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I was curious about what was involved with calibrating the MFJ259 - so I did some searching and found this webpage:
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It appears to be quite involved job to re-calibrate the MFJ device compared to the nanovna calibration, but of course as Frank has essentially stated - you need to know how to use your tools. In any case - there is quite a bit of info on the page, if any MFJ-259 owners are interested. ...Larry On Thursday, September 10, 2020, 2:15:34 p.m. EDT, Frank Howell <frankmhowell@...> wrote:
Hi Dave, Did you calibrate your 259 and did you buy it new? I can tell you from many customer service calls to MFJ that many complaints arrive from customers who purchased the 259/269 units used. The buyer never RTM, never cal'd the A-A. MFJ sells cal kits for them and discusses that need in the manual. Now, from my experience on my workbench, most test equipment errs more on the extremes, whether it's voltage, capacitance, resistance or RF. I have no clue why how how your got the "20%" error measurements. What were you comparing the MFJ 259's readings to? On your statement, "And MFJ misleads on being capable of reading the complex portion of the impedance.? Most don't.? Only a few at the high end of their pricing do, with bad tolerance.? Not so with the NANOVNA's!", how does the MFJ reading mislead in ways that Martin himself has not told users how to add the sign of the j to the 259/269's readings? e.g., see . High end of whose pricing? MFJ's on the 259? Not sure what you're saying here. Please explain. The NanoVNA is an incredible price point. It is not an "antenna analyzer" in the way that most hams approach such a device. There are many other brands of A-As but MFJ established the market for such a device. I have several others besides the MFJ 269 (and the 259b before it). But the 269 is a small RF lab in a box. The NanoVNA, even with the A-A firmware, is much more challenging to use in the field as many other posters here have stated. The intended use case often drives what is satisfactory. The NanoVNA has stupified many purchasers who jumped at the price tag and the buzz about it when what they wanted was a "cheap" (single port) A-A. I'm not posting this to argue nor was I when I called out 1of11's "MFJ must be peed-off" statement which I know directly to be false (love or not, 1of11). I'm posting this to articulate that there is a context in which we all evaluate gear. You have yours regarding yoru new or used 259. MFJ can't keep up production to fill orders for their A-As and have the next-gen on the design board. Their market for antenna analyzers is reasonably secure as they've diversified their product line in this niche. I have 5 versions of the NanoVNA besides my 269. I'll calibrate it from time to time but it will be in my field gear bag for some time to come. 73, Frank K4FMH |
