[TowerTalk] More information about my problem; . Re: Heliax acting strangely: Help?

Jim Brown jim at audiosystemsgroup.com
Mon Oct 16 14:19:16 EDT 2017


On 10/16/2017 5:35 AM, Dave Sublette wrote:
> The Rig Expert AA-600 has TDR capabilities.  I don’t know about the other, lower frequency range models.

Most instrumentation that hams can afford take the inverse FFT of a 
swept measurement of the line for TDR. This a quite solid method, widely 
used in pro audio for at least 35 years. To get good resolution (that 
is, to see small things or get decent precision of WHERE the problem 
is), a very wide sweep is needed. 500 MHz is sort of a practical 
minimum. The VNWA 3e can sweep to 1.3 GHz, and produces excellent TDR 
results.

https://www.sdr-kits.net/index.php?route=web/pages&page_id=68_68

Four-five years ago, I paid about $700 with a calibration kit, shipping 
included. The exchange rate is a bit better now.

73, Jim K9YC




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