The T41 from 4SQRP and V11 boards.
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All: Recent there was a negative post about the V11 boards and the T41 from 4SQRP. I got this private email from Neville Marr, ZL2BNE, who has been following the T41 from its inception. He has a T41 from 4SQRP and speaks positively about it. I asked him if I could re-post his email because I know there are a lot of 4SQRP radios out there and he wants everyone to know that it is a good radio that he uses on a regular basis. I, too, have a 4SQRP T41 and it is a very good radio. He gave me his okay to post his email. Jack, W8TEE =============== ? Hi Jack, We haven¡¯t communicated in quite some time but I continue to check-in on the softwarecontrolledhamradio group from time to time. I¡¯ve recently reviewed postings and one took my attention ¡ for the wrong reasons.? /g/SoftwareControlledHamRadio/message/33358 The post was pretty disparaging of the V11 receiver performance, among other things calling it an intolerable toy radio. I see no point in giving such posts oxygen on the forum but I felt a need to let you know my experience is totally different. You will recall I was an early adopter of the T41 project, I had V10 boards made and did my own thing. You will also recall I was quite critical of some aspects of the project. I always had issues with the transmit side of my V10 T41 but never the receive side. The receiver worked from day one. In my case I don¡¯t hear any noise on rx with a dummy load connected. I can easily hear my Marconi sig gen set as low as it will go at -127dBm. It¡¯s a very good receiver. Over time I made a number of hardware changes to my QSE, I built two filters of my own design, one follows the QSE the other follows the PA. Final transmit change is adopting the K9HZ PA. Today my radio works faultlessly using Greg¡¯s T41EEE. I got everything where I wanted and started logging contacts in August 2023. I¡¯m not much of an operator but do put my creations on the air. I¡¯ve just interrogated my log to discover I¡¯ve logged exactly 100 contacts using my T41. Quite a cool number. I¡¯ve had the T41 on the air more times than that, mainly local nets, but all the same 100 in the log. Below is a breakdown of the 100. I¡¯ve worked every continent except Africia (Africia is notoriously difficult to work from NZ, South Africia is the rarest DX from NZ). So thank you for getting the T41 up and running. I am a little sad that V10/11 got supplanted by V12 because V10/11 is a very good radio. I do hope people can get V12 to a place where V12 T41 are on the air too. My T41 is my go-to radio, my daily runner. ?Cheers, Neville ZL2BNE ? ? ? -- Jack, W8TEE |
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All: Agree. Most people probably aren't aware of and don't appreciate the effort David (NG0S), Ron (AG1P, SK), and the others at 4SQRP put into the T41 Project. The inventory/holding costs were a huge financial burden on the group and Ron kitted the bags of parts and, given his health, I'm sure it was a monumental burden on him. Greg (KF5N) made Herculean contributions to the software from the outset and went on to make changes to the boards themselves. I think most people are aware of the largess provided to the project by Dr. Bill Schmidt (K9HZ) in providing boards at cost plus the improved PA design. Oliver King (KI3P) has made major improvements in the software as well as the design/layout of the PCB plus some really nice images of the board layout. We now have over 3200+ members on the T41 site and many have made improvements/suggestions that have nudged the Project to its current state. I finally have my new system to the point where I can test the current state of the software and Oliver has that in great shape. Al and I have finished the last update to the book and it now appears that Amazon is shipping the new updated version of the book. You can tell if you have the final version by looking at the cover. It should look like: and have a new chapter at the end of the book (Chapter 20, Calibration). Like some of you, I ordered copies for Al and I to review and they sent the wrong edition. (If this happened to you, it is very easy to return them.) Al is turning over the design to Bill and I'm handing off the software to Oliver going forward. Oliver will hold our last software release on Github (without future forks), plus a second release specifically for debugging/enhancements. Al and I will continue to monitor this site, but will be more in the background. We plan on doing more operating, working on some new stuff, plus eating bon-bons and getting to know our XYLs! Alas, I didn't make enough from the Project's book to buy my Swiss chalet, but Al and I are pleased with the direction things are going. It's been fun... Jack, W8TEE
On Friday, April 11, 2025 at 03:48:02 AM EDT, Harry Brash via groups.io <harry.brash@...> wrote:
Jack
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I was interested to read Neville's comments re /g/SoftwareControlledHamRadio/message/33358
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I haven't used T41/V12 boards at all but, looking at the circuits, the V12 RX circuits seem almost identical to the V10/11 in every way that matters .? My experience of the V10 RX performance is very positive, similar to Neville's.? The main? changes I have made and experiments I have tried relate to the TX side of my T41/V10 rather than the RX,? ?I've (successfully) tried some of Greg's hardware mods by hacking my V10 QSE board which now has lots of cut tracks and extra solder links on it !
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I also use Greg's excellent T41EEE software.and have replaced the original T41 V10 PA by the K9HZ PA.
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By the way, I think Neville did his own thing building his T41 rather than building a 4SQRP kit.
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For me, T41 EP V10/V11 has been and remains a great project.
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Thanks.
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Harry? GM3RVL
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-- Jack, W8TEE |
¿ªÔÆÌåÓýWell Harry¡ here is a list of the differences between the V10/V11 series RF boards and the V12 RF board.? Just for reference: ? ? 1. Functions of the QSE and QSD combined into one board for synergy. 2. Si5351 LO is on the RF board to keep RF lines short. 3. Quadrature LOs are generated in the si5351 directly allowing much greater frequency span of base-level transceiver, now covers 600KHz-150MHz+. 4. Improved anti-aliasing filters using reformed filters and ultra-low noise Op Amps (AD8599 and OPA2209) 5. TX to RX Feedback line to facilitate auto-calibration. 6. New MMIC RF front-end gives flat gain over entire receive range and better than 0.5uV sensitivity. 7. Ultra-wide band impedance matching RX Input transformer facilitates isolation and static drain. ? 8. New high speed CW key-shaping circuitry for perfect keying. 9. Optional 32 dB in half steps RF gain control on front end (PE4302). 10. Optional TCXO for less than 0.1ppm frequency drift. 11. Optional precision-adjustable RF power output from exciter in 0.5 dB increments (PE4302, 32 power steps from for 1mW to 1mW) 12. Compatible with V011 hardware (but requires V012 Main board). 13. 4-layer board for reduced RF cross-talk and IMD. 14. Built only what you want/ need concept. 15. Same size as V10/V11/V12 Main board. 16. Single 12V connection. Onboard voltage regulators just for RF board. Distributed power model. 17. Works with either V10/V011 LPF and PA boards, or with enhanced V12 LPF and K9HZ boards. 18.? Optionally add a second RF board for second RX (great for DXers). ? ? I may have a few V11 boards left¡ I¡¯ll have to look.? If not, the Gerbers are out on my GITHUB for those who must have them. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Harry Brash via groups.io
Sent: Friday, April 11, 2025 2:48 AM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] The T41 from 4SQRP and V11 boards. ? Jack ? I was interested to read Neville's comments re /g/SoftwareControlledHamRadio/message/33358 ? I haven't used T41/V12 boards at all but, looking at the circuits, the V12 RX circuits seem almost identical to the V10/11 in every way that matters .? My experience of the V10 RX performance is very positive, similar to Neville's.? The main? changes I have made and experiments I have tried relate to the TX side of my T41/V10 rather than the RX,? ?I've (successfully) tried some of Greg's hardware mods by hacking my V10 QSE board which now has lots of cut tracks and extra solder links on it ! ? I also use Greg's excellent T41EEE software.and have replaced the original T41 V10 PA by the K9HZ PA. ? By the way, I think Neville did his own thing building his T41 rather than building a 4SQRP kit. ? For me, T41 EP V10/V11 has been and remains a great project. ? Thanks. ? Harry? GM3RVL ? ? |
¿ªÔÆÌåÓýHi Harry, Thanks for the note. ? I just checked my records and I sold a total of 218 full sets of V10/V11 boards (plus odds and ends of full sets).? But that was two plus years ago.? I may still have sets of V10/V11 bare boards in the recycle box¡ I¡¯ll dig around to see if I can find some for you because the demand for the V10/V11 sets has dried up as of the V12 release.? In any case, the GERBERS for the V10 and V11 boards are all available at no cost on my GITHUB.? The 4SQRP boards (+GERBERS) are not available to me so I can¡¯t support them as of now. ? Beyond that, I¡¯ve sold 1,200+ sets of V12, and 150+ in stock that I will sell at Hamvention in about a month.? Last year I sold 200 sets at FDIM and HamVention alone in just 4 days, and I expect to do that and more this year, since I now have an inside booth (4111 for those who will attend). ?I will take paper orders if I run out (I expect that will happen because I only have so much space in my luggage).? I will also be selling the latest T41 book (signed copies) from Jack and Al at Hamvention in my booth (NOT at FDIM where Jack and Al will be selling the book). ? I won¡¯t be able to support older versions of the T41 past free GERBERS and documentation.? The cost of doing so is prohibitive.? I have thousands of US dollars tied up in parts and boards¡ and can only support so much.? I don¡¯t know if Greg supplies boards for your V10/V11 projects or not¡ I don¡¯t really follow what he does (and hence can¡¯t/ don¡¯t/ won¡¯t comment on it). ?I do see some new directions on the horizon for the T41 after V12.? The RF performance is outstanding¡ now to supercharge the user interfaces and the I/Q processing parts. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch ¨C K9ZC Staunton, Illinois ? Owner ¨C Operator Villa Grand Piton ¨C J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Harry Brash via groups.io
Sent: Wednesday, April 16, 2025 1:11 AM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] The T41 from 4SQRP and V11 boards. ? Bill Thanks for the long list of specs of the T41-V12. I suppose that Andy G8HCK passed on my inquiry to him for a couple of V10/V11 QSE PCBs and you may be wondering why I¡¯m looking for such old technology.? I¡¯ve been using my original V10 QSE board so much for hardware development that it is starting to fall apart with all the cut traces, solder jumpers and extra mounting holes.?? Fortunately, it still works in its original form. For my purposes, the V12 RF boards are too dense for much hardware experimentation, particularly with 4 layer boards.?? I feel that they don¡¯t encourage the original ¡°EP¡± concept that Jack and Al first promoted.? I see the V12 concept as almost a pre-production prototype for a commercial radio with very tight specs.? I really admire the way that your team are striving to make it all work and I wish you all every success. My T41 interests now lie in the direction which Greg KF5N is taking both for hardware and software development.? Of course it is a positive sign of an on-going healthy project like the T41-EP that it can and does evolve in several directions and long may that continue ! 73 Harry GM3RVL |
jjpurdum
K9HZ