News, Updates and Other Minutiae

I have, for quite a while, provided modified versions of the code for my projects free of charge. However, the cost of webhosting for this site has tripled in the last couple of years and the little I make out of the pcbs I sell goes nowhere near covering this cost.

As of October 2017, I will be asking for a donation in exchange for providing custom modified code for my projects to help keep this site available.

February 2018

Updated Australian Band Plan page with the latest info (under 'Misc' heading).

November 2017

A modification plus software to allow the Simple DDS VFO to be re-calibrated as often as you want without having to re-program the PIC has been added to the Simple DDS VFO page. Simple DDS VFO bug problem fixed. Code uploaded to webpage as version 'c'.

October 2017

There is a bug in the Simple DDS VFO code. See Simple DDS VFO page for the problem and updated code. Included an add-on for the Simple VFO project to indicate which step size has been selected. Simple DDS VFO project updated and software file uploaded. The pushbutton on the encoder is used to change step size (step sizes 10Hz, 1kHz and 10kHz).

September 2017

Noise Canceller kits now available.

July 2017

Updated both the DDS Xtal Substitute and DDS Xtal Substitute Mark 2 projects into one project. The original webpages are available to download as PDF's.

May 2017

New project added - my version of the X-Phase noise canceller. PCB available and a kit of parts to follow soon

January 30 2015 update on the PSK kit project

Started on the test equipment to characterise the xtals for the filters. To make sure that I have an accurate frequency counter, I finally cased and made operational a 10MHz OCXO that has been sitting on the shelf for months. Not GPS locked (yet).

OCXO construction OCXO construction OCXO construction

Not sure how I'm going to label this one, it gets rather hot and sticky labels..... well, they don't, er, stick! Haven't measured the temperature of the case, lets just say, you don't hold it for very long.

OCXO construction

For the frequency counter, as I need 1Hz resolution, I used this design from the Burnham Beeches Radio Club. It is based on a design by EI9GQ. Rather than make a new pcb for it, I repurposed an old one that I built ages ago from a design in the last remaining Australian electronics magazine. Was never happy with it, so now it has a new life.

OCXO construction

Still need to put it in a case, but here it is reading it's own 10MHz oscillator source. The OCXO is bang on 10MHz according to the zero beat method of comparing it to WWV (after a 30 minute warm up).

OCXO construction

This is it's baby brother, same design, built a little while ago without the option of the OCXO frequency source. And yes, it also is waiting to be labelled.

OCXO construction

4 February 2015. Just a quick pic of the OCXO frequency counter now boxed up. Labelling can wait until later.

OCXO construction

January 28 2015 update on the PSK kit project

So much for the middle of January for the last of the parts, they arrived two days ago, nearly the end of January. No matter. I was in the workshop today, so here is a sequence of photo's showing the assembly of the receive section of the PSK kit. The reason there are no xtals in the filter yet, is that i still have to build the equipment necessary to characterise the 200 odd xtals I ordered for this. How it is shown here is very similar (minus any tweaks), to how the instructions will be for building the final kit. The receive section and oscillators will be first. Then this part will be setup and made operational before building the transmitter section.

1st stage PSK receiver construction 2nd stage PSK receiver construction 3rd stage PSK receiver construction 4th stage PSK receiver construction 5th stage PSK receiver construction 6th stage PSK receiver construction 7th stage PSK receiver construction 8th stage PSK receiver construction

The transformers used to isolate the input and output audio paths have a "P" on one side to signify the primary. This is the side that will be interfaced to your computer/laptop that you are using.

input/output transformer marking

January 2015 update on the PSK kit project

90% of the parts for prototyping the re-vamped PSK20 kits have arrived and the rest should be here by the middle of January. Originally, I was hoping that the kits would be available early this year, but some parts, notably the PA transistors are on a 12 week lead time, which I can do nothing about, so the release will be somewhat delayed. As things progress, I will post the news here and on several Yahoo groups that I will list closer to release time.

A quick update on happenings - Dec 2014

As a few know, I am working on re-engineering Dave Benson's PSK series of kits, getting them ready for re-release. The first batch of prototype pcb's arrived yesterday and I've already found two mistakes. Just as well I know where to get them made real cheap! First mistake is not removing a via after re-routing a track (luckily, that one is not going to cause a major problem) and the second was not putting the right size holes for the cans of the transformers in the output bandpass filter. I dare say I will find something else. Another problem related to this time of year (Dec 2014), is the slow down of the delivery services due to large demand and components being on back order and taking a while to turn up. Here is a pic of the first prototype pcb.

First PSK prototype pcb

And before you ask "Where is the PA stage?", that is the next stage once this part has been sorted. Also, to get the pcb's within the 100mm x 100mm prototype pcb limit of my manufacturer, I have made all off board connections via flying leads instead of having them pcb mounted. Still waiting for parts to build and debug the first prototype, so it looks like my initial timeline of having these ready early in the New Year will be pushed back somewhat. There are some other changes I have in mind, one of which is the use of the Si5351 oscillator chip to replace the two oscillator crystals. The aim being to make these more frequency agile.