It is a little bit of pity that you did not mount the antenna’s in free air. Lying on the floor/table definitly influences the VSWR and frequency-response.
true and I did hold it on the cable when measuring, and put it on the (concrete/iron!) floor LATER and took the picture
It looks good, so I ordered one.
Hi all! I am building a Pi-based RAK2245 gateway and I already have 1090Mhz 26 inch 5.5dBi ADS-B antenna mounted on the roof, which I would like to re-purpose and use it for this gateway; at least temporarily. I know it’s not ideal for the US-based 915Mhz, but will it work decently for now, or should I just bite the bullet and buy a new one?
byte the bullet imho and buy a tuned antenna for 915…
If the off frequency antenna is a poor match at a frequency it was not designed for, there is the possibility you could damage the gateway.
Do you feel lucky ?
Has anyone been able to conduct antenna gain tests on the RF Solutions 3dB SMA antenna?
We’ve used many of these with good success, but I’m doubtful of the 3dB claim, since that’s a hard value to manufacture to, especially at the price point.
What I can’t find in the specs is the SWR of this (possibly china made) antenna… did you measure that ?
Haven’t been able to thus far. You’re correct, the specs are minimal. I have the original RoHS certificate but that obviously contains no info about antenna params.
I can’t name the brand/source, last couple of years I ‘collected’ many of these.
But I can tell you that the ones with a length of 210 mm gave me the best results
So that’s probably the one you use
Yes, mine measure ~210mm too. I believe they all come from the same factory anyway! They’re great antennas, but I doubt the 3dB gain quoted is true. We’re actually running some tests at the moment and trying to squeeze as much out of the unit as possible, but have to assume antenna gain in our tests as we don’t have the equipment to test it inhouse. Something around 2.2dB would actually be ideal!
I had also one that was likely a 2.4GHz antenna sold as 868, indistinguishable from outside. The I found a couple of sources for the right ones.
In my informal trials, however, they do not seem better than a GPA.
Build your own test equipment, its easy;
The new RAK 6dBi antenna.
I have just received one of the new RAK 6dBi (800mm long) colinear antennas. Will be range testing later this week and will publish the results. So far the S11 results (VSWR) look good particularly as the one antenna will work on both 868MHz and 915MHz. Tuned just right for both bands.
The real test is transmitting from a node set up a few kilometres from my gateway into an application which runs a logger.
does it look like this one … only one dollar per dBi
Just completed a small project on agriculture metering. with 10dbi antenna on the gateway side. 3dbi external antenna on some nodes and some nodes with PCB antenna. here are some pics.
getting around 6km in PCB antenna(not tuned properly) and 9km in 3dbi external antenna.
RAK831 gateway fully powered by Solar and 5-day battery backup. (Off-Grid).
Yes @BoRRoZ it looks the same in that its white, long and slender
When I look at the RF performance details there are differences which tell me its a different antenna. It makes it hard when I follow your link the images are for a 470-510MHz antenna and the specified connectors are different.
that’s only the sticker … I think
anyway… I don’t have 100 gateways
*in a related search I found this Italian shop with LoRaWAN products
Are you reading data off the meters with this or taking your own measurements?