Power supply: Still dead

That power supply that I thought was working again after replacing the fuse? Yeah, not so much. I turned it on again a few days later and the ammeter instantly went up to 27A while the output voltage was only around 2V.

Spent some time poking around some more, but it’s been sitting on the table since then. Last week I ordered some μA723 voltage regulators to fix someone’s Astron RS-35M power supply. Since I had a few extras (ordered 10 of them), I popped one into this dead power supply. Fortunately it’s socketed, so replacing it was pretty easy.

Plugged the power supply in, turned it on and much to my surprise, the power supply seemed to be working again! 13.7V at the output and seemed pretty stable.

Thinking everything was good again, I turned the power supply off and unplugged it, put the cover back on, plugged it back in and turned it back on.

Poof, back up to 27A and no voltage.

Well crap.

Went back in, put in a new μA723, turned it on and it was back to 13.7V. Left it running for a few minutes, turned the power supply off, turned it back on a few minutes later and it was back to 27A and no voltage.

Well double crap. So it looks like there is a deeper issue with the power supply that’s causing it to kill the voltage regulator.

Field Day 2018

This year’s Field Day was a pretty good one.

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.

Field Day antenna setup at the house
Field Day antenna setup at the house

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.

WA4USN CW/digital station
WA4USN CW/digital station
WA4USN phone station
WA4USN phone station

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.

We were lucky enough to have a couple of CW operators who were going at a pretty steady pace both days. It was fun to watch them operating. Some day I hope to be there doing CW.

Sunday CW operating for Field Day
Sunday CW operating for Field Day

New battery for the Voltohmyst

Finally got around to replacing the old corroded soldered-in D cell in the RCA Voltohmyst with a new battery today.

1.5V Battery
1.5V Battery

Snipped the wires off the battery and into the trash it went. Had to drill out a rivet to remove the battery holder clip.

Voltohmyst battery removed
Voltohmyst battery removed

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.

New battery holder
New battery holder

Now it’s got a new battery that can be replaced whenever it’s needed.

New battery installed
New battery installed

Next thing to do is go through the  manual and read up on how to calibrate the meter.

Museum Ships Weekend 2018

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.

A new oscilloscope

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.

Tektronix 222 oscilloscope
Tektronix 222 oscilloscope

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 Etherkit Si5351 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.

Tektronix 222 display
Tektronix 222 display