[Elecraft] Keying Waveform Measurement

[Stephen W. Kercel]

Mark:

Yes, you're right; the 465 does have a 20 V/div max using 10:1 probes.

The lesson from you is essentially that when all else fails, read the 
instructions. According to my probe manual, the probes are actually good to 
500 V up to 10 MHz, then they derate to about 175 V at 30 MHz. They are 
much more than adequate for observing the output of a full-featured K2.

Yes, I remember "hot carrier" FETs and the lethally high voltages required 
to operate them.

73,

Steve
AA4AK


>Sheesh...these young uns!  200V P-P should be no problem for a 'scope.
>(If you look carefully, the probe is probably a 10:1 voltage divider.)
>To show 200V p-p as a full scale deflection (assuming 10 divisions
>vertically on the screen) would require 20v p-p per division. Just set
>the vertical scaling at 20v p-p/div. If you're using official Tek
>probes, you can ignore the 10:1 built into the probe because the scope
>will compensate for it automatically. If the thing doesn't have
>scalings up to 20v p-p you would need the high voltage probe set, but
>I don't remember using them for normal (non broadcast) transmitter
>service.
>
>Shouldn't be a problem -- after there are those of us who used this
>scope, (and its predecessors) to trouble shoot vacuum tube equipment.
>(Remember vacuum tubes? sometimes known as 'thermionic FETs'? They
>take high voltages!)