M0UAW's Blog

If you've any interest in reverse engineering old code, Ghidra does a pretty good job of it though it does seem rather massive overkill to run it against <400 bytes of assembler.  I hope nobody objects to this, I've tried and tried to locate schematics and information on this oddball radio but even the people I've managed to track down from Garex/AKD don't seem to have it.   If you own this code and object to my posting it here, please contact me, I *will* remove it but also bear in mind reverse engineering is legal.     This is the code from the AKD: LAB_fc00 XREF[1]: fffe(*) fc00 8e 00 1f LDS #0x1f fc03 86 2d LDAA #0x2d fc05 97 20 STAA DAT_0020 = FFh fc07 86 00 LDAA #0x0 fc09 97 22 STAA DAT_0022 ...

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 ...

****UPDATED 2026****   There's new spike protein mutations doing the rounds out there, be careful people    From 2022:   Two and a quarter years in, Corona Virus finally got me. I got a message from someone I'd spent 30 minutes in fairly close proximity with, two days after the fact they felt a 'bit off' and tested positive, they suggested I might want to test.   So, I did.    And yeah, wow, that red line appeared almost instantly and just got darker the longer I left it.   Cue a few days of feeling pretty crappy, sore throat, breathless, headachey and I've been vaccinated so I only got a mild case.   After effects, it ruined my taste buds, even the smell of coffee makes me heave now and even weeks after,  I can't taste properly, far worse than when I was a smoker.  

I'm not nostalgic about valve radios, not at all. This sort of thing leaves me cold.   I'm a fan of the sort of solid state radio where you can understand the circuit, the ones where if they have software it's only there to give a PLL some divider values and maybe hold a memory or ten instead of  the radio being a peripheral for a computer.  So when I saw an AKD 2001 for sale on eBay, untested for spares/repairs I put in a cheeky bid and won it for a bargain £8.  The AKD radios were reasonable quality little units with OK performance but they looked like something that was built from a kit with a microphone and two digit, seven segment channel display that are both more than a little reminiscent of a CB. They're also really dated (unless they've been updated after purchase) with 1750Hz toneburst for repeater access and 25KHz channel spacing which makes them less useful than they could be with modern repeaters needing CTCSS and often being on a 12.5KHz channel.  ...

 I know, I know, it's been a while.   Life gets in the way and all that.   Since I last posted, hmm,   New equipment (that I can remember, there is more): FTDX10 Anytone AT5888UV Retevis RT95 Baojie thing FT450 VR5000 IC-R72 Fairhaven RD500 Astron RS35  And, the current favourite, purely because it's so hackable, an AKD 2001 2M FM set which is due to arrive in the next day or two.    All the big name stuff is nice, I love the FT-DX10 for example, the Anytone and Retevis are cracking little radios and great value but for pure fun, the AKD looks to be possibly the best value of all and I've got plans for it which include replacing the original PIC 16C55 microcontroller, I may even document them here.