Recently this NanoVNA product popped up on my radar<\/a>, and like normal, I was a bit behind the group in discovering it. It is relatively newly available, but seems to be rapidly becoming known because it is both inexpensive and very functional. What a wonderful and useful project. There is a group devoted to the project.<\/a> There is also a secondary product fork recently begun.<\/a> The second fork will have a larger screen. Software will not be compatible between the two. (update….maybe more than one fork, rapidly changing).<\/p>\n\n\n\n The NanoVNA itself appears to well suited to the home hobbiest, both in price and utility. As an open source hardware design, being produced by various vendors, it is not coming out yet as a mil-spec “ruggedized” product. It is also not $50,000 USD. Also, caveat emptor. The calibration dummy load supplied with the units I obtained measured an intermittent 50K ohms instead of 50 ohms. A second unit supplied a load that measured 43ohms. [I used a known 50 ohm load for the calibrations.]<\/p>\n\n\n\n Dummy loads aside, it appears I wound up with a cheap copy of the cheap copy of the open source hardware. Yet both units appear to function, at least well enough for the 30Mhz of spectrum of interest here at W4KAZ. All images below were captured on a Samsung Galaxy S7, rather than spend a lot of time dorking around with rapidly developing beta software. Truth is – I was in too much a hurry to tinker to take the time for the software, which seems to be FB. Good enough is often “best”. Engineer the Possible. Plenty of time for software later.<\/p>\n\n\n\n RTL-SDR:<\/strong>\u00c2\u00a0 The RTL-SDR 2.6Mhz high pass broadcast band filter.\u00c2\u00a0\u00c2\u00a0 This filter is quite good.\u00c2\u00a0 Its only drawback is that the cut off is above the 160m band.\u00c2\u00a0 This helped a lot in testing to find RFI problems, but I needed a filter that allowed 160m.\u00c2\u00a0 If 160m is not required this is an inexpensive rx only solution.\u00c2\u00a0\u00c2\u00a0 AE5X also has posted a quickie scan of this filter recently<\/a>. My own scans…<\/p>\n\n\t\tFilters Tested<\/h2>\n