====== Rohde & Schwarz Counter FET-2 ====== Counter FET-2 BN 4737/2; manufactured by [[Rohde & Schwarz]], Munich. The Rohde & Schwarz counter was launched around the year 1968. The counter can be used as an event / pulse counter in the basic version and with the corresponding plug-in units as a frequency counter or for period duration measurement. {{:images:werkstatt-rohde-schwarz-fet2.jpg?direct&600|Rohde & Schwarz FET2}} ===== Technical data ===== * [[Principle]]: Counter with a gate circuit and counting decades * [[Frequency range]]: 1 kHz - 100 MHz * [[Frequency display]]: [[digital display]] with [[Nixie tubes]] * Input voltage: 20 mVeff - 10 Veff ==== Power supply ==== * [[Mains operation]]: 115, 125, 220, 235 V; 60 VA ==== Dimensions ==== * 484 x 149 x 343 mm, weight 15 kg ==== Accessories ==== * Frequency counter unit BN 47371 * Period plug-in unit BN 47372 * Time / TIME unit 47373 ---- {{:images:werkstatt-rohde-schwarz-fet2-b.jpg?direct&600|Rohde & Schwarz FET2}} ===== Operation ===== When the set is connected to the mains and supplied with power, the Mains indicator light comes on. Pressing the mains switch button brings the display with the nine Nixie tubes to life, and the ZERO button can be used to reset the counter. The FREQUENCY unit is required to operate the FET2 as a frequency counter. When the START INT. button is pressed, the FET2 acts as a frequency counter. The repetition frequency, on which the accuracy of the display is depending, can be selected with the measuring time switch. {{ :images:werkstatt-rohde-schwarz-fet2-c.jpg?direct&400|Rohde & Schwarz FET2}} When working with 100 ms or 10 ms, the frequency is updated quasi-continuously, every frequency change of the signal generator is tracked. If measuring times of 1 or 10 seconds are selected, the decimal point moves to the left and more decimal places are displayed, but the refresh is delayed. Alternatively, a single measurement can be triggered by pressing the START HAND button and the measured frequency then stops. Period durations can be measured with the period plug-in, and pulses can also be counted with the FET2 when using the INPUT COUNTING GATE. There was also the FET1 version of the counter, which can only measure frequencies up to 12 MHz and display them on 6 nixie tubes. On the back of the device there is a standard frequency output of 5 MHz, a standard frequency input for a highly stable 5 MHz signal and two thirty-pin sockets in accordance with DIN 41 622, on which the frequency is output in binary form per decade. ===== Technical principle ===== Counter with gate circuit and counting decade, display with nine Nixie tubes. {{:video:rohde-schwarz-fet2.mp4?direct&600|Rohde & Schwarz FET2 in operation}} ==== Components ==== The set is built with silicon semiconductors, the display uses [[Nixie tubes]]. ===== Technical documentation ===== ==== Development ==== {{gallery>:images?werkstatt-rohde-schwarz-fet2*.jpg&0&80x80&lightbox&showtitle&titlesort}} ==== Further information ==== * [[https://www.radiomuseum.org/r/rohde_fet_2_bn_4737.html|Rohde & Schwarz FET-2 on the website of www.radiomuseum.org]]