Antenna for cordless phone
in [Design]
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From: John on 23 May 2010 20:26 On Tue, 18 May 2010 20:06:41 -0400, "tm" <noone(a)msc.com> wrote: >The information "mpm" posted below is very correct, and in addition, it is >worth noting that the FCC Enforcement Branch is entirely self funded. > >Tom > > >"mpm" <mpmillard(a)aol.com> wrote in message >news:f1806f3a-b092-4b9e-899d-7d514bbe189b(a)d12g2000vbr.googlegroups.com... >> >Here in the US, it's "antenna" and "antennas". >> >You'll find antennae on bugs and cockroaches. :) >> >> >Sorry, that's just a pet peeve. Telecom attorneys make the same >> >mistake all the time! >> >> >Also, if in the US, FCC rules prohibit you from monkeying around with >> >the antennas. >> >Legally speaking, if in the US, you'll just have to live with it, or >> >select an alternate technology / device. >> >> >-mpm- Hide quoted text - >> >> - Show quoted text -- Hide quoted text - >> >> - Show quoted text - > >Not obsessed. Just alerting the OP to federal law. :) >If he chooses to break the law, those same laws provide for fines and >arrest of the equipment (in rem arrest), and the FCC can also refer >cases to the Justice Department for further prosecution. >Monetary fines for something like this can range from a few thousand, >to ten thousand dollars or more. See generally, FCC Rules 47CFR1.80 >Those are the facts. > >Now, does the FCC catch a lot of folks hacking illegal antennas into >their cordless phones? No. >But you might be suprised at just how many violations are issued each >year by the FCC's Enforcement Division. >I have personally been on a couple equipment witch hunts (for >interference) with the Miami and Denver field agents. >The outcomes are rarely pretty in the cases which I'm typically >involved in (the high profile ones). >The average homeowner can expect a Citation (no money fine) for a >first offense, but things can get nasty if they're uncorporative, >etc..., or if the Agent (for whatever reason) feels justified in >pursing the matter more aggressively. > >Plus, in my former career (a post you may have missed?) it should be >painfully obvious why I recoil when I hear that people want to hack >into their consumer electonics. >You would not believe the headaches this can cause for licensed radio >services!! > >But to your facts, >For most unlicened devices like cordless phone and the like, they'll >be registered under Part-15 rules. (47CFR15) >Those rules will provide field strength limits (not transmitter power >output restrictions). Therefore, antennas matter greatly! >The allowable field varies by frequency, according to a chart in FCC >Rules part 15.209 >Before leaving this topic, you should be aware that just because you >might feel Part-15 devices are low power, that DOES NOT mean they are >incapable of causing harmful interference. >Far from it. > >For example, did you know a typical CDMA or GSM cell phone (operating >at its lower power output of ~ -50dBm) actually radiates LESS power >than the maximum permissible under Part-15 Rules for unlicensed >devices? >In other words, something that's unlicensed (and lower power) actually >puts out MORE power than your cell phone -- which is very much a >licensed service (FCC Part 22, 24 or 27) >And note also that Part-15 Low Power does not restrict operation in >the Cellular / PCS bands. >Think about that next time you drop a call. It may just be your >neighbor hacked in an antenna on his cordless phone (or garage door >opener, or blender, or TV or god knows what!) > >This is one of hundreds of examples I could give to you. >So yeah, you might say I'm "obsessed" -- but I am absolutely correct, >and this history books are filled with examples of horrendous >interference cause by well-intentioned folks just like the OP.!! > > >Specific to this exact situation, here is the precise rule the OP >would be violating: > >Sec. 15.203 Antenna requirement. >An intentional radiator shall be designed to ensure that no antenna >other than that furnished by the responsible party shall be used with >the device. > >The use of a permanently attached antenna or of an antenna that uses a >unique coupling to the intentional radiator shall be considered >sufficient to comply with the provisions of this section. The >manufacturer may design the unit so that a broken antenna can be >replaced by the user, but the use of a standard antenna jack or >electrical connector is prohibited. This requirement does not apply to >carrier current devices or to devices operated under the provisions of >Sec. 15.211, Sec. 15.213, Sec. 15.217, Sec. 15.219, or Sec. 15.221. >Further, this requirement does not apply to intentional radiators that >must be professionally installed, such as perimeter protection systems >and some field disturbance sensors, or to other intentional radiators >which, in accordance with Sec. 15.31(d), must be measured at the >installation site. However, the installer shall be responsible for >ensuring that the proper antenna is employed so that the limits in >this >part are not exceeded. > > Don This is one page of about 10 pages of a book that talks about you requirement. If yo want I can send you the other pages . It also talks about the FCC requirements. Part of the Index of the same book: Contents at a Glance Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . xxvii Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . xxix Part I: Building Antennas . . . . . . . . . . . . . . . . . . . . . . .. . . . . 1 Chapter 1: Building Your Own Wi-Fi Antenna Cable . . . . . . . . . . . .. . . . . . . . . 3 Chapter 2: Building a Classic Paperclip Antenna . . . . . . . . . . . .. . . . . . . . . . . 35 Chapter 3: Building a Directional Tin Can Antenna . . . . . . . . . . .. . . . . . . . . . 59 Chapter 4: Modifying Your Access Point with a High-Gain Antenna . . . .. . . . . . . . 81 Part II: War Driving�Wireless Network Discovery and Visualization . . . . . . . . . . . . . . . . . . . . . .. . . 101 Chapter 5: Gearing Up for War Driving . . . . . . . . . . . . . . . . .. . . . . . . . . . 103 Chapter 6:War Driving with NetStumbler . . . . . . . . . . . . . . . . .. . . . . . . . 127 Chapter 7: Mapping Your War Driving Results . . . . . . . . . . . . . .. . . . . . . . . 145 Part III: Playing with Access Points. . . . . . . . . . . . . . . . . .. . . . 169 Chapter 8: Build Your Own Outdoor Access Point . . . . . . . . . . . . .. . . . . . . . 171 Chapter 9: Building a Solar-Powered Wireless Repeater . . . . . . . . .. . . . . . . . . 207 Chapter 10: Creating a Free Wireless Hotspot . . . . . . . . . . . . . .. . . . . . . . . . 237 Chapter 11: Playing Access Point Games . . . . . . . . . . . . . . . . .. . . . . . . . . 267 Part IV: Just for Fun . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . 285 Chapter 12:Wi-Fi Your TiVo . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . 287 Chapter 13: Create a Long-Distance Wi-Fi Link . . . . . . . . . . . . .. . . . . . . . . 303 Chapter 14: Deploy a Car-to-Car Wireless Video Link . . . . . . . . . .. . . . . . . . . 323 Chapter 15: Making a Dynamic Wireless Digital Picture Frame . . . . . .. . . . . . . . 345 Index . 10 Part I � Building Antennas FIGURE 1-3: Parts of a Wi-Fi project. Data Source (computer, etc) Data to RF Converter Radio Transceiver Transmission Line Antenna System Figure 1-3 shows the breakdown. The data to RF converter and radio transceiver are nearly always in the same appliance, and even on the same circuit board as on a PC card. Data Signaling The data signal is the digital signal with which every Wi-Fi access point or client project will interface. In some cases, the data will come from a computer via PC card slot or USB cable. In others it may be an Ethernet camera or the network itself. The data signal is usually based on the Internet protocol,TCP/IP.TCP/IP is a protocol used to transmit data between computers on normal, wired networks.Wi-Fi is meant to convert TCP/IP traffic into radio waves and back. Wi-Fi Devices The category of Wi-Fi devices consists of the digital data to RF converter and the radio transceiver. Most often, these two items are in the same product. In this book, projects will not break down these two components; we�re describing them separately here for clarity. For example, cable and antenna modifications to a wireless access point are covered in several chapters throughout the book.Wi-Fi devices have two jobs: convert the data from the computer into a radio signal, and transmit and receive radio signals to and from the data converter. They come in several forms that can be broken down into the following four major groups: Wireless Access Point : Attached to an Ethernet network, an access point provides a wired network gateway to wireless clients. An access point is the essential component for setting up a typical wireless network. Wireless Client Adapter: Connected or installed in a computer, a client adapter provides wireless connectivity to a wireless access point and then to a wired network. This can be inserted into a desktop computer, a laptop, a USB adapter, or any other computer interface. Wireless-to-Ethernet Bridge: Provides a direct connection between a wireless and wired (Ethernet) network without the need of a computer interface. It usually acts as a client connecting to an access point. Specialized Components: These include dedicated wireless networking devices, audiovisual devices, music streaming devices, digital picture frames, wireless scanners, wireless printers, and many more to come.
From: mpm on 23 May 2010 20:42 On May 18, 6:09 pm, D Yuniskis <not.going.to...(a)seen.com> wrote: > Hi Joerg, > > > > > > Joerg wrote: > >> I'll drag out a GPS and get some actual measurements, > >> if necessary. I've not done an exhaustive survey > >> of where things work/don't work. Though I have found > >> the upper left corner to be a problem area as I am > >> often passing through there when I lose signal. > > >> The antenna that I was *questioning* will (physically) > >> mate to a Linksys wireless router (though not intended > >> to do so, "just coincidence" -- sorry, I don't deal with > >> RF stuff so i can't tell you what sort of connectors > >> they are -- I don't think they will mate with the > >> base unit on the phone :<) > > > Cordless phone on a Linksys router? > > > <scratching head> > > No, I was trying to describe the type of connector on the > antenna that I am "questioning" -- without KNOWING the > proper names for the various RF plumbing! :> > > I figured most folks have seen a linksys router (with > removable antennae) so could relate to that example. > > The phone's base unit is something like a "reverse TNC" > (??) so I can't mate the antenna to the base unit > "as is".- Hide quoted text - > > - Show quoted text - If you give us the FCC ID number off the device, it can be easily looked up on the FCC's "Equipment Authorization Search" web page: Link: http://www.fcc.gov/oet/ea/fccid/ That is why I asked you for the number (May 17th). If the device is new enough to have been recently certified (i.e, within the last decade), there's a reasonably good chance that both its photographs and its parts lists (BOM) are available online at the FCC. At which point, you will not have to describe the antenna to us, and in fact, you may find your answer directly. It is worth a shot, in my opinion. You may have to do an advanced search, if you can't find the FCC ID nameplate, but US law requires it to be permanently attached to the device. Sometimes this is a decal; other times it may be thermoformed into the plastic housing itself (and often difficult to read), but you should be able to locate it. If you still have the User's Manual, look at the Specification Page and the FCC ID can usually be found there as well. -mpm
From: John on 24 May 2010 16:12 On Sun, 23 May 2010 17:42:30 -0700 (PDT), mpm <mpmillard(a)aol.com> wrote: >On May 18, 6:09�pm, D Yuniskis <not.going.to...(a)seen.com> wrote: >> Hi Joerg, >> >> >> >> >> >> Joerg wrote: >> >> I'll drag out a GPS and get some actual measurements, >> >> if necessary. �I've not done an exhaustive survey >> >> of where things work/don't work. �Though I have found >> >> the upper left corner to be a problem area as I am >> >> often passing through there when I lose signal. >> >> >> The antenna that I was *questioning* will (physically) >> >> mate to a Linksys wireless router (though not intended >> >> to do so, "just coincidence" -- sorry, I don't deal with >> >> RF stuff so i can't tell you what sort of connectors >> >> they are -- I don't think they will mate with the >> >> base unit on the phone �:<) >> >> > Cordless phone on a Linksys router? >> >> > <scratching head> >> >> No, I was trying to describe the type of connector on the >> antenna that I am "questioning" -- without KNOWING the >> proper names for the various RF plumbing! �:> >> >> I figured most folks have seen a linksys router (with >> removable antennae) so could relate to that example. >> >> The phone's base unit is something like a "reverse TNC" >> (??) so I can't mate the antenna to the base unit >> "as is".- Hide quoted text - >> >> - Show quoted text - > >If you give us the FCC ID number off the device, it can be easily >looked up on the FCC's "Equipment Authorization Search" web page: >Link: http://www.fcc.gov/oet/ea/fccid/ > >That is why I asked you for the number (May 17th). >If the device is new enough to have been recently certified (i.e, >within the last decade), there's a reasonably good chance that both >its photographs and its parts lists (BOM) are available online at the >FCC. >At which point, you will not have to describe the antenna to us, and >in fact, you may find your answer directly. > >It is worth a shot, in my opinion. > >You may have to do an advanced search, if you can't find the FCC ID >nameplate, but US law requires it to be permanently attached to the >device. >Sometimes this is a decal; other times it may be thermoformed into the >plastic housing itself (and often difficult to read), but you should >be able to locate it. >If you still have the User's Manual, look at the Specification Page >and the FCC ID can usually be found there as well. > >-mpm He probably gave up. It became a bit more complex that he was prepared to tackle. John
From: D Yuniskis on 24 May 2010 20:41 Hi John, John wrote: > On Sun, 23 May 2010 17:42:30 -0700 (PDT), mpm <mpmillard(a)aol.com> > wrote: > >> On May 18, 6:09 pm, D Yuniskis <not.going.to...(a)seen.com> wrote: >>> Hi Joerg, >>> >>>>> I'll drag out a GPS and get some actual measurements, >>>>> if necessary. I've not done an exhaustive survey >>>>> of where things work/don't work. Though I have found >>>>> the upper left corner to be a problem area as I am >>>>> often passing through there when I lose signal. >>>>> The antenna that I was *questioning* will (physically) >>>>> mate to a Linksys wireless router (though not intended >>>>> to do so, "just coincidence" -- sorry, I don't deal with >>>>> RF stuff so i can't tell you what sort of connectors >>>>> they are -- I don't think they will mate with the >>>>> base unit on the phone :<) >>>> Cordless phone on a Linksys router? >>>> <scratching head> >>> No, I was trying to describe the type of connector on the >>> antenna that I am "questioning" -- without KNOWING the >>> proper names for the various RF plumbing! :> >>> >>> I figured most folks have seen a linksys router (with >>> removable antennae) so could relate to that example. >>> >>> The phone's base unit is something like a "reverse TNC" >>> (??) so I can't mate the antenna to the base unit >>> "as is".- Hide quoted text - >>> >>> - Show quoted text - >> If you give us the FCC ID number off the device, it can be easily >> looked up on the FCC's "Equipment Authorization Search" web page: >> Link: http://www.fcc.gov/oet/ea/fccid/ >> >> That is why I asked you for the number (May 17th). >> If the device is new enough to have been recently certified (i.e, >> within the last decade), there's a reasonably good chance that both >> its photographs and its parts lists (BOM) are available online at the >> FCC. >> At which point, you will not have to describe the antenna to us, and >> in fact, you may find your answer directly. >> >> It is worth a shot, in my opinion. >> >> You may have to do an advanced search, if you can't find the FCC ID >> nameplate, but US law requires it to be permanently attached to the >> device. >> Sometimes this is a decal; other times it may be thermoformed into the >> plastic housing itself (and often difficult to read), but you should >> be able to locate it. >> If you still have the User's Manual, look at the Specification Page >> and the FCC ID can usually be found there as well. >> >> -mpm > > He probably gave up. > It became a bit more complex that he was prepared to tackle. Sorry, no, I had said I would drag the base up to the roof and walk the area to try to record where *exactly* the dropouts were with the base ON THE ROOF. Then, repeat the exercise with it back inside on the counter. I figured any other chat on the subject would just be speculative without hard facts. But, I've been busy getting ready for a 1,200 mile road trip (new tires, today... I'll change the oil tomorrow, etc.) and trying to get other "obligations" off my calendar. Cordless phone just didn't rise to the level of urgency to bump some of these other things :> I'll try to print out a couple drawings of the neighborhood so that when I "make the rounds" I can just mark "good" or "bad" as appropriate. Just need the *time* to do it! :-/ Thx, --don
From: D Yuniskis on 24 May 2010 22:02
Hi Joerg, Joerg wrote: > John wrote: >> Just try the vertical whip installed as elevated as possible outside >> the house and with the main unit as close as possible to the antenna > > Cordless phones aren't strictly vertical anymore, most don't even have > as much as a stub for an antenna. Just traces on the board or some wire. > When I took apart our previous ones after they were failing I was > amazed, they had two antennas diplexed in the handsets. The "handsets" have a short whip -- about 6" long (non retractable). Actually, there are two choices for the antenna -- I can't recall which ones I have installed currently (probably the longer of the two sizes). The "base" has a similar size (maybe 8"?) though packaged more like the antennae you find on a wireless router (i.e., encased in plastic or somesuch) > I think Don doesn't want an antenna on the roof so a yagi or something Yes, I would not like to end up with an antenna on the roof. Though, I might be able to locate it *in* the "ceiling". Or, in the chimney for the fireplace (as I plan on removing the fireplace -- silly thing to have in this part of the country! :> ) Again, a lot of this "exercise" is a practice run for me to sort out the issues that will affect doing the same thing with WiFi access point :-/ (the adage "make one to throw away" :> ) > else directional may be his only option in order to get another 5-10dB. > But I believe that the base will lose its FCC registration if you do that. I figure if I just take the entire base unit up to the roof, there's nothing "questionable" about that! I.e., just like having another "story" on the house. From there, I can see how *good* the signal would be (with no cable losses, etc.). If that isn't going to cut it, I may just wait for the access point and use a WiFi phone (assuming I can get better coverage with WiFi) |