I may have led this question astray.. I hope this wraps it. > Comments in line... >> I have it connected through a tuner and then to the SB-200 and then Dipole >> >> K3/100/ATU <-> MFJ tuner <-> SB200 <-> Dipole >> >> If I use Auto mode on the KAT3, put the MFJ tuner in Bypass and hold TUNE >> then the KAT3 goes and brings the SWR (according to the display) to a >> favorable value (1.0 to 1.2). I use a MFJ tuner between my Rig and Amp >> because the Old Bard told me to. Actually my setup is different than >> what I just described, but I'm simplifying this for the question at hand. >> >> [ What I really do is K3 <-> Small MFJ Tuner <-> SB200 <-> Big MFJ Tuner >> <-> Dipole ] > > I don't know why the "Old Bard" told you to do that. It makes no > sense to me. First of all take the small MFJ tuner out of the line > and connect the K3 directly to the SB200. The tuner in the K3 will do > the job of the small MFJ tuner. No sense adding tuner loss between > the Amp and the rig. I suspect the "Old Bard" told you that because > the input of the SB200 is not 50 ohms. More about that later...
I thought I wrote it, but perhaps it was ommited. When I run the K3/100/ATU I put the small tuner between the Rig and the amp in Bypass. It's more or less an RF speed bump when I use the K3 ATU. I do not tune with the rig-to-amp tuner ever, when I use the K3. I merely was indicating that I glance at the power meter on it and was wondering about that when I was using the K3/ATU in AUTO. The K3 is not my only rig. When I select a different transmitter, one that does not have an ATU, then I do need the small tuner between the other rig and the amp. Hence, that is why it's inline. The old-bard remark was in context of using a NON-ATU-equipped rig before the amp. > This indicates that the SB200 input is not 50 ohms. You may have some > troubles with the SB200 input, but you should be able to adjust that. > Look at the SB200 manual and see if it has input matching adjustments. > > You certainly don't need two tuners for the SB200 input! I certainly agree. I leave the conventional tuner between the rig and SB-200 in bypass when I use the K3. My K2 has no ATU so I need it then. My K3 has an ATU so I don't need it then. >> So, can someone explain in basic terms what's happening when I use Auto >> mode on the KAT3 and see favorable SWR on the KAT3 (via K3 display) but do >> not see favorable SWR on the MFJ tuner? > > Here's what is going on. In the configuration you have now, you are > correcting the mismatch between the small tuner and the K3. When you > remove the small tuner you will be seeing the input of the large tuner > (If you have the amp turned off or in standby.) That is precisely what I was doing before I owned the K3/100/ATU. I would match the rig (YaeKenCom) radio without an ATU. See above about putting it into bypass when I'm operating K3/100/ATU. > 1. Put the K3 in tune (hold the XMIT button). Adjust the large tuner > connected to the output of the Amplifier for the lowest SWR. You want > the amp turned off or in standby at this point. [steps] Yes, I do that too. In my station, I put the analyzer so that I can select a transmitter of K3, YaeKenCom, or Analyzer. This way the coax path is nearly identical between the analyzer down to ant. vs. the rig down to ant. Not identical but close enough that when the time comes to put the key down my match is pretty close and I trim it up on the big tuner (amp to antenna). Then when I select analyzer, I read the R/Z/SWR values off the analyzer as I do my darndest to match with the manual conventional tuner between the amp and antenna (big MFJ tuner). Then when I got it setup, I switch Tx back to K3, and use the AUTO tune function of the K3's ATu to polish up and away I go with nearly full PEP power that I can get. In all instances that I use the K3/ATU, the tuner between the K3 and Amp is in bypass. In all instances that I do not use the K3/ATU then the tuner between the other rig and the amp is NOT in bypass. In all instances the big-tuner between the Amp and Antenna is NOT in bypass. > Now you're good to go :o) I think so, thanks! _______________________________________________ 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
