TRX DUO APPLICATION BASED HF SDR TRANSCEIVER (RED PIYATA)

Here we take a look at the TRX Duo, a Linux Based SDR Transceiver.
Purchase links:
s.click.aliexpress.com/e/_Dmz...
s.click.aliexpress.com/e/_DEQ...
s.click.aliexpress.com/e/_Deq...
s.click.aliexpress.com/e/_DFv...
s.click.aliexpress.com/e/_Ddq...
Downloads:
github.com/pavel-demin/red-pi...
downloads.redpitaya.com/downl...
drive.google.com/file/d/1_PL2...
00:00 Introduction & Hardware Overview
01:54 Specifications
03:18 Pavels SD Card Image
04:48 HPSDR Demonstration
08:08 8 Band WSPR Configuration
10:19 Red Pitaya SD Card Image
11:01 Network & Wifi Support
11:53 App Market Place
12:10 PowerSDR & HPSDR Support
12:29 Outtro
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#TechMinds #SDR #HamRadio

[@M0SZT]

Listen, it's costing me an arm and a leg watching your great videos, ever thought of introducing cooking?

[@TechMindsOfficial]

Hahahhaa havnt you seen my cooking Chanel? Lol.. Seriously though, that would just contain eggs n bacon! lol. Thanks for watching Carl and sorry about the bank balance! 🤪

[@siffler1234]

lol carl, i feel your pain, i think i've spent £2000 over the past year, de m1dls AKA homebrewham👍👍

[@paulmaine6433]

Welcome to the hobby! Go dig a big hole and start throwing money into it - that’s the radio hobby!

[@Mr0rris0]

Make for us big pilaf or glaze a ham

[@Randrew]

@M0SZT My suggestion: Hit the Thank$ button up above or use his PayPalMe link to kick in a lesser amount of dough for test equipment and radios so you and I can continue to enjoy this stuff vicariously!

[@dffabryr]

Amazing!! After your videos I get too rig hungry !!! And I miss those years I had a lot of time in the air, a lot of friends, a lot of time to run experiments, rig mods ...uhhhh ... now my family have the priority so radio must wait for my golden years not so far away

[@howforless]

I saw these on aliexpress about a month ago and was wondering what exactly the performance was. Thanks for the video, i might have to pick one up.

[@sirkyoj1]

Thats looks so much cleaner than rsp1a!

[@michaelmcdonald76]

They look a decent bit of kit cheers for video like the idea of being able to run linux on it too

[@siffler1234]

thanks for this matt, another purchase after a great demo from yourself mate, if you're doing requests, ali is doing a usdx with built in atu-100, 😊😊😊😊

[@siffler1234]

delete the link above if not allowed mate,

[@TechMindsOfficial]

I do have a ATU100 video coming soon, but it’s the top notch version with cool display!

[@siffler1234]

@@TechMindsOfficial lovely, thank you👍👍👍👍

[@paulmaine6433]

Very nice video! I currently own a Red Pitaya STEMLab 125-14. Mine can transmit 10mW. I am using Pavels code. The 125-14 cost USD $415 plus an aluminum case for $46 and lastly an RF transformer for $77. The 16 bit Red Pitaya cost $688 plus a case! The device in your video is less than half of 16bit RP. I have a home brew 30w power amp with home brew low pass filter. I’m very interested in purchasing what you show in the video! I love my Red Pitaya!

[@peteride-kostic737]

The reason the original redpitaya 125-14 outputs 10 dBm vs 4 dBm for this clone is because it uses an symmetric differential op amp to interface the output of the DAC instead of a balun. The positive is the increased output power the negative is that the signal on 28 and 50 mhz contains undesired spurs other than the harmonics (see previous comment)

[@AbuSous2000PR]

imagine if it could cover frequencies above 60Mhz..that will be a game changer for real I am trying to do the same thing with Pluto+ but I am having limited success Many thx for your hard work man

[@JonAhlquist]

Can you list your problems? Perhaps someone can make a suggestion. It might be better to post your problems at the "Tech Minds" video about the Pluto Plus: kzbin.info/www/bejne/nprKlZugaZuUi80

[@thunderbolt997]

one could use a RF upconverter to transmit data at e.g 2Ghz (0-60MHz --> 2Ghz) and then another downconverter (2Ghz --> 0-60 Mhz) to receive signals at 2Ghz

[@marceldaverveld]

I use the Red Pitaya as a HPSDR receiver together with CW-skimmer. This creates a 8 band simultaneous CW decoding DX-cluster that i can connect to from my log-program, i rarely connect to an internet DX-cluster since.

[@bobgerzoff5072]

I've been wanting to do that for a long time. There are no nearby DX-cluster stations near my QTH. Can you point me to a website esource that would tell me how to go set up something like this. Thanks. Bob WK2Y.

[@WhichwayJanus]

Is it possible to open the case? The fasteners in the corners are too small for me to make out what tool could remove them. Thanks.

[@edstroh6811]

Tech Minds, can you please elaborate on the setup of the TRX-Duo in PowerSDR? I can't get it working. :(

[@user-kn2ct2iz3l]

I noticed that analog inputs at SDR DUO are not working at all. I mean slow ADC inputs that used for display power and SWR measurements in Thetis etc. Look at pinout and see that analog inputs not corresponds to FPGA pins. Is this TRX DUO construction issue or I doung smth wrong?

[@Randrew]

Hit the Thanks button up above to support Tech Minds getting test equipment (me promoting this, not Matt)

[@TechMindsOfficial]

Another Super thanks that I missed! You're a star! Thank you!

[@JonAhlquist]

Does anyone have a good application for two transmitters in a rig like this, assuming they could be amplified to 1-5 watt levels?

[@vourkosdude]

Is there a way to make it a Navtex transmitter? 490 + 518 khz with FSK modulation?

[@PhantomWoIf]

does it receive SSB on 14200KHz better than an Icom IC-7300 does ?

[@sk718serg]

Hello! Does the duo have a port for controlling external BPF and LPF filters?

[@jiriculak6115]

Yes it does. It uses openhpsdr protocol 1 and there is gpio

[@robinivetic1365]

Tech Minds what is maximum samples of trx duo, Pavel images, exactly sdr-tranciever , or wide tranciever blocks for GNU radio offer 1.25MHz and 2.5MHz for 125-14 RP, RP 122-16 RP can do better, think 10.24MHz. If this is mix between 122-16 and 125-14, what is max. bandwith that TRX DUO can offer

[@lfusari]

Hi do you have compared with Red Pitaya 16bit performances ? Thanks

[@ErwinSerle]

This device is not 16 bit. See my explanation below.

[@babass521]

Good morning, I want to get into sdr technology and use a TRX SDR ... The TRX duo I find it a bit expensive and I found the TRX SDR transceiver on the web which is called USDX+ ... I would simply like to know if I can couple the PowerSdr software that I find quite a lot on this product or does it need compatibility!! I would also like to know if PowerSdr can be compatible with any Sdr transceiver? I also have HackRF one and I would also like to know if I can make it also compatible on this sdr software ... Usdx+ also has the CAT control commands ... If this is possible I would like to know if the information of my Usdx+ will be visible in Power Sdr via Cat control like transmit power? Can each SDR Transceiver be made compatible with this software only via the sound card and Cat Control interface or via the RS232 serial port? Thank you in advance for your answer, which I look forward to!! Questions that I ask myself about the world of sdr that I find much better than the analog transmission of previous years ... Yours 73's

[@RichShmit]

The PCB of TRX-DUO has a symbol of open hardware. Where can I find EDA files of this SDR?

[@ZL1CVD]

I haven't found it either

[@philipjohnson5511]

I own a Red Pitaya SDRlab 122-16. The receive port is connected to a 40 meter end fed half wave antenna and the transmit port is connected to an amp the puts our about 2 watts on ssb, The amp outputs into a 10 meter half wave end fed. I have had some fun making 10 meter ssb contacts with this set up. The price of the Red Pitaya makes it unattractive. I wondered when a Chinese clone would show up.

[@aidenkaiser9341]

What amplifier did you use for the Red Pitaya? Did you need a RX/TX antenna switch?

[@philipjohnson5511]

@@aidenkaiser9341 It is one the the cheep China ones that that are made for 1-900mhz. no t/r switch. I think Mat may have reviewed it. Hey, China manufactures here is an opportunity for you. build an amp for these SDR products with a tx input and and rx output with a t/r switch built in controlled by a digital output.

[@johnrader-tm7ht]

Just purchased one, followed instructions about wifi dongle, copied the files from pavel-demin github, to a fat32 formatted sd card 16 gbyte. I have tried every way to access the TRX DUO, I run win 11 pro. Have the wifi dongle installed in usb port, even connected an ethernet cable from my computer to the trx duo. Am I missing something to detect/ see the trx duo? Have tried to connect trying different ip addresses in my browser, edge and firefox. How do I connect to the trx duo

[@johnrader-tm7ht]

additional-- The sd card is installed in the trxduo but no lights either led8 or led9 lights up with sd card inserted.

[@TechMindsOfficial]

If you connect it directly to your home wifi router, does your router assign the TRX-DUO an IP address? If you log into the router you should be able to see which devices are connected. If there is an IP address assigned, just enter that IP into a computers browser that is on the same netowork. That's where I would check first. Thanks

[@peteride-kostic737]

This is a good video but it is not entirely clear to me if this redpitaya clone includes or not an antialias filter on its inputs to avoid unwillingly down converting signals above 60 Mhz (such as FM band , GSM and even WiFi signals) into the main 0-60 mhz baseband. The story is similar on for output ports of course (anti alias filter ?). To answer the question, yes I have build a 300 W amplifier able to amplify the 4 dBm signal of the 16 bit redpitaya but this was not easy at all. The first problem I encountered was amplifying the 10 and 6m bands cleanly as the second and third harmonics mixed with the 125 Mhz clock signal in the input of the first amplifying op-amp at the output of the DAC. This produced undesired spurs on 25 mhz (when transmitting 50 mhz) and 41 mhz (when transmitting on 28 mhz). Using bandpass filters for 10 and 6m bands to clean the output signal before it is amplified solved the problem. For redpitaya boards equipped with baluns at the output of the DAC instead of op-amps, filltering out the 125 mhz clock signal before the first amplifying stage solves the problem too. Many people built 100w plus amplifiers for the redpitaya, it is perfectly possible to get a stable operation with a single PCB offering 50dB plus gain IF all interstage input impedances are normalized to 50 ohms ( to avoid destabilizing interstage reflections). Of course, the antenna and input switching relays inside the amp must provide together a minimum of 60 dB isolation, otherwise the 50 dB amp may oscillate (this happened to me). The second biggest problem I encountered was the overshoot and overdriving problem; given the very high gain of the amplifier, a small difference in the input signal makes a huge difference at the output of the 50 dB amp...After losing a few transistors in the final stage, the problem was solved easily with limitters (diode schotky plus diode zenner) at inputs of the second driver and final stages. I don't mention swr and current protections mechanisms that are required for any high power amplifier and that I also had to build for obvious reasons.

[@jinzepeng6765]

The input has LPF, but the output is directly processed by the DAC through the balun

[@philipjohnson5511]

I'd love to se the schematic. Care to kit it up?

[@JonAhlquist]

How can we encourage Chinese manufacturers to build an external (clean!) multi-watt power amplifier for this? Haven't they already done most of the engineering with the other low-power SDR transceivers that are available? AliExpress lists an inexpensive 1-1000Mhz amplifier that claims to produce 2.5 W out from 2 mW in, but it is unfiltered.

[@JonAhlquist]

Could someone review the TRX DUO as a diversity receiver? I have seen that the TRX DUO can be controlled by THETIS software for diversity.

[@TechMindsOfficial]

I’ll try this once I have my antennas back up.

[@user-kn2ct2iz3l]

kzbin.info/www/bejne/eZiTi4yknpeGmbM

[@aidenkaiser9341]

Hi Tech Minds. Do you know if this SDR supports signal diversity mode with it's two inputs?

[@TechMindsOfficial]

The SDR will as they are independent receivers, it’s down to the software used. Not sure if there is any software that supports that at the moment but worth some research.

[@aidenkaiser9341]

@@TechMindsOfficial HPSDR supports signal diversity reception and has it built into the software which it looks like this supports after doing some digging. Very cool! Perhaps a future video could be what type of amplifiers work well with software-driven SDRs like this? Thanks

[@TechMindsOfficial]

@@aidenkaiser9341 Already made a video a while ago, check it out kzbin.info/www/bejne/r4DOlZpnoayZm9U

[@aidenkaiser9341]

@@TechMindsOfficial I watched that video but it was more for 2.4 ghz / wireless applications. Do you have any recommendations on amplifiers for the HF band segment? Thanks again.

[@DaJetzi]

Diversity with Red Pitaya is shown here. kzbin.info/www/bejne/eZiTi4yknpeGmbM

[@alexandrgavrisch6548]

Модуль бюджетный. Полноценно не работает с Thetis. Требует основательной доработки прошивки.

[@f5nfb446]

Can i transmit in CW with this SDR transceiver ? I can't see connectors to a paddle or a morse key...

[@TechMindsOfficial]

It would be done via software.

[@f5nfb446]

@@TechMindsOfficial So this radio is not made for me. CW is manual or it's not CW... Thank you.

[@bigal159]

Wondering if this can be used as a spectrum analyser?

[@peteride-kostic737]

Yes it can - up to 60 mhz

[@bigal159]

@@peteride-kostic737 Thanks Peter...is their some software you could point me to please?

[@audio_engineer]

It can and for greater than 60MHz with the addition of a few inexpensive parts from eBay or Amazon. I am not sure it would make for a good every day analyzer but if you don't mind a little work and some software tweaks I suspect it might do just fine for experimenting and home hobby work. It might be an even better SA than that. If you get this to use as a SA, please let me know how it works for you.

[@leonardoelias22]

This is a good one, but the price x.x

[@DaJetzi]

Tell me where you can find a multipurpose device that can also be used as an SDR transceiver for this price? Btw on ebay they are cheaper.

[@chrisw1462]

A bit expensive for it's capabilities. The HackRF has a much wider range, can transmit up to 30 mW in the same range as the TRX, and is only $35 more expensive.

[@jiriculak6115]

well yes and not - 8bit ADC/DAC vs MIMO and 16bit RX / 14 bit TX manthat is much more dynamic range than hackRF. You would not run HackRF as transeiver, unless you had input output BPF, LPF and step up ATT fitted controllable via SW. This is more likely to be transceiver kit but I agree - at 200USD Plus, yu need another 200usd for BPF and PA, etc.

[@stevenwilson1690]

I agree with Jiri - the 16 bit AD puts the dynamic performance up there with the top end receivers on the market like the ICOM 7610, Apache Labs radios, etc. What this is missing is the IOs available on a Red Pitaya to control things and inputs like for a CW keyer!

[@stevenwilson1690]

I went and looked at the actual device - they DO Have the IOs available Just not through the metal case. So it looks like a full-up clone of Red Pitaya.

[@TechMindsOfficial]

That’s correct Steve, something which I should of shown in the video.

[@hudefuk]

Wow! What is it that this tiny gizmo cannot do?

[@Randrew]

Transmit further than your front door.

[@TechMindsOfficial]

Haha well, I managed WSPR into Europe on its measly little 2.5 millionth wattages.. 🤪

[@Randrew]

@@TechMindsOfficial Why the heck did you leave your front door over in Germany? ;)

[@rlt422]

Two questions EVERY hard core computer geek asks of ANY new bit of hardware. "Can it run Linux?" and "Can it run Doom?" LOL

[@TechMindsOfficial]

Haha Doom was like my first game addiction! Back in the day..

[@HyperMAX9001]

DOOM networked over HF frequency with these would be cool.

[@JonAhlquist]

The TRX DUO and the Pluto Plus (kzbin.info/www/bejne/nprKlZugaZuUi80 ) have very different frequency ranges, and the TRX DUO has 16-bit analog-to-digital reception and 14-bit digital-to-analog transmission, while the Pluto Plus has 12-bit resolution for receive and transmit. Even so, they have the same Xilinx Zynq 7010 SoC (dual core ARM A9 with FPGA), 512MB memory, clock, and gigabit ethernet. Can they be controlled by the same SDR software with the same drivers?

[@ErwinSerle]

Quote : and the TRX DUO has 16-bit analog-to-digital reception .... No it has not, see my comment below on the ADC chip used = 16 bit. But software is not rewritten so uses still 14 bit. The designer is cutting corners here. Also the original Red Pitaya SDRlab 122.88 16 bit has a 7020 FPGA chip instead of the here used 7010 and can therefore run 16 channels in parallel for 16 bit input. This new device can at max run 8 channels in parallel for 14 bit input. Do the math : 16 x 16 256 channelbits in parallel, TRX DUO 8 x 14 = 112 channelbits in parallel 44% compared to the original.

[@JonAhlquist]

​@@ErwinSerle Thanks to you and Luca IK2LRN for prodding TRX-DUO creator Jinze (Justin) Peng in an online discussion in March 2023 so that Jinze recompiled software so that the TRX-DUO can now operate at 16 bits instead of 14 bits.

[@stewartrv]

So is this basically a Red Pitaya clone then? If so which one?

[@Randrew]

Closest current match I can see is Red Pitaya's "SDRLab 122-16". That one has a different FPGA from the Zynq family with more IO, internal RAM and high speed transceivers that probably didn't exist on whatever previous product this "TRX DUO" is based on.

[@edwinrichter3181]

@@Randrew its a mixture of STEMlab 16 and STEMlab 14 ... FPGA from STEMlab 14, Transformer Frontend from STEMlab 16...

[@ErwinSerle]

As the software used is strictly 14 bit for the FPGA ADC IP Cores the advertised 16 bit ADC is only referring to the chip used. All applications should be re-written by the Chinese designer to make use of the 16 bit chip. As long as he only offers new hardware the capabilities of the LTC2208 are un-used.

[@justDIY]

Too bad the TX frequency is so limited. There's not many affordable options out there for software driven networked VHF/UHF transmitters. For HF I'd go with a Hermes over this.

[@lfusari]

Current Software doesn't support 16 bit RX than you pay for 16bit and you use 14bit !

[@PauloHenrique-hg7iw]

se fosse ate 500MHZ seria ótimo mais ate 60MHZ apenas e muito limitante

[@jinzepeng6765]

In fact, due to the use of the powerful LTC2208, it has the ability to receive undersampling up to 500M, but the sensitivity will drop every time it crosses a Nyquist interval, requiring LNA+BPF

[@PauloHenrique-hg7iw]

@@jinzepeng6765 let's see when a version that covers up to uhf with a good value will be released

[@chipensa501]

The output power is silly.

[@CrumResearch]

LoRa?

[@3dPrint_and_chill]

At that price I'd get a G90.

[@Randrew]

If you're comparing this to a G90, then you probably don't have a use case for a Red Pitaya (clone).

[@audio_engineer]

I understand that line of thinking but this is a world-class receiver with specifications near the best receivers currently available. Is it a bit howya doing? Sure. Does it cost an order of magnitude less than a turn key radio from Japan that still cannot top the RX performance of this kit? Yes. I have a couple of very high-performance SDR transceivers (Hermes and Hermes Lite 2 Plus) and they are not as good of a receiver as this (at least on paper and from the video, in person) but cost more. That is not a fair comparison since they are different radios with different use cases and features but as far as a receiver and the ability to amp up the output to a respectable 50-watts for a couple of hundred extra $$ you get a nearly world-class receiver plus a superb output 14-bit DAC that when properly filtered (included with the price of building your own amplifier) will sound amazing for under $500? That may not be for you but I suspect this will be for a lot of people that like to experiment and enjoy having cutting-edge performance at a price that can be more easily justified.

[@digitalmediafan]

2.5mw ?! Ridiculous, at last 5w would be far more usable

[@Randrew]

This device (Red Pitaya) has similar origins and aims to HackRF - first an experimenter's platform, then anything hobbyists can make of it. And it seems hobbyists have made a *lot* of it.

[@DaJetzi]

Red Pitaya was never intended as an SDR transceiver. So why should it have an output power of 5W?