[Boatanchors] Re Ranger and keyer

[JAMES HANLON]

Corner 5,  You asked about using your electronic keyer with a Ranger I,

You are probably correct about needing to key -50 volts at low current.  So the first thing I would ask is what is your keyer able to handle.  Do you have any ratings on your keyer, or do you have a schematic for it?  What does its output look like?

Presuming that it cannot handle -50 volts directly, I would suggest you use it to key a small electromechanical relay which can in turn key the Ranger.  I can send you a small, mercury-wetted, single pole single throw relay whose coil measures 300 ohms and which will operate from a 5 volt dc power supply (a Western Electric type 345 relay).  It is very fast, its operate and release times are under a millisecond, so it will be a very good keying relay.  Its contacts can switch up to several hundred volts of either polarity and as much as 2 amps.  Its contacts do not bounce open on closure like many dry-reed relays do, so again it's very good for keying.  The only strange thing about it is that it is position sensitive.  You need to mount it so that the arrow on the case points upward so that the liquid mercury inside does not flow onto the contact and short it out.

If you are interested, let me know.

Jim, W8KGI