Famous Czech manpack radio set for a short range communications. Very probalby based on (not only) the idea of KlFuSpr.d (Dorette), the RF-11 was the first post-IIWW small manpack radio. Its concept is very simple, VFO-PA while transmitting, preamp and superregeneration detector while receiving. There were three variations of this radio produced (in the order of appearance):

RF-11 - the primary model, uses 23-28 MHz band, thus, is compatible with e.g. A7b and other radios of these times.
RF-11M - modified version, now in the 48,5-51,5 MHz band.
RF-11M/2 - almost the same as RF-11M, slightly modified circuitry.

The radio is equipped with four 1L34 tubes, one 1H34 tube in the quartz calibrator box. Powered form three "D" size dry cells for a filament and one 120V anode dry battery, the radio can run for about 12 hours of operation. Very good documentation can be found here..

The field operational results of those radios were mostly poor - mainly because of the low sensitivty, bad reliability and low frequency stability. At the other hand, there were no other such a radios in our country at those (and many following) years...