Nuts and Volts - April 2010

OPEN COMMUNICATION

■ FIGURE 6. The PC screen display for the SDR-IQ is derived from the SpectraVue Software and shows frequency on the horizontal scale and signal amplitude in dBm. The waterfall display is optional.

239 UHF coax connector and an MFJ 16010 antenna tuner ( www.mfjenterprises.com). The tuner consists of an L-network with switchable inductor and tunable capacitor. It lets you match the high impedance of a wire antenna to a 50 ohm input on the radio. Adjusting the tuner lets you optimize signal strength on the frequency you are receiving.

If you do not have a good antenna, you may be disappointed at your results which may cause you to give up before you really get to experience the true pleasure of SWLing. If you are going to invest in a radio, spend the few extra bucks to get a great antenna.

HOW TO LISTEN

Night time is the best time for listening. The bands are quieter and the signals travel farther. From my house in the hill country of Texas, I can hear both coasts easily and almost anywhere in the US. Start listening to the 49 meter band around 5. 9 MHz and tune up from there. Another good spot is the 31 meter band in the 9. 5 MHz range. There are lots of international broadcasts there. The 20 meter ham band in the 14 to 14. 3 MHz range is also fertile territory. You will need to use your BFO to hear the CW and SSB voice signals.

Shortwave is AM, so is very susceptible to noise interference. Noise is random amplitude variations. It can come from lightning and other atmospheric effects but most of it is man-made. Auto ignition noise is one source. Fluorescent lights and the new compact fluorescents (CFLs) are horrible offenders. Turn them all off before tuning in. If you are still getting lots of noise, it could be some other appliance. Turn off anything that creates interference. If it has one, use the noise blanker on your radio.

Remember to be patient. You will usually need to listen for a while before the station identifies itself and its location. On the AM band, you may only get the call letters, but just keep listening until you can figure out where the station is located. Lots of SWLers keep a

SOURCES

For more in-depth coverage of the SWLing hobby, try these targeted magazines.

Monitoring Times www.grove-ent.com

Popular Communications www.popular-communications.com

Passport to World Band Radio www.passband.com

log recording the time, date, frequency, call letters, and location. Some stations will even QSL. This is where you send a report of reception and signal strength along with the time and date to the particular station. They, in turn, send you a QSL card which is a post card usually with the station call and location acknowledging your report.