridge would also be illegal. However in most places there is a limit on the amount of power one can use before it requires a license. Since an antenna analyzer puts out a few microwatts, if that, no one seems to care. I do not have the capability to measure the power level of mine, but I expect that it is less than a regenerative receiver. It would be easy to test, place one on an antenna and try to tune it in with a portable receiver. If you can hear it, move away and see how far it goes. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM IL Voice: (07)-7424-1667 U.S. Voice: 1-215-821-1838 Visit my 'blog at http://geoffstechno.livejournal.com/ |
Is an Antenna Analyzer an FCC violation?
"Thomas Magma" wrote in message news:602zi.82535$rX4.27870@pd7urf2no... Hi, I'm trying to determine if using an antenna analyzer is technically a violation of the telecommunications Code of Federal Regulations. Typical antenna analyzers inject a incident CW or sweeping CW to the antenna and measure its return loss (reflection). Very few frequency bands have a CW or sweeping CW as their allowed modulation type. The way I see it is that by using an antenna analyzer you are intentionally radiating an improper modulation type that was allocated for the band and therefore you are in violation of the Code of Federal Regulations. Anyone have any thoughts on this topic? Thomas Magma Low power test gear is listed as a permitted form of radiation. While a signal generator is permitted for use as a test instrument, it would not be legal to use it for say a transmitter on a ham band that you are not licened to use. YOu could legally use it for a ham band transmitter if you followed all the other part 95 rules. |
Is an Antenna Analyzer an FCC violation?
Low power test gear is listed as a permitted form of radiation. While a signal generator is permitted for use as a test instrument, it would not be legal to use it for say a transmitter on a ham band that you are not licened to use. YOu could legally use it for a ham band transmitter if you followed all the other part 95 rules. Hi Ralph, I don't mean to sound offensive, but do you know for a fact that low power test gear is a permitted form of intentional radiation? I wonder what constitutes 'low power'. Do you know where this is written so I can research it myself? Thanks, Thomas |
Is an Antenna Analyzer an FCC violation?
I'm trying to determine if using an antenna analyzer is technically a
violation of the telecommunications Code of Federal Regulations. Typical antenna analyzers inject a incident CW or sweeping CW to the antenna and measure its return loss (reflection). Very few frequency bands have a CW or sweeping CW as their allowed modulation type. The way I see it is that by using an antenna analyzer you are intentionally radiating an improper modulation type that was allocated for the band and therefore you are in violation of the Code of Federal Regulations. Anyone have any thoughts on this topic? By your logic a noise bridge would also be illegal. However in most places there is a limit on the amount of power one can use before it requires a license. Since an antenna analyzer puts out a few microwatts, if that, no one seems to care. My understanding is that the popular MFJ antenna analyzers generate around 2 volts RMS of RF at their output port. This works out to around 80 milliwatts into a 50-ohm load... comparable to what a small QRP transmitter would deliver. I do not have the capability to measure the power level of mine, but I expect that it is less than a regenerative receiver. I think that it's more than you might expect. These analyzers don't use a tuned detector - they use a simple diode detector (admittedly with low-threshold / "zero bias" Schottky diodes) and they need a reasonably hefty signal. I've heard that there are some analyzers which use some sort of mixer-and-filter arrangement to sample the RF (thus allowing the analyzer to reject incidental off-frequency RF such as the AM broadcast-band signals that render MFJ analyzers rather useless on 80 and 160 meters) but I haven't seen one myself. As to the issues of legality - IANAL, but I think that there's probably a way to justify their use under the CFR. For one thing: CW modulations are authorized under Part 97 on almost all of the ham bands (everything other than 60 meters, I believe). Stick to the bands on which you have operating privileges, and you're probably safe there. Feel free to turn the analyzer on and off to send your callsign in CW at the end of your test, if you're feeling cautious :-) For another: Part 97 specifically authorizes "test transmissions" on any band authorized to the control operator (with restrictions on pulse and spread-spectrum test transmissions). For a third thing: it's quite possible that these devices would emit a low-enough power level that they would qualify for use under Part 15 "intentional radiator" standards... and such devices are permitted to operate in most frequency bands. Such devices to have maximum-power limits, which are measured in microvolts-per-meter field strength at a specified distance - limits and distances vary by frequency band. For a fourth: they *might* also qualify for legal use under Part 18 (Industrial, Scientific, and Medical Equipment). These devices can also operate in most frequency bands (although there are several subbands which are specifically authorized for them and are thus recommended), subject to maximum-field-strength limits similar to those specified for Part 15 devices. I doubt that the FCC has the inclination, desire, or resources to try to forbid or limit the use of antenna analyzers. If they did, they'd have to start raiding labs all over the country and confiscating multi-thousand-dollar vector network analyzers, S-parameter test sets, and so forth. The Benevolent Association of Agilent And Anritsu Equipment Owners would no doubt start writing harsh letters to their Congressmen :-) In practice, I suspect that you're quite safe in using such devices as long as you aren't causing harmful interference to licensed users of the bands in question... and if you believe that you are, you should of course cease transmission immijitly! -- 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! |
Is an Antenna Analyzer an FCC violation?
I doubt that the FCC has the inclination, desire, or resources to try
to forbid or limit the use of antenna analyzers. If they did, they'd have to start raiding labs all over the country and confiscating multi-thousand-dollar vector network analyzers, S-parameter test sets, and so forth. A network analyzers is not marketed as an antenna analyzer, or even an intentional radiator for that matter. I have a signal generator, an amplifier and an antenna in my lab but it does not mean I can sweep the entire LF to UHF bands at any wattage. For a fourth: they *might* also qualify for legal use under Part 18 (Industrial, Scientific, and Medical Equipment). These devices can also operate in most frequency bands (although there are several subbands which are specifically authorized for them and are thus recommended), subject to maximum-field-strength limits similar to those specified for Part 15 devices. I was just looking through Part 18 and it really is unclear to me, however one thing was clear to me, ISM devices are prohibited for use in certain bands. One of which is search and rescue. So now how can I test my ELT antenna installation on my aircraft if I'm violating FCC rules? Thomas |
Is an Antenna Analyzer an FCC violation?
Thomas you can start around here in the Part 15 rules.
[Code of Federal Regulations] [Title 47, Volume 1, Parts 0 to 19] [Revised as of October 1, 2000] From the U.S. Government Printing Office via GPO Access [CITE: 47CFR15.3] [Page 676-679] TITLE 47--TELECOMMUNICATION CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION PART 15--RADIO FREQUENCY DEVICES--Table of Contents Subpart A--General Sec. 15.3 Definitions. (dd) Test equipment is defined as equipment that is intended primarily for purposes of performing measurements or scientific investigations. Such equipment includes, but is not limited to, field strength meters, spectrum analyzers, and modulation monitors. "Thomas Magma" wrote in message news:Ih3zi.82605$rX4.66763@pd7urf2no... Low power test gear is listed as a permitted form of radiation. While a signal generator is permitted for use as a test instrument, it would not be legal to use it for say a transmitter on a ham band that you are not licened to use. YOu could legally use it for a ham band transmitter if you followed all the other part 95 rules. Hi Ralph, I don't mean to sound offensive, but do you know for a fact that low power test gear is a permitted form of intentional radiation? I wonder what constitutes 'low power'. Do you know where this is written so I can research it myself? Thanks, Thomas |
Is an Antenna Analyzer an FCC violation?
Thomas Magma wrote:
I doubt that the FCC has the inclination, desire, or resources to try to forbid or limit the use of antenna analyzers. If they did, they'd have to start raiding labs all over the country and confiscating multi-thousand-dollar vector network analyzers, S-parameter test sets, and so forth. A network analyzers is not marketed as an antenna analyzer, or even an intentional radiator for that matter. I have a signal generator, an amplifier and an antenna in my lab but it does not mean I can sweep the entire LF to UHF bands at any wattage. Then you need to get a better signal generator. For a fourth: they *might* also qualify for legal use under Part 18 (Industrial, Scientific, and Medical Equipment). These devices can also operate in most frequency bands (although there are several subbands which are specifically authorized for them and are thus recommended), subject to maximum-field-strength limits similar to those specified for Part 15 devices. I was just looking through Part 18 and it really is unclear to me, however one thing was clear to me, ISM devices are prohibited for use in certain bands. One of which is search and rescue. So now how can I test my ELT antenna installation on my aircraft if I'm violating FCC rules? You test it during the time window when testing ELT's is allowed. Since such devices have been around in one form or another for longer than most everybody currently alive and the FCC has shown no interest in them to date, the empirical evidence is the FCC doesn't care about them. And for the nitpickers, yes if you hooked one to an antenna and left it turned on for days, someone might start caring. -- Jim Pennino Remove .spam.sux to reply. |
Is an Antenna Analyzer an FCC violation?
Dave Platt wrote:
My understanding is that the popular MFJ antenna analyzers generate around 2 volts RMS of RF at their output port. This works out to around 80 milliwatts into a 50-ohm load... comparable to what a small QRP transmitter would deliver. However my measurements of an MFJ-259B and an MFJ-269 both show constant output throughout the frequency range of +7.0dBm +/- .5dB which is 5mW and not 80mW. 73, Larry, W0QE |
Is an Antenna Analyzer an FCC violation?
In article ,
Larry Benko wrote: My understanding is that the popular MFJ antenna analyzers generate around 2 volts RMS of RF at their output port. This works out to around 80 milliwatts into a 50-ohm load... comparable to what a small QRP transmitter would deliver. However my measurements of an MFJ-259B and an MFJ-269 both show constant output throughout the frequency range of +7.0dBm +/- .5dB which is 5mW and not 80mW. Interesting - thanks, that's quite a bit lower level than I had [obviously,mis-]remembered. That'd be about .5 volts RMS rather than 2 volts RMS, IIRC. -- 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! |
Is an Antenna Analyzer an FCC violation?
Jimmie D wrote:
That explains why it didnt work so well as a RX VFO.I needed about 13db I may try again with a little amp. I wonder if the vacuum tube dip meters aren't the most powerful signal sources we typically use to explore antenna characteristics, especially when the coil is tightly coupled. 73, Chuck ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups ----= East and West-Coast Server Farms - Total Privacy via Encryption =---- |
Is an Antenna Analyzer an FCC violation?
"Jimmie D" writes:
That explains why it didnt work so well as a RX VFO.I needed about 13db I may try again with a little amp. If you listen to the signal, it's quite unstable. So probably not very useful as a VFO. |
Is an Antenna Analyzer an FCC violation?
A network analyzers is not marketed as an antenna analyzer, or even an
intentional radiator for that matter. I have a signal generator, an amplifier and an antenna in my lab but it does not mean I can sweep the entire LF to UHF bands at any wattage. Then you need to get a better signal generator. I meant "does not mean I can legally sweep the entire LF to UHF bands" I was just looking through Part 18 and it really is unclear to me, however one thing was clear to me, ISM devices are prohibited for use in certain bands. One of which is search and rescue. So now how can I test my ELT antenna installation on my aircraft if I'm violating FCC rules? You test it during the time window when testing ELT's is allowed. This does not apply to the newer 406 ELT's that are currently being sold, and which are monitored by very sensitive LEO, MEO and GEO satellites. A band that is also recognized and protected by the ITU. |
Is an Antenna Analyzer an FCC violation?
"Ralph Mowery" wrote in message ... Thomas you can start around here in the Part 15 rules. [Code of Federal Regulations] [Title 47, Volume 1, Parts 0 to 19] [Revised as of October 1, 2000] From the U.S. Government Printing Office via GPO Access [CITE: 47CFR15.3] [Page 676-679] TITLE 47--TELECOMMUNICATION CHAPTER I--FEDERAL COMMUNICATIONS COMMISSION PART 15--RADIO FREQUENCY DEVICES--Table of Contents Subpart A--General Sec. 15.3 Definitions. (dd) Test equipment is defined as equipment that is intended primarily for purposes of performing measurements or scientific investigations. Such equipment includes, but is not limited to, field strength meters, spectrum analyzers, and modulation monitors. Thanks Ralph, I have the CRF in front of me and can see where test equipment is defined. However, I can seem to find where it says that test equipment is exempt from any sort of intentional radiation at any power levels. Do you know where? Thomas |
Is an Antenna Analyzer an FCC violation?
And for the nitpickers, yes if you hooked one to an antenna and left it turned on for days, someone might start caring. Hi Jim, I'm not necessarily worried about interfering, disrupting or jamming other receivers in the area, a fast sweeping 3 or 7 dbm CW would not likely interfere. I am worried about what is legal and what is not legal. Regulatory bodies such as the FCC/ITU do not use statements or issue licenses under terms 'it's not likely to' or 'its not much of a concern', they prefer to issue specific modulation types and field strengths. Thomas |
Is an Antenna Analyzer an FCC violation?
I have the CRF in front of me and can see where test equipment is defined.
However, I can seem to find where it says that test equipment is exempt from any sort of intentional radiation at any power levels. "I can't seem to find"...that is... |
Is an Antenna Analyzer an FCC violation?
On Thu, 23 Aug 2007 16:46:04 GMT, "Thomas Magma"
wrote: I am worried about what is legal and what is not legal. Hi Thomas, Then sifting legal advice from ad-hoc postings is a poor remedy for worry. 73's Richard Clark, KB7QHC |
Is an Antenna Analyzer an FCC violation?
On Thu, 23 Aug 2007 16:46:04 GMT, "Thomas Magma" wrote: I am worried about what is legal and what is not legal. If worried, write the FCC for clarification Lots of folks here are guessing --- IMHO Lamont |
Is an Antenna Analyzer an FCC violation?
We have had regulation of RF emissions since 1912... I have been an
active ham for 45 years... I have read most of the back issues of QST over the years, clear back to the start.... I keep up (mostly) with regulatory and enforcement actions that affect hams.... Never, ever, have I run across an action by the FCC against a ham for using a piece of test gear that radiates low power signals... When that does happen perhaps it will be time to discuss it... denny / k8do |
Is an Antenna Analyzer an FCC violation?
In message , The Shadow
writes On Thu, 23 Aug 2007 16:46:04 GMT, "Thomas Magma" wrote: I am worried about what is legal and what is not legal. If worried, write the FCC for clarification Lots of folks here are guessing --- IMHO Lamont Asking for clarification is absolutely the last thing you want to do. Have you never heard of 'Let sleeping dogs lie'? Most authorities (at least in the UK) have a policy of "If in doubt, say no". Alternatively, the response may come from some junior employee who has no idea what you are talking about, and in case he/she is wrong, will simply give an unconsidered "No" as a 'safe' answer. -- Ian |
Is an Antenna Analyzer an FCC violation?
I am worried about what is legal and what is not legal.
Hi Thomas, Then sifting legal advice from ad-hoc postings is a poor remedy for worry. I agree with you, however this is not the intelligent answer I was looking for. I like to think there are people that participate in certain newsgroups that are more knowledgeable on specific topics than I am. If I start asking questions to the FCC or ITU it will be a huge drawn out process. I was hoping someone knew the answer so I wouldn't have to go that route. Thomas |
Is an Antenna Analyzer an FCC violation?
On Thu, 23 Aug 2007 19:59:05 GMT, "Thomas Magma"
wrote: I am worried about what is legal and what is not legal. Hi Thomas, Then sifting legal advice from ad-hoc postings is a poor remedy for worry. I agree with you, however this is not the intelligent answer I was looking for. Hi Thomas, I hesitated to jump in at: On Wed, 22 Aug 2007 23:47:22 GMT, "Thomas Magma" wrote: So now how can I test my ELT antenna installation on my aircraft if I'm violating FCC rules? Where the intelligent response would have been "What about FAA rules or CFR 91.207(2)(d)(4) (where you would struggle to qualify as an inspector)?" As I have been authorized to work under both authorities (I've done plenty of Navigation Aids, transmitters and Flight Recorders) that particular question seemed to evidence a struggle in the tarpits. 73's Richard Clark, KB7QHC |
Is an Antenna Analyzer an FCC violation?
"Thomas Magma" wrote in message news:dGlzi.84070$fJ5.16631@pd7urf1no... I am worried about what is legal and what is not legal. Hi Thomas, Then sifting legal advice from ad-hoc postings is a poor remedy for worry. I agree with you, however this is not the intelligent answer I was looking for. I like to think there are people that participate in certain newsgroups that are more knowledgeable on specific topics than I am. If I start asking questions to the FCC or ITU it will be a huge drawn out process. I was hoping someone knew the answer so I wouldn't have to go that route. Thomas Au contraire. In the past I have queried the FCC on a number of issues and received prompt and definitive replies. Doing thus gives you the FCC stance on the issue -- not the News Group guesses Lamont |
Is an Antenna Analyzer an FCC violation?
Denny wrote:
We have had regulation of RF emissions since 1912... I have been an active ham for 45 years... I have read most of the back issues of QST over the years, clear back to the start.... I keep up (mostly) with regulatory and enforcement actions that affect hams.... Never, ever, have I run across an action by the FCC against a ham for using a piece of test gear that radiates low power signals... Perhaps not against hams, but cases of FCC enforcement actions against commercial users of test equipment have occurred. A typical case is radiating on an antenna test range with a bit too much power, or without the necessary experimental Part 5 license. There are also cases of companies getting tagged for doing things like testing a radar, but that's something designed to radiate, not a piece of test gear. The general rule is, if they can't detect it at the property line, you're probably legal. |
Is an Antenna Analyzer an FCC violation?
Perhaps not against hams, but cases of FCC enforcement actions against commercial users of test equipment have occurred. Jim, I am a pilot, etc. I am aware of enforcement actions against radio repair stations for radiating excessive power on the same frequency as the VOR on the field, etc... But, I was very specific in my comments... No enforcement action against a ham for using test equipment - ever - insofar as I know... This is so unlikely as to equal betting on the Megamillions Lottery this weekend, for several reasons... The first reason is that we are licensed to radiate those emissions in the first place... The second reason is that unintentional interference must be accepted in the ham bands per the regulations... The third is, Rily has a sense of humor... 73 - denny |
Is an Antenna Analyzer an FCC violation?
Thomas Magma wrote:
I am worried about what is legal and what is not legal. Hi Thomas, Then sifting legal advice from ad-hoc postings is a poor remedy for worry. I agree with you, however this is not the intelligent answer I was looking for. Why? Are you seriously worried about getting arrested for using an antenna analyzer? It's really time to step back and take a deep breath, Thomas. If you can get wrapped around the axle about this non-issue, there are plenty more legalistic pitfalls in amateur radio to give you an ulcer. I like to think there are people that participate in certain newsgroups that are more knowledgeable on specific topics than I am. If what you are looking for is specific written words blessing the use of antenna analyzers, I doubt that such a thing exists. Then again, I haven't looked for anything either. People have been sending tiny amounts of RF up their antennas to find out things about it since before Methuselah, selling and buying instruments of apparent contraband without anyone getting too excited. 'Til now. Respectfully suggest that you start looking for your evidence. Most of us are happy to assume that when used for the intended purpose, an antenna analyzer is legal and acceptable. If you think it might not be - and I have to assume that you do, do the research and prove it. That's my answer. You can decide if it is intelligent or not ;^) If I start asking questions to the FCC or ITU it will be a huge drawn out process. I was hoping someone knew the answer so I wouldn't have to go that route. It might make for part of Riley's speech at Dayton next year... ;^) - 73 de Mike KB3EIA - |
Is an Antenna Analyzer an FCC violation?
Denny wrote:
Perhaps not against hams, but cases of FCC enforcement actions against commercial users of test equipment have occurred. Jim, I am a pilot, etc. I am aware of enforcement actions against radio repair stations for radiating excessive power on the same frequency as the VOR on the field, etc... But, I was very specific in my comments... No enforcement action against a ham for using test equipment - ever - insofar as I know... This is so unlikely as to equal betting on the Megamillions Lottery this weekend, for several reasons... The first reason is that we are licensed to radiate those emissions in the first place... The second reason is that unintentional interference must be accepted in the ham bands per the regulations... The third is, Rily has a sense of humor... As Homer Simpson once mused: "Can God Make a Burrito that is too hot for him to eat?" It was a well deserved citation against that radio repair station. And the antenna range too. But neither of those are the same issue. But since we have descended from the sublime into the ridiculous, I have noted that it is occasionally possible to accidentally make a QSO with another OP while connected to a dummy load. I've done this a number of times on PSK31. Are there specific rules and limits to the radiation from dummy loads? And if not, are Dummy loads illegal? - 73 de Mike KB3EIA - |
Is an Antenna Analyzer an FCC violation?
Michael Coslo wrote:
People have been sending tiny amounts of RF up their antennas to find out things about it since before Methuselah, ... Mike, do you really think the Nephilim were people? -- 73, Cecil http://www.w5dxp.com |
Is an Antenna Analyzer an FCC violation?
In article ,
Michael Coslo wrote: But since we have descended from the sublime into the ridiculous, I have noted that it is occasionally possible to accidentally make a QSO with another OP while connected to a dummy load. I've done this a number of times on PSK31. Are there specific rules and limits to the radiation from dummy loads? And if not, are Dummy loads illegal? - 73 de Mike KB3EIA - It IS possible to radiate from a Dummy Load, enough energy to commuicate with another station. Example. Years ago, I was a Traveling Radioman for the old Northern Radio Company of Seattle, Washington. I had a Northern N550 MF/HF SSB 150W PEP Transceiver on the testbench connected to a Bird 1 Kw Dummy Load. I was doing a final tuneup on the Transmitter, which was Crystal Controlled, and one of the channels was KMI @ Point Reyes California, the AT&T HighSeas HF Station for the Pacific. As I was testing with a two tone Audio Test Signal, I heard the KMI Operator come back with a "Who the heck is on my input Freq on KMI-1201?". We carried on a nice chat for about 5 minutes, and I called him on the Landline after that for another 30 minute chat. He said he routinely got signals from Radio Shops, doing tuneups on his Calling and Working Frequencies, when the Band was Wide Open. His Receiving Antenna Array was a set of Phased Rhombics, steerable over a 270 degree Arc to the West. Bruce in alaska AL7AQ ex-FCC Field Inspector for Alaska -- add a 2 before @ |
Is an Antenna Analyzer an FCC violation?
Cecil Moore wrote:
Michael Coslo wrote: People have been sending tiny amounts of RF up their antennas to find out things about it since before Methuselah, ... Mike, do you really think the Nephilim were people? I guess it depned on whther you thing they were descended from the begatten of Seth and Cain or the Anakim. I wonder if they used an antenna analyzer on the Ark?? ;^) You been out of town? I haven't heard much from you lately. - 73 de Mike KB3EIA - |
Is an Antenna Analyzer an FCC violation?
"Michael Coslo" wrote in message ... Cecil Moore wrote: Michael Coslo wrote: People have been sending tiny amounts of RF up their antennas to find out things about it since before Methuselah, ... Mike, do you really think the Nephilim were people? I guess it depned on whther you thing they were descended from the begatten of Seth and Cain or the Anakim. I wonder if they used an antenna analyzer on the Ark?? Nope the Doves had Radar (;-) Lamont |
Is an Antenna Analyzer an FCC violation?
Bob Miller wrote:
I have an Oak Hills Research WM-2 QRP Wattmeter, which includes a 0-100 milliwatt scale. With an MFJ 269 Antenna Analyzer hooked to the transmitter side of the wattmeter, and an MFJ dummy load hooked to the load side of the wattmeter, I get a reading of 3 milliwatts forward, 0 milliwatts reflected. Not sure whether the FCC is concerned with signals at the 3 milliwatt level... Most if not all the part 15 rules are defined in terms of field strength, not power. 3 mW is way, way more than enough to exceed some of the limits on some frequencies, when connected to even a poor antenna. For example, Part 15 shows, in 15.209, that intentional radiators aren't allowed to produce a field strength greater than 100 uV/m (with exceptions) at 3 meters from 30 - 88 Mhz. 3 milliwatts will produce *1,000 times*, or 60 dB greater than, this amount when connected to an isotropic antenna. Hook it to a dipole to get another few dB. The limit for class A digital devices (one class of unintentional radiators) is the same in that range, according to 15.109. So don't think that just because you consider a signal to be QRP that it's legal. That said, I agree that chances of prosecution are zero for using these devices unless serious and/or intentional interference results. And I strongly agree with the folks who have said that the last thing you want to do is force a specific ruling on the matter from the FCC. Roy Lewallen, W7EL |
Is an Antenna Analyzer an FCC violation?
Roy Lewallen wrote in news:13cv2n6r7q05s78
@corp.supernews.com: .... Most if not all the part 15 rules are defined in terms of field strength, not power. 3 mW is way, way more than enough to exceed some of the limits on some frequencies, when connected to even a poor antenna. I wrote a little article to inform people in the BPL debate... it started out as: How much radiated power does it take to create an S9 signal? Try this quick quiz: What is the EIRP of a 7MHz transmitter that results in a S9 signal at a receiver located 1km from the transmitter, is it closest to: 1. 5 Watts; 2. 1 Watt; 3. 300 milliWatts; 4. 5 milliWatts; 5. 3 microWatts. Answer: e, it is just 3 microWatts EIRP. Remember that it takes less than a nanoWatt EIRP (ie 10E-9 Watts, a thousandth of a millionth of a Watt) of leakage of radiofrequency energy at 7MHz from BPL enabled power lines 10 metres from a dipole to cause S9 level interference. Are you ready for BPL enablement of your home and neighbourhood? http://www.vk1od.net/bpl/AreYouReady.htm Owen |
Is an Antenna Analyzer an FCC violation?
Michael Coslo wrote:
You been out of town? I haven't heard much from you lately. I have moved to a new QTH and only had dialup for awhile - hardly worth the effort of dialing. -- 73, Cecil http://www.w5dxp.com |
No tuner dipole ; was: Is an Antenna Analyzer an FCC violation?
I have moved to a new QTH and only had dialup for
awhile - hardly worth the effort of dialing. -- 73, Cecil http://www.w5dxp.com =================================== Cecil , Great antenna web site . Intent to implement your 'no tuner' dipole with 450 ohms feeder by adding bits of feeder operated by relays with quadruple change over contacts. I assume it is alright to build the lot in a box made of MDF with the 450 Ohms ribbon coiled up. An open perspex sheet would be somewhat difficult to accommodate in my shack. Frank GM0CSZ / KN6WH north of Scotland |
No tuner dipole ; was: Is an Antenna Analyzer an FCC violation?
Highland Ham wrote:
Cecil , Great antenna web site . Intent to implement your 'no tuner' dipole with 450 ohms feeder by adding bits of feeder operated by relays with quadruple change over contacts. I assume it is alright to build the lot in a box made of MDF with the 450 Ohms ribbon coiled up. An open perspex sheet would be somewhat difficult to accommodate in my shack. The only way to coil up 450 ohm line is to keep all parts of each coil at least 3-4 inches from all other coils. A spiral will work but you certainly *cannot* successfully coil up balanced ladder-line as you can with unbalanced coax. -- 73, Cecil http://www.w5dxp.com |
Is an Antenna Analyzer an FCC violation?
On Sat, 25 Aug 2007 08:31:08 -0500, Bob Miller wrote:
On Fri, 24 Aug 2007 18:50:30 -0700, Roy Lewallen wrote: Bob Miller wrote: I have an Oak Hills Research WM-2 QRP Wattmeter, which includes a 0-100 milliwatt scale. With an MFJ 269 Antenna Analyzer hooked to the transmitter side of the wattmeter, and an MFJ dummy load hooked to the load side of the wattmeter, I get a reading of 3 milliwatts forward, 0 milliwatts reflected. Not sure whether the FCC is concerned with signals at the 3 milliwatt level... Most if not all the part 15 rules are defined in terms of field strength, not power. 3 mW is way, way more than enough to exceed some of the limits on some frequencies, when connected to even a poor antenna. For example, Part 15 shows, in 15.209, that intentional radiators aren't allowed to produce a field strength greater than 100 uV/m (with exceptions) at 3 meters from 30 - 88 Mhz. 3 milliwatts will produce *1,000 times*, or 60 dB greater than, this amount when connected to an isotropic antenna. Hook it to a dipole to get another few dB. The limit for class A digital devices (one class of unintentional radiators) is the same in that range, according to 15.109. So don't think that just because you consider a signal to be QRP that it's legal. FYI, I checked the MFJ-269 manual, and it claims: "a relatively pure (harmonics better than -25dBc) signal of approximately 3 Vpp (aproximately 20 milliwatts) into 50 ohms." So my measurement of 3 milliwatts on the wattmeter could have been low. Bob k5qwg That said, I agree that chances of prosecution are zero for using these devices unless serious and/or intentional interference results. And I strongly agree with the folks who have said that the last thing you want to do is force a specific ruling on the matter from the FCC. Roy Lewallen, W7EL During the 1960's I engineered the antenna systems that flew on the early TIROS weather satellites. The antennas radiated both RHCP and LHCP. In the earthward direction the gain was approximately 3 dBi. At the ground station I operated the antenna had a 16 dBd gain at the beacon frequency of 136 MHz The beacon xmtrs output power was 5 mW. While the satellite was at maximum slant range (just over the horizon) of 1800 miles, the signal level from the beacons was several dB over S9 on R-390 receivers with their associated frequency down converters. Walt,W2DU |
Is an Antenna Analyzer an FCC violation?
Perhaps the answer here is to only use the analyzer on bands that are
not in active use at the time, like say Noon on 75 meters. I'm speaking of when propogation is dead on thise bands because of time of day. Would the legality of it change? Probably not, but by doing it that way you would have minimized the possibility of intererfering with any other users that could hear you. On Sat, 25 Aug 2007 19:42:26 -0400, Walter Maxwell wrote: On Sat, 25 Aug 2007 08:31:08 -0500, Bob Miller wrote: On Fri, 24 Aug 2007 18:50:30 -0700, Roy Lewallen wrote: Bob Miller wrote: I have an Oak Hills Research WM-2 QRP Wattmeter, which includes a 0-100 milliwatt scale. With an MFJ 269 Antenna Analyzer hooked to the transmitter side of the wattmeter, and an MFJ dummy load hooked to the load side of the wattmeter, I get a reading of 3 milliwatts forward, 0 milliwatts reflected. Not sure whether the FCC is concerned with signals at the 3 milliwatt level... Most if not all the part 15 rules are defined in terms of field strength, not power. 3 mW is way, way more than enough to exceed some of the limits on some frequencies, when connected to even a poor antenna. For example, Part 15 shows, in 15.209, that intentional radiators aren't allowed to produce a field strength greater than 100 uV/m (with exceptions) at 3 meters from 30 - 88 Mhz. 3 milliwatts will produce *1,000 times*, or 60 dB greater than, this amount when connected to an isotropic antenna. Hook it to a dipole to get another few dB. The limit for class A digital devices (one class of unintentional radiators) is the same in that range, according to 15.109. So don't think that just because you consider a signal to be QRP that it's legal. FYI, I checked the MFJ-269 manual, and it claims: "a relatively pure (harmonics better than -25dBc) signal of approximately 3 Vpp (aproximately 20 milliwatts) into 50 ohms." So my measurement of 3 milliwatts on the wattmeter could have been low. Bob k5qwg That said, I agree that chances of prosecution are zero for using these devices unless serious and/or intentional interference results. And I strongly agree with the folks who have said that the last thing you want to do is force a specific ruling on the matter from the FCC. Roy Lewallen, W7EL During the 1960's I engineered the antenna systems that flew on the early TIROS weather satellites. The antennas radiated both RHCP and LHCP. In the earthward direction the gain was approximately 3 dBi. At the ground station I operated the antenna had a 16 dBd gain at the beacon frequency of 136 MHz The beacon xmtrs output power was 5 mW. While the satellite was at maximum slant range (just over the horizon) of 1800 miles, the signal level from the beacons was several dB over S9 on R-390 receivers with their associated frequency down converters. Walt,W2DU |
Is an Antenna Analyzer an FCC violation?
"Jimmie D" ) writes:
I think I remember a test conducted to see how much power it would take to communicate across the United States coast to coast. They started out making the contact at near legal limit and were still able to detect the signal at just a few milliwatts. As I remember a few was less than 10. I am sure this was part of a ham magazine article from many years ago. perhaps someone else here knows the details better than I. Don't forget that the rise of QRP activity forty years ago came due to the realization that you didn't always need high power. ANd one subset of QRP is to try to communicate with as little power as possible. Sometimes that was deliberate, dropping power until the signal was no longer receivable at theother end. Michael VE2BVW |
Is an Antenna Analyzer an FCC violation?
Jimmie D wrote:
... I think I remember a test conducted to see how much power it would take to communicate across the United States coast to coast. They started out making the contact at near legal limit and were still able to detect the signal at just a few milliwatts. As I remember a few was less than 10. I am sure this was part of a ham magazine article from many years ago. perhaps someone else here knows the details better than I. Jimmie It seems to me, many here have suggested there are "tons" of active hams out there; some have even went so far as to claim the bands are "crowded." Surely, taking in to account the above, the few brief milliwatts from an analyzer are of no real consequence amongst this "rf pollution" ... and ten milliwatts would never make it across such a country of such active hams. Regards, JS |
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