I started this project as an attempt to teach myself about how computers worked. As such comments, useful links, or anything else related would be appreciated. Prior to this my experience in electronics was mostly microcontroller based. The computer is perpetually half done (it could be more it could be less, I only design the logic for the chunk I’m working on) but currently consists of about 300 transistors. I’m pretty sure that the computer follows ‘Harvard architecture’ (corrections welcome) as the RAM and ROM are strictly segregated. 4 bit is used loosely data width is 4 bits but instruction width is 8 bits as some instructions include 4 bit values. some stats: RAM: 16 nybbles (dictated by address register width) ROM: 16 bytes (dictated by program counter width) clock speed: more than one (the computer is currently not clocked as much of the sequential logic has yet to be built)
Probably because I mention used equipment in articles like this one, and probably because I am slightly vocal about what I consider to be hams with an overly optimistic opinion of the worth of their used junk, I am sometimes asked what I think fair prices for used amateur radio equipment would be. It being a slow weekend, I sat down and thought about it so I could put it into words and numbers.
For this analysis, I am making three assumptions: 1) that the equipment works – if it’s broken junk, that’s a whole other issue; 2) that the equipment isn’t somehow historically significant – a collector’s item of some sort; and 3) that the radio is in excellent condition with no serious blemishes, damage, etc., and comes with all its original accessories in similar condition.
In general, it seems that most of the major manufacturers have a 1-2 year warranty, and a 3-5 year product cycle. That is to say, you buy a brand new Yaesu XYZ-1329 now, and in 2020 you can probably expect an XYZ-1430 to replace it in the Yaesu product line.
Within those parameters, this is how I calculate the fair value of used equipment:
0. Start with the current advertised price of a new model of the equipment. If it has been replaced in the product line, then use the current advertised price of whatever replaced it.
1. -10% per year cumulative while still under warranty, and another -20% when the warranty comes off. Assuming a 1 year warranty, you can multiply the price from above like this: *0.9 (age < 1), *0.65 (1 < age < 2, out of warranty), *0.6 (age < 3), *0.5 (age < 5), *0.4 (age < 6), *0.25 (age < 10), *0.2 (10 < age)
2. If the rig has been replaced in the product line, apply another *0.75 for each time it has been replaced.
3. If the rig has been used in a location with smokers or dogs/cats/fur-bearing monsters, apply *0.75. People could argue this I suppose, but the amount of crap in the air getting sucked into the rig via fans just squicks me enough to apply this.
And that pretty much covers it. So if I look at something like a Kenwood TS-2000, I see an advertised price of $1700 CDN today. Therefore, a 14 year old TS-2000 from a non-smoking, non-cat home would be thus:
$1700 (TS-2000, Radioworld) * 0.2 = $340
A 10-year old Kenwood TS-850 from a cat-owning smoker would be:
$2000 (TS-590, Radioworld) * 0.25 (age) * 0.75 (smoke/cats) * 0.75 (replaced in product line) = $280
I know that many amateurs seem to think that their old equipment is as valuable today as it was when they bought it back in the 00’s / 90’s / 80’s… but that’s simply not true. In addition to the general issues of wear and tear on moving parts and time working its magic on capacitors, there’s other factors – better use of battery power, modern computer interface capaibilities, improved TX and RX capabilities, and more that can be found in an up-to-date radio. Obsolete radio equipment cannot be expected to hold its value like gold.
Anyway, that’s how I figure it, and it’s why I don’t buy much in the way of used equipment – because finding a fair price is very difficult.