[Amps] Dummy load varying R

[Ian White GM3SEK]

Roger (sub1) wrote:
>> That is making the assumption stretch that the measuring instrument is
>> correct. As I said earlier the 259 has problems with the digital display
>> readout section and we havent heard back yet what the analog VSWR meter on
>> it reads.
>
>Last I knew and it has been long time, accurate, calibrated instruments 
>were expensive. Course it was cheaper to get them calibrated than to 
>purchase the equipment to do the calibration and then sent it in for 
>calibration.
>
>I do hear tell there are some pretty good ones becoming available at 
>reasonable prices, although they are a tad more than what MFJ sells.
>

This is about much more than a higher price point. It's about a new 
generation of amateur-priced vector impedance meters that are in a 
totally different league from the traditional MFJs and Auteks.

The key feature is the built-in error compensation. Before making a 
measurement, the instrument "requests and requires" that you step 
through a calibration procedure which involves connecting first an 
open-circuit, then a short-circuit and finally a 50R reference load. The 
instrument computes its own internal errors - and then removes them from 
your measurement results.

With these new-generation Vector Network Analysers, you are now playing 
alongside the professionals. The accuracy of your measurement is no 
longer limited by the instrument but by your own care, skill and 
understanding as a user. That is a challenge... but it's also an 
education.



-- 

73 from Ian GM3SEK
http://www.ifwtech.co.uk/g3sek