www.shaneburrell.com BLOG Search – Rescue – Scuba – Diving – Telecom – Electronics – HAM Radio

30Dec/090

Apple Tablet – AKA The iSlate

I've been seeing various publications report that the iSlate is real and will be out on the market soon.  The applications for a inexpensive tablet PC with a virtual keyboard is really appealing to a lot of applications I think about daily.  For law enforcement it would be the perfect medium to complete paperwork, get signatures and be a general purpose device much more useful with a SSD than the current offerings of heavy rugged laptop currently used.  The medical field tablets have been used for quite some time now.  For technicians and tool makers this could be the perfect platform to provide a rich and powerful GUI to there wares via bluetooth or USB.

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30Dec/091

SS7 – A-Link M3UA MTP2 . Now what?

Well if you have been following along you either have a M3ua link up and running or you really want one, peeking ahead to see what it'll do.  Well my first application was something very simple.  I wanted to do my own CNAM lookups so I built a small TCAP query interface.  It  allowed me to pass a DN via IP and returned the Callers Name. Very useful when you have  a VOIP switch and want to provide real cnam.  

30Dec/090

SS7 – A working A link. From MTP2 to M3UA.

I won't go into the basics of SS7 here but here is a quick tutorial to get you started if you need help.

http://pt.com/page/tutorials/ss7-tutorial

At this point I assume you have a A Link or two of them, some hardware including some type of interface card like a Sangoma A101. If you have the gear, I prefer to use commercial gear to get m3ua rather than a link to the PC when possible.

I normally use the CentOS distro because its easy to get, has all the components and is very stable.  Main things you'll likely need in it are development tools and lksctp.

With the sangoma card you'll want to download and install the mtp2 driver.  There is sample code included and instruction on getting the MTP2 layer up and running.

29Dec/090

Zeagle Ranger BC – Some version history

First my standard disclaimer.  This blog is for information only.  I don't warranty any of the info and I'm rarely right so use common sense.  With scuba gear always consult a professional.

About a year or so ago I picked up a used inexpensive Zeagle Ranger BC.  I had used them at the squad and really liked it. On the first dive or two I noticed it was a bit different than the other Zeagle rangers folks had. The first thing was that it didn't have  a chest strap at all.  My first thought was I was just going to purchase a upper section to gain the strap.  After looking at other BC's I realized that the buckle size was different as well.  Thus I began my hunt on EBay for a used Ranger BC that had the chest strap. It took a few months but I did purchase one.  After setting them side by side I could see many differences.  Here is  a short list:

29Dec/090

SS7 Getting started with a Link – The overview

One of the biggest hurdle in working with SS7 is getting a link in a form to work with.  Normally at most CLEC's, it comes in on a 56k DDS line or if you are lucky its one of the channels (56k) on a DS1 line.  Sangoma has the A101 card as well as MTP2 driver for linux that works great at getting the SS7 link into something you can use.  If you have a DDS version of the link you'll need a bit of Adtran or other gear to convert this to a DS1 and map it to a channel so the A101 can talk with it.   Once you get the link to a PC thats where the magic happens.

29Dec/092

SS7 for the common person…

Many of you that know me are aware I've been pretty deep in the telephony world for quite some time. Everything from putting fiber into the ground to SS7 links.  Over the years I've written a lot of code to do SS7 messaging and signaling either for gateway type applications or full blown ss7 data servers.  Many have inquired about wanting SS7 but had no real understanding of what they wanted and certainly didn't want to pay to figure it all out.   I still think there is a void there between commercial full blown SS7 and the SS7 tinkerer.  This article will an introduction be for the latter.

17Dec/090

River Diving 101

I recently had the opportunity to dive in one of our local rivers, the Tuckasegee.  It was very close to dark by the time we arrived. There were three divers affording us a safety diver and several SRT (Swift-water Rescue Technicians) on the bank.  Since at least two of us had never been diving in this kind of current much less in the dark it seemed we were well prepared.

It was a cold night in the 50's and the water temp according to my Suunoto gage was 43 degrees. I had all of my 7mm gear on but could certainly feel the cold water.  One difficulty I hadn't thought about was getting myself in a 7mm suit with booties, no less, down to the dive site with my equipment.  We had some dive handlers that helped but it was a careful stroll down the embankment thru heavy brush to get to the waters edge.  Not something that was particularly fun in a wetsuit and booties.

After getting our gear on someone who knew how to do this gave us some quick advice and made it a point that it was just that, advice.  He reiterated a few times that it was an acquired skill diving in current and navigating to the bottom. I of course had no real idea what he was talking about I just knew I was going to do my best to apply what he was saying once I got out there.

We had a target area about 25 feet out in the river we wanted to go over well.  Initially I went up stream a bit then attempted to descend and begin the search.  I quickly floated downstream past our target area and had to swim to the edge and walk back up. Not something with scuba gear on your back you would like to do many times in a row.

Second try, I went a bit further and tried to visualize my speed vs where I went at to determine if I was going to over shoot.  First I dipped down into the water and completely emptied my BC,  snagged an additional 8 lbs of weight as I walked by the bag, and found the secret.  What is that you ask, well head down butt up is the best way I know to describe it.  I forced my head down to the bottom. The current took care of getting the rest of me planted well enough with the pressure of the current pushing down on me to hold me in place.  I could now crawl around and examine the bottom.

First small problem that arises. Am I even at the target site?  I browsed around for a bit and realized if i didn't keep my body laid out the way it was I would be whisked off downstream.  Struggling around I finally noticed some light from the bank and used the lines of wash to establish I was near slightly upstream from the target area.  The important point here is use the lines of the wash underwater to use a parallels along with light source on bank to tell where you are.  I searched much of the target area and was able to hand around for about 10 minutes before making a mistake move that whisked me away quickly downstream.

Walking back up, I shared what I had learnt and headed back upstream.  This time I perfectly "landed" the target area and reproduced it several times until I ran out of air and we packed up for the night.  With each dive I got better and better at managing the current, my position, and my dive light.  The only scary part of the night came while I was at about 15 feet searching.  I was windshield wiper searching the bottom and suddenly a bright rainbow flash was suddenly right next to my head. It was a 12-16 inch rainbow trout swimming happily right next to my head.  I almost spit the reg from my mouth. He just hovered around me like I was supposed to be in the water.

15Dec/090

Getting scuba equipment on EBay

Getting into diving can be a very expensive proposition.  I myself didn't have a $5000 to throw around and figured that if I dug around on eBay long enough and did my research I could spot some solid equipment save some money.  Well its turned out really well and figured I might as well share the experience.

First off BC's are fairly easy to find.  I've swapped out on eBay several times with just about every brand. The two I like the most are the Zeagle Rangers and the Mares Syncro (Rec) or Dragon.  I really like these regs and they are sturdy BC"s that you can get a great deal buying used on eBay.   I have purchased several and here is what I have learned.

Two big items to look for on the Zeagle ranger is does it have a chest strap and what size are the shoulder buckles.  Older one don't have the chest strap and have smaller buckles.  It hard to swap shoulder sections with these.  I would avoid them unless you just get a killer deal. I have one of these and it dives great but the chest strap is nice for an instructor wanting to pull you around where he needs you.  Another thing is the Zeagles have a tendency for the glue holding the bladder to come undone.  Get pictures of where the inflator hose connects to the BC and see if its come loose.  Its fixable but I'd steer clear if you are a novice when it comes to glueing things.

The only real thing I've noticed that affects the Mares and Zeagle or any BC for that matter is look at the inflator.  Get them to take it off and look for corrosion of the pull wire, valves, and hose connector.  Plan when bidding to have to purchase a inflator hose and low pressure hose.  As well as some cleaning.

Regulators are a piece of kit I was really scared to buy.  I've learnt not to buy regs that are apart or not connected a first stage.  Unless its new of course or getting sold separate.  I've purchased many brands and the one that sticks out is Mares.  In particular the proton series.  I don't know why but I've purchased several of these and they all work, all the time.  Can't say the same for any other brand.  The last two sets I've purchased I got with everything including gages and computers.  Absolutely no problems other than taking one of the octo's for service for some minor free flow. It was a $15 repair and is as good as new.

Dive weights and belts.  I don't buy weight anymore. Its a pain and easier to just pick it up local.  Belts can be had cheap. The only good deals I've got on weight was entire scuba lots.

Lights.  I've picked up a number of really nice lights.  The big thing to look for is assume you'll need new bulbs.  I've never purchased a poorly treated light but I have gotten a light with bad bulb.  They don't last forever.  Also check the inside view of the light. I've never gotten a corroded light but I'm sure they are out there.

Wetsuits.  I've never purchased a wetsuit or drysuit but booties, hoods, and gloves are plentiful and really easy to pick out using a pic or two.

Dive computer .  There are two main types. Computers that have PSI and more of a dive watch that doesn't have PSI.  My favorites are the Suunoto Cobra and Vyper.  The cobra has PSI and the Vyper does not. Both are similar in function.  Be prepared to spend some money on an interface cable for a computer if you want to connect it to a PC.  Most do not come with it.  Also be mindful of what it takes to replace the battery. Some are a kit some you can just buy the battery.

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15Dec/090

NAUI Open Water Cert

After playing with diving in a pool for over a year I finally got to do my open water and high altitude certification.

Pool Skills - We all met up at the pool which had been ultra chlorinated.  Many of us didn't have all the gear we needed such as weights etc and had to beg borrow and steal.  Everything went great until we got to the survival swim. MySelf and my brother had been going to the lake for years. Doing stunts and such from an inter-tube or wakeboard. We considered ourselves fish in water.  At this moment however we were a few minutes into the swim and both on the verge of drowning.   A simple skill neither of us really knew we didn't know.  After we both gave up, winded and beaten down, the instructor gets us back in the water demonstrates the proper technique and sudden we were masters at the survival swim. It was simple don't exhale all the air which makes you float.  The doggie paddle wasn't needed.

Day 1  of Open Water Dives

Lake Jocassee in South Carolina was our dive spot.  We went over all the gear and about signals etc.   We were all taking in as much as possible as its a lot to remember.  Not remembering could be a real problem when you are 40' with no way to talk other than with your hands.  I learned a lot in the first 20 minutes of diving.  We had one that had trouble clearing at first.  We did three dives this day all simple dives mixed with skills.  Buoyancy seemed to be the big issue with everyone.  Otherwise it was uneventful and a fun day of diving.

Day 2  of Open Water Dives

Lake Jocassee in South Carolina was our dive spot once again.  The day started off with some humor and some engineering.  Someone, I won't say who, put there first stage on the tank and turned on the air.  Unfortunately it was backwards and the air pressure was so great we couldn't get the yoke to release.  After some engineering, ribbing, and laughs it came off and was put back the right way.  There were some equipment struggles at first at the surface so the instructor asked me to go own down with him for a bit.  I was really surprised after getting to about 38' when he signaled for my emergency ascent skill.  I wasn't ready for it but didn't' panic and completed the skill well.  I think the only skill I haven't mastered at this point is always remembering to blow bubbles when the reg wasn't in my mouth. I forget to do this a lot so I've been spitting it out and bubbling to try and get it to become instinctive.  Another person goes so I go down a few feet to watch.  They did fine and the day was starting off really good.  Then the same person that put there gear together backwards was up.  He started his ascent on queue then after a few feet up panicked. Spit the reg out and did the quickest hand over hand up a rope I have ever seen.  I'm just glad it wasn't me.   After the skills were complete we dove down to the "Junk" and actually for the first time just dove for the fun of it.  Me and my dive buddy were open to dive around the junk and actually pay attention to what was around us rather than worry about skills.  This is certainly what I signed up for and it was a great day of fun.  Our instructor was great, he really knew what he was doing and really did a great job of showing us what do do and expect.

Jackson County Rescue NAUI Certs

Jackson County Rescue NAUI Certs

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15Dec/090

Scuba Diving Pre – 101

I recently got the opportunity to become a open water certified diver.  Prior to getting certified, after many trips to the pool to test how I might like diving, it didn't take long for me to realize its one of the most interesting and fun activities I have ever done.  It requires a lot of things to go right and little to go wrong to ruin your day.

During the pool visits prior to starting the certification process I got to experience a lot of " things going wrong".  Some of the things that happened are extremely funny now but were most likely terrifying moments.  In the end the pre-dive experience certainly showed me what not to do and how crazy a bunch of guys can get when unsupervised and not knowing any better.

One of the most memorial moments is all of us sitting around the pool switching out tanks when sudden it felt like an plane had crashed into the ground and forced the earth around us to shake.  We all looked at each other then a the huge cloud of bubbles coming up from the pool.  After putting two and two together we realized that a diver was in the pool, alone and something had gone terribly wrong. Luckily the person at the bottom of the pool knew it was time to surface and didn't let the explosion underwater thwart his exit from certain death.  After he was deemed ok we figured out that if your gauge o-ring seal decides to rupture and spit your gauge off the end of the hose, it results in a thunderous boom as well as sudden loss of air.   Lessons learned here are don't dive by yourself even with other people on the surface and if you suspect bad gear fix it. They likely won't make it to you in time if something does happen.  If air is leaking from a part profusely its more likely it will completely fail once underwater.

Another event that comes to mind was the horse play that occurs when people that should know better get together.  For everyone's reference, pulling a regulator out of someone's mouth in three feet of water could potentially drown that person. Even if all they have to do is stand up.  The sudden panic from water rushing into ones mouth after being in the water for the first time with scuba gear will most certainly end the scuba experience.  It was admittedly one of the funniest things I have ever witnessed and most would agree was well deserved punishment for things this individual had done in the past.

In looking back, I got to experence a lot going wrong prior to acutally be trained properly on how to handle it.  I knew what to do when my air suddenly stopped, minus cursing everyone around me to make sure I let the person know that turned my air off underwater I was upset about it.   I quickly learned not to panic because panic was going to cost some ribbing by my peers.

In closing, if you haven't tried diving please goto your nearest NAUI or PADI instruction site.  Book some pool time and get your open water certifcation.  If you chose the Pre-101 method be warned it will be tried by fire event filled with some panic and laughing.

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