User:Tfeierabend
From MariachiWiki
Helpfull Information for Mariachi Radio Experimenters
Some Ideas and Suggestions on Radio Equipment and Antennas
Here are some general guidelines to follow when obtaining a radio for Radio-Meteor work and some thoughts on antennas that are simple and inexpensive. Antennas can be built for very little money and as we have demonstrated, made out of the junk others throw away. Spend the money on the radio and get the best available. The radio is the part of the system that has the most stringent requirements and specifications.
The best value for money and a radio that is quite suitable for Radio-Meteor work is the ICOM PCR-1000, PCR-1500, PCR-2500 series. The PCR-1000 is not in production but they are available in the used market. The PCR-1000 covers the frequency range needed and has the sensitivity, frequency stability and frequency resolution we require. We have used many of these and the reliability has been very good. You will need a computer to control and operate the PCR-1000. This can be done nicely with that clunker stored under the workbench. I have a dual radio system using two PCR-1000 radios controlled by the same 400 Mhz Pentium and running Spectrum lab. This system works with no problems. Expect to pay 300 to 400 Dollars US for a PCR-1000. A bit higher for the newer models, PCR-1500 and PCR-2500.
The ICOM R-8500 is also an excellent choice but it is not in production either. Even on the used market expect to pay 3 or 4 time the price of the PCR series. It does have the ability to disable the AGC system and can be operated without a computer supplying control commands to the radio. There are some excellent freeware programs available to control this radio and the PCR series.
WINRADIO manufactures an impressive line of receivers that operate as either PC cards that are installed inside the PC case or as external units. They are in the price range between the PCR series and the R-8500 mentioned above.
ANTENNAS for Radio-Meteor work are available off the shelf or they can be built and make a nice class project. There are many options for the antenna builder to consider. Remember that an antenna 1) can be a bewildering array of electrical conductors and 2) an antenna is not a device that acts alone. There are very mechanically simple antennas such as a half wave dipole and complex arrays such as the Log Periodic Dipole Array or LPDA. Antennas are always reacting to the immediate enviroment and this must be considered carefully. The immeiate enviroment refers to any other wires , cables or metalic object in the vicinity and the proximity of the antenna to the earth below it. So it is best to keep the antennas simple when first starting out. Next I suggest you follow in the footsteps of all antenna builders and remember to NEVER THROW ANYTHING OUT. That 100 foot outdoor extension cable that Dad ran over with the lawnmower last week is a priceless asset to you. Cut the ends off it, roll it up and put it in the junkbox. Scrap peices of small PVC pipe and Mom's old plastic kitchen cutting board are gold to the antenna builder.
Where to put the antenna is the next item to consider. We are all used to seeing antennas mounted atop tall towers and well above rooftops on houses. This is not necessary and can cause other problems at times. If your attic space is under a wooden roof it could be installed up there. There are long term benefits to this approach. The enemy of antennas are the elements. Rain, wind, snow , ice and large fat heavy birds are not beneficial. Corrosion can ruin and will ruin all outdoor TV antennas after a time. Your antenna can be snug, warm and dry up in the attic. Remember to place it at the highest point in the attic and as far from other wires or cables as you can . If the attic is somewhere that is frequented by others, tuck it away so it can't trip anyone or otherwise interfere with those who might have to move through the area.
The antenna must be connected to the radio. This is done most easily with coaxial cable. The type we all use for Cable TV and Satellite TV antennas is fine and is referred to as RG-6. In fact, all of the usual TV type hardware is usable for this application. It is available locally at home stores and is inexpensive.
In the future I will update this page and discuss some specific antenna options based on Mariachi Antennas that we have constructed in the past. One of these may fit your requirements.
73 Tom Feierabend
