M0UAW's Blog

Per previous post, my unusal/1st gen AKD Some notes:   Processor: MC6802 PLL NJ88C30, PLL Reference Oscillator 10MHz, Ref Osc divisor = 400, channel spacing = 25KHz On RX VCO runs at RX Frequency - 1st IF (10.7MHz) TX VCO runs at TX Frequency.  EPROM 27C128 Mapped to $E000-$FFFF (mostly unused, No code before FC00, only 1K used)   It seems to be a very simple design where the various 'peripheral' parts are memory mapped using a 74LS138 3-8 Decoder, it's not fully decoded so any write which addresses A13, A14, A15 or any combination will enable an output on the 'LS138   CP is the clock pulse for the 4024 Binary counter which generates the 1750 Toneburst  CLK is the PLL Clock Latch is the PLL Latch signal FPSEL and FP14 are related to the front panel, not sure how that works yet OE is the EPROM Select  And some NOR logic:   'FP' signals are related to the front panel, the front panel connector:   Amazingly, the entire operating code for the rad...

 One of a sporadic, few posts about my memories of radio, electronics, computers and whatever else strikes me might be interesting.   My first transceiver, an imported FCC spec Midland 100M, the very first contact was someone two streets away, maybe 150mtrs, because the final was blown, i had the stereotype DV-27 on a biscuit tin, no idea about SWR. I knew a bit about radio and electronics, I'd built a few things from Everyday Electronics and even modified them to do 'stuff', I repaired radios and cassette players for friends at school, more by luck and persistence than any actual knowledge but I learned. However, the insides of the Midland were a whole new level and I really didn't know an awful lot, plus I had nobody to ask, the internet was only a military research project called DARPANet so, as tempting as it was to tinker, I had to take it to the local CB shop and was mildly terrified because CB was illegal to use back then in the UK * (see below).   The owner was ...