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Out with the old – In with the new

Progress is developing with the Codan.

Originally the radio was a “Remote Head” radio, but I was wanting to use it as a base radio. So I welded up all of the extra holes in the face plate then drilled and cut some new holes to turn it in to a base radio.

Before I could start installing the Arduino powered Direct digital synthesiser (DDS), I needed to remove the un-required circuitry and and wiring. Continue reading “Out with the old – In with the new”

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Codan 7277-TB Options PCB

Before modifying of the Codan could take place, I needed to work out what had been fitted to it and what was surplus to my requirements.  The Codan radios where very popular for use with the Royal Flying Doctors service, which used an emergency tone alert when assistance was required.

This radio had two of these emergency call boards and also another undocumented one bolted to the front panel.

I posted a question on the Codan Yahoo Group if anyone knew what it might be.  Without the remote control radio head it made it very difficult to identify the purpose of the board. On removal of the board, the radio became silent.
Ken – VK6YKG closely inspected my photos of the PCB and came to the conclusion that it may have been used possibly as a tone squelch PCB given the use of the NE567 tone decoder IC. Maybe it was used for decoding FSK, RTTY or even WeFAX.
After working out that the board was intercepting the AF audio between the Mute PCB and Remote PCB, I have since removed it as it is surplus to my requirement.

Continue reading “Codan 7277-TB Options PCB”

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Back again, hello Mildura

Here is the blog that never started.

Initially I registered my own domain name because the new id.au domain names were so cheap. I just had to have one.

After several failed attempts here is my third go at blogging.

After a move to my new home Mildura and a career change, maybe blogging might stick this time – one can only hope.

So here is my new project – a Codan 7727 HF radio. They were extremely popular during the eighties, but fell out of popularity when PLL became popular and Channel crystals became $50 a pop.

The plan with this girl is to replace the crystals with a DDS powered Arduino kit designed by VK5ZLR.

Let’s see if I can blog the process of my new found project.