Re: [Elecraft] KAT100 LEDs Gone Wild
that did it, thanks - Original Message - From: "Jack Brindle" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: Sent: Saturday, November 20, 2004 2:05 PM Subject: Re: [Elecraft] KAT100 LEDs Gone Wild Roy; Try adding several feet of coax between the tuner and the antenna and try again. It appears you may have a voltage maximum occurring at the tuner - adding the coax will move it out a ways. There are just some impedances and feedline lengths that tuners have a difficult time handling. If, by chance the antenna is open-wire fed, then add coax between the KAT100 and the balun... Note that the Bird will see different line characteristics than the KAT because it has a different placement in the line, and thus different voltage/current values at that point. It is the values at the tuner that are critical, because they are what the tuner's LC circuits have to match. One other thing - the K2 gets the SWR from the KAT, so if the KAT's SWR display is changing, the K2's SWR display should also be changing. If all else fails, make a video of the display and advertise it on late-night TV. Late-night viewers will buy anything these days, and you just might get rich doing it! On Nov 20, 2004, at 8:22 AM, [EMAIL PROTECTED] wrote: I thought that installing MCU1.05 there would be ample RF sampling rates taken to avoid erratic LED displays. The updated firmware seems not to be the solution. With a 50 ohm dummy load on the KAT100 output only the leftmost LED lights up and K2 SWR is 1:1 regardless of power or band in use. With the Carolina Windom 80 attached to the KAT100 output and a Bird 43 wattmeter between the K2 output and KAT100 input, I found the reflected power stayed at zero and the forward power stayed at max (regardless of band or power setting) while the KAT100 LEDs and K2 SWR reading were going wild. The wildest LED and SWR activity occurs on 30 meters but does not occur on all bands. I have already removed the white wire from pin 7 of the K2 end of the IO port and put a .01 pF cap from the white wire to the bare wire on pin 1. My shack is on the second floor (over my garage) and I have tried to be as attentive to grounding as possible. I use a common grounding point that attaches to a 1/2 " copper pipe (used only for grounding) that goes down approx 10 feet to an eight foot buried grounding rod. I believe the K2 erratic SWR activity will stop when the KAT100 LED stray RF problem has been eliminated. Has anyone made any changes or done any bypassing inside the KAT100 to eliminate stray RF and tame the LED display? Roy Morris W4WFB - Jack Brindle, W6FB, ex-WA4FIB - ___ 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 ___ 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
Re: [Elecraft] KAT100 LEDs Gone Wild
Roy; Try adding several feet of coax between the tuner and the antenna and try again. It appears you may have a voltage maximum occurring at the tuner - adding the coax will move it out a ways. There are just some impedances and feedline lengths that tuners have a difficult time handling. If, by chance the antenna is open-wire fed, then add coax between the KAT100 and the balun... Note that the Bird will see different line characteristics than the KAT because it has a different placement in the line, and thus different voltage/current values at that point. It is the values at the tuner that are critical, because they are what the tuner's LC circuits have to match. One other thing - the K2 gets the SWR from the KAT, so if the KAT's SWR display is changing, the K2's SWR display should also be changing. If all else fails, make a video of the display and advertise it on late-night TV. Late-night viewers will buy anything these days, and you just might get rich doing it! On Nov 20, 2004, at 8:22 AM, [EMAIL PROTECTED] wrote: I thought that installing MCU1.05 there would be ample RF sampling rates taken to avoid erratic LED displays. The updated firmware seems not to be the solution. With a 50 ohm dummy load on the KAT100 output only the leftmost LED lights up and K2 SWR is 1:1 regardless of power or band in use. With the Carolina Windom 80 attached to the KAT100 output and a Bird 43 wattmeter between the K2 output and KAT100 input, I found the reflected power stayed at zero and the forward power stayed at max (regardless of band or power setting) while the KAT100 LEDs and K2 SWR reading were going wild. The wildest LED and SWR activity occurs on 30 meters but does not occur on all bands. I have already removed the white wire from pin 7 of the K2 end of the IO port and put a .01 pF cap from the white wire to the bare wire on pin 1. My shack is on the second floor (over my garage) and I have tried to be as attentive to grounding as possible. I use a common grounding point that attaches to a 1/2 " copper pipe (used only for grounding) that goes down approx 10 feet to an eight foot buried grounding rod. I believe the K2 erratic SWR activity will stop when the KAT100 LED stray RF problem has been eliminated. Has anyone made any changes or done any bypassing inside the KAT100 to eliminate stray RF and tame the LED display? Roy Morris W4WFB - Jack Brindle, W6FB, ex-WA4FIB - ___ 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
Re: [Elecraft] KAT100 LEDs Gone Wild
Roy, Getting a really good RF ground for a 2nd story shack may require more than a 1/2 inch copper pipe, it may be a good ground at DC, but actually may have a high impedance at RF (depends on the frequency). The easiest thing to try is a quarter wave counterpoise wire (open at the far end and out of the way - that end WILL have high voltage RF on it). Cut one for each band (fan out the ends). The wire can be stretched out on the floor is necessary, but neater and safer if it is run outside. If you can get it in a straight line, so much the better, but not a requirement - but do make gentle bends (radius of a large coffee can) if you cannot run it straight. The characteristics of a quarter wave wire apply - high voltage RF on one end and zero volts on the other. The zero volts end is a good RF ground point - connect it directly to your KAT100. 73, Don W3FPR - Original Message - I thought that installing MCU1.05 there would be ample RF sampling rates taken to avoid erratic LED displays. The updated firmware seems not to be the solution. With a 50 ohm dummy load on the KAT100 output only the leftmost LED lights up and K2 SWR is 1:1 regardless of power or band in use. With the Carolina Windom 80 attached to the KAT100 output and a Bird 43 wattmeter between the K2 output and KAT100 input, I found the reflected power stayed at zero and the forward power stayed at max (regardless of band or power setting) while the KAT100 LEDs and K2 SWR reading were going wild. The wildest LED and SWR activity occurs on 30 meters but does not occur on all bands. I have already removed the white wire from pin 7 of the K2 end of the IO port and put a .01 pF cap from the white wire to the bare wire on pin 1. My shack is on the second floor (over my garage) and I have tried to be as attentive to grounding as possible. I use a common grounding point that attaches to a 1/2 " copper pipe (used only for grounding) that goes down approx 10 feet to an eight foot buried grounding rod. I believe the K2 erratic SWR activity will stop when the KAT100 LED stray RF problem has been eliminated. Has anyone made any changes or done any bypassing inside the KAT100 to eliminate stray RF and tame the LED display? Roy Morris W4WFB ___ 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
[Elecraft] KAT100 LEDs Gone Wild
I thought that installing MCU1.05 there would be ample RF sampling rates taken to avoid erratic LED displays. The updated firmware seems not to be the solution. With a 50 ohm dummy load on the KAT100 output only the leftmost LED lights up and K2 SWR is 1:1 regardless of power or band in use. With the Carolina Windom 80 attached to the KAT100 output and a Bird 43 wattmeter between the K2 output and KAT100 input, I found the reflected power stayed at zero and the forward power stayed at max (regardless of band or power setting) while the KAT100 LEDs and K2 SWR reading were going wild. The wildest LED and SWR activity occurs on 30 meters but does not occur on all bands. I have already removed the white wire from pin 7 of the K2 end of the IO port and put a .01 pF cap from the white wire to the bare wire on pin 1. My shack is on the second floor (over my garage) and I have tried to be as attentive to grounding as possible. I use a common grounding point that attaches to a 1/2 " copper pipe (used only for grounding) that goes down approx 10 feet to an eight foot buried grounding rod. I believe the K2 erratic SWR activity will stop when the KAT100 LED stray RF problem has been eliminated. Has anyone made any changes or done any bypassing inside the KAT100 to eliminate stray RF and tame the LED display? Roy Morris W4WFB ___ 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
