On Mon, Mar 21, 2022 at 11:04 PM, Jeff Dutky wrote:
...
Ch 1 (otherwise the scope seems to be in excellent working order). I am
testing the bandwidth using a Tek 067-0532-00 calibration fixture (constant
amplitude signal generator) for the range from 65 MHz and up, and a TinySA for
the range below 65 MHz. Channel 1 rolls off at about 7 MHz (yes, SEVEN, single
digits, not a typo) and then has a gradual decline in sine wave amplitude,
while channel 2 is essentially flat up to about 75 MHz than has a much steeper
decline up to 125 MHz where it then levels out to much more gradual decline.
Hi Jeff,
7MHz is pretty low so the signal degradation should be easily visible. Why not check for the waveforms at test points 6/7/8/9 before and after the preamp as shown in the schematic before swapping hybrids?
Ozan
