IWA 0257 Muiderkring Radio slide rule full set 1960 Germany Holland

This interesting slide rule was developed by De Muiderkring from Holland and produced by IWA with number 0257. The Muiderkring was a group of Radio amateur enthusiasts from Holland. This model was dedicated to the use of radio tubes. It can be used to calculate Resonance frequenties, self induction, carrier waves and sound amplification. It is in hardly used condition. It comes complete with pouch (marked Muiderkring) and Dutch manual. All sides is clear and the cursor is intact with special blue markings. It measures ca 15,5 cm or 6 inches long. Check the attached video on how to work your vintage man tool : slide rule operation instructions!