Hi Mike, W4UM, See below.
Merry Christmas! John, W2GW -----Original Message----- From: John E. Reiser [mailto:reis...@optonline.net] Sent: Monday, December 01, 2008 4:20 PM To: Tom Hammond; elecraft@mailman.qth.net Cc: Jerry Liley K0GUG Subject: RE: [Elecraft] Running an ICOM PW-1 Amp with the K3 Hi Tom, I have been driving my Icom PW-1 with my K3 for nine months now without any problems. I use it for CW, SSB and digital modes. I simply have a coax jumper between ANT1 on the K3 and Input 2 on the PW-1, of course. And PTT is accomplished by means of a shielded cable from Radio Shack that has RCA plugs on each end. I don't use any connection for ALC with the K3. However, I am very careful not to overdrive the amp. Let me explain. My "other" radio is an Icom 756 Pro 2. It gets very little use anymore, but I left it connected to Input 1 on the amp. Besides a coax jumper, the Pro 2 is connected to the amp with a special cable provided by Icom. The cable provides for PTT and ALC. When one first sets up the amp, one is instructed by the manual to calibrate the ALC. This is accomplished by means of a screwdriver adjustable potentiometer on the back of the amp. The meter on the front panel of the amp has a switch-selectable ALC scale with a red line mark at mid-scale. The ALC is calibrated by adjusting the pot such that the needle does not go past the red mark. Two identical sets of input jacks and ALC-calibration-pots are provided on the amp, for Input 1 and Input 2, respectively. Before I connected the K3, I calibrated the ALC on the Input 2 side using my Pro 2. My thinking was (correctly or not) that as long as I controlled the drive from the K3 so that the ALC meter on the amp stayed below the calibrated red mark, all was well. Now, when I use the amp, I set the output of the K3 to 20 watts. That gives me about 600 watts out, as measured on my LP-100A watt meter. The ALC meter on the amp stays within the lower (leftmost) third of the scale. The overdrive-protection circuits in the amp have never activated. The difference between 600 and 1000 watts out is negligible at the receiving end, of course. With the Pro 2 I used to set the drive to just give me 1K out, although I could have pushed it to 1100 or 1200 on some bands. It took about 25 to 30 watts of drive. Of course, with the ALC connected, the ALC never went past the red mark on the meter. So, bottom line, I am able to use the PW-1 with my K3 but, without ALC, I have to be careful. In writing this note, I'm merely sharing my own experience, in case it can help someone. Others may have a better solution, perhaps using the negative-going ALC mod to the K3. 73, John, W2GW -----Original Message----- From: elec...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net]on Behalf Of Tom Hammond Sent: Monday, December 01, 2008 11:00 AM To: elecraft@mailman.qth.net Cc: Jerry Liley K0GUG Subject: [Elecraft] Running an ICOM PW-1 Amp with the K3 I'm about to loan my K3 to another local ham who currently has an IC-7800 and PW-1 amplifier. His IC-7800 has been sent in for service so it's temporarily out of the picture. However the PW-1 is still in play and this local is gonna want to use it with the K3. Is anyone running a PW-1 with their K3? If so, please contact me a.s.a.p. so I can exchange some info with you. Specifically I need to know what it took to interface the two devices and to get them to function without any hiccups. Appreciated. 73, Tom Hammond N0SS _______________________________________________ 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 _______________________________________________ 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
