Pay More and Get Less. Flash the Cash!

More progress on the MHST rig and thus some more sharing. I note that when there is nothing but boring words, the interest level drops. This often happens on the weekend posts. So, for this last day of March 2025, hopefully more interesting stuff. The MHST project has two main elements and these are of course the hardware and the software. The more visible of course is the hardware and even then, not much of that. The not so much seen of course is the software. Both are needed to be working for the total rig to work. I posted a video about some of the progress and problems if only to show it was alive. One comment -- hey you have the presence of the opposite sideband image. That was true as the video was done without any adjustments. Contained internally within the QUISK software is a means to compensate for not so perfect hardware where component tolerances do not create the perfect 90-degree phase shift. In fact, you have the capability to make these adjustments over the whole band o...

I am happy to report that I now have the Pi Pico able to work with the RPi5 SBC. The issue was that the package to recognize the Pi Pico has to be manually loaded into the QUISK directory. Once installed what should normally happen is that when QUISK is executed that radio should show up on the menu. It didn't on the RPi5 SBC. It was a mystery as using essentially the same process the radio did show up on the Windows 10 machine.  Then, I decided to closely read the instructions where I spotted something you needed to do differently for the Linux install. Dah RTFM! Suddenly the MHST rig is in the list. I still have a few warts to polish off but a huge step in reducing the size of the rig with the bonus of the features in the Linux form factor versus the Windows 10. One really important Linux feature is the Pulse Audio Control Panel that is loaded in a terminal like this. sudo apt-get install pavucontrol This control panel gives you a whole series of adjustments and selections with r...

A productive day yesterday on two fronts. I visited the XYL at the cemetery to bring some of her favorite flowers and was happy to see that the headstone was installed. I had been told it might take six months. Now no longer an unmarked grave. The second front was the MHST is back on track. As I had suspected it involved the software. This requires a bit of explanation that deals with the two different approaches using the QUISK software. (Windows/Linux) But let us start with some fundamentals of the I/Q implementation which is basically sound cards -- TWO of them. One sound card, typically external, involves the processing of the I/Q data stream to/from the computer. The second sound card handles the Audio output and Microphone input. This often is an external sound card built into a mic/headset dongle. In a Linux implementation using a RPi3, RPi4 or RPi5 there is an issue with using any internal sound cards on the SBC. In the earlier Pi Models, there is an on-board Headphone jack but...

For some strange reason my mind works while I sleep and often, I will awake with an answer to a confounding problem from the day before. That didn't happen last night! Instead, I did think of a new mantra to describe the situation. Things simply do not aright themselves through spontaneous correction. Yesterday was both a Good Day and Bad Day at the bench with the MHST project. First the Good News. I was able to get a HIGH on GP2 when you hit the PTT button on the QUISK panel. It all boiled down to adding a #define statement in the Arduino IDE that cites the Pin title and GPIO Pin Number.  That worked but for as fast as the Pi Pico is (133 MHz) there is a noticeable delay (with no internal delay statements in the code) from button engagement until there is power on the pin and the same is true once the button is released. Thus, not like unkeying the Microphone and you are in receive. More opportunities for going down the rabbit hole. But then the two Bad News Stories. I noticed a w...

One regular blog reader turned to chatGPT with my problem stated in yesterday's blog.  The answer was in the form if you were using Micro-Python or regular Python for coding. Indeed, the pin designations were different from what I had posted. I thought this is the answer. Well sadly none of that compiled in the Arduino IDE. But the exercise convinced me that indeed there has to be something different in the way the pins are named. The ever-curious blog readers would ask -- why does the built in LED code work? In fact, the often-used example in how to code the Pi Pico is the Miyagi LED ON LED OFF tutorial. If that works making a Pin HIGH should work. One possible and likely THE reason -- the built in LED IS NOT a Pin on the Pi Pico and therefore no Pin is specified in the code. This cannot be this hard. Perhaps another run at chatGPT only specifying only show code that can be used in the Arduino IDE. It all comes down to asking the right question to the problem at hand. Well, I mad...

  As hams we all love the challenge of a mystery especially when a process approach can help unravel that a malicious person put a pin in your coax. That is why you aren't hearing stuff and the SWR is through the roof. That didn't happen but is an example and something that is physical in nature -- you spot the pin, pull the pin and all back to normal.  On the other hand, where the issue is software the obvious is not easily seen or detected. The off the wall SWR and nothing being heard were huge clues in our example. Those clues are not so clear in a software problem I have with the Pi Pico. You hit the PTT tab on the QUISK software and thanks to KK4DAS the on-board LED lights green, so you have a visual cue that the MHST is in the transmit mode. But we need one more action in the code and the very same sequence of code that lights the on-board LED must also create a HIGH signal on one of the GPIO pins to trigger the TR relay system. This sound so much like the Blinking LED t...

The Fix Is In!   The MSHT project started with a board found in the junk box. Like Mary Jo, it had been around the block and in the back seat of the 57 VW Beetle more than a few times. Since building that board I have improved how I design PCBs like more generous pad sizes and using better components. These older boards are subject to frequent repairs. Repairs included replacing the I/Q stereo jacks at the lower LH corner, replacing the two 10K pots (left edge below the LO SMA connectors) and finally a small circuit board for right side ADE-1. The pads for the ADE-1 were really small and a touch up with the soldering iron lifted the pads off the board. But this is a good thing as the ADE-1's sold by https://www.mostlydiyrf.com can easily be integrated into a design of a radio-built Manhattan style similar to what I did for the repair. Fixed. This video is a bit long but on a 28-inch screen sure lets you see the signals. Keep in mind this is a minimalist SDR. Look and listen and th...

  Two issues: Only one USB port recognizes Com21 and an ADE-1 had to be replaced. The ADE-1 being bad showed up when the Spectrum showed DSB. Two sidebands, same signal. When you know stuff, you can do stuff! Someone suggested to me to dump any Tesla stock now -- its headed for the crapper. 73's Pete N6QW

The following statement contains Religion, a Mystery, a Failure and a Proclamation of Frustration which best sums up the current state of the MHST project. Oh my God, the MSHT stopped working and I have no clue as to why and have not been able to isolate the root cause. After yesterday's euphoria of having the rig launch it does no more. The software boots up properly with no error messages and the settings in QUISK have not changed. I see a spectrum on the monitor but no signals. The Pi Pico is generating quadrature LO signals. I even swapped in a different RADIG board -- nothing changed and that was after swapping in new ADE-1's on the original board. I was able to test the 2nd Board using the original lash up with a non QUISK controlled LO, and it works FB.  So, possibilities -- corrupted software, a bad sound card (a second sound card shows the same issue). Maybe there is a problem with the Pi Pico board, and I have in hand a 2nd Pi Pico so we can test that possibility. But...

With a huge Tip of the Cap to KI3P, Oliver, from the Vienna Wireless Society who wrote the software to have the Si5351 talk to QUISK and interface with a SDR Radio!  Needless to say, I was inspired by the work of the Vienna Wireless Societies Maker Program. Thank you, guys, for making something very possible. We now have the frequency of the MHST being controlled by QUISK. This is HUGE!!!!!!!!! Pi Pico Controller Proof of Life Right now, it's just working on Receive and the code needs some work for transmitting. Once I get that fixed, I will be happy to share my work. HUGE caution here, you need more than a passing skill at software installation and the ability to troubleshoot. I have only been successful getting this to work on Windows 10 but the Linux R Pi5 has not worked for me. VWS Shows up on the Windows 10 List Serial Port com21 The Windows / Linux Problem. Despite the very same process the VWS SDR does not show up on the same list when using the Raspberry Pi Linux form....

 For the last couple of weeks, we have been having earthquakes here in SoCal and two of them were 10 miles from my QTH and thusly I have more than just a casual interest. So, an Internet search turned up this Seismograph and yesterday a key part was delivered by Amazon. Yes, it is not a lab quality device but likely would indeed register a 4.1 Quake (that is what we had). It does involve an Arduino so in my wheelhouse and is a one and done type project. If anything, a great party curiosity or just plain time killer to build and killing time spent watching the screen.  The project uses a simple 4 wire OLED for a display. But what would be cool is a 3.5-inch Color TFT and it could be programmed so that anything greater than some set value to flash on the screen "Run, Duck and Cover". All sorts of possibilities. Them that know can make it go. Temperature check -- this might be a great time to pick up a slightly used Tesla EV. It is all over the internet that these vehicles are b...

We are now moving to the arcane part of the project, the software to run the MSHT. Software is elusive and its installation is made even more difficult if like me, you type with only two fingers! The QUISK software was developed by Jim Ahlstrom N2ADR, and it has been around for some time. It can be configured via a menu selection to operate with some very popular radios like the Hermes Lite 2 and if you own an old Soft Rock V6.3 it will do that as well.  It comes in several varieties and can be installed on both Linux and Windows based machines. Installation on L inux machines is a bit more involved than on a Windows 10 machine. We are at a junction in that the Linux approach has been beset with some issues with trying to use a Pi Pico to control the frequency via QUISK. After loading QUISK on a big box Windows 10 64Bit machine the Pi Pico seems to respond better.  So, I may have to initially use a Windows 10 Machine to get the prototype working and then try to port that ove...

The heart of the I/Q SDR is to provide Quadrature LO signals to the ADE-1's. For the initial development work I was able to springboard off of the work of W9RAN and wrote code to provide the two Quadrature signals from a Si5351 using the Seed Xiao RP2040 as the controller. The Seed Xiao is half the size of the Arduino Nano, and its clock speed is 8X faster with 2MB of program memory. For testing and development this works well. But this is unsuitable for the final configuration as it is not under direct control of the QUISK software. The ultimate final configuration is to have a Raspberry Pi Pico interface with the QUISK software so there is direct control. That is currently in work and maybe the long pole in the tent. If you would like a copy of the Quadrature Seed Xiao Sketch, drop me an email to my QRZ.com address. Them that know can make it go. 73's Pete N6QW

  Starting at the 12 O'clock position we have the Band Pass Filter and the Orange wire at the top connects to one of the amplifier steering relays. On receive this leaf actually is connected to the output side of one of the steerable relays. On transmit the orange wire is now connected to the input side of the steerable RF amp. As we move around the clock the splitter is connected to the BPF. This splitter consists of 8 Bifilar wound turns on a FT-37-43 core. The end of one winding connects to the start of the 2nd winding which in combination connects to the band pass filter and the two free ends are connected so that one lead goes to the input of one ADE-1 and the other end to the 2nd ADE-1 input. These two windings are bridged with a 100 Ohm resistor. Why you ask the resistor well that is a good question whose answer likely involves elements like providing a constant load and balancing signal levels. At the five o'clock position is our sideband inversion relay which is not ne...

Last night at 8:17PM we had a 3.9 Magnitude " shake, rattle and roll" event and Bill Haley and the Comets were nowhere in sight. About 10 miles from my QTH. Happy St. Patrick's Day! The ever-skeptical ham wants to see the plots and the circuits. Today we will look first at the all-important Band Pass Filter. (This gives pause that maybe every ham has Thomas as a first name.) Credit goes to VU2ESE for the BPF used in the Bitx40 and the 1st item is just a lift from that project starting with the plot and then the circuit. The 50 Ohms resistance is for simulation purposes and not installed when placed in the circuit.   Now that is a flat Band Pass!   This uses standard values!      We next turn our attention to the J310 Steerable Amp stage that is used as the Rx RF Amp on receive and the Tx Pre-Driver on transmit. This circuit is for 40M and provides 10dB of Gain. We must add the steerable relays so that is in essence the direction of amplification is steered for i...