JunTek PSG9080 Programmable Signal Generator (80 MHz - 300 MSa/s - 14-bit)

[jpshea]

Can the PSG9080 do (constant frequency) AM and frequency sweep at the same time?

[radiolistener]

Can the PSG9080 do (constant frequency) AM and frequency sweep at the same time?

No, modulation mode and sweep mode are different modes and available on separate screens.

I'm wondering, what you're trying to do with AM modulation in sweep mode? 

[XeRoX]

Hello!!

I just beginner in electronics.

I also bought JUNTEK PSG9080 in DEC 2020. I wanna pass out triangle signal to op amp but with external voltage offset by another op amp (both op amps are powering by external 9V BAT->3.3V LDO->OP AMPS). Then I connect GEN_GND (just GND without output !) to my offset amp then oscilloscope start display offset voltage with some noise component. My offset op amp produce 100 mV signal. If I try power generator from classical supply with 50 Hz transformer can it help me keep my 100 mV signal in clear?

Also I have another question about this generator - can I use it for getting amplitude-frequency response diagrams ? I saw sweep mode but can't synchronize gen output with "in X" on oscilloscope(( Does it really possible with such equipment?


Thanks all for answers !!

[jpshea]

@radiolistener for EMC immunity testing

[ozcar]

Also I have another question about this generator - can I use it for getting amplitude-frequency response diagrams ? I saw sweep mode but can't synchronize gen output with "in X" on oscilloscope(( Does it really possible with such equipment?

If the sweep does not provide a sync output, maybe instead you could FM modulate one channel by the other.

[XeRoX]

Hello!! My question about noise is not correct and actual more. I just used oscilloscope incorrectly. I connect generator out both to osc and op amp input. Then I try to get signals from generator and from op amp input synchronously I just connect offset amp output to GND by generator and oscilloscope cabels    Sorry for incorrect question.... Also I already have checked and working chassis of power supply 5V / 3A with linear stabilizer) I'm not sure that I need in such construstion in generator right now ......

[radiolistener]

I'm not sure that I need in such construstion in generator right now ......

if you want to put external voltage offset, you're needs to remove DC offset of generator.
Otherwise you can burn out generator with external voltage.

It means you're needs to connect output through some capacitor or transformer or use some buffer amplifier.

[DROBNJAK]

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).

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.

I have an application where I need the accuracy of 1 Hz or better at around 60-70 MHz.

Can you please tell me if you can achieve such accuracy with PSG9080 sig-gen?

What kind of signal generator can guarantee such high accuracy?

[mawyatt]

Doubt the PSG9080 or most lower cost AWGs can achieve that level of accuracy. Likely require an external reference like a GPS reference for use with the AWGs that have an external reference (10MHz) input.

Think most of the mid-level AWGs from Siglent and Rigol will work with an external GPS reference, I know our SDG2042X works with 10MHz external references although we don't have a specific GPS reference. The higher end AWGs from KS and Tektronix should also work with an external GPS reference.

Best,

[DROBNJAK]

Doubt the PSG9080 or most lower cost AWGs can achieve that level of accuracy. Likely require an external reference like a GPS reference for use with the AWGs that have an external reference (10MHz) input.

Think most of the mid-level AWGs from Siglent and Rigol will work with an external GPS reference, I know our SDG2042X works with 10MHz external references although we don't have a specific GPS reference. The higher end AWGs from KS and Tektronix should also work with an external GPS reference.

Best,

Thanks for the tip. I didn't know that GPS reference is so good. That can save me some money.

On another note, in Rigol's DSG800 1.5 GHz spec sheet is says, pg.2 section: "Internal Reference Frequency", that it can deliver "< 5 ppb" frequency accuracy. That's 5 parts-per-billion which I find astonishing. Its just pitty it is out of my price range.

Is < 5 ppb frequency accuracy really common in that price range of AWGs?

https://www.rigol-uk.co.uk/jg/wp-content/uploads/2020/06/Rigol-DSG800-Datasheet.pdf

[rf-loop]

Doubt the PSG9080 or most lower cost AWGs can achieve that level of accuracy. Likely require an external reference like a GPS reference for use with the AWGs that have an external reference (10MHz) input.

Think most of the mid-level AWGs from Siglent and Rigol will work with an external GPS reference, I know our SDG2042X works with 10MHz external references although we don't have a specific GPS reference. The higher end AWGs from KS and Tektronix should also work with an external GPS reference.

Best,

Thanks for the tip. I didn't know that GPS reference is so good. That can save me some money.

On another note, in Rigol's DSG800 1.5 GHz spec sheet is says, pg.2 section: "Internal Reference Frequency", that it can deliver "< 5 ppb" frequency accuracy. That's 5 parts-per-billion which I find astonishing. Its just pitty it is out of my price range.

Is < 5 ppb frequency accuracy really common in that price range of AWGs?

https://www.rigol-uk.co.uk/jg/wp-content/uploads/2020/06/Rigol-DSG800-Datasheet.pdf

This is only if you buy it with Optional OCXO reference.

Reference frequency 10 MHz
Temperature stability
In temperature range 0℃ to 50℃ , reference to 25℃ < 2 ppm
Aging rate < 1 ppm/year
With option OCXO-B08 < 5 ppb
With option OCXO-B08 < 30 ppb/year

+/- 5ppb is not very good.
+/- 50mHz @10MHz 

Also did not find what is initial accuracy after factory product line calibration. Hard to believe they can promise its initial limit is <5 ppb

standard version 2ppm alone mean max +/- 140Hz error with 70MHz and then also aging.

With Rb or GPS you can get lot of better than this OCXO Option version "5ppb" class what is "only"  5x10^-9 + aging etc.

[makoshatu]

Hi! Could anybody properly install the PC software for this PSG9080? I downloaded both the english and chinese version of the software from the Juntek website, but the zipped english version has CRC error. The CN version can be installed, however it could not register an .ocx controler. I added that .ocx file to the Windows and I registered it manually, so the software now can be run (an error message still show, but it can be okayed). Unfortunatelly, it does not show any text on the GUI, only the different values (frequency, amplitude, phase, etc.) can be set (if you know that what are you setting actually...).

[hflorin]

Hi there,

@SERJSOCHI

In your first post, you asked this:

Does this generator have a sweep sync output signal (see picture)?

    * sweep_sync.png (92.71 kB, 800x480 - viewed 533 times.)

In the second post I saw that you also bought one PSG9080:

Hi. I received this generator today. The speaker is very loud, sealed it with tape, now it sounds much better.
What is the best way to remove the gray bumper, as it interferes with placing the device on the shelf.

Please tell me, does this generator have a sweep sync output signal like in your picture?

Many thanks,
Florin

[radiolistener]

Please tell me, does this generator have a sweep sync output signal like in your picture?

Unfortunately no, it doesn't have sweep sync output.
Hardware allows to implement it, so I hope manufacturer will add such option in the future firmware.

[Neper]

Hi all,

I'm new here. Just got a new PSG 9080 yesterday. The brand of mine is JOY-IT instead of Juntek, but it looks identical.

Been playing around a few hours and so far things look OK. I have two short questions/remarks, if I may...

1. The Apple store has an App from Juntek for controlling a PSG9080 per Bluetooth from a iOS device.  Installed and tried it but it doesn't find the generator. JOY-IT say their PSG9080 doesn't have Bluetooth. Then again, there is no mention of Bluetooth in the Juntek docs either. Has anyone ever tried this App with the original Juntek 9080?

2. Is there a way of setting the output voltage in other units than Vpp? I'd much rather use Veff or dB.

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...

Ralf

[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]

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.

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.

2. AFAIK Vpp is the only way

How really stupid.

3. The firmware seems to be v1.2 so no newer than what you probably already have.

I've sent them an email and they say they've corrected one bug and one spelling error. I'm suitably impressed.

Ralf

[radiolistener]

2. Is there a way of setting the output voltage in other units than Vpp? I'd much rather use Veff or dB.

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).

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...

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 

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: [Select]

PSG9080_ARB.exe COM17 -read 1 wave01.txt
Write arb wave from text file to PSG9080:

Code: [Select]

PSG9080_ARB.exe COM17 -write 1 wave01.txt
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: [Select]

PSG9080_ARB.exe COM17 -read16 1 wave01.txt
Write arb wave from text file with 16-bit format to PSG9080:

Code: [Select]

PSG9080_ARB.exe COM17 -write16 1 wave01.txt

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.

[Neper]

My 9080 is too big to put it where I need it. All because of those stupid ears. I've had a closer look and they appear to be glued to the rest. Has anyone succeded in removing them without breaking everything?

Ralf

[radiolistener]

The source code for the arbitrary wave upload and download command line tool for PSG9080

https://github.com/qrp73/PSG9080_ARB

[torch]

Some questions for those that have bought one:

1. I read that one channel cannot modulate while the other is sweeping. Can one channel generate a basic waveform while the other channel is sweeping?

2. Is there a marker function?

3. The on-line manual shows trigger input and output bnc connectors on the rear, but from what I read here they don't appear to actually be present and the teardown video shows unpopulated points on the circuit board in that location. Are there different versions available? Did anyone get one with trigger I/O ports on the rear? (The JoyIt version also shows these rear panel connectors on the website images).

[radiolistener]

1. I read that one channel cannot modulate while the other is sweeping. Can one channel generate a basic waveform while the other channel is sweeping?

Yes, the second channel just keeps the last wave settings in Sweep mode.

2. Is there a marker function?

No.

3. The on-line manual shows trigger input and output bnc connectors on the rear, but from what I read here they don't appear to actually be present and the teardown video shows unpopulated points on the circuit board in that location. Are there different versions available? Did anyone get one with trigger I/O ports on the rear? (The JoyIt version also shows these rear panel connectors on the website images).

The rear BNC are used to connect with other PSG9080, one connector for previous PSG9080 and the second connector for the next PSG9080 in a sequence. It uses some internal and strange pulse structure, so you will be unable to use it as a trigger or a sync for the sweep.

[radiolistener]

some pictures from my tests taken with 14-bit ADC running at 96 MHz:

1) spectrum sine wave 3 MHz 4.1 Vpp (actual 2.05 Vpp at 50 Ω input)
2) spectrum square wave 3 MHz 4.1 Vpp (actual 2.05 Vpp at 50 Ω input)
3) oscillogram square wave 50 kHz
4) oscillogram ramp wave 10 kHz
5) oscillogram triangle wave 20 kHz