Comments on: A Tale of Two Meters http://kb6nu.com/a-tale-of-two-meters/ My personal adventures in amateur radio Thu, 20 Nov 2008 18:29:22 +0000 http://wordpress.org/?v=2.6.2 By: Bob K0NR http://kb6nu.com/a-tale-of-two-meters/#comment-366 Bob K0NR Sun, 29 Jan 2006 01:26:58 +0000 http://kb6nu.com/?p=756#comment-366 Dan, Another issue to consider is traceability of the measurement. Most of the ham-grade stuff doesn't address this at all. You see specs that are typical at best and calibration is totally ignored, which is probably OK for the hobbyist market. "Real" instruments have to demonstrate that their accuracy is traceable back to NIST (or similar standards authority). This gets into serious metrology, calibration and traceability issues that tend to drive up the cost of the product. Of course, this probably doesn't apply to the ham/hobbyist. Bob K0NR Dan,
Another issue to consider is traceability of the measurement. Most of the ham-grade stuff doesn’t address this at all. You see specs that are typical at best and calibration is totally ignored, which is probably OK for the hobbyist market.

“Real” instruments have to demonstrate that their accuracy is traceable back to NIST (or similar standards authority). This gets into serious metrology, calibration and traceability issues that tend to drive up the cost of the product. Of course, this probably doesn’t apply to the ham/hobbyist.

Bob K0NR

]]> By: Dan KB6NU http://kb6nu.com/a-tale-of-two-meters/#comment-337 Dan KB6NU Fri, 27 Jan 2006 16:43:14 +0000 http://kb6nu.com/?p=756#comment-337 Here's a comment from Vic K2VCO on measuring inductance: Remember, the measured inductance of a toroid depends on the frequency at which it's measured because of the characteristics of the toroid material. I don't know the frequency used by the AADE unit, but if it's far from the operating frequency of a particular toroid, the results might be misleading. If you must measure the inductance of a toroid, it would be better to use something like an antenna analyzer which will allow you to select the frequency at which the measurement is made. Here’s a comment from Vic K2VCO on measuring inductance:

Remember, the measured inductance of a toroid depends on the frequency at which it’s measured because of the characteristics of the toroid material. I don’t know the frequency used by the AADE unit, but if it’s far from the operating frequency of a particular toroid, the results might be misleading.

If you must measure the inductance of a toroid, it would be better to use something like an antenna analyzer which will allow you to select the frequency at which the measurement is made.

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