The KD-4 / KD-41 relays were superseded by the KD-10 / KD-11 relays respectively in 1975 as a product enhancement. The KD-4 / KD-41 relays were initially designed to handle the middle range (0.75-20 ohms) impedance reach. The present design KD-10 / KD-11 relays offered three distinct ranges of the impedance reach and this expansion of the range was the most significant change. The KD-10 / KD-11 relays were also designed to seamlessly fit into the same case with the same terminals and perform virtually the same function. The other improvement was the incorporation of fine adjustment potentiometers P2C, P3C, P2A, and P3 which are connected in series with the course adjustment resistors. Since the pots were labeled and mounted in the front of the relay, this has made calibration and maintenance a great deal easier for the relay technician or engineer.
|
Relay Ohms | Taps |
|---|
| 0.2-4.5 | 0.230 | 0.307 | 0.383 | 0.537 | 0.690 | 0.920 | 1.230 |
| 0.75-21.2 | 0.870 | 1.160 | 1.450 | 2.030 | 2.900 | 4.060 | 5.800 |
| 1.27-36.6 | 1.500 | 2.000 | 2.500 | 3.510 | 5.000 | 7.020 | 10.00 |