NanoVNA V2 Plus4 Review, 4GHz VNA

Review of the latest 4GHz, NanoVNA V2 Plus 4. The latest documentation and software may be found here: https://github.com/joeqsmith/NanoVNA_V2Plus If you have comments or suggestions on the documentation, feel free to leave them on the EEVBlog site at: https://www.eevblog.com/forum/rf-microwave/nanovna-custom-software/msg3304902/#msg3304902 Characterizing crystals https://www.eevblog.com/forum/rf-microwave/fun-with-crystal-filters/?PHPSESSID=lnr626eqefd2d4ah3el0jeiat2 Attenuators https://www.eevblog.com/forum/projects/20db-rf-attenuator-seeking-feedback-to-improve/msg2898698/#msg2898698 HCXQS Group's Tindie store https://www.tindie.com/products/hcxqsgroup/4-nanovna-v2-plus4/