Saturday, September 30, 2023

Forty Years of Personal Computing - Wyse-85 Terminal

By the summer of 1985, my original CT-64 terminal felt limited. Sixteen rows of 64 characters didn't seem like enough. Especially when at work I regularly used screens with at least 25 rows of 80 characters. In 1977, terminals with such capabilities were around $1000 -- way beyond my modest budget. By 1985, much more capable terminals were available for about half that price. It was time to upgrade.

August of 1985, I purchased a Wyse-85 terminal for about $700 -- a good price for the time. The terminal offed a DEC VT-220, VT-100 and VT-52 emulator, so it was plenty capable. It sported 24 or 25 rows of 80 or 132 columns on the screen. I purchased the green phosphor screen.

The most important thing, however, about the Wyse-85 compared to the CT-64 was speed. The CT-64 was limited to a paltry 1200 bps. The Wyse-85 had a top speed of 38400 bps. Thirty-two times faster. The CT-64 would take more than eight seconds to write every character on the 16 x 64 screen. The Wyse-85 could write an entire 25 x 132 screen in less than a second. 

The Wyse-85 was such a joy to use compared to the CT-64, I couldn't believe I hadn't done this sooner. 

I did have trouble with this terminal when I tried to use it in the shack back in the late 1980s. The keyboard scan generated a fair amount of RFI. Putting several ferrite toroids on the keyboard cable helped a little, but did not eliminate the problem. 

I still have this terminal. It's been stored in the original box since November of 1994. I hope it still works.

Tuesday, September 19, 2023

Demise of one 80/40/20m Dipole

I was QRV in Gordon county briefly - only a couple of weeks. I managed to erect the 80/40/20m dipole I had up in Warren county, which previously flew over Fulton county. It was a cobbled-together mess, made from wire left over from the original 80/40m dipole, newer traps, and old insulators and rope.

Using the Mark III Antenna Launcher, I did a good job casting over a tree in the front yard. Weight sailed up over the tree and came right down beside the trunk. The 1/16" guide line went back out to the antenna launcher, and then the 1/4" nylon halyard came back over. Perfect.

At the far end, I had more trouble. Not wanting to crawl over a fence, I cast sideways to branches overhanging the edge of the yard. The first toss wasn't great, so I pulled it down. Second toss got stuck in the tree, and I lost the weight. I was down to my last antenna weight. I confidently tied it on, pulled back, let it fly, only to watch it sail off the end of the fishing line and into oblivion. Nuts. 

With no weights handy, I couldn't use the antenna launcher. I opted to use a small hammer and toss the halyard over a branch about 20 feet up in the tree. At least I didn't lose the hammer. 

The resulting installation sloped the dipole from about 25 feet on the south end, to about 60 feet on the north end. No matter - it would work. At least, until I could make more weights and get it higher in the air. 

I used it to make about 100 contacts for the NAQP Phone in August, plus a little casual operating. Then I found most of it lying on the ground after a few windy days. Inspecting the remains showed that the wire between the 20 and 40 meter traps had broken. That particular segment was pretty old, being part of the original 80/40m dipole, and might have used wire from the ancient untuned doublet before it.

This meant that one of the 40m traps was still up in the tree. Looking carefully, I could see it about 50 feet up. Untying the rope, I could not get it to drop, and instead pulled the halyard to recover the rope. The wire ended up coming off the insulator, leaving wire and one trap stuck in the tree. Drat.

The rest of the antenna lay across the yard and lower driveway. I don't use that driveway, so I didn't think about it. However, some folks came to visit the parsonage and apparently didn't see the traps laying there. Two of the trap forms got crushed in the process. Doggone it.

I guess I have to rebuild this antenna from scratch, using new wire and traps. That will take some doing, as most of the parts are back in Gwinnett county. Plus, I have to make more antenna weights to put it back up. 

In the meantime, I'm off the air in Gordon county.