Mobile phone external antenna - Page 1
Forum section: electronics / rf-microwave

author: IanWalrus
author_rank: Newbie
timestamp: February 12, 2022, 07:48:10 pm
content: I've got a metal shed; it acts as a great faraday cage, in that I get no mobile signal or wifi inside whatsoever. But if I open the door (to the outside world) I get a 4G signal on my phone. I want to get a signal on my phone, but keep the door shut.I could get a cheap modem (I can mount outside) and feed a lan cable thru the wall, but this would mean buying a 2nd SIM - I'm a cheapskate and want to use my existing SIM, but that would mean having to take it out of my phone, which is not easy to do and I wouldn't want to do it regularly. It's not a SIM that can be (easily) cloned, and besides, that would break all sorts of rules/laws.So I've been looking for something like a car-kit with external antenna that would connect to my phone via USB C, but all google keeps showing me is results for is signal boosters (costing £££) or bluetooth car kits. I don't need a booster and I don't need a bluetooth car kit. I want a cheap way to get a signal thru the metal walls - I'm open to suggestions!

author: geggi1
author_rank: Frequent Contributor
timestamp: February 13, 2022, 07:30:47 am
content: Install a window

author: biastee
author_rank: Regular Contributor
timestamp: February 13, 2022, 07:36:13 am
content: "Antenna Passive Repeaters For Indoor Recovery of Microwave Cellular Signals"https://www.microwavejournal.com/articles/6899-antenna-passive-repeaters-for-indoor-recovery-of-microwave-cellular-signals

author: IanWalrus
author_rank: Newbie
timestamp: February 13, 2022, 01:45:11 pm
content: 'Passive Repeater' was the magic phrase I needed, thanks!

author: El Rubio
author_rank: Regular Contributor
timestamp: February 22, 2022, 06:53:03 pm
content: curious if you picked up a passive repeater and what was your experience with it.I have never been very impressed by those devices and as a matter of fact, have never actually seen one make any improvement. However, I haven't seen one since the early 90's. Someone in our area was selling these things.a cellphone booster amp is perfect for areas where you have cell service outside, but not so much inside. I'm not sure what the rules are in your country, but don't just buy the cheapest thing on Amazon. These devices are easy to start oscillating and cause interference. A good analogy would be when a singer's mic gets in front of the speakers at a concert and it squeals. Same pricipal if the two antennas are too close to each other. The cheap chinese crap boosters have poor shielding and can oscillate just because one antenna is close to the amplifier. In the US, decent boosters start around $300-400. Ideally, get something that covers all of the bands that your wireless carrier covers and has adjustable gain or attenuation switches . Never, ever get one with a rubber whip antenna ( like an old bag-phone) connected directly to the amp. Good luck with the passive repeater. Maybe you'll find one with just enough magic in it.

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 02, 2022, 11:51:08 pm
content: QuoteAn active is in almost all Country illegal. To get an Propper "active" you need contact the Cellphone Provider.

author: cdev
author_rank: Super Contributor
timestamp: March 03, 2022, 12:29:59 am
content: Someone shouldask their cellphone providerabout their eligibility to host a micro cell or whatever they call it. Legally, to fill in a black hole in their cell coverage, Its a win win situation. Suppose their business has a parking area or auditorium where cell phones dont work. Well, so thyey do work, the cell company can coe in and wire up a cell simply to extend coverage into the dark zone...That's their job after all. We pay them to cover us. Nobody is stealing anything.The "passive repeater" is just two antennas with some coax connecting the two. Its not a repeater, and since it does not involve any active electronics, cant be illegal. Its not connected to any phone electrically. Its just an RF pipe that extends the reach of the already existing signal into an area its having trouble getting into. Like a basement parking garage in a metal framed building that acts like a Faraday cage. A bigger parking garage might be entitled to its own microcell.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 03, 2022, 01:23:10 am
content: I had a problem similar to the OP, a metal roof combined with marginal coverage at my location almost totally eliminated indoor cell phone reception. Purchased an active repeater from a local brick and mortar store and it has generally solved the problem. Reception is still a bit shaky on the far end of an attached garage separated by three interior walls from the indoor antenna, but I can live with that. It has been several years since I purchased it, but as I recall the cost was a little over $100 US.I suspect that it is legal, the large chain running the stores is unlikely to be selling totally illegal stuff. One way this might be true would be if the ERP was less than 100 mW. Here in the US that lower power level makes it OK. And 100 mW is plenty to cover a reasonable size house.Doing a quick web search it seems prices have gone up dramatically. Part of that may be inclusion of 5G bands. The device I have is much simpler appearing than the ones shown in the web page below.https://www.bestbuy.com/site/searchpage.jsp?st=Cell+phone+signal+booster&_dyncharset=UTF-8&_dynSessConf=&id=pcat17071&type=page&sc=Global&cp=1&nrp=&sp=&qp=&list=n&af=true&iht=y&usc=All+Categories&ks=960&keys=keys

author: cdev
author_rank: Super Contributor
timestamp: March 03, 2022, 02:07:07 am
content: Of course they are legal, but the prices are just nuts..Remember what I said about them being responsible for their own network performance. Since we (end users) are paying for the cell service, we should be able to get a dial tone and clear reception, and transmission, period.Don't buy the service twice.. As you are already paying for it without buying all that expensive junk.The record for wifi range is over 200 miles.LinkCell phones are somewhat different, but line of sight limits the range, because of the curvature of the earth.If you are standing on the surface of a flat earth, your radio range is not very far at all. Maybe 5 miles.Most cell phones have some kind of external antenna hookup (usually beneath some small rubber plug) Depending on the phone, the addition of a real gain antenna can multiply range many times.. That is the best way to get cell phone coverage far away from the roads.. You may have to climb a bit to get up high enough but ones chances are fairly decent in most areas.. Some mountain you can see is likely to have a cell you can hit. You can in a pinch make a corner reflector.It could be worse.. Imagine you were in North Korea.. where making a long distance cell phone call is a capital offense. punishableby execution.

author: El Rubio
author_rank: Regular Contributor
timestamp: March 03, 2022, 01:21:37 pm
content: Cell phone boosters are legal in the US. However, interference caused by a poorly designed or poorly installed device is not legal. FCC rules state that if you are approached by a representative of any wireless carrier and told your booster is causing interference, you are required to shut it down until you can fix the interference. This can be a rep from any carrier, not just the one you have service with.Cost-wise, these devices have not gone up much over the last 5 years or so. They typically cover the most common frequency bands. Those are converted to 5G as customer base dictates. 3 G is pretty much gone already and some existing 3G channels are being converted to 5G. In some instances, 5G could be a problem for these bi-directional booster amps.Proper installation is very important and you generally get what you pay for. A $100 booster can be ‘made’ to work, but a $400 Weboost will usually work properly.

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 03, 2022, 02:06:16 pm
content: I would say in quite every Country outside of the US its illegal to use an Repeater.

author: cdev
author_rank: Super Contributor
timestamp: March 03, 2022, 02:14:13 pm
content: Quote from: Lord of nothing on March 03, 2022, 02:06:16 pmThe US now has pretty much 100% of cell phone equipment containing GPS and sending highly accurate GPS location and timing info. So as long as a repeater forwards that info, and is FCC type approved, they likely don't care if one is being used. A GPS chip and an ovenized crystal oscillator for the timing and location aspects may add significantly to price.

author: themadhippy
author_rank: Super Contributor
timestamp: March 03, 2022, 02:59:14 pm
content: QuoteIn my book having a venue were mobiles dont work is a win,lost count of the number of times a productions atmosphere has been ruined by some inconsiderate idiot not switching there phone to silent

author: CatalinaWOW
author_rank: Super Contributor
timestamp: March 03, 2022, 04:26:50 pm
content: While it would make sense for a service provider to fill holes in a coverage map where those holes encompass multiple homes or portions of roads, I can't imagine that they would have much interest in solving problems inside a single occupancy dwelling. Except possibly to sell additional equipment.

author: Halcyon
author_rank: Unknown
timestamp: March 04, 2022, 03:09:16 am
content: Quote from: Lord of nothing on March 02, 2022, 11:51:08 pmThat was the old way, not true anymore in many parts of the world.You can now buy off-the-shelf products which don't require a licence or "permission" to operate from the carriers. One of the main players isCel-Fi. They make all kinds of 3G/4G/5G repeater products for buildings and vehicles. They are carrier approved in Australia, US, Canada and parts of Europe. They even make multi-carrier models. But in respect to the OPs requirements, these products are not cheap.

author: Lord of nothing
author_rank: Super Contributor
timestamp: March 04, 2022, 07:41:48 am
content: QuoteI could not find a List.

author: cdev
author_rank: Super Contributor
timestamp: March 04, 2022, 02:00:19 pm
content: Quote from: El Rubio on February 22, 2022, 06:53:03 pmNobody sells any product called "passive repeater" ..Seems you two are confusing a "passive repeater"WHICH IS MERELY TWO ANTENNAS connected together,with some active electronic device, which needs regulatorytype acceptance. Security being a primary concern, anything that functions as a cell phone repeater is designed to, if it is legal,must interface in a responsible way to these needs..Those devices almost certainly are basically a small cell site. And as all of them need to pass the location information. Not just the location of the mini cell equipment the location of the caller as its received by the phone's own GPS chip.. When a cell phone operates it needs to send its GPS coordinates as it communicates. You can't use the cell phone system in the US without sending that information. Its for emergencies, and for your own safety. Its often accurate to just a centimeter or so and can be sent as often as 10 or 20 hz. Enough to interpolate your heartbeat.Also, Large areas people often find themselves in modern cities are often privately, not publicly owned.But their owners often want them to have cell service.

author: cdev
author_rank: Super Contributor
timestamp: March 04, 2022, 02:20:17 pm
content: Cell and/or GPS jamming are very illegal, at least they are here. Corporations pay for air waves and it wouldn't do for the local governments allowing the stealing of their property. (/sarcasm)Without airwaves, you can't view the ads that (juridicial) people pay for to present to you. Also your precise location information is necessary to determine what ads to show you. Thats valuable information, essential to advertisers. It becomes their property.Quote from: themadhippy on March 03, 2022, 02:59:14 pm

author: madires
author_rank: Super Contributor
timestamp: March 04, 2022, 02:43:11 pm
content: Picocell or WiFi-calling (VoWiFi), whatever your mobile operator supports. But you'll need internet access in your shed.

author: El Rubio
author_rank: Regular Contributor
timestamp: March 04, 2022, 11:53:06 pm
content: Quote from: cdev on March 04, 2022, 02:00:19 pmNo confusion, here is a typical cell phone passive repeater. Yes, it is basically two antennas end to end. This one has the disadvantage of also eing glass mounted:https://www.amazon.com/Strength-Booster-Antenna-Passive-Repeater/dp/B000KNNKVSActive repeaters are simple bi-directional amplifiers. They are not small cellsites, microcells, femtocells, or any other ‘smart’ connection device. They have no location or timing of their own. They just pass the mobile signal from the inside antenna through the amp to the outside antenna to be directed to hopefully a nearby cell site. Simultaneously, it receives the cellsite signal on the outside antenna and routes it through the amp to the inside antenna and hopefully to your cell phone. Hence the name “bi-directional”. Like any wireless device, they have to be FCC approved and have an FCC ID on the label. They also must include circuitry that can detect oscillation and fold power back to reduce the chance of causing interference. The owner is also required to register the device with their carrier- not many actually do.

author: El Rubio
author_rank: Regular Contributor
timestamp: March 05, 2022, 01:05:33 am
content: Quote from: cdev on March 04, 2022, 02:20:17 pmIn the US, jammers are illegal. In fact, only the Secret Service and Dept of Defense are allowed have them. I have found several in smaller prisons and jails mostly. These places are run by county sheriffs that think they can do whatever they want. Until they do a little digging and find out that the FCC can fine them. Several years ago, there was a Florida man…have you noticed that most all goofy stupid things people do are usually done by “a Florida man”? Sorry , I digress. The FL man had a jammer in car because he was tired of all the folks driving and paying attention to the road. He was fined $48k.A jammer in a movie theater may also block calls on the street out front and the restaurant next door. Many of those may be emergency calls. It has nothing to do with adverts.

author: tannersimmons78
author_rank: Newbie
timestamp: March 24, 2022, 07:16:34 pm
content: Yes, try a passive repeater!

author: Dehv
author_rank: Contributor
timestamp: March 30, 2022, 11:50:32 am
content: First you need to figure out what band of lte your phone is using, with an app such as "Network cell info lite".In Usa and Canada, Most likely in the bush it will be a 700mhz 4g band.You could get "booster/repeater kit".Cheaper doesn't matter if your band is supported (dont need multi band expensive units) and it has AGC ( auto gain control). All of the chinese cheapos under $60 i've used now have AGC to limit feedback.To avoid feedback with an active (powered) booster, my preference is to make the interior antenna the vertical plane; the exterior horizontal, ideally with shielding between the two (steel shed walls). Keep the two antennas as far apart as possible.Another option is just mate the interior and exterior antennas passively with a coupler fitting instead of the repeater unit, using as short a cable as possible.Keep in mind most generic LTE outdoor antennas are tuned for 850mhz to 2100 ish (in Canada on band 2, 4, 5, 7, AWS etc), so aren't tuned for 700. The 700 yagis are slightly wider usually with on 4 or so directors rather than the skinny longer ones for 850 to 2100 with 7 or 9 directors.The indoor nipple type ceiling mount are wider bandwidth so should be fine down to 700.Hope this helps.

author: cdev
author_rank: Super Contributor
timestamp: March 30, 2022, 12:27:08 pm
content: Another reason jammers are and should be illegal is people depend on cell phone service for burglar alarms.Luckily they tell you when they suspect jamming. Some GPS's do too.

author: Dehv
author_rank: Contributor
timestamp: March 30, 2022, 07:39:33 pm
content: I'm CANASA certified alarm installer. lte can be jammed, only flagging the lost connection depending on how often the module checks in. 5 minute, 30 seconds, whatever the installer set.unless there is a secondary reporting device...Home phone lines can be cut, battery in alarm box, voip interrupted by backbone vulnerability,An IP module would be best if thieves cannot access the buried fiber/DSL/ cable.I digress.THREAD CREEP, back to cell repeaters!