Hi Gil,
I followed your advice and soldered the 47-resistor to a short coax (before I connected it with two alligators), and the graphic is smoother now as you can see but still not the horizontal line like in theory. Just for fun I let the MR100 sweep over the whole range with open input (nothing connected).

The CB-antenna was mounted on my car where it used to work quite well (I never measured SWR there). Unfortunatly the car is a Berlingo with plastic roof, so I put two stranded wires on both sides downwards to ground it with the metal chassis. Maybe not the best solution. I just measured the values without the computer, but I will repeat it with laptop and software.

It's very interesting to play around with that nice little gear and wonder how to interprete the results it shows. If the results are real and not artefacts we can learn a lot about our antennas and I would like to discuss the experiences with anyone who checked anything that may work as an antenna.

73 to all who want to understand how it works.

Hello Gil,

thank you for your quick response. I don't refer on calibration itself since I had the strange result with the Dummy before calibrating, too. Meanwhile I checked a mobile CB-antenna (the only one nearby because I'm not at home), a Sirio HI-Power 4000 N, which should have an VSWR < 1.2:1, but MR100 measures more than 3:1 and ~70 ohms on the CB-Band. Same with a short whip from ALAN 95plus, it shows ~150 ohms while the manual sais, it should have 50.
I suspect the new MR100 is damaged. But how could I check it if it were so?
Has anyone measured a small resistor over the whole frequency-range?

After watching Gil's videos about the MR100 I bought one, calibrated it and started the WIN-PCC-Sark100-Software. Everything works fine, but when I scan my 50-Ohm-Dummy (homebrew bundle of 1/8W resistors in oil) from 1-52 MHz it shows a strange picture: from 1-4.6 MHz it's SWR 1:1, Z=R=50 Ohm, as it should be. From 4.6 MHZ until 52 the SWR increases in a zig-zag-curve up to 1:5.5, Z remains at 50 Ohms and R goes down to 12 Ohms. Very puzzeling.

Then I scanned a small 47-Ohm-resitor, and the reading are weird ups and downs in SWR, R and Z all over the frequency range. Shouldn't it stay in a line? How can I trust the MR100 when checking my antennas? What is your experience if you own the MR100 or the SARK100?
Please help!

73     Henry

P.S.: Can I post the graphics here (bmp)?