DELF├ŹN



The very popular, simple and inexpensive ARDF receiver for 2m. Made by the Radiotechnika Teplice Company, it helped many people to start with ARDF and achieve even a national-grade prize. Again, very simple design, single mixing superheterodyne with free-running VCO at 135MHz, 10,7MHz IF 100kHz wide (FM broadcast IF filter) and simple AF. The receiver has a surprisingly wide input (RF) sensitivity adjust range (more than 60dB), thus, it allows a very precious goino either from kilometers or meters, when combined with the AF sensitivity control.

The antenna is a collapsible HB9CV with elements partially made from steel ribbon. Very good for penetrating the bushes, but very unstable in windy weather or a fast run. The antenna photographed is missing the coax cable - now in a progress of restoration.

The weakest point of this radio was the battery - originaly designed for a single 6F22 9V battery, the radio drained the relatively expensive battery in a hours. Thus, there were frequently used two 4,5V flat batteries "outboard" the radio, making it a little bit heavy and uncomfortable to carry...



All photos are © OK1UHU, 2011