LHS Episode #072: We Need Cache

Welcome to another fine and dandy episode of Linux in the Ham Shack. The end of 2011 and the beginning of 2012 have been very busy for your stalwart co-hosts, but we press on. Shows are being recorded, content is being disseminated and our listeners are being educated--sort of. We hope everyone has had a wonderful start to the new year and best of luck in all your endeavors, present and future. Oh, and if you find a free moment or two, please tell a friend about LHS. The publicity will do us all good.

73 de The LHS Guys

Making yourself clear on the Radio

A few days ago I was putting together a piece of training for our local A.R.E.S. Group and it dawned on me that I should share it with everybody. So after I finished the net I took a little time to flesh out that training and what I ended up with was this article. You are welcome to use this as a basis for training in your group or as a reference for your own self training. Don't forget to let everybody know where you got it.

Speak slowly and clearly

When we say speak slowly and clearly what we mean is sometimes at normal conversational speed  words run together when you are talking on the radio. Most radio equipment doesn't reproduce all the audio frequencies of human speech or hearing. This can make it difficult to understand what someone is saying on the air. When you have some hearing loss it is even worse. I have some low end hearing loss so most of the time I have to add a speaker to my rig that produces more low frequencies to make the speech ineligible to me in noisy environments.

Annunciate. Some people don't consider that when they speak they are trying to convey information. I know several people that just engage there mouth and let the words fall out without giving a second thought as to if the person on the other end of the conversation is having to decipher the noises emanating from their mouth. It is sometimes difficult to understand a conversation when you are in the same room with someone if the are slurring and mumbling their words. It is even more difficult when you are on a noisy frequency or using a narrow band width mode like SSB, or D*STAR. When you add the stress of a net situation people tend to speak faster than they normally would. They also tend not to speak clearly. This makes the problem even worse.

Use Standard ITU Phonetics

Another consideration is the use of phonetics. In most cases phonetics can greatly increase your ability to understand and be understood when conditions a frequency are not optimal. Ham radio operators are as a rule a playful bunch so we do things to make talking on the radio more fun like making up funny phonetics for our call sign. Unfortunately during emergency and disaster communications play time falls by the wayside and these home brew phonetics become more of a problem than an asset. Most of the time these home brew phonetics in no way resemble any of the standardized phonetic systems. When These operators find themselves in a situation where they need to be understood their home brew phonetics really don't help. That is why the ITU Phonetic alphabet is the agreed upon standard for amateur radio emcomm communications. Every radio operator should be able to at least spell their call sign with these phonetics. Memorization of these phonetics is not difficult. Some operators can jump to phonetics without even thinking about it. Since so many letters in the English language like E,B,V,C and others sound so much alike it is very important to know the standard ITU phonetic alphabet.

Do not yell, Don't whisper

Yelling at a microphone is a problem that has propagated down through the hobby. Many of us have come into the hobby by way of the citizens band service. Operating AM on cheaply made and badly maintained equipment in that service. Many others use sideband radios on a regular bases. On AM and Sideband speaking louder into the microphone can give you a small increase in the output power of your radio. Since we are using primarily FM radio equipment this is not the case. Without going off into an explanation of how FM works lets just say that yelling at your microphone causes distortion making it difficult to understand the information you are trying to convey. Since the equipment that we use on VHF and UHF is Frequency Modulated the Amplitude of your voice can cause more problems than you would think.

Whispering into the microphone also has problems. There are some operators out there that speak very quietly into there microphone. This results in a full quieting signal and barely understandable audio. Some times the microphone gain or deviation on your radio may not be adjusted properly. if you do not speak up while transmitting this can make the problem worse. In the case of a Net Control located in a noisy environment it makes your transmissions unusable. It also waste valuable time while the Net Control attempts to take your traffic. We don't always have the luxury of calling a net from the comfort of our home.

Don't eat the microphone.

Eating the microphone or holding it to close to your mouth is another bad habit that has trickled down through the hobby from the days of carbon microphones and the poor quality microphones of the past. Today the microphone supplied with a standard piece of amateur radio equipment is very good. Eating the microphone presents its own set of problems. Holding the microphone to close to your mouth can overdrive the diaphragm in the microphone and audio stage of the radio causing distortion which most often results in muffled audio. You may also experience Flat Topping of your audio signal that is very similar to clipping in other audio equipment. Over deviation of your signal is also a problem you may experience. Over deviation is a problem because most repeaters are equipped with a band pass filter to eliminate unwanted noise on nearby frequencies. This means that in some cases you could be sitting under the repeater running a hundred watts and not be able to key the machine because your signal exceeds the width of the passband. Another problem that may occur from eating the microphone is known as P-pops or Clicks. These are most common when the microphone is held directly in front of the mouth. These are not only annoying but can also make it difficult for net control to understand the information you are trying to convey. It is always best to hold the microphone off to one side of the mouth. I also like to use what I call the “Thumb Rule”. If I am holding the microphone to transmit I should be able to extend my thumb and lightly touch my chin or lower jaw. This seems to be just about the right distance and works well with most radios including hand held transceivers.

Lastly a word on hand held transceivers. Most HT's come from the factory with the microphone gain turned up higher that mobile radios. So the built in microphones are “Hotter” than one might expect. They are designed to be held a foot to eighteen inches away from your mouth. Eating the microphone on these will cause many of the problems listed above to be much worse. External microphones will depend on the design of the microphone.

Q signals, codes and jargon

Since from time to time we will be transmitting information for use by non-hams such as our served agencies we need to keep Q-Signals, Codes, and Jargon to a minimum. Our served agencies have there own language or jargon and in most cases it doesn't even remotely resemble the jargon that we use as amateur radio operators. The National Weather Service has its own language for describing weather and that is the only possible jargon that we may need to use. That information will be covered at Skywarn School where it will be covered by the folks that know what they are talking about.

Codes and Ciphers are prohibited by part 97 so they are not appropriate for any reason.

Q-Signals are a problem in amateur radio today because everybody wants to sound like a professional radio operator and they think that Q-Signals help achieve that goal. Q-Signals were designed to make cw operation easier and have no place on a phone (Voice) frequency especially during an emcomm net where the transmission and reception of clear and concise information is critical. Lastly, There is a place for Over, Out and Roger in emcomm communications. Most amateur radio operators tend not to use them correctly. My personal opinion is that if you want to acknowledge a transmission the word “Received” works just fine.

These are just a few of the things that can help all of us improve our communications skills. Clarity in communications is always important. It is even more important when we start to deal with Emergency and Disaster communications. Remember we are not transmitting for ourselves. We are transmitting for everybody.

LHS Episode #071: Nudge, Nudge

In Linux in the Ham Shack's sexiest episode ever, the guys take on some sensuous applications from the Python world. Dan, KK7DS, has been writing cross-platform software for D-STAR and rig programming for some time. Richard and Russ take on a couple of his more prominent works: d-rats and chirp. On the purely Linux and Open Source side of the program, there are some valuable nuggets that we'll let you all listen to find out about. And they try not to get too excited, but with this being Episode #071, it's hard not to. Thanks to everyone for downloading the show and have a Merry Christmas and bountiful New Year.

73 de The LHS Guys

LHS Episode #070: The Stroke

Welcome to another installment of Linux in the Ham Shack. In this episode, our mostly unprepared hosts discuss a couple of interesting topics. Yes, really, they are interesting. In the Ham Geeky™ section, Richard plows the fertile fields of contest loggers for Linux, as well as cross-platform solutions, including running your own favorites under WINE. In our Linux Geeky™ area, Russ discusses the VLC media player among other things you'll just have to listen to find out about. Several pieces of feedback are discussed and there is the usual assortment of witty banter, mindless rambling and quasi drunkenness. No, that's not right--I meant quasi drunkenness. So sit back, strap in, and enjoy the ride.

73 de The LHS Guys