1N4746 18 Volt 1 watt zener diode formerly, "18V1WZNR"
18 Volt, 5%, 1 watt, Zener Diode, 4 for .99
Most used in the MFJ-1270, B, or C as CR1 and MFJ-1278 as the protection diode.
May be used in other radio and 13.8 VDC devices as overvoltage protection.
When overvoltage of lightning spikes occur, this 18 volt, 1 watt zener is prone to short, and blow the fuse in your TNC or remote node. This saves the other circuitry in the device. All that is necessary is to replace the overvoltage protection diode. It fails when a surge of power line glitch enters the TNC or node. It will short and open the fuse, to protect other components in the TNC or node.
In 85% of the node or TNC failures, all you have to do is remove the defective CR1, zener diode and replace it with one of these 18V1WZNR.
This 18 volt Zener diode is employed in other TNC's, KPC's and Packet controllers as the polarity and spike protection diode.
This is the one item in a packet controller or TNC that is most often destroyed or shorted during lightning storms or power-line glitches. Keep several on hand so you can return your TNC or Node back to service, fast.
RASCAL-II plus
Specials ...