++++++++++++++++++ Date: Mon, 04 Mar 2002 14:48:31 -0800 From: Wayne Burdick Organization: Elecraft To: WA5PB Cc: Elecraft Subject: [Elecraft] Re: Lo P ATU -- help! Bill, The Lo P message usually means that the KAT2 is working into a very low impedance load--so low that it can't develop sufficient voltage to accurately measure the SWR. If this is the case, your mag mount or its coax may have changed in some way that affects these two bands. Since Lo P could also indicate that the power output was too low from the K2, you should check output on 15 and 17 meters into a dummy load. There are some filters in the K2 that are shared on these two bands, so it may be more than a coincidence that they're the only ones affected. If 15 and 17 meter output seem OK and the antenna does, too, try the troubleshooting procedure in the KAT2 manual. You may have lost a component or relay. We included menu entries for all 8 inductors and capacitors, allowing you to step through them individually and make sure each has the expected effect on SWR when working into a dummy load. 73, Wayne N6KR WA5PB wrote: > > Hey Gang, > > I am in need of some assistance. Today, while taking the K2 mobile I have > experienced a little problem. My standard mobile operation with the K2 has > always consisted of the K2 w/ its ATU running into a 10m mobile magmount > whip. Up till today, I have been able to tune at least 10-20 and often 40 > using the ATU without any error displays. Today, while trying to tune on > both 15 and 17 meters I keep getting at Lo P reading while I hit TUNE..... +++++++++++++++++++ From: "WA5PB" To: "Wayne Burdick" Cc: "Elecraft" Subject: Re: [Elecraft] Re: Lo P ATU -- help! Date: Mon, 4 Mar 2002 19:32:24 -0600 Wayne, Ok, I checked all of that. I have tracked it down to K11 (yep, hosed it up by plugging the battery to the AUX RF connector only once and VERY briefly), talked to Scott and we checked some other things together and got a confirm on K11 being toast. The two inductors have been good for two years nearly, so I doubt they were hurt any, though I will check them out at install time for the new relay. Scott's putting a relay in the mail to me tomorrow. Thanks for the QUICK response and GREAT service. You guys are the best! Pass the Kudos on to Scott also, please. Also, thanks to all the other guys on the list that sent me things to check and suggestions - I really appreciate it. :-D p.s. To all K2 owners, take Gary's warning (it's in a KAT2 builders note on the website) about marking the ATU and battery connectors seriously! If I had left that thing connected any longer it could have been WAY worse. Also, installing options late at night when you are too tired is also NOT a good idea. Trust me, that new battery option or other thingee CAN wait until the next day. ;-) 73 from a VERY satisfied, WA5PB, Bill Allen +++++++++++++++++ From: "WA5PB" To: "Wayne Burdick" Cc: "elecraft list" Date: Tue, 5 Mar 2002 06:43:48 -0600 Subject: [Elecraft] Mobile with the K2 (was Lo P ATU -- help!) Wayne, You brought up something that I have been wondering about. As to using the K2 mobile with its ATU for 10-20 coverage, what monoband antenna should give best reception and transmit, theoretically. Since the ATU is tuning for received and transmit, would the ideal setup be something like a Hamstick designed for 20m since it has the longest electrical length? Has anyone done any experimenting with various wavelength mobile monoband antennas with the ATU? 72 es OO Bill Allen, WA5PB WA5PB home page http://www.pbpage.org/bill/ FISTS #7332 -- FPqrp #337 10-10 #71178 -- K2 #1068 QRP-L #2357 -- SOC #469 QRPARCI #10983 Flying Pigs QRP Club Int., W8PIG - where OO does not mean "Official Observer" http://www.fpqrp.com ----- Original Message ----- From: "Wayne Burdick" To: "WA5PB" Sent: Monday, March 04, 2002 19:58 PM Subject: Re: [Elecraft] Re: Lo P ATU -- help! Glad to be of help, Bill! Have fun with the rig. I use a very small 11 m magmount (Radio Shack) for mobile ops myself. Lots of fun to try to work 10-12-15-17-20 meters with the little critter. I've made contacts on all five bands. The best DX was Taiwan--broke a pileup at 8 watts on 10 meters from my Honda CRV! 73, Wayne +++++++++++++++ Date: Tue, 05 Mar 2002 07:56:56 -0800 From: Wayne Burdick Organization: Elecraft To: WA5PB , Elecraft Subject: [Elecraft] Mobile with the K2: whips, feedlines, etc. WA5PB wrote: > You brought up something that I have been wondering about. As to using the > K2 mobile with its ATU for 10-20 coverage, what monoband antenna should give > best reception and transmit, theoretically. Since the ATU is tuning for > received and transmit, would the ideal setup be something like a Hamstick > designed for 20m since it has the longest electrical length? Hi Bill, I've never tried the 20 meter resonator on the bands above 20 meters, but this should work, and certainly would work better on the lower bands than the 10 meter resonator. Another approach would be to try to get a whip that's longer than 8 feet on your vehicle (flexible at the top, and avoid parking garages). Perhaps a few feet of the radiator could be oriented horizontally. The feedline you use might also be an issue. Typically you'll have 10-20 feet of coax between the radio and the base of the whip, and an extremely poor SWR on most bands prior to tuning. You could minimize feedline losses by: (a) putting the whip closer to the front of the vehicle and shortening the feedline; (b) putting the KAT2 at the base of the whip and routing control and RF cables back to the K2; (c) using balanced feedline between the KAT2 and the antenna and low-loss baluns at both ends. Simple baluns would be quite efficient if optimized for one part of the HF spectrum, say 14-30 MHz. (b) is a very common solution for high-efficiency mobile operation. I haven't seen much discussion of balanced feedline in mobile installations. It would be interesting to A/B test configuration (c) vs. straight coax on each of several bands with a given resonator. 73, Wayne N6KR +++++++++++++++++++