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Re: clock calibrator

 

Looking at an eBay photo, I see the fastest sweep speed is 0.01 mS/Div. If 10 MHz were visible, it would show 100 cycles of waveform across the screen, not useful for seeing the waveform drift across the screen when compared to the trigger freq.

It should work to divide both signals by 50 or 100 to see 1 or 2 cycles on the screen.

Might be easier to just feed both signals into a mixer and low pass filter and look at the very low frequency difference signal.

John

On 9/11/2022 3:45 PM, Jeff Green wrote:
I was given 2 10:1 probes and I used my Leo
Bordnar "Mini Precision GPS Reference Clock."
Output signal is a square wave at 3.3V CMOS levels with 50 Ohms characteristic impedance. Output drive level can be adjusted.
Output power level (measured at 10MHz, fundamental power channel):
+10.3dBm, drive setting 32mA
+9.9dBm, drive setting 24mA
+9.0dBm, drive setting 16mA
+6.4dBm, drive setting 8mA
10.3dBm at 50 ohms is a bit more then 0.71V. I might not be providing enough signal to get any display.
I'm trying to locate a schematic for the Hitachi to see if there are any obvious filters on the V and H input.
Considering this unit was designed primarily for a portable analog TV waveform monitor, so it's possible it is bandwidth limited.
The fact it is battery powered is nice.
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