Tuesday, 31 May 2022

Irwell HF Transceiver VFO Oscillator Module Re-Visited Pt1

 

Si5351 VFO Banner

My last blog post was in February of this year (2022) and it is hard to believe we are now at the end of the month of May and close to the halfway point of 2022!

I expect followers of the blog may have been left wondering if my Irwell HF Transceiver project has been abandoned but alas that is definitely not the case!

Thursday, 10 February 2022

Balanced Modulator For The Irwell HF Transceiver

Before I get into the first blog post for 2022, I would like to take the opportunity to wish everyone who follows the blog a belated happy new year.

Happy New Year Image

HF Transceiver - Modulator

"High Performance AM, CW & SSB Modulator for the G6LBQ Irwell HF Transceiver"

In this blog post, I cover work on the first of the transmitter modules for my Irwell HF Transceiver, a multi-mode modulator that is capable of SSB, AM and CW modes.

Wednesday, 1 December 2021

The Cascode IF Amplifier Revisited

 For my original Cascode IF Amplifier article click here.

Cascode IF Amplifier Updates

"For The G6LBQ Irwell HF Transceiver"

Welcome to my blog post on the Cascode IF amplifier where, I address a problem that I discovered with the AM demodulator circuit and I also update the PCB to include the S-Meter electronics.

A note to self for future reference: 

"pay closer attention to manufacturers' product data sheets"

Radio research department

Thursday, 28 October 2021

Part 5 Of A Digital VFO For The G6LBQ Irwell HF Transceiver

For part 1 of the Digital VFO click here.

For part 2 of the Digital VFO click here.

For part 3 of the Digital VFO click here.

For part 4 of the Digital VFO click here.


Digital VFO I/O Expander Module

"For The G6LBQ Irwell HF Transceiver"

Welcome to part 5 of my blog post series covering the Digital VFO developed for use with my “Irwell HF Transceiver project”.

In this concluding article, I present the I/O expander module, which interfaces to the STM32 microcontrollers I2C bus, its job is to extend the number of digital outputs available and provide switched logic outputs to drive my BPF and LPF transceiver modules.

I/O Expander Illustration
Illustration of the I/O expander   


Monday, 18 October 2021

Band Pass Filtering For The G6LBQ Irwell HF Transceiver Part 3

 For part 1 of the BPF module click here.

For part 2 of the BPF module click here.

HF Transceiver - Band Pass Filter Module

"High Performance RF Band Pass Filtering For The G6LBQ Irwell HF Transceiver"

In this blog post, I conclude the development of my high performance RF Band-Pass Filter suitable for the Irwell HF Transceiver as well as SDR receivers and other transceiver builds.

G6LBQ Multi-band BPF Filter Board

Wednesday, 1 September 2021

Band Pass Filtering For The G6LBQ Irwell HF Transceiver Part 1

 

HF Transceiver - Band-Pass Filter Module

"High Performance RF Band Pass Filtering for the G6LBQ Irwell HF Transceiver"

In this blog post, I lay the foundations for a high-performance RF Band Pass Filter  suitable for the Irwell HF Transceiver as well as SDR receivers and other transceiver builds.

For my own transceiver project, the filter module needs to meet the following criteria:

  • Have a sufficient number of filters to enable general coverage reception of 0.5MHz to 30MHz and provide uniform high performance for any given frequency within this range.

  • Be usable on the transmit path with a rf power handling rated at 1 watt.

  • Provide good suppression to frequencies that fall below or above the desired frequency pass band.

  • Provide low insertion loss within the wanted pass band & good return loss.

Sunday, 15 August 2021

Part 4 Of A Digital VFO For The G6LBQ Irwell HF Transceiver

For part 1 of the Digital VFO click here.

For part 2 of the Digital VFO click here.

For part 3 of the Digital VFO click here.

Digital VFO & RF Oscillator Module

"For the G6LBQ Irwell HF Transceiver"

Welcome to part 4 of my blog post series detailing the Digital VFO and RF oscillator module for my “Irwell HF Transceiver" project.  

The PCBs have arrived from the fabrication plant so it is now time to get busy with the soldering iron and hopefully call time on this part of the project, or at least for now. Providing there are no issues with the PCBs or hardware, all that remains to be done is software updates to coincide with the future development of the project.

G6LBQ STM32 SI5351 VFO Boards

A trio of G6LBQ VFO boards.


Friday, 6 August 2021

Part 3 Of A Digital VFO For The G6LBQ Irwell HF Transceiver

For part 1 of the Digital VFO click here.

For part 2 of the Digital VFO click here.

Digital VFO & RF Oscillator Module

"For the G6LBQ Irwell HF Transceiver"

Welcome to part 3 of my blog post series in which I present details of the hardware for my Digital VFO and RF oscillator module. This is a significant building block for the “Irwell HF Transceiver" project and I Present my buffer amplifiers for the SI5351 ICs and design a PCB to produce a completed working module.

G6LBQ Si5351 Buffer Circuit
My prototype SI5351 buffer & signal splitter circuit!  

Friday, 30 July 2021

Part 2 Of A Digital VFO For The G6LBQ Irwell HF Transceiver

For part 1 of the Digital VFO click here.

Digital VFO & RF Oscillator Module

"For The G6LBQ Irwell HF Transceiver"

Welcome to part 2 of my blog post series in which I present further details of my Digital VFO and RF oscillator module for the “Irwell HF Transceiver" project. This is a significant building block and is solely responsible for frequency generation and the control of other modules in the project.

Since I posted part 1 on the blog, I have made good progress with the software changes that I outlined. I have added additional commands to JA2GQP’s source code for the I2C Multiplexer and I am now at the stage where I can communicate with two SI5351 devices to produce two chip independent clock signals. In order to achieve this, I have had to make changes to both the main code as well as the SI5351 library file.

For now, I only need to generate two clock signals for my transceiver, one for the VFO and the other for the BFO. This will permit the radio to run as a single conversion superhet in its current state. Once further modules are developed, the receiver will be upgraded to a dual conversion superhet, this will require a third clock signal  for the requisite conversion oscillator.

The additional software code required to support a third SI5351 is going to be a bit more difficult for me to implement. I hope to replicate JA2GQP’s BFO oscillator code for this as it includes a routine for calibrating the BFO frequency and saving it to memory. If I can do this, it should also pave the way for implementing an IF shift control.

Tuesday, 20 July 2021

Part 1 Of A Digital VFO For The G6LBQ Irwell HF Transceiver

 Digital VFO & RF Oscillator Module

"For the G6LBQ Irwell HF Transceiver"

In this blog post, I present my digital VFO and RF Oscillator module for the Irwell HF Transceiver project, which is based on the Silicon Labs CMOS SI5351 Clock Generator.

Before we begin, I would like to pay homage to an era in my life which has flourished and brought great happiness, prosperity and achievement. 

I make the aforementioned statement with a sense of humbleness and I also feel privileged to have experienced great wealth in the recent flourishing times. 

If all this has got you thinking, I have won the national lottery or been a beneficiary to a nice windfall you are excused and forgiven :)  The truth is I have only ever been good at making other people wealthy and said people choose to forget what the catalyst was for their wealth status. Those people know who they are, shame on you!

I digress a little as I sailed off course for a moment there but suffice to say I am very happy with my modest lifestyle.

Thursday, 24 June 2021

A HF Receive RF Pre-Amplifier For The G6LBQ Irwell HF Transceiver

 

HF Transceiver - Receive Pre-Amplifier Module

"A look At RF Preamplifiers For The G6LBQ Irwell HF Transceiver"

In this blog post I take a look at RF Preamplifiers and build a suitable module for my Irwell HF Transceiver project.

The RF preamplifier is one of the most important stages in a receiver and it has to meet certain criteria in order to cope with the vast range of signals available at its input. A poorly designed RF Preamplifier can destroy a receiver's overall performance so care must be given to the implementation of this stage.