Great video, Rick. Your measurement demonstrates that the oscillator purity is excellent; probably good enough for on-the-air use to generate CW. '73 Marty, K1FQL
Cuidado com esse tipo de chave para usar em sinais de RF, a resistência dos contatos pode chegar a algumas dezenas de ohm, eu fiz um atenuador com essa chave e não ficou bom, com a chave H-H ficou melhor. Uma pergunta, você acha que essa etapa de IF que você montou pode funcionar bem no lugar da etapa de IF clássica dos rádios que usam três transformadores de IF?
Thank you for the good advice on the switch. So far I have not had any issues with this switch, but it's good to know that they can fail in this way. I don't know if this amp would be correct for a radio with I.F. transformers. The radios I build are copies of work done by others and is a version of a bitx from Ashhar Farhan (VU2ESE) and Wes Hayward's (W7ZOI) and Bob Kopski's (K3NHI) TIA amp. 73
The display is connected to a different version of my Front Panel that uses an Arduino NANO instead of the more advanced MEGA 2560. Because of the limited memory and I/O space in the NANO (vs. the MEGA), the NANO version is very limited in features. Here's the link to the NANO Front Panel www.remmepark.com/circuit6040/MAX-SSB-NANO/max-ssb-nano.html 73
Thank you GiorgioFirpo! Yes, in the early days of my homebrew attempts I was intimidated by the complexities of the projects on the web and books. I found that I had to start small by building very simple circuits first; e.g. AF amplifiers, RF oscillators, et cetera building up my construction skills over time. One project that helped me was to take a transistor AM radio, draw a schematic by following the traces of the PCB, then *carefully* remove the parts from the working AM radio one stage at a time and build it homebrew style as modules. When I was done I had a modular homebrew AM radio. :-) Also, there a a lot of inexpensive AM radio kits, buy two and build the first one using the PCB supplied in the kit, and build the 2nd one as homebrew example: www.aliexpress.us/item/3256806101211832.html?spm=a2g0o.detail.pcDetailTopMoreOtherSeller.2.508a1479jZx2Lw&gps-id=pcDetailTopMoreOtherSeller&scm=1007.40050.354490.0&scm_id=1007.40050.354490.0&scm-url=1007.40050.354490.0&pvid=72d37e26-289d-4277-9b1e-149a87b08a58&_t=gps-id:pcDetailTopMoreOtherSeller,scm-url:1007.40050.354490.0,pvid:72d37e26-289d-4277-9b1e-149a87b08a58,tpp_buckets:668%232846%238113%231998&pdp_npi=4%40dis%21USD%214.63%210.99%21%21%2132.87%217.02%21%402103080717244106061061390e4344%2112000036620087800%21rec%21US%21%21ABXZ&utparam-url=scene%3ApcDetailTopMoreOtherSeller%7Cquery_from%3A
I would try changing the impedence and use a parallel coax system to feed it out of the basement. Now. I don't know the impedance you are using, but. You can approximate with parallel coax and eliminate/ reduse interaction with metal objects along the run
Hi Rick, Very interesting ! Just started the build and completed just the Mega connected to the display. Loaded the code, and I was greeted with some light from the display. I can see the splash screen, and next I see a popup saying that I have an alarm (SWR too high....SWR tripped at 9.900). Mind you, I have not yet connected anything else but the display to Mega2560. Is this to be expected ? 73, HAns PA3CRZ
Thank you! No, I don't have plans to try a larger display at this time. I'm currently using a 3.2" ILI9341 based display and the text on the screen is large enough for comfortable tabletop operations. The key here is the ILI9341 chip-set in the display, if a larger display that uses the ILI9341 could be found then it could be a drop-in replacement. A larger display with a different chip-set would probably require some of the code be rewritten and different display libraries may also be needed. Here are some sources for the 3.2 inch display I used: www.amazon.com/3-2inch-Module-Display-ILI9341-320X240/dp/B0BZGSPP1V/ref=sr_1_4?crid=2NGS6I029BQCL&keywords=3.2%2BInch%2B320X240%2BSpi%2BIli9341&qid=1689515924&s=electronics&sprefix=3.2%2Binch%2B320x240%2Bspi%2Bili9341%2Celectronics%2C79&sr=1-4&th=1 www.ebay.com/itm/3-2-Inch-320X240-SPI-Serial-TFT-LCD-Module-Display-Screen-With-Contact-Pane-/203014329796 73 - Rick - N3FJZ
Hello user-1166, thank you for the complement. No, it's was designed for SSB based on my understanding of how SSB works. Because of the stability of the Si5351 VFO/BFO it can receive AM if tuned precisely, but there are no provisions for transmitting on AM or other non-SSB modes. 73 - Rick - N3FJZ
Wow weve come a long way where we can obtain cheap filter kits. Is there a discussion of the various i.f. frquencies used i.e. is it a function of crystal availability or transceiver design? I know 9 MHz has long been a favorite for single conversion rigs iirc. While the kit availability is nice I decided that Im going to slog through the math and measure them with a vna (I need to find one yet) partly to choose my own lower i.f. freq of 2 MHz or 2.5 MHz.
Yes indeed, it's very rewarding to build your own crystal filter. The MAX-SSB front panel software makes it easy to experiment with various I.F. frequencies (i.e. crystal filter center frequency) be being able to change the I.F. frequency on-the-fly directly from the Settings menu without the need to change it in the source code. Not only that, you can change the I.F. frequency real-time while listening to the results which allows you to fine-tune the I.F. to match the crystal filter's frequency exactly. 73 Rick N3FJZ.
Yes indeed! As a matter of fact, in Wes' whitepaper on this amplifier, the title is "...Adding AGC to a Termination Insensitive Amplifier..." (w7zoi.net/tia+agc.pdf). I want to explore adding true AGC to my MAX-SSB in the future but haven't yet had quality time to do this properly, but having the variable gain amp in the RX path as part of the base design was a good start for when I'm ready (for now I'll use it as a manual RF gain control). I use the variable gain amp in the TX path as a way to make the output power variable. I like to "tune-up" my 80 meter loop/transmatch using about 500 mW then slowly bring up the power to 20 watts once the tuning to an SWR of 1:1 is complete. 73 - Rick - N3FJZ
@@Circuit6040 I think if you are going to add AGC its worth taking your time and doing it rite..... and RF control is the way forward and creating the balance of stages... beautiful work mate I love your stages and your design makes trying them out sooo easy and real time... I will give the link to Wes's paper a good looking at, thank you!
@@paulsradiohacks You're welcome. Here's another one of Wes' papers on AGC (www.ka7exm.net/hycas/hycas_200712_qst.pdf). If I do go forward with adding AGC to my rig, this would probably be the one I would consider. 73 - Rick - N3FJZ
if you have a full size loop (100 to 150 ohm resistance) then rather than ladder line you can also consider sat tv "Shorgun twin" 75 ohm co-ax & just feed balanced between the centres,,, as it is screened its routing is "idiot proof" like normal co-ax & it doesn't have to be kept clear of metal... at 2x75ohm = 150 ohm it is pretty well matched to the loop too
StreakyP, great idea! I have an old run of abandon C/Ku band dual 75 ohm coax going from the house to where the old 10 foot TVRO dish was one located. This would be a great experiment to try in the future. Thanks for the suggestion 73 Rick N3FJZ
TeknoTrek, Thank you for the kind comments. Yes, I intend on posting videos for all the modules as I complete them, and I'm looking forward to the day I can show a completed rig in operation. Stay tuned... 73 - Rick - N3FJZ
W1RMD, Thank you for the kind comment. I spend about a week building each module a few 10's of minutes here and there, but if I were to count the total time non-stop (like a 9-5 job) I would estimate between 3-6 hours per board actually soldering et cetera, but collecting the parts, and the preliminary work (finding RF circuits by other homebrewers on the internet to copy, designing the layout, drawing schematics, testing prototypes) does of course take much longer. This is definitely not a project if you wanted to build something quickly. This is a project to enjoy the learning and building process, sort of like those RU-vid videos you see where someone builds a sailboat from scratch starting with a stack of lumber, or mountain climbing, just to see if one can do it. 73 Rick N3FJZ
@@Circuit6040 I've been a ham for 30+ years, and have just recently started to understand electronics. I've never attempted anything that used ic's or toroids before, other than those kits that only teach you how to solder. Good analogy with the boat. I've heard some say that restoring radios is like restoring old cars. I have noticed on these dyi projects they end up a LOT more complicated than originally planned. You're right, if you are building to learn and enjoy the circuits you'll be okay. If you are building just to get an end result, you will have a life of frustration. Just go a buy what you want and save the trouble. Thanks to channels like yours, it is possible to understand what you're building and learn in the process. Excellent sounding radio! Thanks again and 73!-W1RMD.
As a telegraphist I would like to point out that having CW playing in the background is a terrible-terrible idea. I can't focus when two people are talking simultaneously.
kmnl926, yes indeed, using KiCad and other design tools (and having PCB's produced, or etching my own) is definitely on my future to-do list; however, right now I have set a goal for myself to build as much of my rig by hand using Manhattan construction as possible. I guess it's like a cook challenging themselves to bake a cake from scratch vs. using a cake mix. I made some obvious exceptions of course with the display, Arduino and GPS to keep the development effort reasonable.
Hi Rick, I would like to know if you have configured the GPS UBLOX module in order to generate the PPS even when there is no fix . Many thanks, Antonio (IW0FCI)
antaf56, No, the (hardware) 1 PPS pulse (that gates the frequency counter and generates the interrupt to the Arduino) is only generated when there is a solid fix on the satellite(s); however, te NMEA sentence serial data is output even without a fix. When the Arduino is first powered on, it sends commands to the GPS module. I got the idea from videos created by iforce2d ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-q4ZA6KtYGRg.html and ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ylxwOg2pXrc.html
stevec5000, yes, the dual gate MOSFET is indeed a solid performer for RF amps; however, I wanted something that was a little more available (in a through-hole package) and a little less expensive. Also, I trust the designs of Wes w7zoi: w7zoi.net/tia+agc.pdf
stevec5000, It's the traditional Manhattan construction technique (see: dixiepixieproject.blogspot.com/2009/11/manhattan-pads-and-the-origin-of-term.html ) Pads are punched out of double sided copper PCB board with a 0.125 sheet metal punch. Since each pad is double sided, I solder each Manhattan pad to the tin plated steel sheet; HOWEVER, this can sometimes be a real chore and is very tedious to get right. If you use too little heat the pad will sometimes solder fast to the sheet where you don't want it the moment it touches the sheet, if you use too much heat (to give you some time to precisely place the pad) you risk causing the copper to de-laminate from the Manhattan pad. I only continue to use this method because I have developed a decent muscle memory and dexterity to get it right most of the time. If I had to do it over again, I would simply use single sided PCB for the Manhattan pads and supper glue them down on the substrate. As a matter of fact, I'm thinking about trying the PCB method in the future just to see if I like it better.
@@Circuit6040 Olá, já pensou em usar uma pcb dupla face onde a face de baixo é usada para gnd e a face de cima como trilha de sinal e alimentação? Tenho uma placa de um transceptor de avião que é feito dessa forma, mas a trilha de gnd fica pelo lado dos componentes, eu estou tentando imaginar qual seria a diferença, você sabe? 73
@@canaldopicco Yes, I agree, using glue would be much better. Years ago I used the glue method and ran out of glue one day and I tried the soldering method and it worked and I been doing it like this ever since. It works good for me but I would not recommend it to someone who is already using the glue method. (Translated by Google) Sim, concordo, usar cola seria muito melhor. Anos atrás eu usei o método de cola e fiquei sem cola um dia e eu tentei o método de solda e funcionou e eu tenho feito assim desde então. Ele funciona bem para mim, mas eu não recomendaria para alguém que já está usando o método de cola.
@@canaldopicco I'm not sure what the difference would be, I would think it would have very little affect unless the circuit was VHF, UHF or microwave, it that case using a circuit board at all would require a very critical layout and transmission line rules for the circuit traces would be much more strict. I am avoiding using PCB's for my hobby work because I used PCB's many years ago (for non-RF work) and wanted to do something that had a good track record of RF circuits, and I did not want to get off track by having to learn a new software package to master the PCB design. Maybe some time in the future I will try PCB's for RF work, but for now I sticking with Manhattan construction because I know it works well. 73 Rick N3fjz (Translated by Google) Eu não tenho certeza de qual seria a diferença, eu pensaria que teria muito pouco efeito a menos que o circuito fosse VHF, UHF ou micro-ondas, nesse caso usar uma placa de circuito em tudo exigiria um layout muito crítico e as regras de linha de transmissão para os traçados do circuito seriam muito mais rigorosas. Estou evitando usar PCB's para o meu trabalho de hobby porque eu usei PCB's muitos anos atrás (para trabalho não-RF) e queria fazer algo que tivesse um bom histórico de circuitos de RF, e eu não queria sair da pista por ter que aprender um novo pacote de software para dominar o design de PCB. Talvez algum tempo no futuro eu vou tentar PCB's para o trabalho de RF, mas por enquanto eu continuo com a construção de Manhattan porque eu sei que funciona bem. 73 Rick N3fjz
stevec5000, each flash of these red indicators indicates that the NMEA sentence from the GPS module was successfully decoded. The NMEA sentence is where the MAX-SSB front panel gets the time. There are two indicators in this video, but each do the same thing, I was just testing two ways of flashing the indicators, in the final release there is just one indicator. Having a red indicator on the LCD screen saved me from having to have yet another LED in hardware. 73 Rick N3FJZ
@@Circuit6040 Dear Rick, I just finished the PCB design of the Max Front Panel and I'm double checking it now, I will send it to manufacuturing in a couple of days. I think in 10-15 days I will be able to test it. Once I am sure it works properly, I can send you the gerber files, if you want! You made a great design and I believe this can give a further value to your effort. The board dimensions are 120x80 mm and the PCB is on only 2 layers and has everything on it with a 3.2'' display, I used smd and thru hole components. I respected wire by wire your design. The Schematic and PCB development has been made with Easyeda. I'll keep you informed on the progress. Thanks again, 73 Antonio (IW0FCI)
@@antaf56 Wow, 120mm x 80mm in 2 layers, I'm impressed, that's about the size of a typical smart phone. I can't wait to see it in action. Keep up the good work. 73 - Rick - N3FJZ.
@@antaf56 Yes, I received the images. Wow, beautiful work! You have certainly put in a lot of love and effort in its design and words cannot describe the joy I feel in seeing it. Thank you for taking the time to give my schematic and software an actual PCB to live in :-) I an very excited and looking forward to seeing it in action.
Thank you @plusorminusandtime, Beginning a long time ago (1962) I remember that I always wanted to build my own radio. Along the way there were many false starts, errors, mistakes and smoke, but I think I have finally achieved my goal with the help of examples from books, podcasts, the internet and RU-vid. I'm indeed "standing on the shoulders of giants"
Great 👍 Be careful with these TIAs though, they are relatively easy to overload (comparing to a regular feedback amplifiers). You may hear AM broadcast stations on 40 meters during the night if the gain before the IF will be too high. Make sure most of the gain happens on the IF or AF.
Thank you R2AUK, I will definitely keep this in mind. Yes, I remember seeing Alan Wolke (W2AEW) testing the TIA amp and how too high of an input signal causes it to overload ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7TtKE39TWpI.html 73 - Rick N3FJZ
Yes. I just updated my website with additional information on its construction. www.remmepark.com/circuit6040/Link_coupled_transmatch/Link_coupled_transmatch.html
Thank you! I just updated my website with additional details on how I built my transmatch. www.remmepark.com/circuit6040/Link_coupled_transmatch/Link_coupled_transmatch.html
People lilke You, Nick M0NTV, Paul VK3HN, Charlie Morris ZL2CTM, SolderSmoke, NA5Y, and some others great h-brewers ;-) Made my days! Thank You! SQ3DLA. Waiting for the next parts! (TIA-s with gain controll!)
I find myself asking that same question sometimes :-) I guess the simple answer is "because it could be done". For voice SSB, a few 10's of Hz ether way is hardly detectable, and I don't plan to do any digital work with the rig that would require that kind of precession, so I guess it goes back to my days working in an instrumentation standards lab in the '80's where precision was everything and took a lot of effort and equipment to achieve what a few dollars can do today. It's just fun and so satisfying to be able to do it now at home :-) . 73 - Rick - N3FJZ
Hi YE3CIF, just to let you and other know that the AGC feature will probably come somewhat later since I have not actually incorporated AGC in any of my earlier rigs. Because AGC will be be a new experience for me, I will want to do a lot of research and experimenting before I would feel comfortable publishing details of a working circuit. 73 Rick N3FJZ.