Antenna for cordless phone
in [Design]
|
From: D Yuniskis on 17 May 2010 12:32 Hi Joe, Joe G (Home) wrote: >>>> *But*, there is one section (0.52 miles? :> ) where I lose reception. >>>> But, I suspect these operate on a different frequency than >>>> my "cordless" (902-928MHz)? (sorry, I know *nothing* about >>>> cell phones -- thankfully! :> ) >>> In the tests we did on a farm - we found the the problem was lack of >>> "line of sight" between the base and handset antenna. >>> >>> If you duck behind the metal shed or building was the problem. >> This is an "industrial cordless" -- intended for long range, etc >> (600mW Tx). I can get ~0.5 mi *obstructed* connections but getting >> much further than that (an extra block or two) is the problem. >> I am hoping that getting an antenna "outside" -- or at least >> "off the kitchen counter" -- will give me that little bit extra >> that is needed. > > You may try an experiment with a long piece of wire rapped a few turns > around the base antenna and get the rest of the wire outside. <frown> I don't think that's likely to produce any results (at 900MHz). I'd imagine just connecting the "dual band" antenna (for the *cell* phone) would give better results than that! :<
From: John on 17 May 2010 12:52 On Sun, 16 May 2010 10:28:24 -0700, D Yuniskis <not.going.to.be(a)seen.com> wrote: >Hi, > >Sometimes (rarely), on my "evening sabbatical", I carry >a cordless phone (NOT a cell phone) with me. This has >sufficient range to cover almost the entire "development" >(e.g., I can get about half a mile, as the crow flies). > >*But*, there is one section (0.52 miles? :> ) where I >lose reception. > >I've toyed with the idea of adding an external antenna to >the base unit (which currently just sits on a countertop) >to try to improve on that. > >I rescued a "dual band" antenna kit (AllTel) for a cell phone. >But, I suspect these operate on a different frequency than >my "cordless" (902-928MHz)? (sorry, I know *nothing* about >cell phones -- thankfully! :> ) Contrary to the popular believe antennae do not increase the transmitting power. They change the transmitting power from some directions into other directions. You probably are not interested in sending signal to the moon so rather then wasting that signal change it to the horizontal plane. First you must you must establish the horizontal area that you want to cover and if your transmitter is at the end of the terrain you may design a small Yagi like the type used to receive TV. You can design an antenna that will give you a pattern like a fig. of an heart, a figure of eight or a very directional antenna. The directionality will depend on the number of elements. Ideally you build 2 antennae of the same type and use one for one unit and the other for the other unit. Coupling to the base unit is another problem. Not easy. Describe, please the area you want to cover if you want to make a project out of it. I can help. John
From: D Yuniskis on 17 May 2010 13:23 Hi John, John wrote: > On Sun, 16 May 2010 10:28:24 -0700, D Yuniskis > <not.going.to.be(a)seen.com> wrote: >> >> Sometimes (rarely), on my "evening sabbatical", I carry >> a cordless phone (NOT a cell phone) with me. This has >> sufficient range to cover almost the entire "development" >> (e.g., I can get about half a mile, as the crow flies). >> >> *But*, there is one section (0.52 miles? :> ) where I >> lose reception. >> >> I've toyed with the idea of adding an external antenna to >> the base unit (which currently just sits on a countertop) >> to try to improve on that. >> >> I rescued a "dual band" antenna kit (AllTel) for a cell phone. >> But, I suspect these operate on a different frequency than >> my "cordless" (902-928MHz)? (sorry, I know *nothing* about >> cell phones -- thankfully! :> ) > > Contrary to the popular believe antennae do not increase the > transmitting power. They change the transmitting power from some > directions into other directions. Correct. I'm not expecting to "boost" the Tx power. But, rather, get it someplace from which it is easier for me (at the remote end) to pick it up (likewise, for the base to pick up my *remote* signal!) > You probably are not interested in sending signal to the moon so > rather then wasting that signal change it to the horizontal plane. > First you must you must establish the horizontal area that you want to > cover and if your transmitter is at the end of the terrain you may > design a small Yagi like the type used to receive TV. No. Antenna will be located in almost the exact center of the area to be covered. I.e., "walking around the neighborhood" (my "walk" is just about 2 miles total -- the furthest point being about 0.55 mi from the "base"). > You can design an antenna that will give you a pattern like a fig. of > an heart, a figure of eight or a very directional antenna. The > directionality will depend on the number of elements. > Ideally you build 2 antennae of the same type and use one for one unit > and the other for the other unit. The "remote" is a handheld device. Impractical to change the antenna on it. > Coupling to the base unit is another problem. Not easy. > Describe, please the area you want to cover if you want to make a > project out of it. I can help. The neighborhood is roughly: (view in fixed width font) +-----+ | | | | | | | | | | | | | +------------+ | | | X | | | +------------------+ This is *roughly* to scale. The "base" is located at X. The area is residential in nature so there are houses filling the region. The top of the illustration is at a higher elevation than the bottom -- maybe 60 ft? There are no commercial establishments in the area. Most of the construction is masonary. No dense foliage. The problem area (reception) is at the upper left (and the bottom right) -- no doubt as there are the most "obstructions" along the sight line. 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 :<) This is similar to what the manufacturer suggests for an external antenna: http://www.sn900.com/graphic/extant20.jpg Any pointers appreciated! (RF is BFM!) Thx, --don
From: tm on 17 May 2010 13:56 "D Yuniskis" <not.going.to.be(a)seen.com> wrote in message news:hsrtn3$ejt$1(a)speranza.aioe.org... > Hi John, > > John wrote: >> On Sun, 16 May 2010 10:28:24 -0700, D Yuniskis >> <not.going.to.be(a)seen.com> wrote: >>> >>> Sometimes (rarely), on my "evening sabbatical", I carry >>> a cordless phone (NOT a cell phone) with me. This has >>> sufficient range to cover almost the entire "development" >>> (e.g., I can get about half a mile, as the crow flies). >>> >>> *But*, there is one section (0.52 miles? :> ) where I >>> lose reception. >>> >>> I've toyed with the idea of adding an external antenna to >>> the base unit (which currently just sits on a countertop) >>> to try to improve on that. >>> >>> I rescued a "dual band" antenna kit (AllTel) for a cell phone. >>> But, I suspect these operate on a different frequency than >>> my "cordless" (902-928MHz)? (sorry, I know *nothing* about >>> cell phones -- thankfully! :> ) >> > No. Antenna will be located in almost the exact center of the > area to be covered. I.e., "walking around the neighborhood" > (my "walk" is just about 2 miles total -- the furthest point > being about 0.55 mi from the "base"). > >> You can design an antenna that will give you a pattern like a fig. of >> an heart, a figure of eight or a very directional antenna. The >> directionality will depend on the number of elements. >> Ideally you build 2 antennae of the same type and use one for one unit >> and the other for the other unit. > > The "remote" is a handheld device. Impractical to change the > antenna on it. > > > > 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 :<) > > This is similar to what the manufacturer suggests for > an external antenna: > > http://www.sn900.com/graphic/extant20.jpg > > Any pointers appreciated! (RF is BFM!) > Don, Move the base unit to as high a position as possible, maybe into your attic if you have one. Tom
From: D Yuniskis on 17 May 2010 14:25
Hi TOm, tm wrote: > "D Yuniskis" <not.going.to.be(a)seen.com> wrote in message >>>> I've toyed with the idea of adding an external antenna to >>>> the base unit (which currently just sits on a countertop) >>>> to try to improve on that. >>>> >>>> I rescued a "dual band" antenna kit (AllTel) for a cell phone. >>>> But, I suspect these operate on a different frequency than >>>> my "cordless" (902-928MHz)? (sorry, I know *nothing* about >>>> cell phones -- thankfully! :> ) >> No. Antenna will be located in almost the exact center of the >> area to be covered. I.e., "walking around the neighborhood" >> (my "walk" is just about 2 miles total -- the furthest point >> being about 0.55 mi from the "base"). >> >>> You can design an antenna that will give you a pattern like a fig. of >>> an heart, a figure of eight or a very directional antenna. The >>> directionality will depend on the number of elements. >>> Ideally you build 2 antennae of the same type and use one for one unit >>> and the other for the other unit. >> The "remote" is a handheld device. Impractical to change the >> antenna on it. >> >> 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 :<) >> >> This is similar to what the manufacturer suggests for >> an external antenna: >> http://www.sn900.com/graphic/extant20.jpg > > Move the base unit to as high a position as possible, maybe into your attic > if you have one. No attics here. :-/ I was hoping to run *an* antenna (on a length of coax) from the base up to a "high(er) spot". Nervous about the roof due to lightning, etc. |