VK5TM


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.

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

Antenna's

Update 11 November 2012.
I have put up what most people would call, I guess, an end fed antenna. I prefer to call it a 22metre length of hook up wire at 5/6metres above ground level.
I have heard VK2's,3's,4's, 5's & 7's plus a ZL1 using it. WWV can be heard at 5MHz, 10MHz and 15MHz so it is working.
There are the constituant parts of a fan dipole sitting in a box waiting to be put up, but I need another support pole at the far end of the yard first. Currently, there are no HF antenna's in the air, or for that matter, any others. I am trying to decide between putting up just a long wire or a fan dipole for HF. Regardless, there will have to be another pole or other fixing point installed. There is a 12m tv antenna tower on the back corner of the house and, as part of the chook enclosure, I put up an ~6m pole on the back corner of the shed/shack. Between the two is not quite long enough for the dipole, so another pole will probably go in the far back corner of the yard. tv tower 6 meter pole Left: Probably a little hard to see, but the tower in front is mine and Right: the ~6m pole as part of the chook run. If I decide to put up a long wire, it will be necessary to use an antenna matching unit. One of my purchases (at a very good price) a while ago was an ex-hams junk box. In it was the remains of an antenna matching unit, missing one variable cap which was later found at the bottom of another box. antenna tuner parts As you can see, there is a lot of cleaning to do before these can be put into service. Yes that is a roller inductor on the right. In the box was also a real valve/tube GDO. Don't know if it works yet. For VHF (2m), I have just completed a 3el Yagi, using materials kindly donated by a friend, in exchange for assembling an SDR receiver for him. It is made from 25mm aluminium square section and 10mm diameter tube for the elements. The day after completion, it was used handheld to receive Arrisat1 with one of those cheap Chinese handheld VHF units. yagi parts mobile whip Left: These are the un-assembled parts of the 3el Yagi. Right: Also included, this 6/2/70 mobile whip(Comet SB-15). completed yagi yagi gamma match close-up Left: The assembled 3 element yagi and yes, the shadow is wonky because the element mounting is wonky (in my defense - I didn't drill the holes). Doesn't seem to affect the performance, but only proper testing would confirm it. Right: A close up of the gamma match, with weather proofing still to be done. The antenna design is by VK5JST, of "Antenna Analyser" fame, and can be found on his website - VK5JST web page