WB4IUY's Random Blog

I've been in Amateur Radio since 1974, and still find new and interesting things to do. I like to build, restore, and operate on the air. This is a blog of various info about my Ham Radio operations and activities, projects, and opinions. Visit www.WB4IUY.net for the lowdown at WB4IUY.

Tuesday, December 11, 2018

DXPeditions Page...

I can't say enough good stuff about NG3K's Announced DX Operations page on the web. It has really helped me keep up with DXPeditions and raise my country count. There's a link under most calls listed, that will automatically take you to DX spots for them, info on where to find more info, the approximate schedule dates, and loads of other info. If you're into DXing, be sure to bookmark it, and keep the page pulled up in the background...lots of info in one spot for DX hunting. I have it linked in the [DX Tools] section of my personal site, but you can get to it directly at https://www.ng3k.com/Misc/adxo.html


Dave WB4IUY



Monday, December 10, 2018

Cushcraft A3 Trap Tips...

I've rebuilt a number of Cushcraft A3 and A3S antennas over the years. (The "S" just means Stainless Steel hardware). Like a dummy, I once totally disassembled an antenna without marking the traps. Cushcraft marks them with invisible ink (just kidding), so you're on your own if you mix the traps up on an older antenna. Turns out it's not too tough to figure out. Also, those crazy little plastic caps that go on the ends of the traps don't hold up very well, and I've found that 2" heat shrink seems to last a lot longer (and is cheaper to boot!). 

I've uploaded a few bits and tips to my site that might help, in case you find yourself trying to identify the traps or rebuild one of these. One is a .pdf from Dale KG5U, one is a .txt file with my tips, and a .jpg pic of a trap with the heat shrink end caps. Hope that helps some of you!!

Go to my website at http://www.WB4IUY.net , mouse over [Workshop]. and select "Schematics Manuals". Scroll down to the Cushcraft section and you'll find it. 



Dave WB4IUY
http://www.WB4IUY.net






Saturday, December 8, 2018

Repairing a Tripp-Lite PR-40 DC Supply

TrippLite power supplies are well made, high quality supplies, but that negative lead regulation is a little odd and difficult to wrap your head around when it comes time to repair them. This supply to me inoperative, so I had to dig in deep to see what was wrong. 

First: TrippLite keeps the schematics for these close to their chest, so it took a bit of searching online to locate someone with an electrical schematic. FYI, there's a great site on yahoogroups for power supplies,  you should join it if you think you'll ever need a schematic or info on a power supply. The link to it is:

https://groups.yahoo.com/neo/groups/powersupplies/

I also uploaded a copy of the schematic in the [Schematics & Manuals] section of my website at:

http://www.WB4IUY.net

I discovered the remaining insulators on the output terminals had failed, and the rest were totally missing, shorting the output/crowbar board to the chassis. This took out all of the pass transistors and a few other bits. I replaced the pass transistors, fabricated new feed-thru insulators to protect the output studs from shorting to the case again, and rebuilt the crowbar circuit. Now, it'll go from no load to 40 amps @ 13.8 VDC with only 0.2 VDC shift. Solid supply! 

 Just cracking it open to take a look...

 Output / Crowbar board removed for inspection...

 Broken insulator...

 The only insulators left... There should be a feedthru insulator and a backup insulator in each stud...

 The PR-25, PR-40, and PR-60 use the same schematic... 2 pass transistors for the 25, 4 for the 40, and 6 for the 60.

 One pass transistor tacked in and boards jumped in place for testing...

 New insulators fabricated...the outside insulator is T-shaped and passes through the chassis, the inner parts are counter bored so they fit together. 

 Outside view with the new insulators in place...

All finished and ready to rock!!


Dave WB4IUY
http://www.WB4IUY.net









Wednesday, December 5, 2018

2 Computers, 1 Mouse/Keyboard!

I run two computers at my operating position in "studio A". Two keyboards and two mice really clutter up the table in front of the radio gear. I stumbled across a piece of free software that allows me to seamlessly slide my cursor from one screen to the other, and the keyboard input follows the mouse. You can copy things to the clipboard in one computer and paste it on the 2nd computer, and even drag single files from one box to the other (only one file at the time, with a 100meg file size limit)

The software was easy to install and ran without a hitch on my junk computers (one old XP Pro box, and an old Dell Optiplex 260 Win7 box). Now, one mouse and 1 mini-keyboard runs both computers at once, I love it! The software is called "Mouse Without Borders". The latest version is on Microsoft and doesn't support XP. I found an older version that does support XP over on cnet. Oh, it'll run up to 4 computers at the same time, too.


I ran multiple monitors on a single computer about 10 years or so ago with a graphics card and some software. In my situation, I'm running multiple 15+ year old boxes at home to share the load, so it looks to be a good answer to my problem. I could buy something new and much faster that would do everything, but I'm a tightwad and am always looking ways to keep old stuff working. It's neat to not to toggle between screens on my primary applications, and everything is fast by each computer running with less overhead. 

Here's a link to the new version for Win7 and newer: 
Mouse-Without-Borders-NEW

Here's a link to the older version that includes Win XP: 
Mouse-Without-Borders-OLD


Dave WB4IUY


Sunday, December 2, 2018

Blast from the past...

A cool snippet of an advertisement from 1940, and this tube is still in operation at many ham stations! I love these old promotional bits. 




Dave WB4IUY