[time-nuts] Cable length calibration

[David]

The Tektronix 1502 uses a tunnel diode pulser to produce a 50
picosecond output step of about 200 millivolts.  There is a misprint
in the theory section of the service manual which says "400 V" instead
of "400mV".

On Thu, 30 Jun 2016 04:19:43 -0400, you wrote:

>If the nominal velocity of propagation is known and length is known delay is easily determined mathematically 
>
>Time Domain Reflectrometry is the usual technique for finding cable length but even there the cables NVP is an essential parameter if you want to compute length but not essential in time nuts application because we are interested in delay which a TDR reads directly When using a TDR its best if cable is unterminated as the discontinuity at the end is helpful as a marker.   Also most TDRs like the Tek 1502 can put 100v or more on the cable which will blow most GPS antennas