#1885

[@jimwolsiffer4397]

Interesting for sure, just ordered a version with an enclosure and color touchscreen for $68 US. Something to play with. Thanks for the video!

[@g0uus]

I found the following about the serial protocol on an AliExpress listing. May be of use to someone (or may be completely wrong!) Explanation of serial port protocol Serial protocol Baud rate：9600 Related instructions: The protocol consists of 9 bytes, byte 1 and byte 2 must be 0X55 0X55. Byte 3 and byte 4 represent the upper 8 bits and the lower 8 bits of the integer part of the frequency, respectively. Byte 5 and Byte 6 represent the upper 8 bits and lower 8 bits of the fractional part of the frequency, respectively. Byte 7 represents the output power. Byte 8 and byte 9 must be 0X0d and 0X0a; the communication baud rate is a fixed value: 115200; E.g： 100.123Mhz +5dB Frequency command：0X55 0X55 0X00 0X64 0X00 0X7b 0x04 0X0d 0X0a 100.123Mhz +2dB Frequency command：0X55 0X55 0X00 0X64 0X00 0X7b 0x03 0X0d 0X0a 100.123Mhz -1dB Frequency command：0X55 0X55 0X00 0X64 0X00 0X7b 0x02 0X0d 0X0a 100.123Mhz -4dB Frequency command：0X55 0X55 0X00 0X64 0X00 0X7b 0x01 0X0d 0X0a 2000.456Mhz +5dB Frequency command：0X55 0X55 0X07 0Xd0 0X01 0Xc8 0x04 0X0d 0X0a 2000.456Mhz +2dB Frequency command：0X55 0X55 0X07 0Xd0 0X01 0Xc8 0x03 0X0d 0X0a 2000.456Mhz -1dB Frequency command：0X55 0X55 0X07 0Xd0 0X01 0Xc8 0x02 0X0d 0X0a 2000.456Mhz -4dB Frequency command：0X55 0X55 0X07 0Xd0 0X01 0Xc8 0x01 0X0d 0X0a It can be found in the table that both the integer part and the decimal part are directly sent integer data, for example, the integer part is 100, and the high 8 bits and low 8 bits of the value 100 are directly sent in the instruction. The decimal part is 123, and the upper 8 bits and lower 8 bits of 123 are sent directly in the instruction. After the MCU receives the instruction, it will automatically synthesize the two integer data into the floating point data required. Note:Computer USB and MCU serial control cannot be used at the same time.

[@R2AUK]

I was looking for something like this. Thanks for sharing!

[@anlpereira]

Great IC. Can you show some application that can be done with this circuit? Thanks

[@KeritechElectronics]

Nice VHF generator! I could use something like that, only lower frequencies, from e.g. 100kHz to 600MHz or at least 150MHz.

[@victorhamenko2788]

может чтото подобное как генератор сигналов SI5351A

[@mx.olydian2111]

Is it reasonable/practical to constrain my circuit designs to ones where I'm not introducing information faster than the quarter wavelength rule suggests? I think for all of my purposes i don't actually need rise times and frequencies that high for 90% of applications My question is does this constrain my hardware choices too much? It looks to me that most of the hardware out there is just too zoomy and I'm not sure how to proceed as a person who would like to design analog and (particularly) digital circuits that operate in the realm of topology instead of geometry How much can i do here? I feel as though the speed of light is plenty fast but most of the PCB design information (and hardware) i can find seems to contradict that perception, it feels like I need a HAM license to make PCBs sometimes

[@x_CrossHair_x]

It amazes me what can be created with these ATMEL Chips. (Many cool toys) To play with.

[@naughtynatwar4326]

Is this chip DDS based or PLL based

[@naughtynatwar4326]

Please answer

[@x_CrossHair_x]

@@naughtynatwar4326 Perhaps try snooping Google for a MAX2870 Data Sheet "PDF" .. it may contain the information regarding your question. If DDS or PLL based..

[@Hellhound604]

It would have been nice if they included a connection for an external reference.

[@andymouse]

Mabe they did as there is one SMA connector facing up that I don't think was covered and it was up with the MAX chip.

[@naughtynatwar4326]

Is this Max2870 dds or PLL based ?

[@reinerfranke5436]

Clever to set the sweep not to jump VCO cores. Not to ask if the sweep is phase-coherent or jump-settle-stay so on.

[@david300m]

Thanks for sharing.

[@chronicfatigue5416]

Marker>counter>on if you want to read the frequency.

[@bob_mosavo]

Thanks 👍

[@naughtynatwar4326]

Is this MAX2870 DDS based or PLL Based pls answer?

[@Yuēhàn24]

Hi. Great video. How accurate is the output level?

[@johnwest7993]

Not bad at all considering what it can do. I just wish it went down to 100 kHz without external mixing. 25+ Mhz is pretty high for a bottom end for what I might do. Of course I can always set up other gear. I'm just getting both fussy and lazy in my old age.

[@davidbisciotti7424]

perhaps change (reduce) the base frequency oscillator on the board (?) to drop the output frequencies? -for the price its worth playing around with

[@bayareapianist]

Perhaps Buy a different thing like NanoVNA. Mines goes from 10k to 6G (maybe 9G?). It does a lot more and has a much easier interface for less than $90.

[@Hellhound604]

Lol, some of use old-timers still break out n sweat when we had to design stuff having to work close to 1GHz. Nowadays you get stuff like this, that would have taken a few racks and weighed a tonne, not so many years ago. (50 years ago isnt that long ago, is it? 😂😂😂)

[@johnwest7993]

@@Hellhound604, most of my tech career I stayed below 100 MHz. Microwave was plumbing and Black Magic to me. Immediately after retirement I did a bunch of LowFER longwave RF which was fascinating, and I learned a whole lot about every frustrating aspect of low frequency RF. But since I got a NanoVNA and a Tiny SA Ultra and pulled out the old bag of tiny hardline, connectors, adaptors, fixed and switchable attenuators, dividers, mixers, prescalers, etc that I've scavenged over the last 30 years at company scrap sales, start-ups shutting down, ham swaps, etc, then recently picking up some odds and ends from China, like preamps and 3 Watt power amps, and watching a whole bunch of YT videos on microwave, I can almost call myself an RF tech now. I just have to learn radar, but I'm in my mid 70's so that's not really going to happen. :)

[@BryanTorok]

@@Hellhound604 That seems like just a month or so ago I was sitting in my bedroom at my parents house as a teenager and listening to the Voice of America from Rome Italy on my Heathkit shortwave receiver. My service monitor, which sold for $35,000 when it was new, only goes to 1 GHz.

[@Braydan789]

I wonder what’s going on in those chips to make those GHz frequencies?

[@gorak9000]

maths

[@joseppuig925]

They usually have an on-chip VCO with PLL running at several GHz, then a chain of programmable dividers that give you the output frequency you want (that's why they put out square waves).

[@misterhat5823]

@@joseppuig925 How exactly do you divide several GHz to get GHz? That approach wouldn't allow for many frequencies to choose from.

[@Braydan789]

@@joseppuig925bleh 🤢, that’s yucky digital stuff I can’t build. One day we will all be able to make GHz frequencies from analog circuits, until then I’m happy with my 24 MHz radios.

[@F_Tim1961]

I've always wondered how a 2 Ghz or so cell phone stays on frequency with case temperatures changing over a 40-50 C range. Anyone know how it happens. ? I suspect the tower system sends tune offsets from time to time or the tower system sends out a beacon that the respective phones can auto zero beat to. .... Love to know the detail on this.

[@LubosMedovarsky]

Ah, STM32F103C8T6 @8:10 🙂 that one is probably a counterfeit as the original costs above $3@2.5k. It's exactly the same type as in those cheap BluePill JTAG/SWD debuggers for around $3.

[@tariqsingh3747]

lcsc will get you real ones for suspiciously cheap

[@ItsTristan1st]

@@tariqsingh3747 I suspect we are usually just ripped off by Digikey et al. We don't understand the value of our money.

[@robinbrowne5419]

Radio and microwave stuff I'm guessing. It would be interesting to see it hooked to an antenna 📡 although it might interfere with cell phones and wifi and such. In any case it is wizardry 👍

[@DimasFajar-ns4vb]

nokia 2g ultrasite edge bts use sma connector sir

[@kennarnett8220]

What is your camera system?

[@IMSAIGuy]

Lumix GX7 with Lumix G X Vario 12-35mm f/2.8

[@kennarnett8220]

@@IMSAIGuy Thank you

[@LubosMedovarsky]

Dare to share a link to that cheap offering? I can only find items above 40 bucks.

[@johnwest7993]

Use these key words [23.5-6000MHz RF Signal Source] and they will take you to a screenful of $26 ones.

[@jeanyvespochez]

the one he uses with a display and usb-c is around $60. the one at $30 have no display and no usb-c, you need some micro controler to set the frequency you want.

[@gorak9000]

all these sites have dynamic pricing these days, so as soon as 3 people buy one in a short period of time, the price goes up. That's how they cache in on videos like this that promote things. Pretty sure you can thank uncle bezos that that nugget of brilliance

[@misterhat5823]

@@gorak9000 Yep. Anytime Big Clive posts an ePay link the prices skyrocket.

[@BryanTorok]

As soon as one of these KZbin folks makes a video and a handful of people buy the item the price will shoot up. Recently, someone here on YT reviewed a mini boombox available at Walmart. I joked in the comments that I should hurry up and buy one before TechMoan reviewed it as they would instantly be out of stock. Another commentor responded, saying I was too late, they were already sold out.

[@JxH]

*ERRORS* 🙂 On-Screen, on the little device screen: • Mhz* MHz • db* dB (in fact, if it's 'power', then dBm maybe?) Sigh, kids these days... LOL !!

[@mnoxman]

Or you get a second one and do work on the plus size at 10.50000 Ghz.

[@JackieKraft]

Good grief dude, You’re starting to worry me about radiation… Perhaps a quick review on Xray detectors… Love the vids, Thx.

[@misterhat5823]

Why? The output power of these things is minimal.

[@JackieKraft]

@@misterhat5823 It’s not that test board that compels me to shove lead down my pants, Like you say that is low power test board… It is more the frequency coupled with the potential high power power supplies that would elude to…I have had my bench clicking a time or two, Just saying.