Shaken-Not-Stirred Technology Mixed Right!

Brett Wynkoop
wynkoop--AT--wynn.com

Subscribe RSS


This site's referrers
reddit.com - 272 hits
moykrest.ru - 185 hits
bxox.info - 158 hits
spbdyet.ru - 124 hits
audiojungle.net - 106 hits

Brooklyn Repertory Opera

Yardscreek Soaring

New Yorkers for Fair Use

Brooklyn On Line

Resume


Stand Alone Sysadmin

Code Immersives

1 2 3 ... Next >>
Baofeng UV5R - Every ham should have one, but not as their only radio.    
In the last several years there has been an influx of cheap Chinese radios making their way to our shores. One of the most popular with hams is the Baofeng UV5R. This article will describe why every ham should have one of these radios in their communications tool kit.

The UV5R is cheap, coming in at about $25 for the HT with standard battery, rubber ducky, ear phone, and desktop charger. The radio covers VHF HI and UHF bands from 136-174MHz and 400-520Mhz with 128 memory channels, repeater offset, dual watch, pl, and dcs. Baofeng combines that with a transmit power of 1 watt low and 4 watts high.

The radio has a nice solid feel and a tough case. It also has a full compliment of accessories to make it even more versatile.

The price makes this the perfect radio to carry when you might accidentally damage a hand held, like climbing a tower and dropping it, or around the water where it might be dropped or you might fall in and flood it.

With 128 memory channels which are easy to program via CHIRP software this radio will cover the communications needs of most hams in the VHF/UHF range.

In addition the radio is FCC approved under Part 90. This is the single best reason that every ham should have it in their kit. Officially marketed as a commercial radio for part 90 land mobile services,
think fire, police, ambulance, taxi and such.

The part 90 approval is very important to 2 segments of hams.

The first is the ham who works in a job where he has to make use of a part 90 radio. This means that he can either carry one radio that will do double duty, or his ham rig can back up his official radio.

The second segment is the ham who serves his community in times of need providing emergency communications. If this ham is working with a served agency or Non-Governmental-Organization which is part 90 licensed he can, upon approval of the license holder, come up on the assigned commercial frequencies to pass traffic directly to them as the situation requires.

It is important to not that as of this writing all commercial land mobile FM in the United States of America has switched to 2.5 Khz deviation, so if you are a volunteer firefighter, before bringing up your UV5R on your volunteer fire fire department's channel make sure you have set the deviation to narrow for that channel.

Why should a fine cheap chinese radio not be your only radio?

Well for starters in emergency preparation the old adage is if you have one, you have none, and if you have two you have one.

These radios have some weaknesses and quality control issues. I first purchased one at the ARRL National Convention in Hartford a couple of years ago. The reverse sma connector needed to be tightened repeatedly, but I thought the issues were eventually solved with a little lock-tite on the retaining nut. Living in New York City it is pretty easy to hit a repeater with very low power, so I did not realize until comparing the radio to a friends unit that she was hearing and hitting the repeaters better than me. A quick check against an output meter showed my radio was putting out 1/10 the power of her radio. Opening the radio up showed the antenna connector to be no longer soldered to the circuit board. Soldering it back seemed to fix things all up and the radio seemed to be at full power on both VHF and UHF. I was once again in possession of a working radio. My joy did not last long. A few weeks later the radio stopped producing power on UHF, but VHF still worked. Well it was cheap, so I just bought another.

I have since gotten reports from other hams of antenna connectors not soldered to the circuit board.

The UV5R also seems to overheat when operated for prolonged periods on the DC adapter. The over heating causes the radio to blank it's display and stop transmitting.

If you live in a high RF zone like New York City you may find it impossible to receive if you move up to a better antenna or even on the rubber ducky in certain areas. The radio has no tuned circuits in the front end and it's wide band operation means that it gets overloaded by off frequency signals very easily. With the radio connected to my mobile antenna and my car within one mile of a local repeater I was unable hear the repeater. At first I thought the the repeater was off the air, then I swapped out the mobile antenna for the rubber duck and bingo I could hear the repeater. The 10db difference in gain and having the radio inside the steel cage of the car attenuated whatever strong signal was overloading the receiver to the point where I could hear the repeater.

One other point that needs to be mentioned is that these radios are not part 95 or Part 80 accepted. This means they can not be used on FRS, GMRS, or MURS, which are all Part 95 services. They are also illegal to use on the Marine Band which is governed by FCC Part 80.

Just because a radio can operate on a frequency does not mean it is legal to do so!

So while the UV5R, and similar radios are good to have in your tool kit they should not be the only VHF/UHF radio in your kit.

73

Brett Wynkoop
WA3YRE


A Day To Remember    
Today dawned grey and cool in Brooklyn. A far cry from this same date in 2001, even so I am given to reflection. On that day the first thing that went through my head when I heard there was a fire at the World Trade Center was that getting to The Medowlands and the Citibank email team where I was consulting on Sendmail was going to be difficult as I had to drive right past the twin towers to reach the Holland Tunnel. As I watched the news report on TV I saw the second plane hit the tower. That is when I knew I was not going to work that day.

My next move was to head outside and see what I could see, but from street level my view was blocked. I quickly climbed to the roof of my building and saw thick black smoke streaming out of both towers of the World Trade Center. I kept an eye on the situation via the local cable news as over the air broadcasts went off line. It seems almost all the local TV stations had their transmitters on the WTC. The City of New York had also made the mistake years earlier of putting all their Police, Fire, and EMS repeaters on the now blazing towers. I knew communications would be crippled within the city.

I went into my office and connected my Yaesu VX-5 to the roof mounted antenna and checked into the local Ham Radio Emergency net. I was asked if I could make my way to lower Manhattan with equipment for communications to support the Red Cross. Having a good bike, and loads of batteries and portable antennas I made my way through the thick black acrid smoke that had come to blanket The Holy City of Brooklyn. What I did that day was nothing more than what was done by many, but the BBC Radio 4 chose to interview myself and other Ham Radio Operators in a piece called "Unsung Heros". Today dear reader I offer you a link to the interview.

Unsung Heros in mp3 format



This Old Mac    
From time to time old hardware comes my way. Often this is hardware that clients are done with after an upgrade cycle. Most of the time this hardware still has plenty of life in it for home use by the average home user.

When this is the case I try to recycle the hardware either for my own use, or for use by family or friends. Last week an Intel Mac from 2008 with Mac OS-X 10.6 crossed my path. After a quick reset of the admin account password and a clean out of the old accounts/files I was ready to install all the standard tools and toys, including the excellent LibreOffice suite. Much to my dismay the current version of LibreOffice does not support any version of Mac OS-X before 10.8 (I have no idea what animal or geographic location that is). After much searching I stumbled across this link:

https://downloadarchive.documentfoundation.org/libreoffice/old/

which provided the older version I was in search of. While I understand the LibreOffice developers wanting everyone that can to upgrade to the latest and greatest there are many perfectly good computers that can not upgrade to the latest OS release for any number of reasons. The users of these computers should also have easy access to Free Software and it should not be hidden from them. I urge all developers of Free Software, not just The Document Foundation, to make it easy to find older versions of their software. This will benefit end users, the environment (fewer computers destroyed and burried), and the Free Software movement in general.

Hopefully this posting will help others find old versions of LibreOffice faster than I was able.





Some Quick Tools for OS X    
I was recently asked by a client to set up an old Mac G5 he had to be the mail and web server for his office. No problem I told him and after he did a fresh install from his 10.5 install disk, created an administrative account, and turned on SSH via the GUI, I fired up ssh from an xterm on my MacBook and went to work.

I quickly determined with Apples use of it's own LDAP server, /usr/sbin/DirectoryService, command line administration was going to be a bit painful for certain functions. Back when Apple used Netinfo a quick nidump/edit/niload cycle allowed for fast and easy modification of both passwd and groups. DirectoryService changed all that and the command line tools Apple provides for interacting with DirectoryService are not as well documented as they could be. In some cases the only documentation is the help message from a utility, or a very poorly written man page which leaves out options the help message includes. To top this off Apple offers no support for any command line operations in OS X.

Some research on the net showed me that just to create a user account was a multi-step process using dscl repeatedly and following on with the use of createhomedir. Not only was creating users from the command line time consuming there were many chances for errors due to the many times dscl had to be invoked with different options and arguments. What is a systems administrator to do? AUTOMATE is the answer, and that is just what I did.

The two operations I decided to attack first were adding users and adding existing users to groups. For adding users I opted for the interactive method where the user was prompted for needed information. For one off user additions I find it an easier model to use than something that takes several options and arguments from the command line.

For group additions I opted for a single command line invocation "addtogroup user group".

So in short order I had the adduser and addtogroup written, doing what I needed, and no more. There is room for enhancement in both of these programs, but they might be useful. You can find them, and any other OS X specific utilities I produce in the future at http://shaken-not-stirred.tekhq.com/osx/utils/.

-Brett
wynkoop--at--wynn.com


Something Simple    
The best Unix Systems Administrators find ways to make systems administration simple and less prone to human error. One simple step I take to make my life easier and leave less chance for errors is to change the GECOS field for root on systems I administer.

Your typical BSD root password file entry looks like:

root:*:0:0:Charlie &:/root:/bin/csh

Which leaves the user's real name from the GECOS field to expand to Charlie Root. What is wrong with that you ask?
We all know that Unix systems use email to communicate status and error information to the Systems Administrator. When you get an email from "Charlie Root" it gives you no clue what system generated the email when looking at the table of contents of your mailbox using many modern Mail User Agents. That means you need to take the extra step of
opening the mail and looking carefully to determine what system it is from.

If we simple changed the GECOS field to something more descriptive we find out what system has the problem even before we open the mail, and we might with that information as well as the subject display have a good idea of what is going on. So I set the GECOS field for root as in the example below:

root:*:0:0:root@box1.example.com:/root:/bin/csh

This causes the name displayed by my MUA to show as root@box1.example.com instead of Charlie Root. This makes my life easier, and I suspect it will do the same for you. Give it a try.

-Brett Wynkoop
wynkoop--at--wynn.com


1 2 3 ... Next >>