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Showing posts from February, 2014

GPS disciplined clock/oscillator

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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 have a lo…

New TRX- IC-7100, a look inside

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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 because of the size o…