I have done several versions of  VFO/BFO circuits using differentmicrocntrolers.  Any of these would work for the Simple SSB transceiver.  Looking at these, you can see that they are also very similar to some of the test equipment I have previously built.  I know that some people who are interested in building this transceiver, have very little in the way of RF test equipment.  So why not build something that can be used to test the modules as they are being built, and then as the Controller,VFO/BFO to finish off the project. Doing something similar to the test gadget ..read more

Well the new toy arrived today, and I have spent the last several hours just playing with it.  It came a fairly well packaged box within a box, with a layer of bubble wrap. I tried to get some pictures, but was having some problems with the camera, so going to use a couple from a post by Herb on the TinySA .IO group.  Overall packaging looks great with a custom printed box , and a molded holder for all the components inside.  This is much nicer than I have seen for most products of any type in this price range After charging the battery, I ran the Touch screen calibrat ..read more

I made a circuit  board layout for the ESP 32 based VFO-BFO using the Wemos ESP 32 Mini controller module.  Sent Gerber files off to China and had 10 made up, they arrived in a little over a week with Express shipping. I built one up and found a few minotr errors I had made in some dimensions, but the boards still worked fine.  I decided I would use this with a Bitx 40 board I have laying around.  I think I will use Pete N6QWs method for doing Upper and Lower sideband selection.  That means adding or subtracting the desired frequency from the IF frequency . For the Bit ..read more

A couple of the projects I have been working on have been put on hold because of the shipping delays caused by the Covid shutdown in many places.  Looking around for something that only required what I knew I have on hand.   I rembered seeing a YouTube video of a SI5351 based VFO with a small TFT display that very nicely simulated a mechanical dial.  Going back I found the video, and there was a link to the website of JF3HZB, the schematic , and Arduino code for the project.  It uses the same 128 x 160 TFT display I have in my VFO-BFO, and a ESP-32 dev. board.&nbs ..read more

With almost everything being shut down from the virus, there must be something good happening.  I think I have found at least one thing.  Since we can't gather together the ability to hold meetings via video conferencing has been really taking off.   Last Saturday we held the monthly meeting of the North Georgia QRP Club via Zoom.  We had around 25 people show up. Mostly members, but also a couple guests including Hans Summers from QRPLabs checking in from Turkey.  He gave a brief history of the QCX transceiver. and informed us that they are only a couple hundred ..read more

I had started on the TinySA from Groups.io HBTE, but am still waiting on some parts that I had orderd than have yet to show up.  Looking around I found a UHF version that covers 240 to 940 MHz. This only uses a single si4432 transceiver module, which I have on hand. So I will try to do a similar UHF version of the TinySA.  Since this does not need the input LPF, mixer, and a high local oscillator, it should turn out to be a small instrument. I have previously used a ESP32 development module, but that was quite large.  Looking around aroound I found a Wemos ESP 32 mini that look ..read more

When I first built the step attenuator,  I wanted it to check  linearity of amplifier stages.  I only needed a relative change in the insertion loss of the attenuator.  Recntly I was able to use my NanoVNA to measure the actual insertion loss across the total frequency range I am interested in.  I also received some questions about showing the actual insertion loss instead of the relative value, Because of this I made a change to the code to switch the display value from relative to actual by a long press of the encoder knob.          First ..read more

I have been playing with building a simple spectrum analyzer for a couple years now.  I have tried several different versions, and have ran into similar problems with all of them.  For what I want I need several different resolution bandwidth settings. For more than two band-widths  the overall complexity becomes greatly increased. I have tried several different approaches, but have not been happy with anything I tried.  I had joined the Homebrew Test Equipment group on Groups.io ( https://groups.io/g/HBTE) , when it started.  Recently there has been a series of p ..read more

I decided to check the step attenuator with the NanoVNA.  It would be nice to see what the linearity of the step attenuator is across the frequency range I am interested in.  After calibrating the VNA I did a series of sweeps from 1 - 250 MHz. This uses the fundamental frequency range of the VNA, it uses harmonics for higher frequency measurements.  I first did the readings using the VNA's internal display, and then repeated with the PC based software. With 0 dB selected the sweep showed about 2.4 to  2.6 dBinsertion loss . The VSWR was between 1.05 and 1.1.  ..read more

This is just quick followup to my last post on the NanoVNA.  I ordered a SNA to UHF female adapter so I could try checking an antenna.  For this I wanted to try the available PC application instead of using the small screen on the unit. This app  is very east to use, just set the comm port and click the connect button.  Then set your frequency range and display type you want.  You then go through the calibration procedure using the short,open,and load standards provided.  You can also calibrate for through, and isolated if you are going to do something like c ..read more