Episode 190 - DuWayne Schmidlkofer - KV4QB Transcript
Eric, 4Z1UG: Welcome to the QSO Today Podcast. I'm Eric Guth, 4Z1UG, your host. I love to find builders of ham radio gear mostly because building for ham radio is an integration project between the analog and digital DC, AC and RF. DuWayne Schmidlkofer, KV4QB is one of the amazing creators of home-brew projects from conception to the finished package. He uses microcontrollers combined with RF circuitry to make some pretty cool and mostly inexpensive projects. His blog is a great read, where he documents each of his projects from beginning to end. KV4QB is my QSO Today. KV4QB, this is Eric 4Z1UG, are you there DuWayne?
DuWayne, KV4QB: 4Z1UG, this is KV4QB, hear you fine here.
DuWayne, KV4QB: Probably around early 1960s, took a little place up East Central Wisconsin, somewhere between Green Bay and Milwaukee, where there's not much else going on. I started picking up Popular Electronics and Radio TV Experimenter and some of the magazines around there. After a few subtle hints, I got a Knight Kit Star Roamer Kit for Christmas. That's a little general coverage receiver and I started listening to shortwave broadcasts and found a bunch of funny sounding things and people just talking there on the ham band. I thought I'd get a little bit more interested in that.
Eric, 4Z1UG: How old were you at that point?
DuWayne, KV4QB: Oh about 14.
Eric, 4Z1UG: How did the first kit go? Was the Star Roamer your first kit?
DuWayne, KV4QB: Yes, it was. It went together real well. I've been you know playing around a little bit electronic. That was the first real kit of sort that I had put together.
Eric, 4Z1UG: In the place you grew up, were there any hams or Elmers nearby?
DuWayne, KV4QB: There was a couple of hams around one that I knew and he's the one that actually gave me the set of his CW learning tapes and a license manual for the novice, so I studied that. He was the one that give me my novice license.
Eric, 4Z1UG: You were about 15 years of age?
DuWayne, KV4QB: Yeah, about there, somewhere.
Eric, 4Z1UG: What was your first call sign?
DuWayne, KV4QB: WN9SSN and then, the next summer, I had to take a trip down to Milwaukee, where the FCC office was to take the general test. Then, I became WA9SSN.
Eric, 4Z1UG: How did it proceed from there? Were you active as a ham in high school, was there a high school amateur radio club?
DuWayne, KV4QB: No, not really an active club. One of the teachers, her husband was a ham. He was a teacher in one of the other schools in a neighboring town, so I met him. Then, there was two or three other amateurs around within fairly short distance.
Eric, 4Z1UG: What was your first rig after the Knight Kit?
DuWayne, KV4QB: I got another Knight Kit, a T-60 transmitter. I put together with that and I had upgraded to a different receiver, bought one from, well that was Lafayette Radio Electronics. It was probably one of the other bigger mail order supplier of electronics and ham radio stuff.
Eric, 4Z1UG: I remember them. They had a terrific catalog. In fact, I think all of those companies in those days had amazing catalogs, you sit by the mailbox and wait for them to come in.
DuWayne, KV4QB: Yes, did that many, many times.
Eric, 4Z1UG: Along with your subscription to Popular Electronics?
DuWayne, KV4QB: Yeah.
Eric, 4Z1UG: Were you a builder as a teenager other than the Knight Kit?
DuWayne, KV4QB: Started out, tried to be, but the hard part was trying to get parts and stuff like that to do anything. There were very few suppliers around. I think one of the ones then was like Poly Packs. They used to advertise in the magazines and you could get as sort of the great assortment of very unusual stuff that you couldn't pick up locally.
Eric, 4Z1UG: What were the things you like to build in those days?
DuWayne, KV4QB: Oh, I did some stuff like I think like I had built up the code practice oscillator and a couple of little things to use with the first general coverage receiver to make it a little bit more usable.
Eric, 4Z1UG: Did ham radio play a part in the choices that you made for your education and career?
DuWayne, KV4QB: Somewhat, I ended up going in the army and decided to sign up for the field radio repair, MOS specialty and spent a lot of time repairing stuff that was kind of similar to amateur radio equipment.
Eric, 4Z1UG: Then, after the army, did you continue … I mean we're going to get to one of the reasons that we're talking tonight and that’s that you're a builder, but the question is are you a professional builder, did you end up doing that as a career?
DuWayne, KV4QB: Oh, actually, after I got out of the army, I got a job as an engineering technician, so I was building prototypes and stuff like that for a couple of the engineers that work in there. They were also hams, but they were kind of into two meter packet and stuff like that, stuff that really I didn't find interesting at the time. They were just starting to get into microprocessor controlled equipment and stuff like that and I thought that point that was more interesting than a lot of the amateur radio stuff.
Eric, 4Z1UG: Are you active on the air now?
DuWayne, KV4QB: Occasionally, I get on every once in a while. I like to hit the like the state QSO parties, just get on for a little while, trying to give people a couple extra points and stuff like that that are into the contesting things like there. We run a little QRP net that I try to get in when the noise level isn't too bad and 75 during the winter, plus some of the little contests that our local QRP club runs.
Eric, 4Z1UG: Are you a CW operator then?
DuWayne, KV4QB: Not really CW. I stick with voice and some of the more obscure digital modes.
Eric, 4Z1UG: Your QRP net then is a voice net?
DuWayne, KV4QB: Yes, we get on 75 meters, it's just kind of like a little check-in thing, kind of little round table for a couple of minutes, once a week.
Eric, 4Z1UG: For people that say that you have to have at least a 100 watts and a wire to run 80 meters, can you put that notion down?
DuWayne, KV4QB: You don't need it, but it sure helps. We try to start out at the QRP level and sometimes the noise levels is bad enough that we have to kind of like go up to 20, 30, 40 watts, something like there. I don't think anybody probably ever gets up above 50 watts though.
Eric, 4Z1UG: What kind of antennas do you operate on 80 meters?
DuWayne, KV4QB: I've got a couple of multi-band ones. I've got a G7FEK that I put up. It's kind of like an all band, but the smallest all band I could stick up in the yard and then, I've got a 80/40 meter fan dipole that's up.
Eric, 4Z1UG: Right, so simple wire antennas is what you're using?
DuWayne, KV4QB: Oh, yes, yes, they work as well as anything. Any kind of antenna no matter what you do is probably going to be some sort of a compromise along the way if it's all band. Go with the simplest and if it works, it works.
Eric, 4Z1UG: You’ll refer to me by Tony G4WIF, who was a guest of the QSO Today Podcast and he says, “You got to have DuWayne, because he's an amazing builder.” I see that you started a blog in 2015, but it seems to me that you've probably been obviously building much longer than that. At the level that you're working at now and I'll put a note in the show notes page to your blog, how did that start and how did that level of building start for you?
DuWayne, KV4QB: I've been kind of working on something on and off for as long as I can remember, maybe a little project, maybe electronics, maybe something completely unrelated to electronics. Over the years, I have acquired a full machine shop. I can do my own metal casting if I really need to make something really unusual. It's just kind of gotten into the mindset that things are much more fun to use that you've made yourself, be it a kit, completely homemade, whatever, you really haven't probably saved any money. Matter of fact, by the time you're done with everything and getting everything around that you need, you probably spent more than if you just went out and bought something to begin with, but I just get more satisfaction using something that I've built, worked, modified myself.
Eric, 4Z1UG: Now, the projects that you feature on your blog are pretty high-tech. Do your projects start with a pencil and paper or do you just dive right in and use some kind of schematic capture program to do your at least the electronic design?
DuWayne, KV4QB: A lot of its pencil paper. A lot of it is I just take one of the little wireless plug-in breadboards, kind of put the stuff together. Once I get it working, then I … Quite often, it confuses people because I may not have a schematic of the thing. I've gone directly from the breadboard that I put together to a printed circuit board.
Eric, 4Z1UG: You'll get it working on the plug board, do you using schematic capture program or some kind of board layout program or are you actually laying the board out with like a resist pencil?
DuWayne, KV4QB: No, did the resist pencils and stuff like that long, long, long time ago. Right now, there's so many different available versions of circuit board design software out there that they're so very easy to use. The one that I'm using right now is called Sprint Layout. It's more of a graphics program than it is a true circuit board CAD program because you're not really required to go and do a schematic. Then, go and convert that to the board layout. You can just lay out the parts directly the way you want them, but it has one advantage that I like is that once I get a circuit done and work and all checked out, I can save that entire part of the board layout as a as a module. Next time, I need to put an audio amp or something in there, I just go grab that layout, stick it on the board, move a couple of parts around, so it fits right and it's done.
Eric, 4Z1UG: Oh that's pretty cool, okay but there's a library for the pin outs that you need.
DuWayne, KV4QB: Oh, yeah, there's the basic library and with this software, it's really easy to go and create your own pin outs or whatever you need. You usually get something that you can go modify into something that's specific.
Eric, 4Z1UG: Do you use a schematic capture program occasionally because I see on your blog that you actually do have schematics of circuits that you've designed.
DuWayne, KV4QB: Oh, yeah, I do it for the individual modules that may be done after I've actually had the board done and then, test it and stuff like that. The schematics are usually of individual modules, not the entire project like in a series of articles that I've been doing for QRP Quarterly on Arduino building blocks. I create a specific building block and just change it to whatever I need or add something on to it.
Eric, 4Z1UG: Do you use LT-SPICE or some similar simulator in order to check things out or is it just you just put on the breadboard?
DuWayne, KV4QB: That depends on what I'm doing. A lot of my stuff is digital or done in software and using simple AC circuits, amplifiers and things like that that I've already tested out. I may have to go and simulate something, see what happens if I change a value or something, but pretty much plug and play modules and then, try to make up for it in software.
Eric, 4Z1UG: What methods have you used to make your own printed circuit boards?
DuWayne, KV4QB: I usually try to use toner transfer. I originally did the first one, where tried to use a laminator and heat. That kind of depends upon the type printer you've got, what type toner it uses, how well it works. Later, I went and switch to what they called the cold method. You actually use a solvent mixture to soften up the toner on the paper that you've got and then, use a laminator or something to apply pressure to it to go and fuse it to the board. I found that out that works real well, even been able to make double-sided circuit boards with that.
Eric, 4Z1UG: What is the toner transfer process? You've created your layout using sprint layout and how does that transfer then?
DuWayne, KV4QB: You take that and you go and format it, depending on if you're doing one side or two side, as you may have to mirror something. Print it out on the piece of paper of some sort. I use something that was recommended by I think you did a thing with him, Chuck Adams and his Muppet board that thing like there. He recommends a glossy laser printer paper or there are some specialty papers for just doing toner transfer. You print it on there and then, depending on which method you go and just apply that to the copper clad board and either heat or pressure or with solvent or combination thereof. Then, when you're done, you go and soak the paper off and that just leaves the toner image on the copper board to act as a resist.
Eric, 4Z1UG: In other words, you're actually putting this paper into a laser printer and the toner from the laser printer itself is what's on the paper. You get that toner to transfer to the board itself.
DuWayne, KV4QB: Now correct.
Eric, 4Z1UG: If you're doing a double sided board, then do you have to drill indexing holes or something like that in order to make sure that they line up front and back?
DuWayne, KV4QB: Depending on the size of the board, index holes or you can just go and line up the holes on the paper, tape the two sides together and basically slide the circuit board in between them, kind of like it was like you was sticking something in a sandwich.
Eric, 4Z1UG: You're using paper. You're not using like, you're not printing on plastic.
DuWayne, KV4QB: No, I just use paper. Other people have used … I mean I've tried using glossy advertising paper and stuff and it works. The best results I've gotten is with this glossy color laser printer paper. It's just more consistent.
Eric, 4Z1UG: You bond the toner to the board and the toner sticks well enough that when you put it into the etching bath, what are using ferric chloride or something like that?
DuWayne, KV4QB: I've used ferric chloride in the past. Lately, I've been using a mixture of hydrogen peroxide and some sort of dilute hydrochloric acid. Actually, lately I found out that there's a lot of toilet bowl cleaners solutions that are basically of dilute hydrochloric acid. When you're done with the etching solution, you use it as the product was originally designed.
Eric, 4Z1UG: You can recycle the toilet bowl cleaner, etch the boards and then, use it as you say. Well that's very cool. I actually hadn't thought of using toilet bowl cleaner, but it might be easier to get.
DuWayne, KV4QB: Oh, it's much easier to get and you don't have to go and store hydrochloric acid. I mean I do at times or have used regular muriatic or hydrochloric acid that I got from local Home Depot and stuff like that. I have to store it out someplace. I can't really keep it out in the garage, so I really don't want to keep that in the house. This other stuff, I can just go and reach under the-
Eric, 4Z1UG: Under the sink in the bathroom?
DuWayne, KV4QB: Under the sink in the bathroom and there it is.
Eric, 4Z1UG: You drill your own boards?
DuWayne, KV4QB: I had used a little Dremel tool with a little drill press adapter for it, but lately I prefer to stay a little CNC engraver, which is basically a little router that I can transfer the CAD files from my circuit board layout program and create drill files and it goes and drills directly. Depending upon the size or the complex of the board, I can actually just have it go and route the entire board instead of etching it, but for smaller surface mount boards, higher density stuff, I still prefer to just use it to drill the holes that I need and then, etch the board. I can use the holes that are drilled as alignment and so everything lines up right on the drill holes.
Eric, 4Z1UG: Now, the CNC engraver is that something that you built yourself?
DuWayne, KV4QB: No, I bought it. They're available for $200-$300 range, depending upon the size.
Eric, 4Z1UG: In fact, it's the same kind of engraver that you'd use to make signs or badges or something like that?
DuWayne, KV4QB: Correct, yeah, they come in different sizes. I've got a very small one. It only handles about four by six inches, but most of my boards are probably less than four inches square.
Eric, 4Z1UG: Now, one of the projects that you've done a lot of and it seems to me that you like to build, I can't say simple projects, but they look like they're maybe more simple projects, maybe it's because of the way that you're building in modules, but your Scalar network analyzer has gotten a lot of press. I've seen it in a number of different places and you even mentioned it when I guess Hackaday did an article on a grid dip meter. I saw that there was a message in there that you said that you could also use a Scalar network analyzer for that. What is a Scalar network analyzer for the listeners and how would a ham use it?
DuWayne, KV4QB: Basically, it's a signal source that's programmable that you can sweep over a set of frequencies. They, some sort of a RF detector that you can go and measure the results. You can do it manual, but basically, I just have a little Arduino that I set up the frequencies, range that I want, it goes and steps through them, does the measurement, plots it on a little TFT color display. Then, got a little cursor that I can scroll across there when I'm done and read off the amplitude and the frequency.
Eric, 4Z1UG: You could actually tune a filter?
DuWayne, KV4QB: Oh that's one of the primary uses for it is tuning filters. You can go and put a return loss bridge on it and basically you've got a very basic antenna analyzer that'll give you the SWR of your antenna across whatever frequency range you want to look at.
Eric, 4Z1UG: You could actually see the bandwidth of the antenna using on your TFT display?
DuWayne, KV4QB: Correct.
Eric, 4Z1UG: How did that project start?
DuWayne, KV4QB: Actually, it started off as the antenna analyzer. I saw the article by K6BZ I believe it was on his Arduino placed antenna analyzer. That was when I was just starting to get into Arduinos and playing with them. I built the antenna analyzer. Then, I realized I could go and just take off the bridge that's in there, the SWR bridge that's in there, take that off, just take the two diode detectors that he had on there and basically measure the output of the signal generator, measure the output of the filter circuit that I was testing. Then, use the Arduino to compute the gain or loss of the stage and then, plot it.
Eric, 4Z1UG: Now, this message from Sotabeams, as a kid, I loved electronic and radio catalogs. You've heard them mentioned on the show before like the Lafayette Radio electronics catalog. Well, the Sotabeams website has the same fascination for me because it is full of unusual and useful amateur radio and hobbyist accessories that will make your operation, especially in the field even better. For example, if you have an old rig and want to get rid of the hash crack popping from low band noise, then look at the DSP audio filters section of the Sotabeams’ website. With a flick of a switch, the noise goes away. Your old receiver will get a new lease on life. You can buy it as an internal board if you want to go in deep and make invisible modifications or you can buy it an external accessory box, maybe to drive an external audio amplifier.
Eric, 4Z1UG: Spend some time looking at the Sotabeams’ website by clicking on the Sotabeams logo on this episode show notes page. I know that you'll be inspired by the amazing array of parts, products, devices and test equipment that you will find there. Remember that Sotabeams will give you 10% off if you put in qsotoday that's one word qsotoday in the coupon code box at checkout. Sotabeams, amateur radio for the great outdoors.
Eric, 4Z1UG: Now, back to this QSO Today. Is the Arduino your favorite go-to microcomputer?
DuWayne, KV4QB: Oh, yes. When I first got involved with computers, computer controlled things back in about 1980 as an engineering technician, we had a project that had a single board computer. It was about a foot square. I had a four megahertz Z80 24 I/O lines on it, 4K ram and three IC sockets that you could put EEPROMs in it. This thing cost about $250. By the time you've got the assembler compiler, the EEPROM programmer, you had another $500 invested in it. Now for $3, you can get one of the small Arduino Pro Minis that runs at 16 megahertz, got 2K of RAM, 32k ROM, 15 I/O lines, another eight that can be used as either analog or digital I/O. It fits in one of the EEPROM sockets of the original of that Z80 system, cost $3 and your software development tools are free.
Eric, 4Z1UG: Would you recommend the Arduino Pro Mini as a place to start for someone who's new to working with Arduinos?
DuWayne, KV4QB: Probably not the Pro Minis. Start with probably just standard Arduino Uno. That’s got more I/O, stuff all brought out, two sockets, it's much bigger. The Pro Mini is basically what I like to use when I'm embedding into an instrument itself. It basically replaces the big IC.
Eric, 4Z1UG: Now, I noticed you'd built a lot of stuff for Altoid cans or something that looks like that. Is that your favorite enclosure?
DuWayne, KV4QB: I kind of like to go with that size, but lately, I've got a 3D printer and I just have a basically template for an Altoid size package that I can modify real quickly, put in mounting posts for any boards, holes or just for the display, any controls. Print the thing up and I can make as many as I want. I don't have to go and nibble on metal anymore.
Eric, 4Z1UG: The 3D printer, what kind of 3D printer are using? This is something that you built yourself and did you have to master some kind of CAD program in order to make the box?
DuWayne, KV4QB: I bought one that was made by 3D Systems. They discontinued them. It had been a $1,000 printer and they discontinued them for about $200. I started out with one of them. Then, later, I got a little Monoprice Pro Mini, which right now sells for about $200-$250. They're fairly small format and I'm in the process of building a much larger one that I've taken modified designs of a couple of different ones and I'm building it pretty much the way I want it. Right now on eBay, you can get 3D printer kits for under $200 that could take a little bit of work to put together and then, you're going to have to learn software or depending upon what you want to design or if you just want to print stuff, you go to this terrible site called Thingaverse. It's probably one of the biggest time sumps I've ever seen. Just scroll through page after page of things that other people have designed that you can go and just download the files for and print away.
Eric, 4Z1UG: Well that's pretty crazy. What kind of CAD program are you using for that?
DuWayne, KV4QB: The one I've got was one that was sold by the company that made the original printer. It's fairly old, but it's more of a 2D based fronting file that I was a little bit more used to than some of the direct to 3D ones that are out there, but there are several free or very inexpensive CAD programs that you can get. It just takes a little while to get used to them because they all do the same thing, but they're just a little bit different. There's a lot of information on YouTube about how to use them, how to set them up and examples and building stuff.
Eric, 4Z1UG: Are you retired now?
DuWayne, KV4QB: Yes, I am. That's when I probably got back into amateur radio, had spent 25 years as a field service rep, spending 100 plus nights a year in hotels and traveling 50 plus thousand miles a year, so I just really didn't never felt like going back home and doing the same thing that I did all week. Besides that every time I got home, I had something else that I had to do that didn't get done during the week.
Eric, 4Z1UG: Well, I guess the reason I'm asking the question is it seems to me that what you're doing is you're learning a lot of new skills, if you're mastering a CAD program in order to print your own boxes, creating programming for your CNC engraver, it's amazing what you're doing. What do you think your investment is in time on a project like the network analyzer from start to finish?
DuWayne, KV4QB: I’ve gone through like two, basically almost three different generations of it now from what I've done, so I have no real idea of the actual amount of time spent into it. Awful lot of the stuff I picked up from different places like, well there's the Poor Ham's Scalar Network Analyzer project that was on Yahoo Groups. Did an awful lot, a lot of my stuff is on. It is based on circuitry that's outer there. There's amazing amount of information you can pick up on the internet, different people's blogs that have basically made the same thing. You kind of go and grab what you like from this site and that site and see what you can put together.
Eric, 4Z1UG: Your blog is amazing from the standpoint that you have a lot of nice references to other people, who are building and people that you're following. It was nice to see that as well. What has been the most complex project that you've worked on or working on?
DuWayne, KV4QB: Probably the latest, well what will be the next iteration of the Scalar network analyzer by doing something like trying to increase its frequency range. It's going to go from a simple sine wave oscillator to one of the little Si5351 multiple output clock generators in order to get rid of the problems with harmonics from the square waves. One of the methods you can do is use a mixer, so you use one clock and then that’s your output frequency and another one that's offset that for whatever your IF frequency and you feed that through a narrow filter and look at the output of that. That eliminates the problems with harmonics and looking at that configuration, it's basically if you don't go in to supply a test signal, basically you have a single conversion receiver. Hopefully when I get it done, it'll give me the functionality that I have of the Scalar Network Analyzer and a measurement receiver that'll do a lot of the functionality of a spectrum analyzer.
Eric, 4Z1UG: Well, I saw that you're also building, is that the Specan spectrum analyzer?
DuWayne, KV4QB: Yeah. I was kind of working on that. That's kind of one of these work-in-progress things, where I'm trying to see ones how to increase their frequency response. I've been looking around that was basically 70 meg spectrum analyzer. You had to go and build some high frequency filters. I looked around that stuff that's used on other things that's unbelievably inexpensive on eBay right now. Instead of a building a filter at 100 megahertz, you can buy little surface acoustic wave filters that are designed for these little remote controls up at 300 megahertz. You can get the entire filter for a dollar with no tuning, no building, nothing else on it. Tweaking it, you can plug it in and it's just redesigning stuff with different frequencies signal generators, but now there's these computer little clock generators that are usable up to hundreds of megahertz that cost you $8-$10 to go and get the entire module.
Eric, 4Z1UG: Is eBay your go-to place for parts and unusual things?
DuWayne, KV4QB: Oh yes because looking around there, it's amazing what you can get and what you can find. Prices can't be beat on most things. A lot of stuff I get, this is the only place I could go and get it. Prices would be prohibitive, I try to go and buy it from DigiKey or Mouser or something like that. Right now, I prefer working on surface mount devices. It's just so much faster than doing through hole stuff and there's just so much more of that stuff that's available in small quantities on eBay.
Eric, 4Z1UG: It's only been within the last couple of years that I've discovered that I can buy a lot of stuff on eBay and as you say from China and it's quite amazing how it's really opened the door to doing all kinds of stuff.
DuWayne, KV4QB: Oh yeah, it's amazing what's available there. If you go, take a look at like if you don't want to build your own circuit boards, right now there's a half a dozen places there that offer ten basic four by four inch circuit boards, double-sided solder mask for five bucks each.
Eric, 4Z1UG: Really?
DuWayne, KV4QB: … plus shipping.
Eric, 4Z1UG: Wow, from China?
DuWayne, KV4QB: Yeah.
Eric, 4Z1UG: Do you have one that you like?
DuWayne, KV4QB: I use PCBWay. I've used Seed Studios, AllPCB, they're all pretty much the same. I mean they offer the deal on this stuff because they're eliminating waste. I mean little circuit boards, a lot of stuff are one by two inches and things like that. They go and lay out a board for commercial run. They've got a 12 by 18 inch panel or something, like they panelized everything. Then, they've got some space left over and if they can go and move stuff around, stick a couple of these little boards in there, they haven't wasted. They aren't wasting any space. They're cutting down on the waste and they're making enough to more than cover their cost.
Eric, 4Z1UG: Right and they've got you for a customer so-
DuWayne, KV4QB: Yeah.
Eric, 4Z1UG: Those little tiny circuit ports are ideal for if you want to build filters or amplifiers or stages for your various projects.
DuWayne, KV4QB: Oh yeah, you can do them. There's one in the States there, OSH Park, they basically wait until they get enough stuff to go and build a panel and have it made. They charge a dollar a square inch for three boards shipped to the US. I'm not sure what their foreign shipping is, but you can go, but the Chinese ones give you better prices on them.
Eric, 4Z1UG: The quality is good.
DuWayne, KV4QB: Oh the quality is great on all of them. I've ordered some boards with one of Pete Juliano's projects. I designed a little Si5351 board that has a display on it. I've used it for multiple things and it's on the blog, but I ordered like 50 boards. I get 50 board delivered for $65.
Eric, 4Z1UG: That's amazing. These, you could actually kit up and either sell them or give them away, right?
DuWayne, KV4QB: Yeah, I’ve sold enough to recoup my cost on them like there and I still have a bunch of them around; I’ve given them away. Right now that little thing that I mentioned, Arduino with a display as an analog meter replacement for projects, right now, I've got that prototype done. I had to just put display in there and plugged in. I'm using it to develop it. Once I get down what I want, I'll just go in design board just for it to make it smaller. I can make one just exactly the same size as the display, about an inch and a half by two and a half inch, that just kind of fits right on the front panel.
Eric, 4Z1UG: Well, I think maybe it was speaking to Pete that I first heard this idea of you create a portion of a circuit and you just re-use it. I think that's amazing. It's an amazing idea because why would you keep redesigning it over and over again, especially when you can just now lift the design out of your file and put it in the corner of the board. I think it's a great idea.
DuWayne, KV4QB: Yeah, you put it in there like there and then, just if you have to move any parts around, I just kind of move the parts around a little bit. Five minutes and you're done with that part of it. You already tested, you build it before.
Eric, 4Z1UG: I guess what it means for you though is that you can always learn something new. As you're building a project, you've already built these other stages and so to bring the project together, you're just integrating that but if there's a new aspect to the project like working with the Si5351 or designing a new filter or a mixer or something like that then you can spend the majority of your time working on that aspect. Then, bring the whole thing together at the end.
DuWayne, KV4QB: Oh yeah, it goes real quick. One thing I like about using surface mount components, if I build up little modules and test the stuff up, get them done and I want to go to a full board with several stages put together, I can take my little heat gun and warm up the components on the little thing. Take the tweezers, lift them off and put them where they're going to fit in the other board, hit it with the heat gun and they're soldered on there.
Eric, 4Z1UG: Oh, so you'll reuse them?
DuWayne, KV4QB: Yeah, with through holes, you're tearing up the boards and half the time, you can't recover the stuff, you can't reuse the board because you've tore up the traces and stuff. Surface mount, you just pick them up, put them where you want them, heat them back up and they're done.
Eric, 4Z1UG: Do you have a minimum size limit in terms of the surface mount parts, so that you can still see them?
DuWayne, KV4QB: Oh, I try to go to either the largest sizes for discrete components, probably 1206 or 805 , and the SLP 8s, 14, 16 size ICs. They're pretty easy to work with. Do your own circuit board if you can etch them without any problems. You want to go smaller than that you’ll have circuit boards made at one of the board houses that they're getting to be so reasonable to have boards made some place and shipped in that for some things, it's not really worth the effort to try to do it yourself anymore.
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Eric, 4Z1UG: Now, do you put solder paste or something like that on your boards and then, you place the parts there with the tweezers or do you have some method that allows you to very quickly place the parts?
DuWayne, KV4QB: I’ll solder paste and a tweezers works real well when you're doing single quantity boards. I mean if you're doing something other than a single one, then it might pay to try doing something else, but single boards that's the easiest, fastest way to do it.
Eric, 4Z1UG: Then, do you bake it in your toaster oven or do you have some commercial oven that you use to get those solder to flow?
DuWayne, KV4QB: I just have a reflow workstation. It's got a little hot-air gun on it. Just heat the board up from the bottom, so you get the substrate of the board heated, warmed up. Then, you just go and put the hot air over the top, stuff will melt and the parts will just flow right into place. Surface tension just basically pulls the parts into place. If they aren't exactly right, just push them around with the tweezers a little bit and you're all done.
Eric, 4Z1UG: What kind of hot-air tool are you using?
DuWayne, KV4QB: I bought a real inexpensive reflow workstation, has got a temperature-controlled soldering iron and a little hot air handle that comes along with it. You can adjust temperature and air flow. You can get them on eBay for $50.
Eric, 4Z1UG: Oh, really? You don't have to go with a brand name like HAKKO or something like that workstation to reflow these parts?
DuWayne, KV4QB: No, no. Some people will go to hobby store and get the little heat guns that are used for embossing letters and stuff like that for $10-$15.
Eric, 4Z1UG: Really? That's a great idea.
DuWayne, KV4QB: Or just a regular hot air gun that you can pick up at the hardware store. You just have to go and be a little bit more careful, so the air flow doesn't blow the stuff away or blow parts around. That's the thing I like about the workstation I've got because you can go and adjust the air flow along with the temperature.
Eric, 4Z1UG: You're heating the bottom of the board and then, you've got the air flow tool kind of pointed straight down on the top of the board and that's what gets it to flow and keeps it from blowing away?
DuWayne, KV4QB: Right, the parts are on the solder paste. Just go and stick the board on the edge of a little board holder I've got. Heat the stuff from the bottom, you'll see the solder paste start to melt. When it's pretty much evenly melted across the board, then just going and move the hot air up to the top of board. Then, you go around section at a time till you get all the components to stick into place.
Eric, 4Z1UG: Do you like to work on one project at a time or if we came to your workshop, we'd find that you've got 50 projects running at the same time?
DuWayne, KV4QB: If you're basically depending on parts from eBay, you really need to have multiple projects going because if you order something that you need, you don't know if you're going to get it next week or next month, so you could be just sitting around. Normally, I have three or four projects running at any time.
Eric, 4Z1UG: Of course, your documentation is good, excellent from what I can see on your blog.
DuWayne, KV4QB: That's the hardest part to any of it.
Eric, 4Z1UG: Is the documentation.
DuWayne, KV4QB: Getting documentation if somebody else wants to go and build it.
Eric, 4Z1UG: You document all your projects?
DuWayne, KV4QB: I try to. My documentation may be minimal. I've built a couple of projects, where I've kidded a few out for members of our local QRP Club and stuff like that. I have basically minimum documentation, but should be enough. It's enough to get the stuff put together.
Eric, 4Z1UG: Are you building anything outside of electronics and ham radio that is a big project for you?
DuWayne, KV4QB: No, I haven't done much of that anymore. I had a couple of things I was going to do and after I retired, I've just gotten to the point, where I spend most of my time working on the electronic stuff, I mean my little CNC engraver and 3D printer, they sit on a little table right next to my computer desk. I can go and design up the circuit board, do the layout, send it over to the printer or the engraver and it's done. I really don't have to move.
Eric, 4Z1UG: That's very cool. How about that? The engraver, you say also will do the hole drilling?
DuWayne, KV4QB: Correct.
Eric, 4Z1UG: Maybe it's because I don't understand, so the engraver goes X, Y, but it also goes Z?
DuWayne, KV4QB: Correct, correct, it's got a little holder for either a drill bit or a little engraving bit. It kind of just moves around.
Eric, 4Z1UG: It moves around, but it'll also take that bit up and down?
DuWayne, KV4QB: Yes.
Eric, 4Z1UG: Do you have any YouTube videos of the stuff that you're doing? I didn't find a YouTube channel for.
DuWayne, KV4QB: No, I don't really have any. The only videos I have are stuff that’s I end up embedding on the blog.
Eric, 4Z1UG: If you were going to recommend to a ham, who's just wants to get started into building and acquiring the skillset that you've obviously acquired over years and years, what would you suggest would be his first project?
DuWayne, KV4QB: He'd have to find out what he was interested in besides just the building things. I mean there's all kinds of stuff you can get out there, get a little-
Eric, 4Z1UG: Let's say we're talking QRP for example or HF radio.
DuWayne, KV4QB: You mentioned one that you got there, if you want to go on a kit wise, you got the little QCX kit there that's if you want to get started in building, you’ll put together a couple of kits, get used to the actual building part itself. Then, you can go to whatever you want to. I think there's some very minimalist kind of QRP transceiver kits available from China that you can basically use as the basis for something. I've got one that I did up here a couple of years ago. It was basically the … I'm not sure where the name came from, in China, called it the Frog Sounds. It's a Chinese version of a 49er, 40 meter CW transceiver. I designed a little Arduino based controller and display for a Si5351 clock generator module. I put under front of it and put it in a canned meat, well spam can, so I ended up calling it the canned frog.
Eric, 4Z1UG: It's my understanding, we were talking about this before we started recording and that is as you're also a BitX fan. Could you talk a little bit about the BitX?
DuWayne, KV4QB: I was thinking about, well when I retired, I wanted to build a radio. I took a look around and I found the BitX, the original one, the 20 on the Yahoo group that was on it. There's different versions of it and stuff like that. I started building a modular type version of it that I could go and build different modules, do plug and test each one. I got down and then, of course Farhan came up with his BitX 40 that had everything all laid out there on one board. I kind of gave up on that project and decided I want to go and do a surface mount version of the BitX 40. I laid that out and started building them and then, Farhan came out with his semi kit for $50. I said, “Well, why don't I just go and forget about building my own and put one of those together?” I got one of those, built a digital VFO for it, actually first thing I used the analog VFO when I put a little frequency counter on that I had built previously. Then, last year, he came up with the MicroBitX. It was out for a couple of days. I
had seen some preliminary stuff on it and I saw the …
DuWayne, KV4QB: Finally about two o'clock one Sunday morning, when I found out it was going to be available for sale, I hit the PayPal button and ordered one. About a week later, I had a MicroBitX delivered to me by one of Santa's helpers that was conveniently disguised as a DHL package.
Eric, 4Z1UG: Isn’t that amazing because I think what the MicroBitX, it's under $60 right, delivered?
DuWayne, KV4QB: Well, the BitX 40 is under 60 delivered. The MicroBitX, the all band 3 to 30 megahertz is about 110 delivered, a little bit more if you want DHL delivery. I like everything on it. I kind of just tested it a little bit it. It comes with a two line 16 characters way and I'm in a process of redoing the display, putting about a three inch full graphics display in the front of it instead of that. That's kind of one of the works in progress. I've got most of that done, trying to find a way to get extra I/O. Instead of just having the frequency readout, I want to put a QS meter on it, maybe a power meter, maybe an SWR meter. I'm thinking about creating a standalone Arduino Pro Mini based thing that has like four analog inputs, a couple of digital inputs for selecting the mode, different front panel switches and the push-to-talk switch and its own little graphics display on it and simulate an analog meter that just sticks in there. I can use it in the BitX. I can use it in any other project I want.
Eric, 4Z1UG: You find that BitX, a nice platform for modification, it's a great place to start?
DuWayne, KV4QB: That's pretty much what they were designed for is it's basically a building block. You can take something that gives you the minimum functionality that you need. Then, you can add any bells and whistles that you want to it.
Eric, 4Z1UG: What's the most impressive piece of service equipment that you have on your bench, test equipment?
DuWayne, KV4QB: A little digital oscilloscope, I've used big scopes and stuff like that over the years, but for $250, I got a 100 mega scope, does FFTs, computes, measures frequencies, does more stuff than I ever thought I would need.
Eric, 4Z1UG: Can you control it with your computer?
DuWayne, KV4QB: No, no, other than that that my little SNA Jr is probably the handiest thing I use any time doing filters or responses or anything like that. I need a simple signal generator, something that fits in my hand, like just put it on the desk, don't have to hook it up to much of anything.
Eric, 4Z1UG: If you're working on Arduino based HF gear, then you've got pretty much a full lab with a digital oscilloscope at 100 megahertz and your SNA Jr.
DuWayne, KV4QB: It takes care of just about everything that I need. I mean I'm looking, when I started 50 some years ago, the equipment of the SNA Jr would have weighed 50 pounds, taken up a big spot of desk space and cost thousands of dollars. Now the SNA Jr fits in my hand. It cost me 50 bucks.
Eric, 4Z1UG: What excites you the most about what's happening in amateur radio now?
DuWayne, KV4QB: The variety of stuff that you can do. When I go to our club meetings, we usually do, once around discussion, everybody kind of tells you, tells what they're doing. There's so many people, they all have different interests. I mean I may discuss something on my SNA or some Arduino based project. We've got somebody that comes in, shows his two tube transmitter that he built in a cake pan. Somebody's talking about the contest that they were running and there's just so many things that you can do now.
Eric, 4Z1UG: That's absolutely true. It's amazing, isn't it? Especially with the internet, we can all share this. I think it accelerates the state of the art.
DuWayne, KV4QB: Oh, I did a blog post here over a year ago, but right now, this is being the greatest time ever to be a home builder. I mean when I started, the hardest part was getting information, the documentation on parts and stuff. You had to go and see if you knew somebody that was into business, had a copy of a data book, obsolete copy of a data book from one of the manufacturers, try to find stuff in magazines, go to a library, check out old magazines for the information. Now, you can go on YouTube, do a Google search on almost anything in the world and you get a list of different things to go through and look at.
Eric, 4Z1UG: Yeah, I remember when every electronic builder had to have a wall of data books from every manufacturer.
DuWayne, KV4QB: Oh yeah, they were impressive.
Eric, 4Z1UG: That was your reference library. Now, you can find the part instantly.
DuWayne, KV4QB: Yeah. Once you can find it, you can go and eBay, Bangood, AliExpress, any one of the other sites and order them for ridiculously low prices and you get them in a week or so.
Eric, 4Z1UG: What advice would you give to new or returning hams?
DuWayne, KV4QB: Find a part of the hobby that you like. If you got a couple of different amateur radio clubs in the area, go to a couple of different club meetings. Find out what people are doing. Get into something that interests you. I mean ham radio is no longer just one hobby. It's kind of a bunch of hobbies with one common thread.
Eric, 4Z1UG: What are the channels that people can use to be in touch with?
DuWayne, KV4QB: Oh, the blog or direct email, email@example.com.
Eric, 4Z1UG: Okay that's great. DuWayne, you've been a wonderful guest and a very interesting guest. I really love talking about home brewing and hearing about the secret tricks that people have in order to turn an idea into something that's really cool. Your blog certainly demonstrates that you do a lot of that and I really appreciate your coming on board the QSO Today Podcast. With that I want to thank you and wish you 73.
DuWayne, KV4QB: Thanks much Eric, it's been a pleasure, 73.
Eric, 4Z1UG: That concludes this episode of QSO Today. I hope that you enjoyed this QSO with DuWayne. Please be sure to check out the show notes that include links and information about the topics that we discussed. Go to www.qsotoday.com and put in KV4QB in the search box at the top of the page. My thanks to both Sotabeams and QRP Labs for their support of QSO Today. Please show your support for these fine sponsors by clicking on their links in the show notes pages or by using the QSO Today in the coupon box at the checkout. You may notice that some of the episodes are transcribed into written text. If you'd like to sponsor this or any of the episodes into written text, please contact me. Support the QSO Today Podcast by first joining the QSO Today email list by pressing the subscribe buttons on the show notes pages. I will not spam you or share your email address with anyone. Become a listener sponsor monthly or annually by clicking on the sponsor buttons on the show notes page. I'm grateful for any way tha
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Eric, 4Z1UG: QSO Today is now available in iHeartRadio and the iTunes Store and a host of podcast services and applications. Stitcher is still my favorite. Until next time, this is Eric 4Z1UG 73. The QSO Today Podcast is a product of KEG Media Inc., who is solely responsible for its content.