Re: [Elecraft] driving external PA with K2
To supplement Lee's email, I would say that ALC is a way to protect the PA from overdrive. For example, if I set proper ALC level at my ICPW-1 to get only 500 watts (the full output of PW-1 is 1 kw), even when I turn the RF power control on my IC756pro2 to full scale, the ALC feedback voltage from PW-1 will automatically limit my pro2 to an output power of less than 30 watts. In the case of K2, the output power is less than 15 watts. I do not see any danger to overdrive a PA. Clearly, K2/100 is a different story. 73 Johnny Siu VR2XMC - Original Message - From: Lee Buller [EMAIL PROTECTED] To: Mike W [EMAIL PROTECTED] Cc: Elecraft Reflector elecraft@mailman.qth.net Sent: Friday, July 09, 2004 6:46 PM Subject: Re: [Elecraft] driving external PA with K2 Mike, You already have all the info you need, but I would like to say you will need no ALC at all. If you keep the rig linear and not over drive the amp...there is no need for ALC. This feature is kind of a left over from when tubes were tubes and men were men (sorry Ladies, trying to make a bad pun) Of course, you will not over drive a typical amp with 15 watt of mighty mojo. Now, if you have a KPA100, that is a different story altogther, but I do not want to digress. The main point here is keep the rig linear and do not over drive the amp. Have fun building the keying interface. Works like a champ. Lee - K0WA ___ 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/elecraftHelp: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] driving external PA with K2
Hi Mike, There is a amp-key kit provided by elecraft at a cost of USD5. There is no ALC communication between the external PA and K2. I use my K2 with my ICOM ICPW-1. With an input of 15 watts, I shall get an output of about 300 watts. The output of the PA is controlled by the input power from K2. 73 Johnny Siu VR2XMC - Original Message - From: Mike W [EMAIL PROTECTED] To: elecraft@mailman.qth.net Sent: Thursday, July 08, 2004 7:19 PM Subject: [Elecraft] driving external PA with K2 Hi Folks, Using a basic K2 with no options other than SSB. How can I drive an external PA and have PTT and ALC controlled by the K2 ?. ___ ___ 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/elecraftHelp: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] driving external PA with K2
Within the Elecraft application notes there are details of a partial mod kit available for an external PTT feed: http://www.elecraf t.com/Apps/Amp_keying_ckt.htm This uses a 2N7 and a 2N transistor plus two resistors, and two connectors mounted on a perf board pcb. The transistors are available in the UK though having problems finding the correct mating 8 pin and 2 pin connectors here. Elecraft can supply a partial kit listed at US$5 on the Elecraft website. This includes the transistors, resistors and the 8 pin connectors. You have to provide the perf board, 2 pin connectors and an external phono or whatever connector you decide to use. I intend using this mod to hard key my Spectrum TRC4-10iL 4m transverter which at present is working on RF keying. The PTT mod plugs in at the rear of the K2 RF board at J13 location (if available) Regards, Bob, G3VVT K2 #4168 ___ 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/elecraftHelp: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
