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- Опубліковано 12 лис 2020
- Episode 612
$25 Geekcreit® Signal Generator Module 35MHz-4.4GHz RF Signal Source Frequency Synthesizer ADF4351 Development Board from Bangood: www.banggood.com/custlink/DmK...
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/ imsaiguy - Наука та технологія
Can u imagine if we had these low cost "toys" 30 - 40 yrs ago? I use to DREAM of having a spectrum analyzer and o-scopes back in the 70's but they cost was astronomical! I think it has differential output and should be terminated if not used. TNX 4 the video !
Very interesting how this days we have all these easy avaiable broadband pll ic's with the oscillator integrated such as adf4351 or si5351 for the nanovna. On 2012 i was doing some rf projects and i made a vna and spectrum analyzer project using for the rf generator 3 colpitts oscillators and a sp5655 pll to cover only 60 to 300MHz. For the receving secction a tv tuner with a 45MHz amps cell if filter. It took 8 boards to do this project and now with nanovna and tinysa it's all avaiable very cheap.
Thanks for sharing, those Synth's are really good quality. You're right, the muxout port is for daisy chaining since that is part of the PLL onchip. The 2nd port is built in to the ADF as an aux port which may be powered down by register.
Good to see an HP 8591E still in use! We still have one for EMC measurements at work!
There are some of these 4.4GHz generator-boards with touch LCD which are really easy to handle. I got one of them and tried out it's harmonics in the 10-12GHz range with a satellite LNA. The output can be observed in the 1-2GHz range.
RF Sweep Signal Generator Modul Board 35 Mt to 4,4G + STM32 TFT colour touch LCD
I think I left off last winter wondering what's the similar spec RF range oscilloscope module size board/kit? Was wondering about IIO Oscilloscope with the Adalm Pluto. I've not taken out of the box yet... though will see when I get to this winter. Still focused on the outside chores, though still wondering what is a more portable standalone option maybe like a HackRF Portapack with better performance. Would be neat to see a dedicated module however maybe with a RF power detector module can be made easy?
I’d say there might be an observed harmonic difference between the outputs, giving you a phase differential??
Would be interesting to see on scope, when ya have the box made..😉
I just bought one and did a bit research on it, the sma connector in the middle is an external ref freq input @25 mhz, the jumper next to it enables its function
Correction; the lo can be chosen freely by the designer, in this case it is a 100 mhz so you will have to feed it with a 100 mhz external signal or reprogram the unit to except something else.
There are also units like this with a lcd which has the menu option to change the lo frquency.
I am planing to hook mine up to a gpsdo at 100mhz.
Great Video, thank you for sharing. Would be of interest what the SMA in the middle of the PCB is for.
THE SILKSCREEN SHOWS IT IS A MULTIPLEXED CONNECTION.
I measured only 0dBm from the outputs on this one. According to the datasheet (and the power setting on the display), it should give up to +5dBm. Perhaps a software issue or something. However, this is a great tool for the bucks.
Maybe it's 5dBm differential?
@@tiftik Perhaps. The outputs are shifted 180 degrees apart, so it can be so.
The one that outputs 100MHz is most likely the clock input. I bet that jumper nearby disconnects the oscillator from the ADF4351 chip and allows you to feed in an external low phase noise high stability 100MHz clock signal for better output performance.
I think they added that to allow you to hook two together and run both off the same clock so they will both be in phase
@@IMSAIGuy Yes that would work also---the jumper would disable the onboard clock on the one unit, turning the SMA to an input, to allow the 100MHz from the other unit to be used to clock it. The bare development boards without microcontroller have a similar SMA port, but you have to unsolder a small 0 ohm resistor to disconnect the internal oscillator and allow an external clock to be used (either from a separate source or from another unit to lock them together.)
Hello, do you know what to do with the jumper to use a external oscillator? I dont seem to understand it and dont want to break anything..
@@stortregen5390 The jumper normally just completes the connection between the little onboard oscillator and the ADF4351 IC. If it's a 2 position jumper, you'd move it to the other position and plug your external oscillator into the port there. If it's only one position, just remove it and plug in your oscillator. You won't damage it by plugging in an external oscillator and trying with/without the jumper in various positions (as long as your oscillator isn't putting out too much power.) I'm a bit unspecific because many of these Chinese ADF4351 boards have various (but similar) configurations.
@@ruhnet thank you very much it was indeed a 2 position jumper !!
Good afternoon IMSAI Guy. I would like to pass some information, in the question in the sweep menu, which appears WAIT, try to press the central OK and hold for 3 seconds or more, that it will record the data. Hugs ...
Hello friend, please one question abaut this signal surce: when swich off (take out the power) the freguency still on place or delete?
Great videos! Can the eval board do 100 hertz steps ?
The SMA shows it is a Multiplexed output, or input.
By its location, I bet it is an output.
Just got mine in mail and my programmable attenuator
Hello friend, please one question abaut this signal surce: when swich off (take out the power) the freguency still on place or delete?
a viewer said if you push a button a long time it remembers but I haven't tried it.
Is it possible to create sideband signals along with the main carrier by using that board?
no
That would be a really nice tool if you could plug it into USB and have a script controlling it. Maybe GNU Radio SDR software ?
hello, is the generator able to save a frequency and when turned off and back on again to automatically transmit the saved frequency?
Mine forgets
@@IMSAIGuy Is there a way to let this or an other generator when powered on to automatically transmit on 1 specific frequency ?
@@stortregen5390 If you use your own microcontroller, you could do this quite easily.
Do they make a version that goes down to say 1 MHz and I’m curious how much this was?
no, and read the description
The ADF4351 is limited to 34.375MHz on the lower end. If you need lower frequencies then a suitable similar chip would be something like an SI5351 PLL, which works from 0-200MHz. Or a DDS chip like an AD9833/9850/9851. You can find little modules similar to this one, on Banggood/eBay/Aliexpress that use those chips.
Can U lock it with extern ref ? I would like to try 125 MHz lock fq and 1 GHz output
Yes, you can, but the software on the microcontroller is made to work with the 100MHz reference that is onboard. So you would need a 100MHz signal to have it work correctly with the software it currently has. If you wrote your own software you could lock it with whatever frequency you wanted within the range of the ADF4351 chip.
Checking the ADF4351 datasheet---it shows that the input clock can be anywhere from 10 to 250MHz. But as I mentioned in my other comment, the software has to be set to work with whatever clock speed you use.
I see you've tested this on an Oscilloscope, what I'm wondering is what are the applications for these?
all the same uses as any RF generator. testing equipment, osc scope, counter, spectrum analyzer, testing filters, directional couples. RF amplifiers.
Brother, with this, can the signal of WiFi router be made long range?
no
A user interface that only a nerd could love :-)
Someone has the tell China that we all hate that serif font they use. Are we all on the same page on this?
I bought one, but the UI is in Chinese....is these a simple way to switch to English, or does it have to be flashed with a different firmware?
>>EDIT: No simple way! See below...
I found the firmware source and schematic. UI is in English! Source comments in Chinese. The bad news is that there are two PCB models out there: (1) With No trash can logo below the blue/white switch, that has a 128KB flash STM32 , or (2) With a trash can, ENIG PCB finish and a 32KB flash STM32. The clone models come in form (2) with the smaller flash, so I had to tweak the source to set the flash size to 32KB and the write base address (persistent settings) just above the last used prg code page. Then, adjust the ST32 target part for the project, recompile the whole thing with Keil using the older v5 compiler, and reprogram the flash using a STLink V2 wired to P5 on the PCB.
@@luisderivas6005 I just found the same thing, can you post a link?
You need to plug the OUT- port with a matched load, that should greatly reduce odd harmonics.
I tried as you suggested. It does absolutely nothing.