?BITX on 70MHz (4mtrs) UK/EU Band ?
#ubitxv6
Hi there,
Has anyone modified a UBITX for use on 70MHz (4mtrs)? or used a 70MHz to 28MHz Transverter?
I'm actually looking to make a low power SSB Transceiver for 70MHz. Looking for the basics to work from rather than starting from scratch!
Steve/G4MJW
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TSW's remake of our Teensy 4.1 Raduino Clone firmware
#ubitxv6
TSW has been busy switching to a new display font and reworking the firmware manual as well as improving several of the functions of the TSW T4.1 Raduino Clone firmware.? We believe this is complete and the very latest version has been posted to the TSW website's file section () for download by anyone that has the T4.1 Raduino Clone or is contemplating getting one.? We also included W2CTX's "TSWSETTIME" program in the zip file.? This allows setting the "Real Time Clock" more precisely and if the battery backup option is installed the RTC will keep decent time during the periods the uBITX V6 is turned off.??? -- NO, we have not provided for NEXTION screen usage with the Teensy 4.1 and will never do this as it is a known RFI generator so we refuse to support the NEXTION --
The firmware manual is attached here so you all can read it if you like - more info and ordering information for the T4.1 Raduino Clone is on the TSW website.
Thanks for your interest,
Jim - W0EB
TSW Engineer/Project Coordinator
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Re: New kit: QDX - Digital Transceiver by QRP Labs
Hans has commented on this one earlier. It¡¯s 9V or transistor will burn. If you check the online manual you can change the turns ratio of one of the transformers if you want to use a higher voltage.
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Re: New kit: QDX - Digital Transceiver by QRP Labs
Thank you for the innovative product and explanation!
You described this as needing a 9V power source with an output of 5W.? I noticed the Power Output VS Supply Voltage graph depicted on the shop page shows nearly 8W output at 12V.? Was this included just to show the performance characteristic of the amp section, and not intended to imply it can be run at 12V ?? This also makes me wonder, will the QDX be damaged if it runs at 13.4V ?? Of course I can build a buck converter to use the QDX with my existing field gear power system at 9V, but am just wondering if failing to do so is likely to kill the QDX.
73, N4RL??
?
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Re: New kit: QDX - Digital Transceiver by QRP Labs
On Sat, Oct 9, 2021 at 07:52 AM, Hans Summers wrote:
The main QRP Labs page is
I just read the "draft" manual. So many good ideas for practical designs already worked out by an expert. Hans, Ashhar and Jack (all experts) are forging ahead on new SDR designs and all of them are great resources for practical knowledge. As well as some nice kits coming along, so it seems. Tom, wb6b
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Re: Problems with audio tones (in RX) with uBitx v
#ubitx
#v5
Sorry, the send key got pressed unintentionally.??
Hi Albert,
From my experience, this type of issue is solved by doing the full calibration process as in the video for the v6:
This process does work with the KD8CEC version 1.2 software, just with a different way to get to and adjust the calibration values.? The important thing is to first adjust the BFO to be more towards the low audio tones for the zero beat process, then adjust the frequency calibration, and finally adjust the BFO for best audio.? When doing this you tend to adjust the oscillators to center the signal on the filters and avoid the birdies from the Nano and other signal sources in the radio.??
It will not work with the stock v5 software because that version goes into transmit mode to adjust the frequency calibration.
Hope this helps.
73
Evan
AC9TU
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Re: Problems with audio tones (in RX) with uBitx v
#ubitx
#v5
Hi Albert,
From my experience, this type of issue is solved by doing the full calibration process as in the video for the v6:
This process does work with the KD8CEC version 1.2 software, just with the different way to get to and adjust the calibration values.? The important thing is to first adjust the BFO to be more towards the low audio tone for the zero beat process, then adjust the fre
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Problems with audio tones (in RX) with uBitx v
#ubitx
#v5
?
Hi everyone,
I hope someone can help me troubleshooting my uBitx v5. After wiring up the board I got ?almost no reception on the amateur bands, therefore I upgraded the firmware to CEC 1.2 and adjusted the BFO to 11.056.255 Hz.
After these changes I am able to receive signals and get reasonable audio output, however, at every (~15.9 KHz) I do get a loud audio tone. The tone pitch shifts up (with LSB) when I increase the tuning frequency. When switching to USB I believe the tone shifts 3 KHz up, in USB the tone pitch lowers when the tuning frequency increases.
The frequency of the tone changes also (proportionally) when I adjust the BFO frequency or when applying an IF shift.
Also tried to trace back the issue, when I ground TP20 the tone disappears, however, when I ground the input of the 11,059 Xtal filter (TP17) doesn¡¯t have any audible effect on tone.
Thanks! Albert
PA2AF
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Re: New kit: QDX - Digital Transceiver by QRP Labs
Hans Summers, bom dia.
Gostaria muito de um exemplar completo, inclusive com sua caixa. Estarei te enviando o pagamento. 73's PY2PVB
Rubens Kamimura T¨¦cnico em Eletr?nica e Eletrot¨¦cnica - Aposentado CFT/CRT-SP: 80254934820 Cel. +55 (18) 9-9819-2225 WhatsApp
Em s¨¢b., 9 de out. de 2021 ¨¤s 11:52, Hans Summers < hans.summers@...> escreveu:
Hi all
I am pleased to announce at last the availability?of the new QDX transceiver. I actually developed this nearly two years ago but a lot of things got in the way of finishing the final touches to the firmware and documentation... ya know, Covid19, a new baby in the house, and of course QCX-mini and all it's associated teething troubles, along with keeping QRP Labs going...?
QDX will cost $60 and the optional enclosure will cost $20. The shop page is ? Ordering will open at 1800Z on Monday 11-Oct-2021. The main QRP Labs page is QDX Video:?? Between now and Monday, you can read the manual and ask any questions. Please understand and read the manual before ordering.?
So QDX... a four band 5W digi modes transceiver 80, 40, 30 and 20m. It produces 5W from a supply voltage of 9V using a new Class-D Push-Pull amplifier I developed specially for it. Most importantly, this is NOT an SSB transmitter! It suits any single FSK mode (such as FT8, JS8Call, WSPR, JT4, JT9, JT65 and more). It performs an analysis of the audio output by the PC program (e.g. WSJT-X) to determine the audio frequency then commands the Si5351A Synth to produce that frequency. As such, there is NO unwanted sideband transmission, NO residual carrier transmission, and NO IMD products due to amplifier non-linearities. Just efficient, clean transmission.?
The QDX receiver is a high performance SSB received using an embedded SDR, with a high performance 110dB dynamic range, 24-bit, 48ksps stereo ADC chip and 32-bit ARM Cortex M4 processor.?
All band switching and transmit/receive switching is solid state. No plug-in modules here, no relays. Everything is electronically switched by CAT control automatically when you change the band drop down in WSJT-X.?
QDX also includes a 24-bit 48ksps stereo USB sound card for audio, and a USB Virtual COM serial port for CAT. Transfer of audio from WSJT-X to QDX is noise-free, lossless, just a pure transfer of digital sample information. Transfer of audio from QDX to the PC via the USB sound card is high fidelity without possibility of ground loops. No audio cables, no headaches - just a single USB cable between PC and QDX carries both audio and CAT commands. QDX has only three connectors: DC power, USB and RF (to the antenna).?
The VFO is a Si5351A Synthesizer under CAT command from the PC. So it covers any digital frequency, not just limited to FT8 for example. QDX includes a 25MHz TCXO module as standard, as the reference for the Si5351A Synthesizer.?
QDX includes its own internal signal generator and test tools suite too. You can connect a terminal emulator to it and explore the performance and techniques that make it work, as well as enter any specific configurations you may need. However the terminal application mode is not necessary for ordinary operation and most users will not need it.?
QDX includes the QFU (QRP Labs Firmware Update) bootloader so lifetime free firmware updates are easy to install, just by loading the new firmware file into QDX using File Manager on your PC: works on any OS, no drivers, no software, no hardware e.g. programmer.?
Due to an unfortunate self-resonance QDX assembly requires removal of four 47uH SMD inductors that are to be replaced with four axial leaded inductors (supplied). Furthermore, since QDX uses the AMS1117 voltage regulator, an additional electrolytic capacitor is supplied that must be soldered to connections on the top side of the board. Other risks of using the AMS1117 are mitigated by the fact that QDX has no ports where hot-plugging or shorts could cause any danger of AMS1117 failure - so this is not a risky situation as the first batch QCX-minis had.?
The optional QDX enclosure is the same aluminium extrusion as used in the QCX-mini but of course is cut, drilled and laser-etched differently.?
Initially,?I produced a batch of 500 QDX, which I actually manufactured back in January 2020 before the Covid19 pandemic got started. On Monday 11-Oct-2021 at 1800Z I will put a quantity of 450 QDX in the shop, for ordering. What of the remaining 50... well quite a few didn't make it through the firmware development and testing (when developing the QFU bootloader, I bricked quite a few QDX!)... and I am going to hold a few back in case of issues etc. losses in shipment, etc etc.?
Due to the global semiconductor crisis, several of the ICs used are currently unavailable so I do not know when the next batch of QDX can be made available. I will begin researching sources or alternative ICs.?
So - any comments and questions are welcome, the manual is there, available to read and understand so you can decide whether you would like to order one.?
73 Hans G0UPL
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New kit: QDX - Digital Transceiver by QRP Labs
Hi all
I am pleased to announce at last the availability?of the new QDX transceiver. I actually developed this nearly two years ago but a lot of things got in the way of finishing the final touches to the firmware and documentation... ya know, Covid19, a new baby in the house, and of course QCX-mini and all it's associated teething troubles, along with keeping QRP Labs going...?
QDX will cost $60 and the optional enclosure will cost $20. The shop page is ? Ordering will open at 1800Z on Monday 11-Oct-2021. The main QRP Labs page is QDX Video:?? Between now and Monday, you can read the manual and ask any questions. Please understand and read the manual before ordering.?
So QDX... a four band 5W digi modes transceiver 80, 40, 30 and 20m. It produces 5W from a supply voltage of 9V using a new Class-D Push-Pull amplifier I developed specially for it. Most importantly, this is NOT an SSB transmitter! It suits any single FSK mode (such as FT8, JS8Call, WSPR, JT4, JT9, JT65 and more). It performs an analysis of the audio output by the PC program (e.g. WSJT-X) to determine the audio frequency then commands the Si5351A Synth to produce that frequency. As such, there is NO unwanted sideband transmission, NO residual carrier transmission, and NO IMD products due to amplifier non-linearities. Just efficient, clean transmission.?
The QDX receiver is a high performance SSB received using an embedded SDR, with a high performance 110dB dynamic range, 24-bit, 48ksps stereo ADC chip and 32-bit ARM Cortex M4 processor.?
All band switching and transmit/receive switching is solid state. No plug-in modules here, no relays. Everything is electronically switched by CAT control automatically when you change the band drop down in WSJT-X.?
QDX also includes a 24-bit 48ksps stereo USB sound card for audio, and a USB Virtual COM serial port for CAT. Transfer of audio from WSJT-X to QDX is noise-free, lossless, just a pure transfer of digital sample information. Transfer of audio from QDX to the PC via the USB sound card is high fidelity without possibility of ground loops. No audio cables, no headaches - just a single USB cable between PC and QDX carries both audio and CAT commands. QDX has only three connectors: DC power, USB and RF (to the antenna).?
The VFO is a Si5351A Synthesizer under CAT command from the PC. So it covers any digital frequency, not just limited to FT8 for example. QDX includes a 25MHz TCXO module as standard, as the reference for the Si5351A Synthesizer.?
QDX includes its own internal signal generator and test tools suite too. You can connect a terminal emulator to it and explore the performance and techniques that make it work, as well as enter any specific configurations you may need. However the terminal application mode is not necessary for ordinary operation and most users will not need it.?
QDX includes the QFU (QRP Labs Firmware Update) bootloader so lifetime free firmware updates are easy to install, just by loading the new firmware file into QDX using File Manager on your PC: works on any OS, no drivers, no software, no hardware e.g. programmer.?
Due to an unfortunate self-resonance QDX assembly requires removal of four 47uH SMD inductors that are to be replaced with four axial leaded inductors (supplied). Furthermore, since QDX uses the AMS1117 voltage regulator, an additional electrolytic capacitor is supplied that must be soldered to connections on the top side of the board. Other risks of using the AMS1117 are mitigated by the fact that QDX has no ports where hot-plugging or shorts could cause any danger of AMS1117 failure - so this is not a risky situation as the first batch QCX-minis had.?
The optional QDX enclosure is the same aluminium extrusion as used in the QCX-mini but of course is cut, drilled and laser-etched differently.?
Initially,?I produced a batch of 500 QDX, which I actually manufactured back in January 2020 before the Covid19 pandemic got started. On Monday 11-Oct-2021 at 1800Z I will put a quantity of 450 QDX in the shop, for ordering. What of the remaining 50... well quite a few didn't make it through the firmware development and testing (when developing the QFU bootloader, I bricked quite a few QDX!)... and I am going to hold a few back in case of issues etc. losses in shipment, etc etc.?
Due to the global semiconductor crisis, several of the ICs used are currently unavailable so I do not know when the next batch of QDX can be made available. I will begin researching sources or alternative ICs.?
So - any comments and questions are welcome, the manual is there, available to read and understand so you can decide whether you would like to order one.?
73 Hans G0UPL
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The ubitx does have the rd15hfv1 footprints.
On Sat, Oct 9, 2021, 4:34 PM Lawrence Galea < 9h1avlaw@...> wrote: Good afternoon Farhan He uses the RD16HHF1 up to 70MHz but then changes to RD15HVF1 on 144MHz to? 432MHz
TX Output transistor -?RD16HHF1
 ?TX Output transistor -?RD16HHF1
?TX Output transistor -?RD15HVF1
?TX Output transistor -?RD15HVF1
It would push up the cost of the mbitx?if they?were used and could use the same 12V supply for more output. but it would be less likely to blow the finals Regards Lawrence
On Fri, Oct 8, 2021 at 5:14 PM Ashhar Farhan < farhanbox@...> wrote: He uses RD15HVF1 in the transverters as Sarmaji had recommended.?
On Fri, Oct 8, 2021, 8:40 PM Lawrence Galea < 9h1avlaw@...> wrote: I have two transverters and they both use the RD16HHF1. I have worked barefoot with them on both 50 and 70 MHz and I believe that he uses the same RD16HHF1 on the 144 MHz one
I built an amp almost identical to this one. I used the RD16HFF1 mosfets. It gave between 16 and 20W output from 80m to 10m, and 6W output on 6m. During sporadic E I worked several thousand km on SSB with the 6 watts, and it should be sufficient for a larger amplifier.? Here in the UK was also have &0 MHz (4 metres) but I didn't try these mosfets on that band.
Tony, G4CIZ
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Good afternoon Farhan He uses the RD16HHF1 up to 70MHz but then changes to RD15HVF1 on 144MHz to? 432MHz
TX Output transistor -?RD16HHF1
?TX Output transistor -?RD16HHF1
?TX Output transistor -?RD15HVF1
?TX Output transistor -?RD15HVF1
It would push up the cost of the mbitx?if they?were used and could use the same 12V supply for more output. but it would be less likely to blow the finals Regards Lawrence
On Fri, Oct 8, 2021 at 5:14 PM Ashhar Farhan < farhanbox@...> wrote: He uses RD15HVF1 in the transverters as Sarmaji had recommended.?
On Fri, Oct 8, 2021, 8:40 PM Lawrence Galea < 9h1avlaw@...> wrote: I have two transverters and they both use the RD16HHF1. I have worked barefoot with them on both 50 and 70 MHz and I believe that he uses the same RD16HHF1 on the 144 MHz one
I built an amp almost identical to this one. I used the RD16HFF1 mosfets. It gave between 16 and 20W output from 80m to 10m, and 6W output on 6m. During sporadic E I worked several thousand km on SSB with the 6 watts, and it should be sufficient for a larger amplifier.? Here in the UK was also have &0 MHz (4 metres) but I didn't try these mosfets on that band.
Tony, G4CIZ
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On Fri, Oct 8, 2021 at 10:44 AM, Jack, W8TEE wrote:
Rex (QRPMe.com) also sells Mepads, which makes Manhattan style construction pretty easy for anyone. David Richards (AA7EE) uses them to take homebrew to an art form:
Hi Jack, I know all about the Mepads. They are terrific and I recommend them to the new builders in The Vienna Wireless Makers group for our group build of the SimpleSSB. ?I¡¯ve also just cut up pieces of copper clad for pads and that works well. ?Dave¡¯s work is beautiful to look at¡there is both art and science to doing circuit layouts. ?I¡¯ve gotten better at layout over time. ?I¡¯ve also learned that beauty in layouts doesn¡¯t always lead to better results. ?For amps you need to worry about keeping inputs away from outputs to avoid feedback and oscillation. For filters you have to think about stray capacitance. Every you have to worry about sources of noise. ?It¡¯s different from software - ¡°readability¡± of the finished product is not necessarily a major design best practice. ?Ugly construction is as it¡¯s name applies, but works very well and after you get used to it is very quick to build. 73, Dean
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On Fri, Oct 8, 2021 at 06:04 AM, Bill Cromwell wrote:
Audio filters will do nothing to protect the receiver front end from overloading on strong signals.
Yes I know about that.? :) I have several strong am transmitters nearby.? I have an old that I put between the antenna and the ubitx.? Works great.? And I can transmit through it as well. I have an old laying around.? How does the Hypermite compare to this filter?? Or are they the same?
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I took a different approach.? Using a battery for my BITX and turning the
mains power off, convinced me that most of the noise was originating
from local in-house sources.? I checked noise from each appliance and
found several local culprits that could be quieted down a significant
amount.? This is a different kind of noise, but I was able to bring an S-9
background down to S-2.? Now I can start to seriously look at external
noise and how to make the BITX more resistant to that problem.
Arv _._
On Fri, Oct 8, 2021 at 12:22 PM Rafael Pinto [PU1OWL] < rafaelgcpp@...> wrote: On Fri, Oct 8, 2021 at 04:30 AM, Ashhar Farhan wrote:
A more aggressive front end filter migth eliminate the noise substantially. The ubitx front end is wide open. While tuned to 21 Mhz, it? can overload from a 100 khz noise from an smps.?
The bitx40, being a monobander had the luxury of a triple tuned front end. You could add something similar and see if the noise drops.
I had this weird idea of having some external BPF on the uBitx for 15m, but never went ahead with it. Thinking again it could be rigged just by the T/R relay, but then I would lock the uBitx...
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On Fri, Oct 8, 2021 at 04:30 AM, Ashhar Farhan wrote:
A more aggressive front end filter migth eliminate the noise substantially. The ubitx front end is wide open. While tuned to 21 Mhz, it? can overload from a 100 khz noise from an smps.?
The bitx40, being a monobander had the luxury of a triple tuned front end. You could add something similar and see if the noise drops.
I had this weird idea of having some external BPF on the uBitx for 15m, but never went ahead with it. Thinking again it could be rigged just by the T/R relay, but then I would lock the uBitx...
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He uses RD15HVF1 in the transverters as Sarmaji had recommended.?
On Fri, Oct 8, 2021, 8:40 PM Lawrence Galea < 9h1avlaw@...> wrote: I have two transverters and they both use the RD16HHF1. I have worked barefoot with them on both 50 and 70 MHz and I believe that he uses the same RD16HHF1 on the 144 MHz one
I built an amp almost identical to this one. I used the RD16HFF1 mosfets. It gave between 16 and 20W output from 80m to 10m, and 6W output on 6m. During sporadic E I worked several thousand km on SSB with the 6 watts, and it should be sufficient for a larger amplifier.? Here in the UK was also have &0 MHz (4 metres) but I didn't try these mosfets on that band.
Tony, G4CIZ
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I have two transverters and they both use the RD16HHF1. I have worked barefoot with them on both 50 and 70 MHz and I believe that he uses the same RD16HHF1 on the 144 MHz one
I built an amp almost identical to this one. I used the RD16HFF1 mosfets. It gave between 16 and 20W output from 80m to 10m, and 6W output on 6m. During sporadic E I worked several thousand km on SSB with the 6 watts, and it should be sufficient for a larger amplifier.? Here in the UK was also have &0 MHz (4 metres) but I didn't try these mosfets on that band.
Tony, G4CIZ
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Dean:
Rex (QRPMe.com) also sells Mepads, which makes Manhattan style construction pretty easy for anyone. David Richards (AA7EE) uses them to take homebrew to an art form:
 Look closely and you'll see Hans LPF in the picture. He has more pictures on his website. Everytime I visit there, I want to throw rocks at my stuff!
Jack, W8TEE
On Friday, October 8, 2021, 09:51:22 AM EDT, Dean Souleles <dsouleles@...> wrote:
On Wed, Oct 6, 2021 at 08:31 PM, Tom, wb6b wrote:
Manhattan style, seems a perfect match for these cheap CNC routers
Yes, indeed.? Here are a few more boards I cut on the CNC.? And once the design is done it's a snap to knock out another one. Dean  
-- Jack, W8TEE
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Hi,
Thanks forpointing out the IRFZ24N. I hunted it down and started looking at specs. I will probably get a few in here and give them a try. I haven't found those RD16HHF1 parts except from the offshore sellers (who I have lost most confidence). I haven't made a deep search among the more reliable suppliers. The IRF parts are very inexpensive and apparently more robust so not a lot of motivation for the RD parts.
73,
Bill KU8H
bark less - wag more
toggle quoted message
Show quoted text
On 10/8/21 10:12 AM, Dean Souleles wrote: On Thu, Oct 7, 2021 at 06:04 AM, Ashhar Farhan wrote:
I have had considerable success with IRFZ24N. This was discovered
by W6JL for his ARRL Homebrew contest winning entry. The IRF510s,
idled back to provide 2 watts of drive can easily push a pair of
IRFZ24Ns for clean 50 watts power with 13.8v power supply.
Thanks Farhan. Now that I have built one amp I'm losing my fear of building another :).? A little bit of experience and great Elmer's like you, Pete and Bill goes a long way!
73,
Dean
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Jim Sheldon
Rafael Pinto [PU1OWL]