I’ve been testing the device linked below and had really positive results. Claims up to 10 db TX increase and 11 db RX, both of which seem to be accurate based on my testing. It automatically switches between RX/TX and does actually improve reception, picking up some messages weaker than -150 dbm that could not be received with the same antenna attached directly to a Heltec node.
Most impressive is the TX range increase (to be expected I suppose going from about 20 dbm to 30 dbm.) It filled in a bunch of dead spots in my area. I also tested on the Helium network boosting a 20 dbm device. Packets sent through the same roof mounted antenna hit 25 hotspots with an average distance of 4.5 km and max distance of 8 km without the amp. With the amp it reached 59 hotspots at an average distance of 7.5 km and max 23 km.
It’s also extremely low power consumption… ~8 ma idle, 15 ma RX, 650 ma TX. Easy to run off a small power bank for an extended period of time in a portable application.
$60-70 seems a bit steep but I imagine prices will come down since there’s a ton of these on the market without much demand.