DollaTek U.FL IPEX to SMA Connector Antenna 868-915MHz for Lora Board Lora32u4 II Wifi Lora32-5pcs

I was hoping for 868mhzz but all 915mhzWarm the cover a little to remove it if you want to change the very small coil inside

I bought these antennas for my Stratux ADS-B receiver; the device has two receivers at 1090MHz and 868MHz and I was hoping to shorten one of the antennas for 1090MHz.In reality the antennas appear to be tuned to around 980-990MHz, quite a lot higher than the promised frequency. I managed to stretch and trim one of the antennas for 1090MHz, and soldered a length of wire to another and then trimmed it to 868MHz. The plastic cover pulls off easily so adjusting the tuning is easy provided you have the instruments.The construction of the antennas is fine with a decent SMA connector. I think they will do the job.I haven't used the coaxial pigtails so cannot comment on their quality other than to note the cable is very thin indeed.

Not set up for 868MHz

These are nowhere near 868 tuned. The helical antenna measures in at c.10mm, so more 1090 suitable than for 915 which should measure at 12.5mm and for 868 at 13mm. Having removed the antenna cover (easy) and carefully extended the coil, I am still getting some very poor signal levels, overall a waste of money for my purposes (LoRa).The coax is suspiciously thin and of dubious quality. Not recommended and I wish I had read the other reviews before purchasing myself. I hope that this safes someone some money and time!

As the other reviews here suggest, these antennas are not tuned for 868-915MHz. In my pack of 5 there was no consistency, and the best SWR of them all at 868MHz was 6.8, with the worst just over 10.Verdict - useless.

The tune of these antennas is so bad that the reflected energy caused the accompanying circuitry in my device to malfunction! Properly tuned antenna is fine.