Julian -
Yes, there is. Check the K2 notes pages on the Elecraft web site, or build your own, which is what I did. All that is required, if I remember correctly, is a resistor (anything between 1000 and 2200 Ohms, 1/4 watt) and a NPN transistor capable of handling the required amplifier keying current and voltage. A 2N3053 / ECG125 would be one example. A 2N2222 would be another, but if you are using a vacuum-tube amplifier, check the key up voltage across the amplifier keying jack, and size the driver transistor accordingly. This assumes your amplifier has a positive voltage across the key jack when in standby mode. If it is negative,. you may need a small driver relay. Most amplifiers, not all, will not need the relay. Inside the K2, connect the 2200 ohm resistor from the 8T (8 volts on transmit) line in the K2 to the 2N3053 base, ground the 2N3053 emitter, and the 2N3053 collector connects to the amplifier key port. There is (or at least was) a small kit offered that contains the needed parts and a small PC board. I used a small square of perf-board and hand wired the thing using the component leads, not printed traces needed. I also installed a RCA phono jack on the rear panel using one of the unused extra holes. Of course, you could drill an extra hole if needed, or just use a pigtail with the RCA jack hanging on the end. I also installed a .005 uFd / 500 volt disk ceramic cap across the output jack just in case there were RF issues, but don't know if it was actually necessary. In any case, it works fine. - Jim, KL7CC Julian, G4ILO wrote: > Due to serious illness I am looking at simplifying and downsizing my radio > equipment and returning to QRP using my old K2. Unfortunately the K2 seems > to lack a facility that I used on the K3 namely a KEY OUT jack that could be > used to key an external amplifier on transmit (or in my case the MFJ noise > cancelling box, to avoid having to use the RF sensing.) > > Is there a solution? > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
