In terms of success, this ranks up pretty high.  I wheeled-and-dealed on everything, and I feel like I made out like a bandit!  I didn’t stay very long at Hamvention – I arrived around 8:30 AM and I was gone by around 1:30 PM.

Astron VS-20 Power Supply

It works. I needed a power supply for my bench, and everything new was either adjustable (but not powerful and expensive) or powerful and expensive.  This is better than I thought I’d end up with.

VS-20M Power Supply

RF Millivolt Meter

This is one of those pieces of equipment that I never thought I’d have because they’re fairly specialized.  I saw a few, and after finding the power supply, I looked for one I had already found.  I found this one (with the probe, not pictured) instead.

Millivolt Meter

Percent Explosive Meter

I’m surprised someone else didn’t get this first!  I couldn’t resist it.  This is going to find a place in my basement near a blinking red light.  I’m not sure what it will otherwise be connected to (if anything other than a random/semirandom/not-random time controller), though.

Percent Explosive!!!

Anderson Powerpoles

I’m standardizing on these expensive AF things.  I needed some.

Powerpoles.

Hands On Radio Experiments books

After reading N0AX’s articles in the last few QSTs, the method of teaching has really grown on me.  When I saw experiment #161 in the June 2016 QST, which referred back to a common emitter amplifier, I not only read with interest but also decided to attempt the experiment.  I started looking for all of the experiments and saw that the ARRL prints them in a book.  I found the books at W0TOK books and wheeled-and-dealed to both for $30.  DEAL!

Not from Hamvention: Etherkit Si5351 Breakout

I ordered an Si5351 Breakout Board from Jason/Etherkit a few days before Hamvention and got it on Friday after I returned from Hamvention.  I got one on the kickstarter campaign, but SEE THE UPDATE BELOW! but for some reason it refuses to work despite some troubleshooting.  My guess is that I damaged the chip somehow since I THINK (operative word!) that the two MOSFETs work correctly but my Bus Pirate won’t show an available address .  For whatever idiotic reason, each time I get something from Etherkit, I try to hot-air solder it, and it’s all been without the right stuff (either without a proper hot air rework station or solder paste).  I’ve been set straight thanks to the Twitterverse, and someday will replace damn near every component on my CRX1 and get it to work properly.  And I will always remember the sign in my dad’s auto shop: “Don’t be a fool, use the right tool!”… I’ll also remember Dr. Miller (photography teacher at my high school): “Do not use any equipment for which you have not been trained” (in other words, make sure I know how to set the jumpers before setting power!).

EDIT: I typed all this before testing the new breakout board.  The new breakout board was throwing errors, and I found that the new oscillator pulls more current than the Bus Pirate seems to want to provide.  After finding this, nothing could be found with the I2C search.  I looked back on this blog and found “the CLK pin on the Bus Pirate gets connected to the SCL pin on the demo board and the MOSI pin on the Bus Pirate gets connected to the SDA pin on the demo board.”  I now have two functioning breakout boards! 🙂

Etherkit Si5351 Breakout

That’s it! 73!

Despite working at the food booth for the Milford Hamfest, I did get some time to get into the boneyard.  I came back with a few things.

Astron SS-25M. Yes, the price sticker says “Bad”. No power output. It can be fixed – Astron makes some good products, and I’m sure I can find the schematics online.

Footswitch. Dear reader, you didn’t think I’d use the wooden one forever, did you? 🙂

Kenwood TM-201A. Works, but has quirks (some may be by design – like the fact that I have to use an external speaker!). Power output was 6 watts, although I didn’t play with the power level switch to see if it would go up to 25 watts. I do like the slide-out bracket it uses.

Another view of the Kenwood.

AEP PK-232 Packet TNC.

Parts. I looked through several bags and picked ones with parts I really want. The meter was partly to round up to $4, although I’m sure I’ll use it, too.

Not a bad haul.

-73-

Last summer, a friend brought me an Astron RS-35 Power Supply to repair.  It had been involved in a near-lightning-strike experience that fried the loading coil on an antenna, among other things.  The problem was that as soon as the supply was switched on, it would blow the fuse.  The only thing that was obvious was that something was causing the SCR crowbar circuit to fire and blow the fuse to save the power supply.

I started out by checking the bridge diodes and filter capacitors.  All seemed fine.  I checked the pass transistors and those were fine.  During a last resort, I removed an electrolytic capacitor and replaced it with another of the same value, but less voltage.  My hope was that the voltage on the original capacitor was unnecessary, or that I would have enough time to test a few things before it blew.

Of course, it never happens that way.  I had about 15 seconds (not enough time) before letting the magic smoke out of the capacitor.  So, since I’m not an electrical engineer, I decided to run a few tests on the blown cap.  I noticed that there was no physical damage to the capacitor EXCEPT a small hole in the jacket.

So after staring a little at the schematic (there is an awesome resource on the Repeater Builder website), I decided to remove a capacitor (C6 on the schematic image below).  It seemed like a likely possibility, since this was part of the SCR firing circuit (the part I circled in orange highlighter).

Low and behold, it was it!  I replaced the part with a new one, and the power supply is done!

-73-