Larry's Hall Effect Project

Tuesday my friend, Larry - KB7KMO, came by for a visit and work in my shop.

Larry has been sailing around the world in his sailboat for that last few years. He returns to the Seattle area to see his grand kids and families. We try to get together at least once, each time he is in town.

For this visit, Larry had several projects that we worked on in the shop. He was in need of a way to monitor the output of his generator and/or other power sources that replenish his battery banks.

The Artwork and Toner Transfer
Ready to Etch

There are may commercial products that would work, but Larry wanted to try a custom solution. For this he has found several DIY projects that suggested Hall Effect devices to monitor current.

What was needed was a small DIY PCB to hold the Hall Effect device and the few other devices that provide the input for a monitor and display.

This PCB will be mounted on-or-near the power source. The Hall Effect device that Larry will be using is shown setting on the right edge of the PCB.

My previously used and blogged Toner Transfer PCB method was used to build the necessary remote boards. We used Inkscape to create the original artwork.

Larry Cutting the Reverse Side
Toner Transfer Image

Etching is simple; put the PCB in a ZipLoc Freezer Bag, with a small amount of Ferric Chloride, and then knead while under running hot water. For a 1 oz copper clad, the process takes about 4 minutes.

Larry at the Sink, kneading the bag while running Hot water
over it, which is filled with Etch and His board

The Cut boards,
Ready for Drilling

The Hall Effect device can handle a lot of current (+100 Amps) and therefore large pads were necessary. Additional copper strap will be used to increase the current handling abilities.

This is the first time I have tried making Toner Transfer PCB with large pads or Ground planes,  on my projects I normally avoid them by using cross hatch grid for the Ground Planes. Space for some small capacitors are also included for line conditioners at the remote.

Board Inspection

Larry will finish this project, when he returns to his boat, . . . somewhere on some distant, exotic tropical island paradise !

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When Things Go Wrong

This a dual boot, MS Windows and Ubuntu Post, Ignore it you do not use these.

WARNING - Some things NOT to do.

The other day while Larry - KB7KMO, was here helping me setup and reconfigure my Shop/Shack computers - we ran into trouble.

Larry brought his new laptop (NotPad) and several additional peripherals, including USB hard drives and CD readers - we had lots of equipment, felt invulnerable and therefore we could experiment and do anything.

Larry dual boots his NotePad with both MS Window 7 and Ubuntu - where the original disk space was shrank to about 50% for MS Windows and the remainder for the Ubuntu 10.04 install. He was able to show me many neat things that he has found in the new Ubuntu 10.04 release.

So, back to the current Shop/Shacks problems or challenges that we wanted to solve;

• Fix a non-booting Ubuntu upgrade Workstation 
• Configure an old, but newly recovered, MS Window XP Workstation, given to me by my son 
• Understanding of the new boot process of a good working Ubuntu New Install 
• Fix a non-booting MS NotePad 

We were working on all of the above at the same time, between reboots and as time permitted.

While working with the MS Window XP Workstation, I mentioned to Larry that we (my son and I) were able to restore the OS to factory original, via booting from the RECOVERY partition (the D: drive) and answering a few question - the process was real simple.

Larry checked, he had a unmounted partition on his NoteBook in the same position as a that found for the D: drive on my WorkStation.

"WE" decided to check out what options it may provide, assuming that Larry, at sometime in the future, may want to reset or recover his MS Windows partition. The RECOVERY process has a menu that allow you to pick what you want to do, or abort. But, . . . .

BUT, as we found out, it modifies the Partition Table, and the Master Boot Record (MBR) on the hard disk before it provides a menu and a chance to stop or abort the recovery process!

** We BRICKED Larry's new NoteBook! ** 

** It would NOT boot **

Larry, did not have backups
nor does he have MS install disks!

We used an external USB Drive with Ubuntu 9.10 to inspect the damage - and yes;

• the MBR was damaged or modifed, 
• a new very small MS Windows partition was exposed, 
• and the previously used Ubuntu partition was maked as "unused", 
• the original MS Windows partition may have be foreshortened. 

Nothing we tried seemed to help the situation. We did not want to touch the MS partition if it could be recovered as it contains valuable data. The Ubuntu partition contains a lot of customization and some data that would be nice to retain, but it is replaceable.

After many attempts to repair the damage (and after sometime around 1:00 AM), we decided to reset the "ID" on the Linux partition and attempt to re-install Ubuntu into it's alloted partition, hoping that the process "would" fix the MBR for both it and MS Window. The install process is very slow from the external USB CD drive - I went to bed with Larry camping out in the living room.

The next morning - Great News - it worked! Both MS Windows and Ubuntu booted as expected (or as we had hoped)!

The very first thing we did was install the Ubuntu "Backintime" backup utility. We set it up to backup valuable data from each partition (MSW and Ubuntu) to it self and to the other. Larry will add additional backups to multiple external USB hard drives when he returns home.

Lessons Learned - 

• Have backups of all customization and valuable data! 
• Do NOT boot from the RECOVERY partition unless you really intend to Recover to the "Factory Install", especially if you have modified the system for DUAL boot. 

We were thankful that this had a happy (and/or more knowledgeable) ending,

Now. (when I have time) back to my continued Shop/Shack computer concerns.

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Went to REPC in Seattle

Today, Larry - KB7KMO, and I went to REPC (a pc recycle center in Seattle). I have mentioned this place before on a previous blog. This place is a great place to pick-up computer parts for their internal parts. Many things are quite cheap if you do not mind looking in the bins on the floor, and junk boxes on the tables.

What I find valuable are the DC wall-warts for my QRP projects and components salvaged form junk PC boards.  Old modems seem to provide the most varied components for a very low price, audio transformers, high value caps, heat sinks, and many others.

Today, I had a specific purchase in mind - I wanted an old (working or not) Laser Printer.  My goal is to re-purpose it for "Direct PCB Etch Resist Printing", see previous post regarding Mark's adventure while exploring this new frontier. Mark's write-up describes the modifications needed to a Lexmark E260 printer.  As luck would have it, REPC did not have a salvaged Lexmark printer for me to try, But .  .  .

There was several Old HP LaserJet 1300, with one which was marked down to $30 - and its test page appeared in order. So it came home with me.

The HP LaserJet 1300 appears to have an USB, with 1200 DPI, and PostScript installed.  Also, the paper path through the printer appears to be some what straight, of course some modification will be needed to pass a stiff PCB material through the printer.

Maybe the HP LaserJet 1300 can be modified, or NOT, but it will provide a challenge to see what I can do with it to produce "Direct Laser Printer to PCB" results.

At home, Larry and I wanted to "get started" dismantling the printer to check out the paper path and deciding what modification would be necessary.   We started off on the wrong foot, as we forgot to get a USB cable and a power cord for the printers initial test (I had neither on my boat where we were doing the work), but we did learn how the take the printer apart,  figured out how it works, and how to put it back together successfully.

We also found the reason this printer was cheaper than the others on the same table at REPC - this printer has a broken plastic post inside on the lock lever that holds the toner cartage in place - and therefore would probably not print reliably.  For my purpose, this should not be a problem, it can be fixed.

Later, if all goes well with this modification, I will share the results via photos and a short write up, - or, . . . .  If NOT, what the heck, I will also share the failure.

While at REPC, I also found a "Compact Memory" card reader for my laptop for $1.00, with it, I will now be able to read my photos (from my old camera) for this blog directly into the laptop, maybe? Unlike this post, personally I enjoy blogs with descriptive photos.

BTW, Larry - KB7KMO is my friend that lives on a boat in the middle of the Pacific Ocean, while, as he says, "eating his way around the world".  He is here in Seattle for a few weeks while is daughter is providing him with another Grand Child!    Congrats - Larry, .  .  .  .  Oh yes, the same for, Mom, Dad and Grandma!

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Sailing Vessel KatieLee

I have been working and chatting (via email) with a friend, Larry Littlefield - KB7KMO, who is sailing around the South Pacific at the Marshall Islands in a 45 foot sail boat - The Sailing Vessel KatieLee. Larry says; he is eating his way around the world.

I asked Larry to try to listen to my QRSS, WSPR and PropNet signals on 30m around 10.140mHz from his location - so far nothing. Larry tells me that he downloaded Spectran and ARGO to listen on the band, but again, so far nothing. Larry said that he is planning to replace his random length vertical with a Delta-loop - maybe he will get less noise and then be able to pick up the weak signals.

I asked Larry to key-down (actually mic key-down on AM) on 10.140100mHz for about 10 seconds - I did not receive his signal here near Seattle.

We will plan more experiments, and maybe I will talk him into connecting up the remaining wires to his Transceiver so that he can participate in WSPR to collect and provide spots.

Note: you can see Larry's IP address on my Cluster Map - he is the single "dot" out in the South Pacific. You may ask - how did he get an Internet connection? He uses WIFI from his Sail Boat to an Island shore and a local WIFI hot spot - they charge him for his access.

You can read more about Larry's sailing adventures at: http://svkatielee.blogspot.com

There will be more posted here about our attempts.