Hi Evan,
An update on the investigation:
1) Radiuno tests:
I was able to buy a used Tektronix 2465 oscilloscope over the weekend for a very good
price and could get started with proposed Raduino clock generator test:
Observations:
- All 3 signals are being generated with the expected frequencies,
- CLK#2 and CLK#1 signals are sawtooth shaped,
- CLK#0 looks very different (pls. see the picture on Google photos),
- Frequency range for signals seem to be ok: CLK#2 varies with when I change
bands or tune within a band, CLK#1 varies based on the 'mode' selection (USB or LSB).
CLK#0:
CLK#1: https://photos.app.goo.gl/1GcupVPLvr7UqjyB8
CLK#2: https://photos.app.goo.gl/tzNNQJNFtaNXQTUs9
Note: The reason CLK#0 looks so different could be related to my home made 1:1
probe (I expect regular 100Mhz probes to arrive in the next few days). Based on the
screenshots for some of the measurements, it seems the home made probe work better
with higher frequencies.
Conclusion:
Raduino seems to work.
2) Audio amplifier tests:
I repeated the 'inject an audio signal' test: I connected the audio signal to VOL_H (instead of
VOL_M) this time and GND.
Observation:
The signal was perfectly audible, volume could be controlled via the potentiometer.
Conclusion:
Audio amplifier seems to work.
3) Q74 test:
Resistence measurements of this MOSFET need to wait until I get the 100Mhz probes with a finer tip -
the measurement points are tiny.
Thank you for your support,
-jens
PS: It would be great to have 'reference' oscilloscope screen shots for all of the measurement points
of the uBitx v5.
