The news, opinions and events of VE3OIJ / VE3EEE
VE3OIJ

4 bit computer built from discrete transistors

Equipment, General, Technology

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)

Source: 4 bit computer built from discrete transistors

VE3OIJ

VE3EEE on the air around Christmas

Astrophysical and Geophysical, Digital Modes, DX, Operating

Just for something different, I’ve been using my second callsign lately.  I have been doing mostly digital modes, especially JT-65, between 10 and 30 watts depending on conditions.

Despite the solar conditions (K-index between 4 and 6 for the last few days) there has been some DX on all bands from 80m to 10m.

VE3OIJ

ARRL Field Day 2015

Clubs, Digital Modes, DX, General, Operating, Technology, Voice Modes

It’s the end of June and that means ARRL Field Day 2015.  Squidette (VA3CEW) and I deployed to the Outlet Beach (FN13jv, right beside Sandbanks Provincial Park) to operate a Field Day station as VE3EEE.

Equipment

We went out with the standard VE3EEE portable pack:

  • Honda EU2000i generator
  • Quad core i7 laptop
  • Yaesu FT-847
  • Begali paddles
  • RigExpert Plus TNC
  • LDG automatic tuner
  • Hy-Gain DP-19D dipole (set for 20m)
  • Buddipole (set for 15 or 40 depending on the time of day)

WX

Cold  and miserable with drizzle for basically the entire time.  That was not fun at all.  Nevertheless, we did have shelter, so it wasn’t the end of the world.

Solar WX

There were geomagnetic storms earlier in the week, but they had pretty much abated.  K-index bounced between 1 and 3.  15m down to 80m seemed to be open.  I listened on 10 and didn’t hear anything, so I didn’t bother with 6m.

Results

We made 72 contacts between 40m, 20m, and 15m, almost all digital although we threw in a few CW and Phone contacts just for good measure.

Social

We also took the time to drive across the county to visit the Quinte ARC Field Day site in Ameliasburg.  It was rainy and miserable there too, but they had a great setup with 4 radios going!

Photos

This is the buddipole set up on a sand dune. The tower isn't quite fully extended due to overhead trees. Nevertheless, it's got a good 5-7m over the ambient ground level.
This is the buddipole set up on a sand dune. The tower isn’t quite fully extended due to overhead trees. Nevertheless, it’s got a good 5-7m over the ambient ground level.
This is the buddipole set up on a sand dune. might be a bit easier to see.
This is the buddipole set up on a sand dune. might be a bit easier to see.
Hy-Gain dipole between trees. Had I planned this better, I'd have picked different trees and maybe gone for 40m.
Hy-Gain dipole between trees. Had I planned this better, I’d have picked different trees and maybe gone for 40m.
Looking northwest along the beach road.
Looking northwest along the beach road.
This is the cabin on the beach while we were setting up. The generator is in front.
This is the cabin on the beach while we were setting up. The generator is in front.
This is the VE3EEE operating position. That's a 27" touch screen on the left, which makes operating the radio a lot like a Star Trek console.
This is the VE3EEE operating position. That’s a 27″ touch screen on the left, which makes operating the radio a lot like a Star Trek console.
VE3OIJ

Making WSPR software work on Yaesu FTdx-1200

Digital Modes, Equipment, Operating, Technology

I will state up front: The knowledge I am about to lay down in print was imparted to me by Roger (GW4NOS).  I am putting it here so that a) I can find it again; and b) the internet will archive it for future seekers of knowledge.

The Problem:

Like many people I bought a Yaesu FTdx-1200 and it works very well… except when using WSPR software, there seems to be no incantation that permits CAT control to work.  Like the Reverend Mother told Paul Atreides:

The Solution:

It turns out, however, that the software can be made to work in a few simple steps.

Step 1: Select Yaesu FTdx-9000 on the WSPR software.  Apparently that radio has the same CAT command set as the FTdx-1200.

Step 2: On the radio, menu 039 must match the setting in the WSPR software.

Step 3: On the radio, menu 040 must be 100 ms or greater.  Apparently, the default of 10 ms is too speedy for the WSPR software.

Step 4: On the radio, menu 041 must be “DISABLE”.  Nothing I have uses CTS/RTS flow control anyway.

Once that was done, everything worked perfectly!

VE3OIJ

Fair price of used equipment

Equipment, General

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.

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Darin Cowan - VE3OIJ
@VE3OIJ

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