Wednesday, December 22, 2010

Handiham World for 22 December 2010

Welcome to Handiham World!

As we cruise into the final weeks of the year, we need to remind our readers & listeners that we survive only because of your generosity. Non-profit programs like Handihams look for a significant part of our support at year's end. I hope you will take a few minutes to find the return envelope in your Handiham World print edition and help us out with anything you can. If you don't have an envelope, you can call Nancy at 1-866-426-3442 to donate by credit card, or choose the donate online option at Courage Center's website. The instructions on how to designate your gift specifically to the Handiham program or donate by mail are in your weekly e-letter and on the Handiham website.

Thank you for your support!

Ah, yes. Computers. We love them and we hate them. The ham shack computer is so full of promise; it can do logging, rig control, callsign look up, digital modes, QSL cards, EchoLink, remote base operation, and then switch gears and become the family's web browser and email hub. It may even turn into a gaming console when it is not running the ham station.

That's when everything is working, of course. As computer users, we have all experienced the frustration of a locked-up machine, an unresponsive application, or a blue screen of death or its equivalent. You Mac and Linux users out there have had similar problems, so don't sit there smirking!

Today's topic is computers, mostly as related to ham radio, of course. We'll have a few of the usual weekly features as well.

Patrick Tice, WA0TDA
Handiham System Manager

Multitasking - How much is okay?

graphic of computer
We have all heard the term "multitasking", which seems to be in the popular media spotlight these days. When you multitask, you supposedly do several things at once. Multitasking is supposed to save time and make you more efficient. This is not always the case, as has been often-noted when people who are supposed to be paying attention to a critical task like driving a car are also trying to put on lipstick, send a text message on a cell phone, or (for that matter) find a frequency on their amateur radio transceiver. The results can be disastrous!

On the other hand, sometimes multitasking makes sense. When I am out taking a brisk walk in the park for my daily exercise, I can also take the dog along so that he gets his walk. In addition, I can take along an iPod and listen to the ARRL Audio News and Amateur Radio NEWSLINE. This kind of multitasking works well because the resources demanded for each task do not overlap too much. For example, I don't need to use a lot of brain power to put one foot in front of the other while taking a walk in the park. Instead, that brain power can be used to think about what I am hearing about amateur radio news on the iPod. Occasionally, the dog will need to stop and a small amount of brainpower will be redirected to that interruption. The important thing to remember about multitasking is that each task will require specific resources. Sometimes the resources needed for one task will be the same ones needed for a second task, so it will be necessary to use the resources first for task one then for task two, perhaps switching back and forth between the two different tasks as a way of sharing resources.

Computers work the same way. In a single-processor computer, even though you may be performing multiple tasks, the processor is really only doing one thing at a time. Sharing the resource of processor power can be done by switching between tasks rapidly so that it seems as if the computer really is multitasking. Some computers have multiple core processors, which allows them to run parallel processes for true multitasking. What I am getting to with this talk about multitasking is that it is possible for us to ask too much of our personal computers. You may have found out (as I have) that some software programs simply don't play well with others. You may find yourself having to close one software program before you can use another one. Hardware resources in any single computer are limited as well. If you are using your personal computer for rig control, you are probably tying up a serial port. If you are using your computer for EchoLink operation, you are tying up soundcard resources. You may find it difficult to switch between EchoLink operation and voice dictation using the same soundcard. After using one sound-enabled application, you may find out that the level settings for the next sound application you want to use are completely off base, requiring you to make a trip to the Windows mixer to reset everything. If the ham shack computer is also the family computer, you may run into the problem of who gets to use the computer when you want to get on the air.

The personal computer is really good at multitasking, but there may come a time when you have to decide to set up a dedicated ham shack machine. The advantages are many and include not having to draw straws to see who gets the computer during the big contest weekend, having only ham radio related software that you really need installed on the ham shack machine, and the ability to dedicate hardware settings and connections to ham radio rig control and VoIP applications like EchoLink. You can even set your web browser settings so that frequently used ham radio websites come up right away in tabs. There is also great advantage in returning to the ham shack, sitting down, and finding the computer in more or less the same state that you left it in the last time you used it. Yes, you are still asking the ham shack computer to be a multitasker of sorts but instead of having to do everything that the entire family might demand of it, your ham shack computer can now do targeted multitasking related to amateur radio use and applications. With the price of personal computers falling, it seems reasonable to go the route of a dedicated computer for your ham radio hobby.

"That is all well and good", you say, "but even my ham shack computer doesn't seem to have enough hardware resources like sound card inputs to handle all of the different amateur radio applications."

Ah, yes. That is a common complaint. These days it is not unusual for the ham shack computer to be used in digital modes operation, EchoLink, and remote base operation using Skype. How are all of these sound applications supposed to work on a single machine?

One solution is to add USB sound devices. Each USB sound device functions independently from the computer's internal sound card circuitry. For example, if you use the computer's existing sound card for PSK-31 operation, you may find it more convenient to have a USB headset microphone for use with EchoLink. Since each functions independently, the mixer settings should remain at their proper settings once set up for each application. You can buy USB headsets for as little as $30 on sale, and you can get a pretty good one any time for under $60. The time saved in not having to fiddle around with mixer settings or plug and unplug cables into the soundcard every time you change modes of operation on your ham shack computer is well worth the small expense and effort to get a USB headset installed. Incidentally, if you have a need for a second USB sound system, whether it is a desk microphone, a webcam with USB microphone, or a second USB headset, you can generally simply plug it in to a second USB port and set it up for still another application. This would enable you to have separate sound systems for PSK-31, EchoLink, and Skype. If you are going to ask the computer to multitask on sound operations, this is a great way to cut down on potential conflicts and save yourself a lot of time and grief.

Before we leave the subject of multitasking, I want to share a tip for our readers and listeners who drive a car and operate a mobile ham radio station. All I have in my car is a 2 m mobile rig, but it has a huge potential to distract me from my main task, which should be paying attention to my driving. I find that I can talk on the radio all right while driving and of course everyone understands if you tell them that you need to pay attention to your driving while at a busy intersection or if traffic and weather conditions are deteriorating. The main distraction with mobile operation involves changing channels on the 2 m radio and taking your eyes off the road. I have solved this problem by setting up the radio's memory channels so that I can navigate through them without taking my eyes off the road. One trick familiar to many blind Handiham members who can operate just about any 2 m radio with memories is to set up the local National Weather Service in channel space one. Since the National Weather Service is always on the air, you can just twist the memory channel knob until you find their broadcast and then click the tuning knob clockwise or counterclockwise a given number of clicks, counting clicks to the channel you want to use. Even if there is nothing on that repeater channel, by counting clicks from the known National Weather Service channel you now are assured that you are on the correct repeater. Another thing I figured out was to set up repeaters in memory slots that track logically by geography. For example, I start with my local repeater, then I travel west on the interstate and soon find that I need to switch to a second repeater and then finally a third repeater as I continue going west. On my radio, the local repeater can be found before I even leave the driveway. After that, I have the radio set up so that one counterclockwise click of the memory channel knob takes me to the next repeater to the west. Another counterclockwise click takes me to the third repeater, again as I proceed in a westbound direction. On the return trip I reversed the process and my memory channel clicks take me clockwise as I drive to the east. Sometimes these simple solutions in setting up our radios can minimize dangerous multitasking while driving.

I don't want to say that multitasking is always good or always bad. We all multitask to some extent, and we ask our ham shack computers to do it all the time. The trick is to think things through and plan to set up your station and your equipment so that multitasking works for you! (Read more on the Handiham dot org website.)