I’ve come across some nice vids and links regarding the use of RTL-SDR and/or AirSpy to perform antenna analysis for those of use who don’t have access to Vector analysers and VSWR meters that cover ISM bands.
now I have win 10 back on the old laptop I can reinstall the RF explorer software (they don’t have it for linux) and do some basic little antenna tests
yes, I have 2 couplers … both from eBay one new and one used
the little one is to 1 Ghz, the bigger one 800-2000 Mhz
both work well for my purpose … mini circuits are quality
I’m going to ask my question here as it seems fitting… Obvious eBay rip-off aside, on a few “respected” websites (that’s e.g. Conrad, Reichelt, Voelkner in Germany), I found 4 dB omnidirectional antennas advertised at a fraction of the price of the 0 db antennas also available from these vendors. Is this always a “it depends” and “you have to try it out”, or are there general rules of thumb which specs to expect in a certain price range?
I’m especially curious as this Conrad-brand 4 db antenna comes with plenty of cable and a SMA connector, while for the Aurel GP868 I’m thinking about I’d need extension cabling and adapters, likely adding to further signal loss.
The conrad comes with 5m RG174 attached - not good That will cost you around >4-4.5db of loss - offsetting the 4dbi gain (if that is reliable). for anything more that a couple of meters avoid RG158, RG174 & their ilk as losses too high - look to ultra low loss cables instead.
I have both and I agree with Jeff-UK… I prefer the Aurel GP 868, is build for outdoor use and comes with a reasonable cable (I use it indoors with supplied cable) overall quality is good.
The only disadvantage is, on the supplied cable , the BNC connector on the GW side, the side that goes into the GP is not visible but is an 'F connector :
So to connect this GP to your gateway you’ll need a adapter plug BNC-SMA
Yep, that would be my setup, too. Unfortunately, I may have to get an extension as the 2.5m cable is quite short… …and flat/ribbon cable for the window if I should move the antenna outside.
it’s not a bad idea… the same thing was discussed before with nodes and gateways , creating lists and keeping them up to date is a job… so… be my guest, start that antenna list, find those shops and prices, test those antenna’s
For baseantennas we need a type that can recieve the signal in any position. Not only in one, most vertical.
Mobile nodes are sending in many positions. Vertical, horizontal, diagonal and so on.
Looking for an areal without any fullgw in reaching. Positioning the GWs in an triangle and the node in center. Connect the SCGW`s ( based on WeMos D1 mini and @Charles beakoutboard for this) to Smartfones and TTN-Mapper for testing.
@Nordrunner
Hey this is really awesome
Would you mind sharing the SCGW source code (the one with OLED working) so I can add it to github or just give a link if the code already on github so I can add it to the repo PCB repo?
Thanks, excited to see your test