+++++++++++++++++++++ See also KAT2 Notes +++++++++++++++++++++ Date: Fri, 05 Apr 2002 08:48:36 -0600 From: k4zm at comcast.net Subject: Re: [Elecraft] Best way to check ATU function? To: cyr999 at extremezone.com Cc: elecraft at mailman.qth.net Tim: The KAT2 remembers its settings. The first time you tune up it seeks the best match and then stores the settings on each band. The only reason it should return is if you change to an antenna that requires a different setting. 73 Jim Younce K4ZM K2 SN: 18 ----- Original Message ----- From: Tim and Nancy Logan To: Elecraft Sent: Friday, April 05, 2002 08:03 Subject: [Elecraft] Best way to check ATU function? > Hi folks - > > My ATU doesn't seem to be doing a lot of retuning when I shift between > bands lately. I use a 260' horizontal loop. For example, I can shift > between 20 meters and 30 meters and the ATU will act as if it's already > tuned when you push the Tune button - and show me a 1.1. No relays > clicking at all. The ATU is in AUTO mode. I'm just having a lot of > trouble believing that it is tuning to the maximum. It seems that in the > past it did more "retuning". Can someone suggest the most practical way > to check if the ATU is functioning properly. (I know I'm going to feel > stupid when I hear this answer hi hi). 73/Tim Logan NZ7C ++++++++++++++++++ Date: Fri, 05 Apr 2002 17:37:08 +0200 From: "Ingo, DK3RED" To: Elecraft Subject: [Elecraft] Re: Best way to check ATU function? Hello Tim, like Jim wrote the KAT2 remembers its settings. Try it with the ALT function on this bands or reset ALL band settings (INIT and OFF). -- 72/73 de Ingo, DK3RED Don't forget: the fun is the power! dk3red at t-online.de http://www.qsl.net/dk3red ++++++++++++++++++++ Date: Fri, 05 Apr 2002 11:54:10 -0600 To: cyr999 at extremezone.com, elecraft at mailman.qth.net From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Best way to check ATU function? Tim: >My ATU doesn't seem to be doing a lot of retuning when I shift between >bands lately. I use a 260' horizontal loop. For example, I can shift >between 20 meters and 30 meters and the ATU will act as if it's already >tuned when you push the Tune button - and show me a 1.1. No relays >clicking at all. The ATU is in AUTO mode. I'm just having a lot of >trouble believing that it is tuning to the maximum. It seems that in the >past it did more "retuning". Can someone suggest the most practical way >to check if the ATU is functioning properly. (I know I'm going to feel >stupid when I hear this answer hi hi). 73/Tim Logan NZ7C And it shouldn't! It remembers the last GOOD settings for each band and resets them as soon as you chenge bands. Sooo... unless thre's been a change in the antenna characteristics or you're changing to a significantly different area of the band (esp. on 40M or 80/74M) you may well not notice ANY retuning. Just because the ATU's in AUTO mode, this doesn't mean you still don't need to press the [TUNE] button to have it tune... it will NOT tune without you being in TUNE mode regardless. But, when you DO hit [TUNE], if the ATU sees an SWR less than about 1/5:1, it probably won't attempt to return. 73, Tom Hammond N0SS +++++++++++++++++++ From: "Douglas Westover" To: , Cc: , Subject: Re: [Elecraft] Best way to check ATU function? Date: Fri, 5 Apr 2002 12:55:45 -0800 The ATU relay switching occurs at the same time you change bands so you cant really sort out the two different sets of relay noises. 73, Doug W6JD ----- Original Message ----- From: To: Cc: ; Sent: Friday, April 05, 2002 11:20 AM Subject: Re: [Elecraft] Best way to check ATU function? > Jim - But when it remembers the setting it would have to adjust the inductance > and capacitance to be back at the setting, right? At that point shouldn't I be > hearing the relays doing there job? Thanks again. 73/Tim > +++++++++++++++++++++ From: "Bob Tellefsen" To: , "Elecraft" Subject: RE: [Elecraft] Best way to check ATU function? Date: Fri, 5 Apr 2002 15:59:14 -0800 Tim Set your ATU menu to CAL S and look at the feedline from the antenna. At this point the ATU is bypassed, but the swr indication is still working. You just might already have a good match, and the ATU senses it has nothing to do. 73, Bob N6WG ++++++++++++++++++++++ Date: Thu, 25 Apr 2002 15:40:48 -0500 To: "Art Horne" , From: Dave Gingrich Subject: Re: [Elecraft] K2 ATU At 12:03 4/25/2002 -0700, Art Horne wrote: >Just getting my feet wet with the K2 and it's ATU. I ran into a problem >(for me) that I'm curious about. I have been loading up my antenna ok in a >temprary location with good SWR. I then put it in the attic and when I >tried to tune it (looking at power out) I couldn't get anything but a 100% >reflection on all bands. Of course, I assumed I had shorted or opened the >coax when I shortened my cables. As it turned out the rig didn't cause the >ATU to re-tune when I hit the tune button because the ATU had been selected >to read Power Out. When I switched it back to Auto it retuned ok on each >band and then when I went to Power Out everything was fine. I had assumed >when you select "TUNE" that it woud do just that. Apparently I was wrong. >Should it have? Where was my thinking wrong? It's all detailed in the manual for the KAT2, but here is a summary. There are basically three operating modes of the KAT2 and "Tune". 1. CALp and CALs - Tuner is bypassed direct 50 ohm out. Tune button provides full output set by Power control. Use this if you have a 50 ohm antenna or external tuner. CALp reads power out, CALs reads SWR 2. Auto and Alt - Auto tune mode, tune button provides reduced power and the KAT2 will attempt to match the feedline impedance. Use this to match a directly attached wire or any coax fed antenna that needs to be matched. 3. Pout and x.x-1 - The tune button provides full power (subject to power control) with the tuner in-line, settings remembered for each band/antenna, but it will not re-tune the tuner. I usually run with two antennas attached to the K2. One is a long inverted L with an SGC SG-230 automatic coupler at the feedpoint. Second is an 80 meter horizontal loop fed directly with coax. I need the KAT2 for the loop, but not for the Inverted L (external tuner). So I run through a tune routine on Antenna 1 (the inverted L) on each band to auto-setup a 50 ohm passthrough. I then switch over to Ant 2 (the loop) and tune it for each band. I then switch the tuner to the POUT position so it won't retune. The KAT2 remembers the settings for each band for the Loop on Ant2, and remembers the 50 ohm settings for the SGC tuner on Ant 1, so all I have to do hit Tune on Ant 1 to get the SGC to retune if I change bands. Since the KAT2 remembers the settings for each band, for Ant1 and Ant2 separately, this works very nicely. ================================================ Dave Gingrich, K9DC - Indianapolis, Indiana USA K2 #2211, K1 #931, QRP-L #2376, ARS #1109, FPQRP #389, IRLP #473, k9dc.ampr.org, CCIE #6748 ================================================ ++++++++++++++++ Date: Thu, 09 May 2002 09:21:37 -0500 To: "Joe Randle" , elecraft at mailman.qth.net From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: Re: [Elecraft] Three Questions? >1. Is there a way to "turn off" the KAT2, in case one would want to use an >external tuner? Sure. MENU | ATU | CAL P (or CAL S) should do it. -- snip -- +++++++++++++++++++ Date: Mon, 05 Aug 2002 10:57:43 -0400 From: "Mark J. Dulcey" To: K6TFZ at aol.com Cc: elecraft at mailman.qth.net Subject: Re: [Elecraft] K2 ATU Question K6TFZ at aol.com wrote: > K2 without ATU puts out, for example, 5 watts on 40 meters into dummy load. > Installed and aligned ATU. With 5 watts requested, I get about 3 watts out > into same dummy load and SWR shows close to 1:1. What am I missing? TIA. > Jeff, K6TFZ The metering-adjustment pots on your KAT2 are probably not set correctly. If you have a KAT2 installed, the K2 uses the metering output from the KAT2 to control its ALC instead of the less accurate on-board circuit. So if the power meter on the KAT2 is inaccurate, the output power of the radio will also be wrong. What you need to do (as explained in the alignment instructions for the KAT2): Connect the K2/KAT2 to an accurate external power meter and a dummy load. Adjust the forward-power pot on the KAT2 so that the power reading from the K2 matches the reading from the external meter. Adjust the reverse-power pot to the same rotational position that you just set the forward-power pot to. +++++++++++++++ Date: Thu, 16 Jan 2003 18:32:26 +0000 From: "Julian (G4ILO)" Subject: Re: [Elecraft] K2 Antenna Tuner Question To: "Elecraft List" An interesting thought indeed. I've been waiting for an excuse to write about this... My antenna, for reasons you can read about on my website if you're interested, is a loop of wire run round the periphery of my loft. Since this is a new English house, it's a small loft, which will come as no surprise to anyone who has visited this country. Ever since I moved here, I have fed this antenna with an SGC SG-239 autocoupler at the feedpoint, in the center of one side. The loop is not resonant at any amateur frequency, so its SWR varies from quite high to unmeasurable (i.e. K2 CAL S reads 9.9.) After I found out how great the mismatch losses can be using even a couple of metres of co-ax when the SWR is very high, I felt that matching the antenna at the feedpoint was the only practical solution. (Since the radio shack is also my home office and has to look tidy, running a length of open wire feeder up the wall and into the loft is not an option.) I have been quite happy with the performance of this antenna for over a year, but there was a niggling annoyance that I was not making use of the excellent KAT-2 that I took the trouble of building. So, a couple of weeks ago, I swapped the SG-239 for a 4:1 balun and connected this via about 2.5 metres of RG-213 to the K2 in the room below. I expected to be disappointed, and for this to work not as well as the previous arrangement. Boy, was I in for a surprise! When I switched on, signals on 20m seemed to be about couple of S-points stronger than before. In the evening, the background noise level is so high that the first S-meter bar is always illuminated, which it never was before. All the bands from 20m - 10m seem better than before. When I went on the air for a quick test, I could hardly get off again for people "tail-ending." I wasn't convinced that there was any improvement on the lower bands, but I really have no expectation of being able to work below 20m with such a small antenna. Well, I have just come off the air after making several QSOs on 30m, the first time I have tried it, and my QRP signal got reports of 579 and 589. It's nice to see SWRs of 1.0:1 or 1.2:1. Often, on 10m, the best the '239 would produce was 2.5:1. I leave it to the reader to decide whether the SG-239 is a piece of junk or the KAT-2 is simply magic. Where was all that RF going? All I can say is that, more than 3 years on, K2 #392 still manages to delight me. And I continue to be astonished at what you can work with 5 watts and a loft antenna. 73 de -- Julian, G4ILO. (RSGB, ARRL, G-QRP, K2 #392) G4ILO's Shack: http://www.qsl.net/g4ilo +++++++++++++++++++ From: "Bob - AG5Q" To: "Ignacy (NO9E)" , Subject: Re: [Elecraft] Balun and Range of KAT2 Date: Thu, 23 Jan 2003 10:22:03 -0600 Hi Ignacy, With a high load resistance, the capacitance required for matching becomes very small. At higher frequencies the stray capacitance in the tuner may be too large to allow an ideal match. Here's an interesting java script that will allow you to enter various combinations of load resistance and reactance and find the required L-C values for the tuner: http://www.hoflink.com/~mkozma/match19c.html For example, with a 2700 ohm load, at 28MHz, the ideal capacitance is only 15.3 pf, which is less than the stray capacitance. 73/ Bob - AG5Q ----- Original Message ----- From: "Ignacy (NO9E)" To: Sent: Thursday, January 23, 2003 8:14 AM Subject: [Elecraft] Balun and Range of KAT2 > My KAT2 matches very well on 1.8-10 MHz but the match is less certain on > 14-28. With portable antennas, usually one of 10-12-15-17-20m bands does > not match well ( SWR > 3) , and one or two are around SWR = 2.0. > > As an experiment, I tried matching a 2.7 K resistor. Matches on 160-30m > were quick and to SWR <=1.2. Matches on 20-10 took much longer and SWR > was 1.5 to 8. A simple test with Cs and Ls seems positive. Could my > inductors or capacitances be wrong, or is this due to stray C/L and > higher relative tolerances with smaller coils? > > Ignacy, NO9E +++++++++++++++++