Upon obtaining an amateur radio license or "ticket" generally a hams first investment is in a dual-band hand held two way radio, frequently referred to as an HT or Handy talkie, a term which developed from the old term: walkie-talkie. Customarily the amateur radio operators second investment is in a mobile dual band UHF/VHF transceiver or "rig" which they mount in their vehicle or radio Shack. These two rigs have very similar functionality but the hand held battery-operated rig is usually limited to a maximum output power of about 5 watts. The mobile radio which is connected to the vehicles twelve Volt power supply, or if it used as a base station, to a transformer supplying 12 Volts DC and is capable of transmitting generally up to about 35 watts.

UHF and VHF frequencies are line of sight. Depending on the power output and the location of the transmission aerial UHF and VHF transmissions are able to reach the visible horizon and maybe just a little beyond, but that is the limit. There is one notable exception to this rule which is Tropospheric ducting, where under very unusual and quite rare weather conditions VHF and UHF radio signals travel very much further than the horizon. amateur radio operators take advantage of this phenomena when it does occur by communicating with other hams over great distances.

A 5 Watt Handy-talkie will have an operative range "depending on the terrain and elevation" of roughly 3 miles. A mobile rig on full power with a good antenna in a good location will probably have a maximum range of fifteen to twenty miles under favorable conditions. To get over this limitation in range amateur radio operators make use of radio repeaters, which are frequently owned and operated by amateur radio clubs, but some are privately owned. These radio repeaters are automatic transceivers that listen or receive on one frequency and transmit on a different frequency, this is frequently referred to as "the split". The radio repeater takes the signal that it receives on the input frequency and instantaneously retransmits it on the output frequency using a lot more power, generally about a hundred Watts. In addition to the higher power most of these radio repeaters aerials are located on the top of very high towers or high buildings which actually increases it's range.

A ham's Handy talkie can be used to transmit on the repeater's input frequency and receive on the repeater's output frequency effectively increasing the range of the hand held rig to just beyond the horizon, maybe even as far as thirty or forty miles. Many radio repeater systems have several receiving aerials located throughout the repeater's coverage area but just one main transmitter. In this way a large city can be completely covered with a radio repeater system with hams being able to receive the radio repeater just about anywhere in the city and they are able to be received by the radio repeater or "hit the radio repeater" as it is generally referred to, again from almost anywhere in the city.

Recently some repeaters around the globe have been connected to the World wide web and can be linked to each other using the World-wide-web. For example an ham radio operator in Moscow Russia with an Handy-talkie can chat through their local repeater with a fellow amateur who is driving in their car in New York city United States.

Some radio repeater systems are continually linked to each other but most are linked as and when required by the user and the link is dropped at the end of the conversation.

Most amateur repeaters are open to all licensed ham radio operators at no cost. These radio repeaters do take money to buy, operate and maintain. They are usually funded by club membership dues and events held by the club like Hamfests. If a ham finds themselves using a radio repeater frequently then maybe they should really consider joining the club that owns the repeater and help to finance it.

Article Source: http://EzineArticles.com/4733253

UHF 6 cavity duplexer for radio repeater FREE tune    US $79.99

ICOM REPEATER UHF 440–490 MHz CONTROLLER DUPLEXER    US $1,295.52

UHF 6 CAVITY DUPLEXER for radio repeater N connector SQ    US $100.50

UHF 35W 6 CAVITY DUPLEXER FOR REPEATER FREE TUNING US1    US $74.60

UHF 50W 6 CAVITY DUPLEXER FOR REPEATER FREE TUNING US1    US $83.00

VHF 35W 6 CAVITY DUPLEXER FOR REPEATER FREE TUNING US1    US $74.60

VHF 50W 6 CAVITY DUPLEXER FOR REPEATER FREE TUNING US1    US $83.00

MOTOROLA CDM750 4 CHANNEL Repeater Link HAM RADIO TRANSCEIVER    US $15.50

ARRL REPEATER DIRECTORY 2011 2012 FREE DOMESTIC SHIPPING USPS    US $9.95

Kit 4 Accy Plug 16 Pin Motorola Maxtrac GM300 Repeater    US $12.99

TPL 100 Watt PA8 IFD Continuous Duty High UHF Repeater Amplifier 806 952 MHZ    US $75.00

Motorola Micor TPN1151A Base Repeater Linear Power Supply    US $29.99

RA 2 Repeater Adaptor Motorola GM300 GR300 CDM1250 RICK    US $59.99

Zetron Model 66 Transmitter Repeater Controller Link Receiver Rack Mount    US $79.75

VERTEXWIRES II HRI 100 2 UNITS iNTERNET REPEATER ENHANCMENT SYSTEM    US $.99

View Page:   1  2  3  4  5  6

Okay, let me start with the basics for those of you who are not familiar with Amateur Radio, or Ham Radio. QRP is part of the Q codes. Q codes are nothing more than a collection of 3 letter codes all starting with Q, much like the 10 codes that other radio services use such as 10-4. The Q codes reserved for use by amateurs range from QRA ~ QUZ. Anyway, I am not going to get into detail about Q codes in this article, for those who are thirsty for the details, simply search Q codes and you will find lots to read about.

To get back on track QRP in amateur radio strict terms means "shall I decrease power" or "decrease power", however, when normally used in conversation it typically means that the transmitting station is using very low power output, usually less than 5 watts. To put this into perspective, the average HF Ham Radio transmitter produces in the neighborhood of about 100 watts, and many of these users will add a linear amplifier to their station often cranking up the output to over 1,000 watts. So what does this all mean? Well, let me use the analogy of a light bulb. A 100 watt light bulb is going to be much brighter than a 5 watt bulb, therefore one would assume that the 100 watt bulb would be easier seen at a further distance. This is true of a radio signal as well. So why, you ask, would I like to use 5 watts? My reasons for using a QRP station may be different than the next persons, but I will try to give you some insight into my rationale.

Firstly, I feel that the mark of a good radio station, amateur or otherwise, is the antenna. The antenna is the most important component to a transmitter and receiver. Without an antenna, it won't matter how much power wattage you have, your signal will be greatly impeded. So, when choosing to operate QRP, one must take care in designing the antenna system, something I take pride in. In actual fact, a properly designed and assembled antenna will effectively amplify your signal many times, thus allowing you to be heard as if you were using much more than 5 watts. You are still wondering so what? Well, I guess it makes me feel good to know that I can construct a very efficient antenna.

The second reason I like QRP is that it is very conducive to portable operation. When I say portable, I am referring to operating a radio away from commercial power, in other words running a radio station on batteries. As an example, the family loves camping, I prefer a five star hotel, but to keep everyone happy, I will go, but only if I can bring my radio! Bringing a radio camping is great fun at night once the kids have been tucked into their sleeping bags. Anytime you can get away from the electrical noise of the city, radio reception greatly improves, meaning that I can clearly hear very weak signals. So to get back on track, if I was running a 100 watt transmitter, I would likely need access to 110 volt house current (in the middle of Algonquin Park? I don't think so). Yes, of course I could have my wife and children tote along a couple of 12 volt car batteries each weighing in excess of 50 pounds. Even then they may only last for a few hours of fun at 100 watts. Now we come back full circle to QRP when I run an electronically efficient radio putting out only 2, 3 or 4 watts, (Such as the Elecraft KX1 or TenTec R4030) I only need to bring along a couple of battery packs that would amount to about 10 AA type cells. This arrangement will easily last me 3 to 4 days before I would have to worry about charging them. Or, if I was really eager, I could take along a Gel Cell type of battery and that would last upwards of 2 weeks. I suppose that the morale of this story can be summed up as follows: Mom and the Kids want to go camping, Dad is not so excited! Dad thinks, hummm, I can do some QRP radio operating while camping, OK! Mom and the Kids are happy, Dad is happy!

Article Source: http://EzineArticles.com/5034018

6 Miniature Crystal Controlled 20 Meter QRP TRANSMITTERS    US $12.00

Original DC40 40 meter CW Transceiver from Hendricks QRP Kits    US $35.05

Heathkit HW 9 QRP CW Transceiver PSA 9 PS HFT 9A Antenna Tuner HM 9 QRP Meter    US $305.99

Feet Heathkit Eico Drake Amateur Ham Radio Transceiver Receiver QRP    US $9.99

Millen Receiver Transmitter Crystal Sockets Heathkit QRP Vintage Ham Radio    US $8.49

Portable All Band HF Antenna System Ham Radio Marine Short Wave Shtf Qrp NEW    US $132.00

YAESU FT 817 QRP HF MOBILE    US $495.00

Elecraft K1 2 Two Band Qrp Transceiver Mint    US $325.00

MFJ 971 Portable QRP Antenna Tuner ATU Less than 1 month old    US $54.67

3 BUD CHASSIS 1 CABINET BUD MINI BOX QRP HAM AMATEUR RADIO PROJECTS NOS NR    US $39.99

4 BUD MINI BOXES 1 CHASSIS QRP HAM AMATEUR RADIO KIT PROJECTS NOS NR    US $29.99

MFJ CW FILTER HAM RADIO CONTINUOUS WAVE CWF 2 QRP SHORTWAVE OSCILLATOR    US $19.00

Heathkit HW 8 QRP CW Transceiver Heath Hot Water Handbook Michael Bryce 1991    US $14.95

SW 1 40 Meter Transistor QRP Crystal RF Transmitter Module Amateur Ham Radio    US $24.00

SW 1 80 Meter Transistor QRP Crystal RF Transmitter Module Amateur Ham Radio    US $28.00

View Page:   1  2  3  4  5  6  7