David, No question is quick if you need to understand what is going on <G>!
The amp keying circuit should work unless the output transistor is being forced into conduction from whatever voltage is being applied on its open collector - it should not be if the voltages applied are within a normal range. Without the amp connected, you can check the base voltage of the 2N2222 transistor - it should be very close 0 volts during receive and about 0.7 volts (the emitter/base junction voltage for the 2N2222) during transmit. If those two conditions are not true, then you have something wrong with the keying circuit wiring. During receive, the 2N2222 should be cutoff due to the low voltage at its base and should not conduct even with voltage applied to the collector. Be certain the resistance in the emitter path is quite low - a bit of resistance there could cause the output transistor to misbehave. If your problem still is not solved, try measuring the circuit output transistor voltages (to K2 ground) with the amp connected and the K2 in receive. The emitter should be zero volts, and the base should also be very low, while the collector should measure at the voltage applied externally from the amp. Be certain you have a good low resistance connection from the amp ground (terminal E) to the K2 ground and a good connection from the amps RY terminal to the keying circuit's output collector. If you find the conditions above are OK, you likely have a bad 2N2222. 73, Don W3FPR > -----Original Message----- > > Just a quick question.. > > I've just installed the parts in my basic K2 to externally key an > amp. I've > just tried to key my old FL-2100B with this, but have found that > as soon as > I plug the cable in, the amp keys when the radio is still in RX ?? > > Is there a menu setting I need to change or have I made a mistake on the > circuit ?? The cable is fine as I use this on my FT1000mp to key the same > amp. > > I've checked the resistance on the keying circuit and I get about 18ohms, > when the radio is keyed, as opposed to open circuit when in the > RX state ?? > > Thanks > > David, VK2NU > _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
