Products > Test Equipment
JunTek PSG9080 Programmable Signal Generator (80 MHz - 300 MSa/s - 14-bit)
TheDefpom:
I just finished recording the review and teardown for this (literally two minutes ago!)
The unit is pretty nice, it does have some output voltage linearity issues (it decreases as the frequency increases), but it doesn't really drop that much, you will be able to see that in the video when I publish it, as I show it and step through the frequencies to find out where its dips and peaks are.
I also really like the frequency fine tune in the menu which lets you adjust its output frequency to be more accurate, from factory it is at 50% adjustment, I adjusted mine to 58% to get it almost bang on frequency, unfortunately though this adjustment doesn't have an effect on the frequency counter input, that seems to be a seperate reference (or is not software tied to the fine tuning).
I will publish the video next week once I have had time to edit it etc.
radiolistener:
--- Quote from: TheDefpom on September 16, 2020, 09:26:00 am ---I also really like the frequency fine tune in the menu which lets you adjust its output frequency to be more m from factory it is at 50% adjustment, I adjusted mine to 58% to get it almost bang on frequency, unfortunately though this adjustment doesn't have an effect on the frequency counter input, that seems to be a seperate reference (or is not software tied to the fine tuning).
--- End quote ---
yes, I also notice that frequency fine tune doesn't affect frequency meter.
Here is actual frequency output on my unit for 50 MHz setting and different frequency fine tuning value:
- 49.999713 MHz for setting 49
- 49.999765 MHz for setting 50 (default)
- 49.999817 MHz for setting 51
- 49.999869 MHz for setting 52
- 49.999921 MHz for setting 53
- 49.999973 MHz for setting 54
- 50.000026 MHz for setting 55
- 50.000078 MHz for setting 56
About 52 Hz per unit. 52*50 = ±2600 Hz tune range.
I think it's too high for usual TCXO, it will be better to have about 5 Hz per unit.
TheDefpom:
The step size is dependant upon the output frequency, it is obviously a scaling factor/divisor rather than an offset adjustment, in my case it was only -12Hz off at 80MHz when set to 58.
radiolistener:
Some teardown.
Front panel:
STM32F103RCT6
Crystal 8 МГц
LCD 3.4"
Frontend:
Xilinx Spartan-6 XC6SLX9
FPGA clock oscillator - 50 MHz
Relay HUiKE HK23F-DC5V-SHG
usb-serial CH340
Other IC's marking is scratched.
It looks like it uses R-2R DAC.
radiolistener:
--- Quote from: TheDefpom on September 16, 2020, 10:04:15 am ---The step size is dependant upon the output frequency, it is obviously a scaling factor/divisor rather than an offset adjustment, in my case it was only -12Hz off at 80MHz when set to 58.
--- End quote ---
yes, I know, but it uses 50 MHz oscillator for FPGA clock.
So, when you set 50 MHz, the output will be exactly the same as FPGA oscillator frequency and you will see the real frequency error of hardware oscillator.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version