This purpose is NOT for 2m/440m. It's for 155-160 & 455-460 MHz I have a Diamond X50NA base station antenna, but there is a problem with the female N connector. I don't see a way to remove/replace the fitting. Visually it appears ok, but even after changing fittings on the feedline (N) contact is not good. RLB scans vary and it wasn't acceptable to me. I have to assume the center receptacle is not forward enough (ruling out the name N connectors) Anyway, I'm looking for a replacement and this combo seem to be the best choice (that I have found so far); https://baofengtech.com/product/nagoya-nmo-200c/ https://baofengtech.com/product/nagoya-gpk-01/ I did find this review; https://www.miklor.com/COM/Review_NMO200.php My question was, what I don't like is the (what I call) outdated use of a SO239 instead of a 'N' connector. I realize at VHF, it's not a big deal, UHF is another matter. I look around for other choices and I only found the Tram, a 4 element wimpy design (to say the least). The review did mention the ground plane being important. Between the mini Tram and the Nagoya, input of both?