Started off doing the first hour of Field Day at home running the radio off battery power. With the radio running 25-50 W, I racked up a few good contacts tuning around 10m, mostly from up and down the east coast.
Then it was off to the usual Field Day on the USS Yorktown with the club. This year we were operating with 2 stations plus a GOTA station that appeared to attract some interest.
The GOTA station was run on battery that was being charged by a solar panel, and also featured a couple of VHF go kits and some Morse code keyers to play with.
At the usual operating locations, people were busy making Field Day contacts. I spent about an hour at the phone station operating, but listening to the band chaos wore me out pretty quickly, so I switched over to logging for a bit.
Spent another hour operating Field Day from home on Sunday morning and was able to score a bunch more contacts fairly easily. Then it was back to the Yorktown to finish off the last couple hours of Field Day and then pack everything away.
At home, I ended up with about 25 contacts over the two hours I was operating. On the Yorktown, the club ended up with 582 contacts spread out over 4 bands and 4 modes. Pretty good this year. Maybe it was the sacrifice of AJ4UQ’s HT to the ocean that helped this year.
Finally got around to replacing the old corroded soldered-in D cell in the RCA Voltohmyst with a new battery today.
Snipped the wires off the battery and into the trash it went. Had to drill out a rivet to remove the battery holder clip.
The battery holder is a little on the big side and just fits into the space vacated by the old battery and clip. Soldered the wires onto the battery holder and fastened it to the Voltohmyst using some double sided tape.
Now it’s got a new battery that can be replaced whenever it’s needed.
Next thing to do is go through the manual and read up on how to calibrate the meter.
I ended up being busier than originally anticipated and was only able to operate in Museum Ships Weekend for a few hours Saturday afternoon.
I started off with doing some logging. Band conditions on 20m were pretty crummy and there wasn’t a whole lot of activity we could hear, but we managed to hunt down about 6 other museum ships.
Then it was my turn on the radio and managed to nab a couple more museum ships. Found an open frequency to start calling on, made a few contacts into the Midwest and Northeast. Then a pileup happened and I was working stations as far as CA, and even a few DX stations (Austria, Belgium, and Italy). That lasted about 30 minutes, and then as quickly as the band opened, it shut down again. Towards the end, static crashes from thunderstorms rolling in from the west obliterated any signals we could make out on 20m.
I decided to call it a day around 6PM and turned things over to the evening crew, but I’m not sure they were able to dig up much more activity even after the thunderstorms went by.
There were about 48 contacts, including 10 museum ships (I think) by the time I left. I’ll find out later how the rest of the weekend went.
Saw someone at the TARC swap meet with one of these little Tektronix 222 DSOs for sale, so I bought it. Terrific timing since my Hitachi oscilloscope died a while back and I still haven’t gotten around to looking into it.
It’s little, and doesn’t have a lot of capabilities but I think it will do pretty much everything I need (at the moment). It comes with two scope probes that are permanently attached. It’s designed to be powered with an 8V SLA battery, but it looks like batteries with the right form factor and voltage aren’t readily available anymore. I did find a promising looking battery replacement project though. This one didn’t come with a battery, but a standard sized power jack lets you power it with wall power. It’s even got a RS-232 serial port!
The scope seems simple enough to figure out how to use without a manual, and I was even able to find a service manual online to download.
Here I’ve got one of the channels measuring the output from one of my EtherkitSi5351 breakout boards. I don’t remember what I have my RedBoard making the Si5351 do, but I seem to be getting a pretty good signal out of it.
One of my acquisitions from today’s TARC swap meet was a variable power supply. The person I bought it from acquired a bunch of these from a school district surplus auction. I’ve been wanting to get a variable power supply for the workbench, so I bought one of them for $20. Seemed like a pretty good deal. Almost grabbed a second one from him.
Banana jacks provide AC and DC outputs, and voltage for both is controlled by the knob on the left. Two meters show DC volts and amps, but if you’re using the AC output, you’ll need to measure it yourself.
The panel indicates the power supply will do 0-20 VDC and 0-25 VAC. With no load, the power supply topped out at 35 VDC and 26 VAC. This is an unregulated power supply, so any load is going to bring the voltage down.
Getting inside the power supply requires removing a total of 18 screws (6 on each side, 6 on the top). Seems a bit excessive to me, but I didn’t design the thing. Once the screws are out, removing the top exposes the innards.
Not much to it inside. There’s a big beefy transformer which accounts for almost all of the power supply’s weight. Voltage control is performed by the variac. A large (and loud) 120mm fan (lower right) provides cooling.
The key just turns a metal plate that flips the actual power switch on or off.
The cooling fan gets its own power supply so that it’s not affected by changing the output voltage. It’s just a 12V wall wart that gets powered from the AC input I think (haven’t traced any of the wires to see what goes where).
Plenty of modification potential with this power supply. I’ve got a small list of easy ones that I think I’ll make:
Replace the key with a regular switch
Switch out the banana plugs for 5-way binding posts and Powerpole connectors
Replace the fan with a quieter one
This seems to be a pretty sturdy power supply designed for the harsh environment of a high school lab. Everything inside looks to be in pretty good condition.