YILIANDUO Coaxial Lightning Surge Protector Lightning Arrester N Male to Female 50 Ohm DC 0-6GHz with 90V Gas Tube for Outdoor 4G LTE GPS Ham Antenna 868 MHz LoRaWAN Helium Miner Hotspot Antenna

Does what it says on the tin!

The media could not be loaded. I tested this device on my equipment, did few tests with both a DC power supply and also my wave generator running at 450MHz.Unfortunately, the test failed miserably as the foreign signal (lightning or any external nuisance) went straight in, when I looked inside I could see the core connection going straight through, this meant two things:1) The device offers no protection against any surge, lightning nor any high power surges.2) Connecting the Negative terminal to the ground would reduce the signal qualityEven if the capsule between the terminals *did* offer protection then still, any failures in that capsule would not be detected and the device would act as a disaster waiting to occur.I am scoring this a 2/5, as I don't think it works, the connections are good quality and the price is ok, but as a whole the device does not do the job I'm afraid.

This is, as described, a lightning surge arrester unit with N connectors and the equally important earthing connector with a screw and crimp terminal supplied . It's job is to prevent or limit damage to equipment but it has its limits and like any of this size/type will not help much with a major direct lightning strike on your antenna !It is nicely made and has the ability to (carefully) remove and test/replace the surge arrester device if it has worn out (as they tend to do after a long period in service). My unit contained a 8 mm dia x 6mm high cylindrical device ('2R-90' which likely indicates a 2 terminal 90V working level).In the real world all this would mean I'd choose it for quite sensitive and early suppression of surges etc while being capable of passing up to 25 or 30W of RF power through it.All the above lines up nicely with the sellers suggestion of using this for 4G LTE GPS Ham Antenna 868 MHz LoRaWAN Helium Miner etc. where these are going to be below that 25Watt level. This particular model is less suitable for High Power CB/ Ham antenna use as they can produce much higher voltages and VSWR which will then risk 'tripping' the protection device.Connecting the unit between a lab standard 50 ohm load and VNA the SWR was generally low up to 1GHz after which the usual peaks and troughs appeared. Nothing worse than the sellers specified 1.2:1 was seen so that's all good..In summary this should provide some useful additional protection against static / surges on an antenna feedline and is well suited to 'close protection' in lower powered systems