Products > Test Equipment
JunTek PSG9080 Programmable Signal Generator (80 MHz - 300 MSa/s - 14-bit)
Northerner:
Hi Ralf,
1. You need a Bluetooth module to plug into the TTL port. Seems to be bundled by some vendors but not Joy-IT or Juntek.
2. AFAIK Vpp is the only way
3. The firmware seems to be v1.2 so no newer than what you probably already have.
Neper:
--- Quote from: Northerner on March 26, 2021, 01:13:44 pm ---1. You need a Bluetooth module to plug into the TTL port. Seems to be bundled by some vendors but not Joy-IT or Juntek.
--- End quote ---
The TTL port? Any idea if this would be avaible from somewhere else? Where does your photo come from? The funny thing is that the iOS software comes from Juntek.
--- Quote ---2. AFAIK Vpp is the only way
--- End quote ---
How really stupid.
--- Quote ---3. The firmware seems to be v1.2 so no newer than what you probably already have.
--- End quote ---
I've sent them an email and they say they've corrected one bug and one spelling error. I'm suitably impressed.
Ralf
radiolistener:
--- Quote from: Neper on March 25, 2021, 10:20:25 pm ---2. Is there a way of setting the output voltage in other units than Vpp? I'd much rather use Veff or dB.
--- End quote ---
no, there is no way to change voltage units. Note, that PSG9080 shows Vpp for open output connector (with no load)!
When you connect some device with 50 Ω port (for example receiver or RF voltmeter with 50 Ω input), the actual Vpp voltage will be twice smaller than displayed on the PSG9080 display. Just divide displayed Vpp voltage by 2 and you will get actual Vpp voltage on the load. This is a bit annoying, but for some reason Chinese manufacturers don't want to use more common voltage units. For example, as I know FY6600 has the same issue.
For non 50 Ω load you will needs to recalculate actual voltage (the same as with any other signal generator).
--- Quote from: Neper on March 25, 2021, 10:20:25 pm ---3. JOY-IT have a firmware update for 'their' PSG9080 from March 10 on their website. Unfortunately no further info or version history. Just saying...
--- End quote ---
thanks for the link, it looks that they decided to rename brand name for some reason.
I don't recommend to use their software for PC. Because virustotal report it as dangerous.
And I don't see the reason for the PC software, because it's much better to control it from the front panel.
The only feature that needs PC software is to update firmware or upload arbitrary waveform. But if you decide to do it, it's better to use isolated PC with no internet. Do not share files from that PC with another computers for safety purposes.
I'm thinking about to write open source PC software to upload custom waveforms and firmware. But it needs protocol documentation and research. Unfortunately there is lack of information about protocol.
After some period of PSG9080 usage, I can report some found issues.
Firmware bugs (HW v1.20, FW v1.20, FPGA v1.20 - the latest FW at the moment):
1) Duty cycle don't works properly for the frequency 1'000'000 Hz and above. If you set 999'999 Hz or below that it works ok. But when you set frequency just 1 Hz above, the duty cycle setting is no more works as expected. This is obviously firmware bug, probably just some kind of mistyping in the source code or something like that. But be aware, with current FPGA firmware 1.20 you will be unable to setup duty cycle for the frequency 1 MHz and above. You can setup duty cycle for higher frequency on the display UI, but the actual signal output will be invalid. It stays close to 50% for any setting from 0 to 99.99%, but it is not exactly 50%, the actual duty cycle changes for about 2-5% instead of 0-100%.
2) FM modulation works incorrectly. When you connect FM receiver and test it, you will note a crackle sounds. There is some kind of overflow or incorrect signal processing mistake in the FPGA firmware 1.20. So you will be unable to use proper FM modulation with current firmware 1.20. For comparison AM and PM modulation don't have such issue.
Some pros and cons of PSG9080:
Pros:
- very nice front panel design and feel with convenient buttons and knob (it is based on STM32F103RCT6)
- large contrast LCD display
- FPGA module based on SPARTAN-6 XC6SLX9 which can be nice for custom hobby experiments, but there is a lack of documentation
- you can power PSG9080 from a uni-polar 5V source. For example I'm using 10 Ah USB power bank with 5V/2A output to get full galvanic isolation from mains (actual current consumption is about 0.7-1.2 Amps)
Cons:
- no output for a sweep sync
- sometimes it can produce overshoot voltage when you change settings. It needs to be used very careful with sensitive electronics
- very small SMD VCXO, so I'm afraid you will be unable to replace onboard oscillator
- about -40..-45 dBc even harmonics, probably due to R2R DAC.
- onboard DC/DC is not enough to keep proper voltage for 25 Vpp signals for any frequency and waveform type. If you use more than 10-12 Vpp, you're needs to check the actual output waveform on the load. I think it's possible to replace power supply with a good bipolar linear one.
Second harmonic is about -40..-45 dBc (sine waveform).
Actual bandwidth is about 60 MHz, it produce pretty nice sine up to 80 MHz, but above 60 MHz it has max 3.6 Vpp (max 1.3 Vpp on 50 Ω load) and some amplitude drop if you sweep from 1 MHz to 80 MHz.
Up to 30-40 MHz it has pretty nice flat response.
In overall, it works good enough and very comfortable for a lab experiments where you don't need a low noise or low harmonics distortions.
You can see some waveforms from PSG9080. I used a high speed 14-bit ADC AD6645 working at 96 MHz to capture it. For example, the first picture is a 10 kHz saw tooth waveform, you can see about 30% of the full wave height on the screen (I zoomed it to see more details).
radiolistener:
just made command line tool for PSG9080 to upload and download arbitrary waveforms.
Will be available on github soon. :)
radiolistener:
Here is beta version :popcorn:
For Windows XP and Vista it may need to install .NET Framework Runtime 4.0, for other Windows it should run just out of the box.
Usage:
Read arb wave from PSG9080 to a text file:
--- Code: ---PSG9080_ARB.exe COM17 -read 1 wave01.txt
--- End code ---
Write arb wave from text file to PSG9080:
--- Code: ---PSG9080_ARB.exe COM17 -write 1 wave01.txt
--- End code ---
COM17 is a serial port with PSG9080.
1 is arb wave number
wave01.txt is a file name
Note, it works with unsigned int 14-bit values in decimal format. So, the value should be within 0...16383 range.
The file should consists of 8192 values in text decimal format.
PSG9080 Generator software use 16-bit format for text file. It converts values before upload. And you never know which value will be written. This is why I implemented direct 14-bit format to avoid unexpected conversion loss. PSG9080_ARB uploads exactly the same data as it represented in the file. With no conversion.
In order to support PSG9080 software files with arbitrary wave in 16-bit format, I added two additional option. So the tool can work with text files in 16-bit format:
Read arb wave from PSG9080 to a text file with 16-bit format:
--- Code: ---PSG9080_ARB.exe COM17 -read16 1 wave01.txt
--- End code ---
Write arb wave from text file with 16-bit format to PSG9080:
--- Code: ---PSG9080_ARB.exe COM17 -write16 1 wave01.txt
--- End code ---
The tool has some data checks, so if something is wrong with the data, it will stop operation and show the error.
Also I implemented upgrade commands to upgrade firmware from file without installing a bunch of software, but I didn't tested it, so upgrade command is disabled in this build.
Source code will be published later on github.
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