# The BIG and SMALL ANTENNA topic part 1 **URL:** \ **Category:** Hardware\ **Created:** [June 13, 2017, 8:36am UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880 "2017-06-13T08:36:43Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![BoRRoZ](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/borroz/32/44234_2.png) [@BoRRoZ](https://www.thethingsnetwork.org/forum/u/BoRRoZ)\ **Post date:** [June 13, 2017, 8:36am UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/1 "2017-06-13T08:36:43Z")
![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/4/4edc77f866dd22237a906708d460243c1cbca496.jpg) **everything you always wanted to know or ask about :** different types of antennas diy antennas cable influence (loss / cable types / quality ) best location to place them (indoor or outdoors and where) lightning protection measurement equipment lots of pictures of your setups \* welcome in The BIG ANTENNA topic part 1 šŸ•¶ ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/c/c039efee1e7511d6a40c32aab255963ca136985f.jpg) ---
**Author:** ![Nordrunner](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/nordrunner/32/31038_2.png) [@Nordrunner](https://www.thethingsnetwork.org/forum/u/Nordrunner)\ **Post date:** [June 13, 2017, 11:02am UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/2 "2017-06-13T11:02:06Z")
Hello šŸ™‚ Very good Topic! Have a nice day Jens ---
**Author:** ![GryKyo](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/grykyo/32/47887_2.png) [@GryKyo](https://www.thethingsnetwork.org/forum/u/GryKyo)\ **Post date:** [June 13, 2017, 1:04pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/3 "2017-06-13T13:04:13Z")
Hello Good timing BoRRoZ and a first post from me, I have plenty of newbie questions rattling around in my head. So I have a metal pole above the roof line of my house, about 10m over ground level. I live on the east coast of Ireland and would like to do some learning and testing with some nodes and a ā€œstandard specificationā€ multi channel gateway. Currently I plan to put the following sort of equipment together. **Mounted on the pole:** [Commercially available 10dBi antenna](https://www.aliexpress.com/item/868MHz-antenna-omni-fiberglass-antenna-10dBi-868MHz-outdoor-roof-glide-monitor-repeater-UHF-antenna-RFID-reader/32694420721.html) [1metre N to SMA cable](https://www.aliexpress.com/item/Sale-100cm-RG58-Cable-N-Male-Plug-To-SMA-Male-Plug-Straight-Crimp-Pigtail-3ft-High/32594138389.html) to a IP rated enclosure mounted on the pole. [IMST iC880A](http://webshop.imst.de/ic880a-spi-lorawan-concentrator-868mhz.html) inside the above enclosure [Interface board like this one](https://github.com/ch2i/iC880A-Raspberry-PI) by Hallard Raspberry Pi Zero with[usb to Ethernet adaptor](https://www.aliexpress.com/item/2016-NEW-USB-2-0-to-RJ45-Micro-Lan-Network-Ethernet-Adapter-Card-100Mbps-Asix-AX8872B/32717460559.html?ws_ab_test=searchweb0_0,searchweb201602_3_10152_10065_10151_10068_10171_10084_10083_10080_10082_10081_10110_10136_10137_519_10111_10060_10112_10113_10155_10062_10114_437_10154_10056_10055_10054_10182_10059_303_100031_10099_10078_10079_10103_10073_10102_10096_5030019_10123_10189_10052_10053_10142_10107_142_10050_10051,searchweb201603_13,ppcSwitch_5&btsid=314dcb53-18d4-4681-9e32-fcdecaec24ba&algo_expid=0bd98c37-edaa-473c-814e-dc999d6660ee-0&algo_pvid=0bd98c37-edaa-473c-814e-dc999d6660ee) I have power and space in the attic area of the house and a network switch already there also. I plan to inject POE via a network cable approx 10m to the concentrator using a DC-DC buck converter on the interface board for power inside the IP rated box on the pole etc. **My questions would be** - Do we have any similar gateway specs in service? - Do we have experience with these cheap Chinese 868MHz antennas (quality/performance etc.) - Can somebody advise regarding the cable/pigtail between the antenna-concentrator for performance? - Do we have expertise regarding grounding of the antenna/pole which is not currently protected. I am happy to get involved in discussion so welcome any feedback positive or negative on these parts and compatibility. Thanks in advance. Garry ---
**Author:** ![Epyon](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/epyon/32/8479_2.png) [@Epyon](https://www.thethingsnetwork.org/forum/u/Epyon)\ **Post date:** [June 13, 2017, 8:46pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/4 "2017-06-13T20:46:26Z")
I have tested several China Export antennaā€™s, including the exact one that you are using. While it isnā€™t exactly 10dBi gain, it still performs quite well and is my antenna of choice for my next project. The rest of my setup is pretty much the same as yours. You will need a u.fl-to-N pigtail, not a SMA-to-N. I bought [this one](https://www.aliexpress.com/item/RF-IPX-u-fl-Switch-N-type-male-jumper-cable-15cm-6inch-For-PCI-Wifi-Card/32266853539.html). My coax cable was from a A-brand, but even a lower quality brand shouldnā€™t matter that much if itā€™s only 1 metre. My iC880A is mounted in a IP65 enclosure with the RasPi and connected with jumper wires. For your setup I wouldnā€™t worry too much about lightning protection. You can only do it decent or donā€™t do it at all. Doing it decent involves running a dedicated 35mmĀ² copper wire up to the antenna from grounding rods youā€™ve put in to the ground. Because itā€™s on top of your house, youā€™ll probably be alright. ---
**Author:** ![GryKyo](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/grykyo/32/47887_2.png) [@GryKyo](https://www.thethingsnetwork.org/forum/u/GryKyo)\ **Post date:** [June 13, 2017, 10:00pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/5 "2017-06-13T22:00:34Z")
Very reassuring, thanks. ---
**Author:** ![nickleijenhorst](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/n/53a042/32.png) [@nickleijenhorst](https://www.thethingsnetwork.org/forum/u/nickleijenhorst)\ **Post date:** [June 15, 2017, 7:50am UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/6 "2017-06-15T07:50:49Z")
I have tested between 10 to 20 Chinese 868 MHz / 915 MHz antennas, and my findings are that they are mostly crap. It also completely depends on what youā€™re going to mount it on. Most antennas in China are measured on an old benchtop VNA, and they check the return-loss to see if it works or not. However, they usually screw the antenna directly on the VNA, so the ground area around the antenna is completely different than mounting the antenna on a PCB for example. If you want to get antennas from China, I would advise you to buy 5 different antennas from different manufacturers, and checking the RSSI on the gateway (if you donā€™t have access to a VNA). Connecting the antenna through a U.FL to SMA pigtail usually makes the return-loss even worse, so for those situations a dipole antenna would be more suitable, but those generally cost more. ---
**Author:** ![BoRRoZ](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/borroz/32/44234_2.png) [@BoRRoZ](https://www.thethingsnetwork.org/forum/u/BoRRoZ)\ **Post date:** [June 15, 2017, 10:09am UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/7 "2017-06-15T10:09:25Z")
> [@nickleijenhorst](#): > > I have tested between 10 to 20 Chinese 868 MHz / 915 MHz antennas which do you recommend ? - stupid questionā€¦ off course the ones you sell in the[webshop](https://shop.sodaq.com/en/antennas/) šŸ˜‰ did you ever tested this type of outdoor node antenna ? [http://www.ebay.com/itm/868MHz-communication-antenna-RG58-50cm-inner-hole-waterproof-IP67-RP-SMA-male-/263022485657](http://www.ebay.com/itm/868MHz-communication-antenna-RG58-50cm-inner-hole-waterproof-IP67-RP-SMA-male-/263022485657) ---
**Author:** ![Epyon](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/epyon/32/8479_2.png) [@Epyon](https://www.thethingsnetwork.org/forum/u/Epyon)\ **Post date:** [June 15, 2017, 12:20pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/8 "2017-06-15T12:20:56Z")
By far the best antenna Iā€™ve used (and probably the ā€˜general bestā€™ 868MHz antenna available) is the [Procom CXL 900-3LW-NB/868MHz](http://procom.dk/products/531-cxl-900-3lw-nb868-mhz), but at ā‚¬165 itā€™s not particular realistic for the average tinkerer. ---
**Author:** ![nickleijenhorst](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/n/53a042/32.png) [@nickleijenhorst](https://www.thethingsnetwork.org/forum/u/nickleijenhorst)\ **Post date:** [June 15, 2017, 12:31pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/9 "2017-06-15T12:31:14Z")
Unfortunately Iā€™ve never tested those kind of outdoor antennas, usually we try to get the most performance out of small and cheap antennas! I am a big fan of the molex antennas, but you need to mount them to plastic in order to tune them properly. Iā€™m still in the process of finding good ā€˜whipā€™ antennas that have a SMA connector! ---
**Author:** ![BoRRoZ](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/borroz/32/44234_2.png) [@BoRRoZ](https://www.thethingsnetwork.org/forum/u/BoRRoZ)\ **Post date:** [June 15, 2017, 2:35pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/10 "2017-06-15T14:35:39Z")
> [@nickleijenhorst](#): > > finding good ā€˜whipā€™ antennas that have a SMA ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/f/fe87463993787558a7c90bbecf8350549865913e.jpg) yes Iā€™ve bought also several different ā€˜chinaā€™ types šŸ˜‡ ---
**Author:** ![dbrgn](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/dbrgn/32/25844_2.png) [@dbrgn](https://www.thethingsnetwork.org/forum/u/dbrgn)\ **Post date:** [June 17, 2017, 12:25pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/11 "2017-06-17T12:25:09Z")
We did an 868 MHz antenna test recently: [https://www.coredump.ch/2017/04/13/lorawan-868mhz-antenna-test-part-1/](https://www.coredump.ch/2017/04/13/lorawan-868mhz-antenna-test-part-1/) [https://www.coredump.ch/2017/04/30/lorawan-868mhz-antenna-test-part-2/](https://www.coredump.ch/2017/04/30/lorawan-868mhz-antenna-test-part-2/) Interesting how far some antennas diverge from their specification. * * * I have a question related to dipole antennas: A single element dipole cannot have more than 2.15 dBi gain, correct? So all those dipole 5dBi gain whip antennas available on Ali Express are by definition impossible to have that much gain, correct? ---
**Author:** ![BoRRoZ](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/borroz/32/44234_2.png) [@BoRRoZ](https://www.thethingsnetwork.org/forum/u/BoRRoZ)\ **Post date:** [June 17, 2017, 2:04pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/12 "2017-06-17T14:04:02Z")
> [@dbrgn](#): > > So all those dipole 5dBi gain whip antennas available on Ali Express like this one, less then one euro in quantities and shipped with all kind of lora products > **[This product is no longer available.](https://www.alibaba.com/product-detail/Factory-price-omnidrectional-868-mhz-5db_60524987398.html)** > > This product is no longer available. ---
**Author:** ![Epyon](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/epyon/32/8479_2.png) [@Epyon](https://www.thethingsnetwork.org/forum/u/Epyon)\ **Post date:** [June 17, 2017, 2:12pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/13 "2017-06-17T14:12:23Z")
Whip antennas are by definition monopoles, but when placed on a conducting surface act (somewhat) like dipoles. Some whips have grounding radials in the base of the antenna, but that does not make it a real dipole though. Most whip antennas increase gain by adding resonators or loading coils, but I would take those gain figures with a big grain of salt. ---
**Author:** ![PA1RB](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/pa1rb/32/7509_2.png) [@PA1RB](https://www.thethingsnetwork.org/forum/u/PA1RB)\ **Post date:** [June 18, 2017, 12:45pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/14 "2017-06-18T12:45:05Z")
![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/2/28714781ad23da7b7b5dad761db22cc9c7a00ecc.PNG) A new and very interesting outdoor antenna option: Sirio GP 868 C (dedicated for the European 868 ISM-band) is now available for ordering: [http://www.k-po.com/SIRIO-GP-868-C.2.html](http://www.k-po.com/SIRIO-GP-868-C.2.html) ---
**Author:** ![Gig](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/g/b782af/32.png) [@Gig](https://www.thethingsnetwork.org/forum/u/Gig)\ **Post date:** [July 10, 2017, 12:20pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/15 "2017-07-10T12:20:31Z")
Did someone do actual VSWR & gain test for those 868MHz fiberglass antennas on Aliexpress? > **[US $43.79 6% OFF|6.5dBi 868MHz omni fiberglass antenna Customized 806~960MHz N...](https://www.aliexpress.com/item/6-5dBi-868MHz-omni-fiberglass-antenna-Customized-806-960MHz-N-female-connector-high-quality-factory-outlet/32709193728.html)** > > Smarter Shopping, Better Living! Aliexpress.com > **[US $223.27 6% OFF|Lora 868MHz high gain 14dBi omni fiberglass antenna base...](https://www.aliexpress.com/item/868MHz-high-gain14dBi-omni-fiberglass-antenna-base-antenna-868MHz-outdoor-roof-monitor-antenna-free-shipping/32691472854.html)** > > Smarter Shopping, Better Living! Aliexpress.com > **[US $46.87 6% OFF|868MHz antenna omni fiberglass antenna 10dBi outdoor roof glide...](https://www.aliexpress.com/item/868MHz-antenna-omni-fiberglass-antenna-10dBi-868MHz-outdoor-roof-glide-monitor-repeater-UHF-antenna-RFID-reader/32694420721.html)** > > Smarter Shopping, Better Living! Aliexpress.com Iā€™ve seen that @GryKyo and @Epyon use similar antennas but I find the technical characteristics announced by the seller to be, ahem, extremely dubious. Still, even if you ā€˜onlyā€™ get 6dBi out of their 10dBi antenna, itā€™d be cheaper than the Procom. ---
**Author:** ![BoRRoZ](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/borroz/32/44234_2.png) [@BoRRoZ](https://www.thethingsnetwork.org/forum/u/BoRRoZ)\ **Post date:** [July 10, 2017, 12:40pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/16 "2017-07-10T12:40:17Z")
![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/7/798ad1ab36c5f8787360077c262509ac18aef09b.jpg) received [this](http://www.ebay.com/itm/868MHz-communication-antenna-RG58-50cm-inner-hole-waterproof-IP67-RP-SMA-male-/263022485657) one last friday ā€¦ no time to play yet šŸ•¶ ---
**Author:** ![Epyon](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/epyon/32/8479_2.png) [@Epyon](https://www.thethingsnetwork.org/forum/u/Epyon)\ **Post date:** [July 10, 2017, 1:55pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/17 "2017-07-10T13:55:24Z")
I did some quick testing of the popular Sunhans 13dBi antenna and the A&C 14dBi compared to a regular ground plane antenna (2.19 dBi) by analysing the RSSI of a fixed node around 500m LOS away. While both antennaā€™s functioned better than the ground plane, they certainly donā€™t reach the advertised gains. I would guess something between 3-6dBi at most. ---
**Author:** ![Gig](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/g/b782af/32.png) [@Gig](https://www.thethingsnetwork.org/forum/u/Gig)\ **Post date:** [July 10, 2017, 2:45pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/18 "2017-07-10T14:45:59Z")
While Iā€™m at it, I should add my contribution: A few months back, we bought cheap antennas on eBay, advertised as ā€œ7dBi 868MHz antennasā€. ![](https://www.thethingsnetwork.org/forum/uploads/default/original/2X/5/5262b7cb18dac48f3aebc537ed826747fcc56e77.jpg) They were dirt cheap, so while we knew the 7dBi figure was utter nonsense we decided see if they couldnā€™t replace our plastic indoor antennas. Well, no. We had them tested in a RF chamber at Orange Labs, and they expert opinion was that they were ā€œunusableā€. Something about a 15dB lossā€¦ ---
**Author:** ![denx](https://www.thethingsnetwork.org/forum/letter_avatar_proxy/v4/letter/d/977dab/32.png) [@denx](https://www.thethingsnetwork.org/forum/u/denx)\ **Post date:** [July 10, 2017, 3:21pm UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/19 "2017-07-10T15:21:40Z")
Hi, is anyone using this collinear coaxial antenne solution for lorawan? [http://jeroen.steeman.org/Antenna/collinear-coax](http://jeroen.steeman.org/Antenna/collinear-coax) [http://www.rason.org/Projects/collant/collant.htm](http://www.rason.org/Projects/collant/collant.htm) The solution seems very popular on 1090MHz ADS-B; ---
**Author:** ![RolfNoot1](https://www.thethingsnetwork.org/forum/user_avatar/www.thethingsnetwork.org/rolfnoot1/32/9332_2.png) [@RolfNoot1](https://www.thethingsnetwork.org/forum/u/RolfNoot1)\ **Post date:** [July 12, 2017, 11:28am UTC](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880/20 "2017-07-12T11:28:44Z")
Mostly, antenna gain is misunderstood. For example, if you have a mobile antenna youā€™d better off with a 0dBi antenna rather than a 10dBi antenna. The more gain the antenna has, the more energy will be bundled in one direction. Think of putting a reflector behind a light bulb. All the light hitting the reflector will be reflected, no light will go through. For a mobile antenna you donā€™t want ā€˜black spotsā€™. Effectively, you want your sensitivity/gain be the same in each direction (0dBi). This is called isotropic. Any misalignment in the pattern will yield gain in some direction. A dipole is not fully isotropic (radiating less in line of the dipole and radiating more perpendicular to the dipole), think of a radiation pattern like a squeezed ball. Stationary (gateway) antennas will have more likely gain in horizontal direction and less gain vertical direction. This can be achieved by stacking dipoles for example. An antenna can not output more energy than goes in. On the other hand, an antenna can ā€˜looseā€™ energy. When thereā€™s a mismatch in the antenna (system), part of the energy getā€™s reflected and will not reach itā€™s destination. This is measured in VSWR (or in S parameters). A VSWR of 1 is most ideal: no energy is reflected. [Next page](https://www.thethingsnetwork.org/forum/t/the-big-and-small-antenna-topic-part-1/7880.md?page=2)