VK4ZXI

GPS disciplined clock/oscillator In the electronic wilderness before I re-discovered amateur radio, I have had an interest in mapping from Boy Scouts, and GPS, from boating and 4WD (we belonged to the Mitsubishi 4WD club). I have had GPS devices ever since President Clinton opened GPS for civilian use. I had an ALDI GPS mobile phone tracking system going, but never used. Pretty neat for $80. While Telstra don't advertise it, there is a $10 per month post-paid mobile access that suits such devices. All use is on top of the monthly charge. The tracking device reports its position when requested by SMS. Expensive if running all the time, but cheap if only used when needed, like locating a vehicle in congested traffic to find an alternative route. Enough background. Through my local radio club, I heard about GPS disciplined 10 MHz oscillators, so I just had to have a look. They are easy to find on eBay, but not so easy to find information, documentation or software. Given I ...

New TRX- IC-7100, a look inside I have just purchased a new IC-7100 to replace the FT-857 and FT-897 all-band, all-mode TRX I had. The Yaesu TRX were good radios, but dated designs. The IC-7100 on the other hand is a very modern design and radical form with a separate touch screen controller. The IC7100 is a similar but different design to other modern Icom TRX such as the IC-7410 and IC-9100. All are software-defined radios, with all modulation and demodulation done in software/firmware in the DSP and codec chips. All other signal processing is also done in software. Analogue devices are used for amplifiers and mixers. Band, low-pass and roofing filtering is done with discrete components, but all signal filtering is done by the DSP. I will say more of the design, but for the moment I have some photos of the main unit's PCBs. The mechanical design is simple. The top board is the frontend for both Rx and Tx with most components of one side of the board mainly bec...

Windows 8/Windows 8.1 procedure for unsigned drivers and problems with antivirus There are a couple of problems with "new" software when using Windows 8 or 8.1, not specific to BladeRF, SDR-Console V2, or UT-100C DVB-T dongle betas. My comments are not a criticism of Windows 8, it is a vast improvement on Windows 7 and a necessary path for creating an ecosystem operating system where a common user interface is available on all devices, be they PCs, laptops, tablets or phones. This is necessary for the central administration of all devices in an enterprise setting. In any case, I prefer the Windows 8 interface and access programs in the start tiles system. Windows Explorer has been re-written and is much better. The first issue is that Windows 8 won't install unsigned drivers or even tell you that it hasn't. Given security issues, that is not such a bad thing, but I wish Windows 8 would at least tell you of the problem (as Windows 7 does) when installing drive...

DVB-T, UT-100C new drivers and software, DVB-T Repeater UT-100C new drivers and software There are new drivers and software for the UT-100 series devices from Hides/ITE: https://www.dropbox.com/sh/r80tjnkapkgzeg9/_3yj1s4t9 - I have yet to try them, but they are meant to fix compatibilities with Windows 8 and 8.1, possibly the unsigned driver problem, and more fixes to the PC2TV. I have yet to try them out. Blackmagic Design Intensity Pro capture card I have had trouble getting PC2TV to work but have been concentrating on the video source end. I want to be able to transmit digital video, not analogue (composite or S-video). PC2TV worked with my laptop webcam straight off, so I have been trying to get HDMI video to work. I want to be able to do amateur QSOs with real-time video and audio at high definition; the state of the art. As is noted later in this post, a repeater will assist this. I bought a Blackmagic Design Intensity Pro PCI-E capture card (AU$249)...

Satellite tracking: hardware I have made progress since the first post. I now have the main hardware assembled and am in the process of wiring everything together. The original plan to use a pair of satellite dish positioner wasn't viable. Luckily I discovered that before my order for the second positioner was sent. It is possible to do it that way but there are two problems. First, the positioners are driven by diseqc control. The controller I had was for linear actuators and simply passed the diseqc controls from the satellite receiver through. So I would have needed two satellite receivers with diseqc control for a positioner. Not a big deal except... Second, all the amateur satellite controllers uses conventional rotators, with a 24 VAC motor and 500 Ohm potentiometer. A further consequence of this was that I couldn't use the terrestrial TV rotator as it used a pair of synchronous motors for turning and indicating. Neat system, but couldn't be used. So I had...

I occasionally troll through the "Kickstarter" projects for interesting ones, with both BladeRF and HackRF having their funding from there. http://www.kickstarter.com/ Some weeks ago I came across the "Red Pitaya" http://www.redpitaya.com/ . It seemed like "manna from heaven", a software-defined instrumentation system. Just what I wanted, not having the deep pockets needed for serious HF test gear. I thought I had missed out on the first run, but was down for a subsequent one. However, I received a quote last night, that I immediately accepted. They are due to be shipped February 24, that's only about 45 sleeps... plus shipping time from Slovenia (Eastern Europe is booming, we don't hear much about it here (Australia). I will try and write it up on my other blog on multilevel change) These are the objectives: "INITIAL SET OF OUT-OF-THE-BOX INSTRUMENTS   OSCILLOSCOPE: 2 channels @ 125 MS/s 14 bit digital with external or signal ba...

After much procrastination, my mast is up and I have a wire HF antenna, pending more elaborate VHF/UHF antenna. When I say "mast" I mean mast, it is the lower part of a big yacht mast. All aluminium and only weighs about 80 kg. It is self-supporting but has guys for more stability.     The mast tilts toward the camera position with an elaborate hand-driven pair of linear actuators. Using only half the mast (the other piece bolts on the top), makes for easy lifting. It can be left 2/3 down if needed, so it is not an obstacle on the ground and so I don't hit my head on it!   As you can see, "Ace" is not a mini-zebra, per first photo, and is kindly killing the weeds in the second. He is primarily, a Queensland Cattle dog or Blue Heeler, and yes, they are meant to have long tails for my American readers! The shadow in the shadow is "Jet" as in black, our whippet, also in a compromised position.     The tilting device was made at great...