This is the first ARDF receiver, made in small series in URD manufactory (URD = ústřední radiodílny Svazarmu, centralised radio-manufactories of Svazarm). The receiver is very simple, but has a good sensitivity, acceptable frequency stability and good goniometric performance. The element base of the design is very limited by the possibilities of 1970's Czechoslovakia - there are exclusively domestic production components used.
The weakest point of the radio is the unprotected, fragile, thus easy breakable ferrite antenna rod, protruding out of the receiver about 2cm on both sides. Not looking to that, the receivers were very reliable and thus popular in their times.