VK5TM


News, Updates and Other Minutiae

As a lot of people have pics of things unrelated to ham radio on their websites, I thought I would add a couple of my own (Scroll down for site updates). Banjo, our Red Heeler/Koolie cross at 4 months old. Banjo at 4 months And at 12 months old (Feb 2016) enjoying his birthday breakfast treat of banana on toast. Banjo at 4 months

May 2017

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

27 December 2016

Another addition to the Gallery section. This time, fitting a DDS module to a Philips PM5326 RF Generator to cure a bad drift problem.

26 November 2016

Additional software for the Simple DDS VFO added. This enables the pushbutton on the encoder to change step size (step sizes 10kHz, 1kHz and 10Hz). See the notes in the Download section of the Simple DDS VFO page for more info.

20 November 2016

I have had some interesting conversations with homebrewers over the last few years relating to experiments/modifications of the works published on this website. One of the things on the 'list of things to do', was to publish some of their pics' etc on my website, so along that line, the first one, a filter/leveller for DDS modules from G3OAG, is now on my site. This one and all the others I have available to show, will be posted under the 'Gallery' menu. Now that things are starting to return to somewhat normal around here, I will endeavour to get the others up as quickly as possible (with apologies to those that have been waiting to see their work in lights).

The Gear in the Shack

Some photo's of the equipment in the shack. First up, an FT7. Considered to be a fine rig in it's time when it came out in the late 1970's. I haven't fired this one up yet, so I have no idea what condition it is in operationally. Cosmetically, it's not too bad, but then nobody can see it over radio, can they. picture of ft7 Next up is an FT757GX. From it's serial number, it is one of the very first one's from circa 1983. I bought this one cheap with a receive problem according to the previous owner. Why did I buy it with a fault? Well, one of my activities is PIC programming, so I want to look into doing a replacement cpu for this rig at some stage. picture of ft757 The fault is supposed to be that it drops out on receive occasionally but tx is fine. Most likely causes of this (in no particular order), faulty/aging xtalls, faulty trim-caps in the oscillators and a very common one, faulty diodes (this model uses diode switching instead of relays for much of it's rf switching). There are relays used for power switching and it's possible one of these is faulty. On the test equipment side of things, I have a Marconi TF2015 signal generator, a CTE 1gHz spectrum analyser, UNI-T 100MHz digital storage scope and various multimeters on the commercial side. Amongst the homebrew test equipment, there is an LC meter built from information on the net, an RF Powermeter designed by OZ2PU and published in Elektor magazine, various frequency counters and a valve/tube GDO. picture of tf2015 signal generator Marconi TF2015 signal generator. 10MHz - 500MHz range. picture of cte spectrum analyser CTE spectrum analyser. This unit has internal batteries so that it can be used in the field. All I can say is, you need muscles upon muscles to cart this any significant distance. It is a really heavy brute with batteries in. homebrew lc meter The LC meter built from information on the 'net. 16F628 PIC based homebrew rf powermeter OZ2PU RF Powermeter. Contains an AD8307 and 16F876 and good to approx 500MHz. valve gdo As you can see, the GDO is complete but in pretty rough condition. I'm still debating whether to power it up or not (after doing the necessary safety checks, of course).