VK3HN's homebrew QRP SSB and CW transceivers, demonstrated on portable and mountain-top (SOTA) outings. Homebrew amateur radio modules, testing, tips, tricks! I also build solid state Class D AM transmitters for the shack.
Thanks! Do you mean how many pulses or interrupts per turn, or how many kHz? The optical encoder generates far too many pulses per turn, so I added a line of code to increment a counter and ignore 3 of every 4 pulses. It might have been 7 of every 8 pulses. The code is on github. I cannot recall for sure and the rig is not in use at the moment, but it's tuning rate with 100 Hz increments is about the same as other commercial rigs, say 10kHz per turn.
@@Paul_VK3HN I was just wondering what encoder you used i was going to get one "100/200/360/400/500/600P/R Photoelectric Incremental Rotary Encoder" wondering if to just buy a 100p/r?
@@klejzbigniew I used this one , they are available from lots of sources. www.minikits.com.au/ENC-360-6 I have tried a variety of mechanical encoders, all have worked.
No. The board works as shown but has some labelling errors. I could fix these and put it all on github, if you are keen and would go through with the build. I've moved on to a board half the size with a XIAO ESP32 and 5351 on board. I'm also writing new software that will include additional features such as CW decode on both Tx and Rx. This will be about another 3 to 6 months, based on current rate of progress.
Hello, Paul... could this design be used to transmit and receive on the 1.25m band for Zone 2 and Somalia instead of 2m? I'm not sure which portion of the electronics you would change out, if you even could. Thanks and -73-
Brian, thanks for your comment. The 28MHz transceiver can drive any VHF UHF transverter. If you can find a 28 to 220MHz transverter, it would work just fine. I built the 28MHz receiver/exciter and connected in a transverter from a Ukrainian supplier. You could attempt to build the transverter part but its not a beginner or intermediate project. Good luck.
Thanks for the inspiration. I am currently in the process of designing my first (and almost certainly overly ambitious) scratch build. My aim is to create a ~20w portable SSB transmitter using a class E amp and EER. It will likely be a 20M monobander, and I haven't decided much at all about the receive side yet. For now i'm just starting with the class E PA, but will focus on the voltage amplifier for EER, and microcontroller control of the whole thing next. 73 KK7RWK
Thats a super interesting homebrew project and very modern! The 20w PA should be achievable with all the switching FETs to choose from, although you will need faster ones at 14Mhz. What MCU will you use ? Will you write your own software ?
Yes for sure, going back to when these jingles and signature tunes were in use, shortwave was a competitive place where nations tried to 'catch' listeners. All swept away by internet and social media.
Dear VK3HN, if a short antenna is used inside the house, the signal from the mixer is weak and if section the BF961 amplifier current from the drain is also weak, the LED installed at the source will not light up. like installing squelch control. Can the BF 961 mosfet be replaced with 3N204, or 40673? thank you
I didn't try it on short indoor antennas but I don't think it would work well. Ferrite rod front end might work better on LW and MW. Yes, almost any dual gate mosfet should work.
Sure, TL598 is an updated TL494 which should work fine in this circuit. They are probably not pin compatible so you might have to make some minor changes.
@kittony71 Time is limited at the moment, I suggest you study some TL494 SMPS circuits, read the datasheet, watch some videos and try it yourself. Doing it yourself is the best way to learn.
Just subscribed im thinking your somewhat local to NE Victoria. Looking to set Ham operation in Murray Valley around Walwa. Is there club that i can get guidance from in this region thank you. Jeff Moore
Hi Jeff. I live in Melbourne but have spent time in NE Victoria for walking and portable radio fun over the past 7 or 8 years. I've been to Walwa, on the Murray, lovely spot. Re clubs not sure there are some very active radio clubs in Victoria suggest you search online , you could email Amateur Radio Victoria, very nice people, they might know. Also, find out the contact person for your local VHF repeater, probably Albury. Good luck 👍
Hİ Paul, how did you fix your Lcd screen to the cutted window ? Im placing components of qrp to encloser ( like board, Lcd, encoder etc...) of my MST 2 qrp. But i dont want use screw and and nut while fixing it to front panel due to bad visual. how did you fix LCD screen to the front panel, without screw and nut? heated silicon or glue etc ... 73
Thanks for your comment. The Arduino and display etc are mounted vertically on three pieces of aluminium angle, a horizontal piece and two vertical pieces either side. The big LCD is mounted against these verticals. The whole assembly is self contained and the base is M3 bolted to the chassis floor. You can see this in the video at 0:40 to 0:45 seconds in. Is that clear? To be clear, there are no bolts thru the front panel as you can see.
@@Paul_VK3HN ok Bro, i saw aluminium chassis which is Lcd mounted to , it is really genius action, your rig is really looks awesome, im your close follower. Thanks for your fast reply . Regards from Istanbul Turkey TA1TRX 73 👌👌👌
@@Paul_VK3HN Exactly OZqrp, your countryman from Australia. I know VK2DOB and also i'm following him tube too. Thanks Paul for your support. Regards 73🙏🙏🙏
Your si5351 library is not being found by the Arduino compiler. 1. install the lib by jason NT7S; 2. Upload and run his test script or alignment script to your Arduino with si5351 wired up and verify all is working. 3. If your compiler still cannot see library .h files check you paths in Arduino IDE settings; 4. Then reload my sketch and try again. Let me know if you continue to have problems. All the Arduino help is online from mutiple reputable sources. Good luck! SK . .
Fauloso no tengo tanto conocimiento estoy comenzando en fh espero llegar a lo que pueden hacer ustedes me gustaria tener algun contacto con ustedes ,soy de chile
Hola, gracias por comentar. Cada gran proyecto son muchos proyectos pequeños conectados entre sí. Comience con algunos módulos receptores simples, como VFO analógico, amplificadores y filtros IF, mezcladores, amplificadores de audio y el conocimiento práctico se obtendrá poco a poco. ¡Buena suerte! ¡Es un pasatiempo maravilloso!
You have your own reasons why this AM radio is not equipped with AGC which regulates the G2 voltage. And in front of it the SA612 RF preamp 2N3904 is effective in use. thanks
KISS (keeping it simple). And I don't mind the sound of AM signal fading, it is a nice sound complete with amplitude variations and phase distortion which I expect a working AGC wold smooth out. And yes the RF preamp stage adds 12-15dB or so which can be useful, it depends on your antenna.
The AM transceiver you built is for the vfo+455khz receiver. because the difference in IFT for transmitting Vfo is separate due to the difference in IF, so the dds program is made differently for TX and RX . Thanks
Yes that's right. The receiver VFO is signal_freq + 455, when you go to transmit the VFO is on the signal frequency for AM. This is very easy to do with si5351 PLL clock generator and a microcontroller.
My god, This is absolutely incredible sounds clear love all the filtering. I'm blown away by it's sheer complexity and it looks amazingly well built. A top tier build in my humble opinion. Great video, I enjoyed watching it.
Thanks very much Simon. About 18 months later I came bamk to this project and did some more work on it, mostly adding the remaining bands, bolting everhthing down, and I added a proper AM detector, video here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uasUCzHxIcg.html
One of the joys of building gear is finding old projects and reviving them! Good stuff Paul, and I think that the old 80/20 rule applies to simple receivers and transmitters too - 80% of the performance is gained with just 20% of the complexity. Perhaps you'll pull this receiver out again in a few years and take another spin around the band with it! Cheers, Dave AA7EE
Thanks for commenting Dave. You are right about simple receivers and transmitters demonstrating the 80/20 principle. Another way that I think this is true is that the last 20% of a radio project in terms of features, sometimes takes 80% of the total effort. Which is all to say, as far as HF QRP radio is concerned, simplicity has a lot going for it. My Tentec DC Receiver is safe in its box, it did enough to hold off part stripping or an eBay listing, so it will come out again someday, sooner or later, for another evaluation. Maybe it will be a collectible next time. 73 Paul.
Good tip! Thanks. Actually my tools are quite basic, a proper workshop would produce improvements. BTW I used methylated spirits as a lubricant coolant when tapping M3 holes in aluminium heatshrink material.
Thanks Michel, there's another video made a few years later which shows it more completed. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-uasUCzHxIcg.html
When I have been rock bound and QRP over the many years, I have learned to expect the unexpected. Here in the States on 40m it does not usually take me very long to call out and get a response yet there are times it is like fishing on a bad day and the fish just are not biting. I have a fair assortment of crystals I can choose from for 40m so I can move around a bit and that helps somewhat. Patience is the key for portable operation but you will be rewarded if you just hang in there. 73 de WA4JAT
@@syarifudin8941 I did not use I2C to connect the 20x4 LCD to the Arduino. It is wired direct, in the usual way, just the same as you would wire a 16x2 display.
You could do the board layout with kicad or similar. At the time I'd not learned everything you need to do board layout. I've subsequently made a number of boards using EasyEDA from JLCPCB. I will still do handmade boards for small pieces.
Yes, you can create a board in EasyEDA print it on glossy inkjet photo paper using Laser Printer, and copy mask from paper to PSB using hot iron or laminator.
@@sergeykizilov38That would work. I haven't tried it. Lots of makers have. I'll do more off shore fabricated PCBs in the future, using JLC or similar.
I made all of these cases by hand, just using hand tools. All using aluminium sheet bases and tops, angle sides, front and rears, fastened with pop rivets, and nuts & bolts ranging from M2 to M4, but mostly M2 and M3.
Thank you. I learned on the LowFER band in the USA just what low power, (7 mW EIRP,) low frequency, (1750 meters,) and low data rates, (1 bit per second,) can do for long range communications. I was blanketing about 1/3 of the USA with my signal, essentially in groundwave. Putting the attributes of low data rates and low power together with skip conditions on HF is every bit (bad pun) as impressive. Your simple, low power transmitter shows what can easily be done with little expense. I hope this video convinces others to get into building their own rigs for such tasks, because ham radio is all about learning. Well done.
Thanks John. MW and LW are remarkable bands. We hams have 472khz, 630m, and 137khz, 2200m. I've never transmitted on LW but have listened to a VK3 who was a regular, and he used to say 630m was better than 80m and 160m for reliability. WSPR attains it's remarkable range because of the slow data rate and digital decoding in SDRs. 20m band has improved since this video was made and Au to US and EU propagation on very low power WSPR occurs routinely now. It will never cease to amaze me what radio and the ionosphere can do. 73 Paul VK3HN.
The problem with this is that if you don't have a good permanent marker pen with good ink that has good adhesive qualities, all the work could go in vain or with bad quality tracks. I had these experience several times.
Excellent project. I love it. How can I get few PCB's. I have been a HAM for 35 years. Still I don't have a HF rig. I like to do some project using PCB & Arduino Sketch. 73 de 4S7DB Daya Buddhadasa
Thanks Daya. There are a few errors on the boards . I intended to do a second run to fix these, but life got in the way. So I prefer not to release this project, as people would need ti.e consuming email support. I hope to get back to this so.eday. 73 Paul VK3HN.
