(had to change email subscription to post to reflector. lets see if this one works...)
The AL80A uses a 12V 100mA relay coil that is pulled to ground to activate. There is no back-EMF diode in the circuit. The KX3 keying output is simply the open drain of a 2N7002 low-power MOSFET, also with no back-EMF protection other than its internal channel diode and an additional 0.01 uF cap. You could probably "get away" with it, but I would not recommend it. There is limited protection on the I/O of the KX3. The lines typically have RC networks to limit RFI and current, but driving an inductive relay is asking a bit much. A safer solution would be a simple driver to protect your KX3 from a repair trip to the factory. On a similar note, the Black Friday sale pushed me off the fence and I ordered a KX3 (my first Elecraft), woo hoo! I've got an SB-200 that I can hook up to the KX3 to provide about 80 watts out if I want QRO while saving up money for a linear for the little guy. My SB-200 has the Harbach keying circuit so it's good to go. The Harbach circuit was not quite designed correctly, but that's a story for another list, HI. vy 72 de Paul/N6MGN, Montana On 11/29/2016 1:13 PM, David N. via Elecraft wrote: > Hello AllI just ordered a New KX3 (Kit)I am wanting to know if Keying My > Heathkit SB1000 (Ameritron AL80A) amplifier with key line off of the ACC2 > will be a problemIt says that it is good for 30v @ 100ma. My Amplifier is 12v > relay. Not sure current. I would think itwould be fine. But just wanted to > check. I won't be able to order my KXPA100 till next year. Have to save the > penny's for that one.Thanks > David KR4OWK2/100 4320 > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
