Radio communications
As a child my reading primer was the AT&T basic electricity book. it's too long of a story to go into here but suffice it to say that it was the only book in the house. as a result i have been a lifelong geek ( read amatuer scientist) that lead to my interest in radios. i recall building my first CRYSTAL radio before i started school. i soon progressed to more advanced communications starting with CITIZEN BAND. by the time i was in 8th grade i had my amatuer radio ( ham) license. i could tell you to get your ham license but i know that few of you would do it. so i'll be pragmatic and explain the various radio communications that are license free. the mother of freeband communications is CITIZEN BAND.
to me it wasn't a toy. it was a tool. in the pre-cellphone age i had the distinct advantage of sophisticated personal communications. we had minimum communication problems in hurricane betsy even though all base stations were destroyed then too. WHY? because we ALL had CB radios in our vehicles. in that day and age that was the only two way radio systems available. EVERYONE! the police, the utility workers, the military, emergency services, businesses, the citizenry.... ALL! had CB RADIOS. EVERYONE could talk to EVERYONE!!!! decentralized communications to the max. even though those radios only had 23 channels ( now we have 40 ) and didn't have sideband ( SSB ) ,which triples the channels while effectively doubling signal output, we had more than enough bandwidth to do the job. nowadays we have even less interference problems than then. other important reasons that citizen band is the way to go for emergency communications are the proliferation of the units and most importantly thier RANGE. since they are Amplitude Modulated ( AM ) they reach a lot further than the modern Frequency Modulated units ( FM ) and lack one of the main problems with FM which do NOT PENETRATE TERRAIN. since CB is AM it is reflected off the ionosphere and bounces back down to earth. as a result CB hugs the earth and will go over mountains. FM is blocked completely by any terra firma between the units as well as any substantial building materials. with a CB you can talk horizon to horizon. in sideband mode you can actually talk intercontinental ( under ideal circumstances). SSB is the ONLY form of communications that works under the worst conditions. SSB is the ONLY form of communications from ANTARCTICA! i have talked from mid america to australia, and germany with my CB. I ROUTINELY talk to miami, ancorage, montreal, mexico etc. on my CB ( SSB) NOTE: about ionosphere. it is heated by the sun and forms a CAP over the areas in sunlight. this translates into the enhanced ability to communicate over extended distances during the daytime because the signal reflects very well off this ion cap. especially mid-day. during darkness CB working distance is limited to about 30 miles. no matter what you do.
IMPORTANT NOTE: since we are in the quiet of the solar cycle it is quiet on the CB. we are headed into the SOLAR MAXIMUM around 2012. that is the OPTIMUM TIME for LONG RANGE CB communications.
theres an old saying that old habits die hard. in my case the CB habit still thrives. we use it DAILY. even though we have cellphones we have learned by experience that our CB systems still offer SELF SUFFICIENT communications when the other systems fail. on numerous ocassions when our cellphone and landline systems have gone down WE still had communications. this has happened numerous times.
but there are KEYS to having good communications. as i often tell people radios are like computers in one aspect. they have to be at arms length, turned on and operable. without these three things they are just objects de art! to meet these criteria you have to have your systems UP AND RUNNING NOW! you can't buy the equipment and store it for later use. unless you're a lifelong geek too. we use ours daily to MAINTAIN it's integrity. radio operators set up NETS ( networks) for DAILY communications just to keep the systems in peak operating condition. to fail to do so is inviting disaster. as sure a heck if you leave them on the shelf shut down MURPHYS LAW will bite you in the ass when you REALLY NEED THEM. happens ever time. thats why NETS! having said that lets examine equipment and how to set it up correctly. since there are many resources on this subject ( the best book you can get is http://www.google.com/search?hl=en&sa=X&oi=spell&resnum=0&ct=result&cd=1&q=screwdriver+expert%27s+guide+to+cb&spell=1 ) i will assume you get it and read it because i won't be covering the basics. i will endeavor to explain the TRICKS AND TIPS i have gleaned from a lifetimes EXPERIENCE with CB RADIO.
two way radios emit Radio Frequency ( RF ) radiation through the antenna which is the output terminus of the system. antennas have been a lifelong interest of mine because in the early days that was the main way to improve your capabilities. i have designed, built and tested dozens of antennas for BASESTATION application.by far the DELTA LOOP ( see our communications files ) is not only the best performer but the easiest to make yourself. LOOK IT UP! but if you are going to buy an antenna get an ANTRON 99 for base station. for MOBILE USE the 108 inch whip was the mainstay for decades. but now there are many better choices. the FIRESTICK is hard to beat. but many have their own preferences.
the TRANSCEIVER ( the two way radio ) can be just about any brand name. most are made by the same manufacturers. theres only a couple. but there are important capabilities you'll want to pay attention to. if you don't want to talk from horizon to horizon but rather use it for regional ( 30 mile radius) personal communications theres only THREE KNOBS that you MUST HAVE ! ON/OFF/VOLUME, SQUELCH and RF GAIN. while there are expensive units that have knobs out da wazoo they are only marketing scams. the more knobs the more expensive. some knbs even deteriorate the signal. like ANL ( automatic noise limiter ) and NB ( noise blank ) which can't distinguish between NOISE and weak/ distant communications thus blocking them. but for PRACTICAL use a CB must have an RF GAIN adjustment. in my experience the ONLY reason CB's are not utilized more is because people don't know how-to OPERATE them PROPERLY. they tire of struggling against all the other CB oprerators out there from coast to coast. THATS where the RF GAIN is critical. what it does is tune the RECEIVE aspect of the unit. it has NO AFFECT on the OUTPUT of the unit. the majority of CBer's turn the RF GAIN all the way up thinking that it increases the output power. in reality by doing that they increase the sensitivity of the receiver to maximum. by doing so thier other units get lost in the noise as well as they have to compete with it when they transmit. the proper way to use the RF GAIN is to TURN IT DOWN until all you hear is the unit you are speaking with. that way theres MORE THAN ENOUGH bandwidth on CB for everyone to use it. for instance i keep my units on all the time but i NEVER HEAR ANYONE except my mobile units because i keep the RF GAIN TURNED DOWN so my receiver is de-sensitized to all but units within the known transmit range of my mobiles and vice-versa. so my system works as quietly ( static free) and surely as a cellphone. the other controls ( knobs) are the on/off/volume which is self explanatory and the SQUELCH. the squelch is simply a threshold setting at which the units speaker is activated. it's function is similar to the rf gain. you set it downto where only your units trigger it. the difference being that in a unit without RF GAIN control when the squelch activates the speaker it is flooded with all that noise etc.
ON/OFF/VOLUME, SQUELCH, RF GAIN....thats ALL you need. anymore is fluff, any less and your units useless. SSB is only a required function if you are planning to talk coast to coast routinely. for personal regional comm. it's not necessary. having said that there are many choices. nearly all brands offer at least one unit like such. they are usually the second unit from the bottom in cost. but having used most of them i can say without reservation that the BEST is UNIDEN PRO520. it's compact, has the BIG THREE controls but most importantly it can be TUNED UP in performance ( more on that later) from the factory setting of 5 watts output to 15 watts output in minutes by anyone with a plastic screwdriver and minimum knowledge. you can also increase it's modulation ( more on that later also ) abilities as easily. this one - two punch makes it a fantastic unit. the UNIDEN 520 is a MOBILE UNIT which means it works on 12vdc in an automobile. but it can be used as a base unit by powering it with a plug in wall transformer. thats basicly the only difference between a BASE unit and a MOBILE unit. the base unit operates off either household current OR 12vdc.
for SSB units you can't beat COBRA but just about any are good. i prefer UNIDEN because if you're talking SSB you're talking TOP END units and in that catagory they're all about equally good.
the transceiver is connected to the ANTENNA by the TRANSMISSION LINE. this is made of CO-AXIAL cable. here is the TIP about transmission lines that seems to elude everyone who installs CB's. the transmission line must be cut to EXACTLY a correct length. this dimension is arrived at by the main FREQUENCY that you will be operating at. CB's are tuned to the middle freq. channel 20 from the factory. if you look at the output on a SWR meter ( more on that later ) the power curve appears as a bell graph with max output on ch.20. this is OK but i advise you use some other channel because the only crowded channel is 19 which is the trucker channel. additionaly there are a hugh numberof old CB's in use that only have 23 channels. so a channel above 23 is recommended.. ch. 35-40 are the unofficial SSB use channels. i use 33 LSB ( lower sideband) but 30 is a good optimum.
the formula to cut the ANTENNA ELEMENT is 300 divided by the frequency in megahertz times 39.37 the answer is for a FULL WAVE antenna in INCHES
the formula to cut the transmission line length is 984 times .66 ( decimal 66 ) divided by the frequency in megahertz answer is in feet.
so there you have it the BIG THREE tips for kick ass communications..
1) get a transceiver with a RF GAIN control
2) cut the antenna element proper length
3) cut the transmission line proper length
once you have done those then you can address FINE TUNING and POWERING UP your units
http://groups.yahoo.com/group/Survivorlist/files/Communications/
in conclusion ( for now. i'll continue as interest dictates)
CB is the way to go for long distance communications. but for TACTICAL communications you can't beat the new FM operation FRS, GMRS, MURS and the brand new XRS handitalkies. theres not much i can say about them. theres no way to modify them.they don't make base units. you can't hook an antenna to them. but they do operate like a cellphone because they have scramblers on them so each network can have a different number. they are ideal for short range personal communications. they would adapt well in a worst case scenario because people could quickly set up local communications networks.each user could have thier own "call" NUMBER. it would function like a cellphone system but only within it's network. all i can say is get the most powerful one available.with the most operating frequencies ( for instance you can get units with BOTH capabilities of the FRS system and the GMRS system.even so you'll be limited to 15 miles LINE OF SIGHT communications. they will be crystal clear and private. But FM does NOT PENETRATE ANY TERRA. so it does not work well in mountains except line of site. on the other hand CB signals, which are AM, go into space, bounce of the ionisphere, and return to earth on the other side of the mountain.
Another important DX ( dx= long distance ) communications is a HEADSET. your brain acts as an audio amplifier. when i tell you i've talked to australia, japan and germany with my CB-SSB raios it was always done wearing HEADPHONES. normal communicatios from coast to coast are done without headphones.
while all CB's have an INTERNAL SPEAKER most serious radio operators have a external speaker. all CB's have a plug in the back for external speakers. all cb's will function as either a stationary ( base) or MOBILE application.
