++++++++++ See also K2 Debugging +++++++++++ Date: Thu, 04 Oct 2001 09:41:25 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: [Elecraft] K2 deaf on 80M and CAL FIL problems Robert: >Overall things all seem to be working fine. The exception is that on 80M it >seems pretty deaf! I haven't tried to align the BP filters yet in the event >someone has had a similar problem and would like to share their findings. If it's not the BPF, the it's probably a poorly tinned toroidal inductor lead in either the BPF or the LPF. I'm ATTACHing hereto an article I wrote which may assist you in troubleshooting this problem. It's in PDF format... if you can't load the file into your version of Acrobat Reader, you probably need to update to v4. Version 5 of Reader seems to have problems NOT associated with my file, but problems in general, so unless they have a v6 out by now, I'd go with v4. (NOTE that reflector members will NOT receive the ATTACHment as all ATTACHments are stripped from messages passing thru the reflector). If anyone wishes to obtain a copy of my Cheap 'n Dirty Signal Tracing document(s), they are available from: For the K1: http://home.earthlink.net/~n0ss/k1_signal_tracing.pdf and for the K2: http://home.earthlink.net/~n0ss/k2_signal_tracing.pdf I'm told that these will eventually be posted to the Elecraft web site, but I don't believe they have made it there yet. >Also, does performing spectrogram basically set-up the filters so they are >centered between each other? Is this the main function of using >spectrogram? At present when I go from one filter to the next I find I have >to retune the signal in in order to bring back the signal strength and >intellegibility. This is not the way it should be. Have you downloaded the article from the Elecraft web site? If not, I suspect you should. The article is available at: http://www.elecraft.com/Apps/new_fil_docs/k2_cw_gram.pdf You say, "Also, does performing spectrogram basically set-up the filters so they are centered between each other?". I'm not certain of exactly what you mean by "between each other", but when using Spectrogram, you should set up a MARKER line (in Spectrogram) which sits on the same frequency as your SIDETONE is set to. Then, using noise, the noise peak should be CENTERED on TOP OF the MARKER line. This should, if your 'noise' is random enough to give you something close to 'white' RF noise, place all of the filters right on top of each other, thus requiring NO retuning when you switch from one filter to the next. If you STILL must retune each time, and particularly if you must retune more than 20-30 HZ, there's almost a 100% chance that your BFO is set to the WRONG side of the xtal filter and you have (at least) one bandwidth set to receive on LSB while the rest are on USB, or vice versa. Below is an excerpt from an early revision of the K2 manual. While I _think_ all of the steps still fit with current version K2s, if you find anything which doesn't quite fit, see if you can work around it. About the only thing tht might not still fit would be a different letter showing up on the LCD display, probably a "t". I'm including this excerpt because it does something the newer manuals don't do. It instructs you on how to fine the CENTER of your filter passband with the BFO. Finding the center of the filter is ESSENTIAL to ensuring that the BFO sits on the proper side of the filter when you are setting up the filters. CAL FIL Example (setting up all filters) 1. Connect the frequency counter test cable to TP2 (BFO). 2. Connect an antenna so you can hear some background noise. 3. Switch to a band lower than 15m. (The sideband is inverted on 15m and above, which is confusing during filter setup.) 4. Select CW Normal mode using MODE . 5. Tap XFIL until FL3 is selected. 6. Tap MENU and scroll to CAL. Hold EDIT to move the underline to OFF, then scroll until you see CAL FIL. Finally, hold EDIT again to activate the filter display. 7. The display will now look like FL3 0.40c. This shows that CW filter FL3 is set for a bandwidth of roughly 0.4 kHz. The filter parameter has a range of 0.00-2.49. Above 2.49, the filter parameter changes to OP1-OP5 . These 5 settings are used to select optional fixed filters, such as on the SSB adapter. Above OP5 there is an OFF setting (FL2, 3, and 4 only). If you set a filter to OFF, it will no longer be accessible with XFIL on exit from CAL FIL. 8. Use the VFO knob to vary the bandwidth. Notice that the "shape" of the noise changes. Return to 0.40 for now. 9. Tap BAND- to display the BFO setting, e.g. BF3 110c. The BFO parameter can be varied from 000-255, and allows the BFO to cover about 4 or 5 kHz. (BAND+ returns you to the FL3 display, but for now stay with BF3.) 10. Sweep the BFO value over its full range using the VFO knob. You'll hear the pitch of the noise change. At some point in the adjustment range you'll hear the pitch go very low and then to zero--this is where the BFO has passed through the center of the filter. You may also see a peak in the S-meter reading here. Note this zero-pitch BFO setting (around 130). BE SURE to NOTE the ZERO-PITCH setting of the BFO! Now, given this information, ALWAYS REMEMBER that when performing CAL FIL, _and_ when using a band lower than 15M (80-17M), the BFO settings for filters set using CW (normal) will ALL be BELOW the ZERO-PITCH setting of the BFO, and all BFO settings for CW REV will be ABOVE the zero-pitch setting of the BFO. If you don't ensure that this step is strictly followed, you WILL have to re-tune your VFO in order to find the signal when you switch filter bandwidth settings. IF you must use a band HIGHER than 17M (15M-10M, in order to obtain enough band noise), due to the IF mixing scheme, your CW filters will be reversed, so in this instance, your BFO settings will be ABOVE the zero-pitch setting when aligning CW (normal) and they will be BELOW the BFO zero-pitch setting when aligning for CW REV. BE CERTAIN YOU KNOW WHAT BAND YOU'RE USING and use the appropriate set of BFO settings. >I'm still learning how to use all the functions but a nice rig. I agree completely. Good luck, Tom Hammond N0SS +++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Tue, 12 Jun 2001 08:33:32 -0500 From: "Craig Nicholson" Subject: [Elecraft] No Sigs - Resolution! Several folks asked that I update them as to the progress I made trouble shooting my K2 at the end of Test and Alignment Part II. I was receiving no signals. Initial checks and bias voltages seemed okay as were all the "numbers" in the Test and Alignment Part. First, thanks to Scott, at Elecraft for describing the "long wire" test method. I have a digital meter, but no signal generator and no access to crystals to build the one described in the K2 manual. He described a real complex piece of test equipment: a long stretch of wire with a capacitor at one end. The unsoldered capacitor lead serves as a test probe. By touching it to the input and output of the receiver's stages, you inject noise into the system. As you work your way through each stage, injecting noise at the interface of the stages (usually coupling capacitors) you should hear an increase in noise/signals in the receiver headphones. At the point where nothing is injected into the system, start look'en for trouble. You can work from the antenna jack in or from the IF Amp out to the antenna jack. I traced from the IF amp (where I got signal when I touched the capacitor end of the "highly complex" piece of test equipment to pin 8 and 4 of U12. You know, after 35 years as a ham, I gotta ask why I never heard of this "Long Wire" test thing. . . . . Then again, maybe I did. I guess, "as the years pass" more bits of information drop into the "Bit Bucket" than are retained............ So what I found out. Two things. First problem was due to "soldering iron operator head space and timing" and the other was a "naughty part" issue. To address to former: I had installed C141 completely wrong! Ugh! The label for the cap lies between two unused hole in the circuit board; the coupling of the cap is beneath it. In a myopic state I had install the cap in the unused holes! Must have been in denial when I checked over my board for misplaced parts! Lesson: when you've been trouble shooting for a while, take a break and clear you head/brain/EYES! So fixed that and could hear the internal 7.000 Mhz signal but still no real 40 meter stuff. Kept on going until the signal from the "highly complex" test equipment dropped off at the junction of C7 and C8 in the Band-Pass Filter. Removed and tested the caps: C7 was bad. Replaced it with one of the yet to be installed 100pf - and... The 'lil K2 is ROCK'EN! So sweet the sound of 40m through a receiver that, though not entirely built yet, has the right stuff! Thanks again Elecraft. And, I hope this post helps the other folks trouble shoot their K2's. Now, off to see if I can find another 100pf cap and back to soldering iron.................. - --Craig KW9R ++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Thu, 14 Jun 2001 07:36:52 -0500 From: Lee Buller Subject: [Elecraft] Receiver Repaired - Comments With the suggestions from Gary at Elecraft my K2 is now performing as new. The receiver had died while xmit was OK. The receiver was really degraded. I could hear loud signals but the S-Meter would not move and there was not "static" at all in the receiver. Here is what I found. Remember, this rig has been operating flawlessly for a year and is never taken out of the shack. I removed the SSB Adapter and the NB. I jumpered all the appropriate input and output places. The RX came alive. I returned the SSB Adapter to the rig. The RX was cookin'. I put in the NB...Dead. OK...now we are getting somewhere. Looking at the schematic, the signal path is quite simple when the NB is OFF. So, I inspected the board and decided to reflow the solder joints around the Band Pass Filter. The RX came up but not what it should have been with the jumper installed. I inspected the board again and reflowed Pins 1 and 6 on P1. That did nothing more and did not improve the signals. I pulled the board again and looked at it and could find nothing furthur...so I took at small screw driver and placed in firmly into J12 again. Turned on the K2 and the RX was GREAT! Although reflowing the solder joints was a good idea....I think the issue was oxidation on J12 and P1. My shack is in the back of the garage and it is not air conditioned during the day. I turn in on when I am out here. We've had humid and hot temperatures in Kansas for the last month of so...and I wonder over the year or so the connectors became oxidized. This is only a theory...upon inspection I could find no evidence even using the magnifying glass. Remember, this unit has not been off the desk or opened for a year. I just wanted to give my account of what happened so that others who read this has this little piece (very little) of the knowledge base. 73 Lee - K0WA +++++++++++++++++++++++++++++++++++++++++ Deleted Entry.... ++++++++++++++++++++++++++++++++++++ Date: Tue, 19 Jun 2001 08:01:49 -0500 From: Tom Hammond =?iso-8859-1?Q?N=D8SS?= Subject: [Elecraft] OK, where'd you hide the Signal Tracing PDF??? >Got a file not found message for the signal tracing PDF. Sorry fellas... I revised the Q & D Signal Tracing Article to include the K1, and felt it necessary to change the filename a bit... I did that last evening and didn't get the message out to the reflector until this morning... sorry about that. The NEW filename of the Quick 'n Dirty Signal Tracing (K2 AND K1) is: http://home.earthlink.net/~n0ss/k2_and_k1_signal_tracing.pdf Again, there are underline characters separating each word in the filename, although they may be hidden on your copy of the name. Additionally, the '0' in "/~n0ss/" is a ZERO, not an 'oh'. If you cannot click on the link and go there, please first try Cut 'n Pasting the address into your browser. NOTE that the new document has now BALLOONED to 575kB (somehow due to the added K1 data and graphic), so you would best be advised to DOWNLOAD the document, rather than merely viewing it in your browser. Someone commented that he was unable to view the graphic. This may be due to the fact that the first two pages of the document load very quickly, but then the graphic files kick in and take quite a bit longer to load (especially if you are attempting to view it on-screen). It may have been that the person downloading just didn't realize that he was still waiting for the REST of the document to load. If you do not know how to DOWNLOAD a PDF directly to your PC, here's how: 1) Go to http://home.earthlink.ner/~n0ss/download.html 2) NETSCAPE - When you locate the URL for the file you wish to have to disk (directly from my web page), HOLD DOWN and then CLICK on the URL. Follow the prompts to save the file to whatever folder you wish. Alternatively, once you have found the link to the file you wish to save to dish, you may RIGHT-CLICK on the link and then select [Save Link As..], and then specify the folder of choice. or... INTERNET EXPLORER - Once you have found the link to the file you wish to save to dish, you may RICHT-CLICK on the link and then select [Save Target As..], and then specify the folder of choice. I hope this helps fellas. I apologize to those of you who may have failed in you attempt to download to new file, it should be ready to go now. Once the file is on the Elecraft Web site, I will remove it from my site and include a note with the URL to the Elecraft site. 73 - Tom Hammond N0SS ++++++++++++++++++++++++++++++++++++++++++ Date: Mon, 2 Jul 2001 20:46:47 -0400 From: kb1dxc at discovernet.net (kb1dxc) Subject: [Elecraft] K2 02097 LIVES Thanks Guys, You have pulled me through here. Thanks to Tom Hammond and his Cheap 'N Dirty signal tracing I have found and resolved the problem and it only took a few minutes. I followed his steps as laid out in the PDF file and all was working well from his test point 1 through his test point 7, then at test point 8, I could not find the test point. Can you believe this, even though I was checking each component off as I put them in the board somehow I actually missed putting in D3. I went back and actually found that I failed to check it off. So, now I am receiving like a bandit and I can get on with the alignment. Thank God for you guys that understand this electronic stuff. At this rate I might understand it myself one day. Thanks again, Michael A. Groeschner (kb1dxc) K2 s/n 02097, alive and receiving +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Date: Wed, 17 Oct 2001 09:07:48 -0600 From: "Wishart, John" Subject: [Elecraft] RE: K1 Build Problem (Very Long) Gary, Problems solved. K1 s/n 851 is now operational! After extensive troubleshooting with o'scope, signal generator, RF probe, and DMM, we determined the following: 1. Toroid T1 on the RF board was installed rotated a 1/4 turn off (i.e., leads were in wrong holes). This part was removed and reoriented properly. This allowed the signal to proceed through the rest of the circuitry properly. (Leo, you were right about the AGC line area. That's where we finally isolated the problem down to. It had an elevated voltage on it due to the miswired toroid routing an elevated voltage down to that area.) 2. The above contributed to the difficulties in getting the inductors on the RF board to tune up properly. Aligning these became a lot easier after the above fix. 3. The lab power supply output we were using for testing was defective. It provided sufficient current on receive, but the output voltage sagged badly at transmit current levels. Once we changed to a power supply output that worked right at all current levels, things started to operate well. We were able to quickly align everything at all power levels then. Note: having an o'scope available to monitor the RF out signal is a big help in the xmit alignment, since you can immediately see whether the output waveform is correct and getting better or worse. Likewise with the signal generator (& scope) on receive. I am fortunate to have access to those items at work. Everything seems to work properly now. This is really a neat rig! Thanks for your assistance. And thanks to all those on the Elecraft list who also offered suggestions. Now back to practicing my CW skills:>) Regards, John Wishart, KC0JFH - -----Original Message----- From: Gary Surrency [mailto:gary at elecraft.com] Sent: Wednesday, September 26, 2001 12:32 PM To: Wishart, John Cc: CSinfo Subject: KC0JFH: RE: K1 Build Problem (Long) Hi John, If one band works OK in TX and RX, but the other ones does not - then the problem is almost guaranteed to be on the filter board. It could be as simple as a poor alignment of the 20m Premix or RF band-pass inductors, or even a poorly tinned toroid lead in the low-pass filters. An inspection of the filter board is certainly a good idea, to check for incorrect component location or some soldering error. You should be able to hear the 20m Premix oscillator at 22MHz on another rig. Then peak its associated inductors for maximum signal, or use a scope on pin 6 of J6 or P1 if possible. Tune for maximum output. The slugs in the inductors should peak near the middle of their travel. If no 22MHz signal can be heard, then you may have a short or open on this crystal, or it could be bad. Then attempt to peak the 20m RF band-pass filters for maximum RF output in TX, as you monitor the signal on another rig, or on an RF probe or oscilloscope connected to J7 pin 8, or P2 pin 8. Tune for maximum signal. The slugs in the RF band-pass filters Toko inductors peak near the top of the coil form, just below the chamfer in the plastic coil form. These are *extremely* sharp filters to tune, so they can be difficult to align initially. You can also connect a DC voltmeter set to a low range to pin 19 of the 20 pin connector between the FP and RF PCBs, since this is the RFDET line from the output of the transmitter. You may find this to be helpful in aligning the filter board if you lack the proper test equipment. Many folks have had problems aligning 20m, since it is so sharp to peak the filter board on that band. Tune the slugs slowly as you listen for the TX signal on another rig, if you have no way to measure the RF at the points mentioned. J7 pin 6 now has a lower resistance reading, since we added R39 after the table was created. Ohmmeters of different types can also give different readings if they forward bias a semiconductor device present in the circuit under test. Q7 will get pretty warm with RF output after a period of time in TX. - -- 73, Gary AB7MY ========= gary at elecraft.com Elecraft Technical Support ======================================== - -----Original Message----- From: Wishart, John [mailto:John.Wishart at compaq.com] Sent: Wednesday, September 26, 2001 9:30 AM To: Gary Surrency Cc: elecraft at qth.net Subject: K1 Build Problem (Long) Gary & Elecraft List, I was never able to get the receiver alignment accomplished, so I just pressed on and built the rest of my K1 40M/20M kit. I was able to get the band 1 (40M) xmit alignment sort of done, but the receive and band 2 (20M) xmit still do not work properly. I have checked the RF and Filter boards for solder problems and was not able to find anything there. Of course, that certainly doesn't eliminate that possibility! A more detailed description of the problem & symptoms follows: Display and menu functions appear to work properly. 12.5 VDC supply OK 8 V OK 6 V OK Key - can hear sidetone in headset, I guess that works OK. Tuning OK - frequency changes Bands switch back & forth OK. Receive is just a low constant hiss that varies w/ RF gain control, but no apparent signals (with long wire antenna) on either band. Not able to peak inductors during receive alignment, since there is no change in the noise level on either band. Receive current: 69 mA Transmit - can align on 40M band 1 (i.e., peak up the inductors). Could hear xmit (via dummy load) CW tones on another 40M transceiver (SW40+) at proper frequency. On 20M band 2 could not peak inductors. Power stayed at a constant 0.1 W level. Could not complete band 2 xmit alignment & remaining xmit alignment steps. DCV checks p.30 P1-15 6.1 V P1-16 12.5 V U3-5 4.1 V U3-6 8.4 V VFO Alignment OK - p.38 BPF Alignment, p.40 - not complete, no change in signal when inductors tweaked (slowly) with a long wire antenna. R Checks, p.45 J7-1 2.66K ohms J7-4 20K J7-5 infinite J7-6 1.79K (>>>>>>low, should be 5-7K ohms per manual?<<<<<<<) J7-8 1.78K J8-1 infinite J8-5 99K J8-7 1.581K U4-7 1.725K U8-8 834 ohms U9-7 1.713K D9-C 1.610 K D9-A 930 ohms While doing the xmit alignment on band 1 (40 M), I noticed that the right side panel was slightly warm (from Q7, I assume). When I was trying to do the alignment on band 2, this no longer occurred. If you could provide some assistance in troubleshooting, I would greatly appreciate it. I have a DMM and I built the RF probe mentioned in the K1 manual. I also have access at work to oscilloscopes and frequency counters. I have not located a signal source that goes up to 15 MHz however. I do not have convenient access to a HF transceiver other than my SW40+. I also have a Yaesu VX-5R HT that can receive on 40M and 20M, but not transmit. I did make a cheapo "noise source" out of a low value ceramic cap with a long wire attached to one lead. I am pretty new to RF troubleshooting, but have some experience in electronic troubleshooting in general. If you could be pretty specific on what to check on, that would be helpful. Regards, John Wishart, KC0JFH - -----Original Message----- From: Gary Surrency [mailto:gary at elecraft.com] Sent: Thursday, September 13, 2001 1:48 PM To: Wishart, John Cc: CSinfo Subject: KC0JFH: RE: K1 Receiver Build Problem John, The filter alignment is fairly critial to do, because of the high selectivity of the band-pass filters. You must tune the Toko inductors slowly to find their peak. Do not force the slugs to the bottom of the coil. Verify that the VFO and Premixer stages are working, and try to hear the signal on the K1 from another transmitter set up on the bench operating into a dummy load. That should help you find the peak positions of the inductors. You can also refer to Appendix E of the manual for basic RX troubleshooting. It is often easier to align the filters in TX, once you have finished the assembly. The same filters are used in both RX and TX. You antenna should be OK, as long as it presents an SWR of less than 2:1. The close the load Z is to 50 ohms resistive, the more RF output will be acheived. Use a tuner (the KAT1 for example) if the antenna is not a good match. As most problems I see in service are due to incorrect or missing components, poor soldering or poorly tinned toroid leads, be sure to check your work for those possibilities. A close visual inspection will often reveal the problem(s). - -- 73, Gary AB7MY ========= gary at elecraft.com Elecraft Technical Support ======================================== - -----Original Message----- From: Wishart, John [mailto:John.Wishart at compaq.com] Sent: Thursday, September 13, 2001 12:05 PM To: support at elecraft.com Subject: K1 Receiver Build Problem Elecraft support, I just completed the construction of the receiver portion of my K1-20M/40M kit and started to do the filter board alignment. I have the unit hooked up to a 1/2 size GR5V antenna (no tuner) and I hear a steady unchanging noise level (more of a low hiss) in the headphones. However the noise level doesn't change any no matter what I do to any of the variable inductors on the filter board. All voltage and resistance checks are OK up to this point. The noise level goes up and down with RF gain knob changes. I hooked the antenna up to my SW40+ transceiver and I hear CW signals clearly on it. So I know the antenna is OK, at least for that radio. Is this the proper antenna setup to use for the filter board alignment? I didn't get anything with a straight wire either - same results. Do I need to string up a dipole with coax lead-in (an unbalanced antenna)? Should I try using the SW40 as a signal source (into a dummy load, of course)? Should I be looking further for a problem? Any suggestions? Regards, John Wishart, KC0JFH ++++++++++++++++++++++++++++++++ Date: Sun, 4 Nov 2001 13:01:12 -0500 From: "ZOOM" Subject: Re: [Elecraft] Signal Tracing The coupling switch on your scope also has a capacitive connection. ie: AC DC GND. In AC there would be a capacitor inline to normalize the signal to a zero reference level. The capacitor in a probe is usually used to adjust for linearity. For example most scopes has a precision square wave connection to calibrate the probe. Connecting the probe there and adusting a screw on the probe for best square wave presentation. You should not need to add a cap. Also depending on the bandwidth of your scope will determine if you get a high or low resolution display. Trying to read a 20Mhz signal with a 10MHZ scope will just yeild a block of signal with no definition. Basically will just indicate the signal is there. Regards, Robert VE3RPF +++++++++++++++++++++++++++++++ Date: Sun, 04 Nov 2001 10:58:53 -0800 From: lhlousek Subject: Re: [Elecraft] Signal Tracing Hi Alan, There is no need to couple the probe through a capacitor. Scopes and their probes can be used to measure DC voltages so do not have a blocking capacitor. Most scopes have a 1 meg input impedance and most scope probes have a switch that allow measuring straight through (1x) or through a 9 meg resistor (10x). The 9 meg resistor forms a 10:1 voltage divider with the scopes input resistance. There is a trim capacitor in the probe in parallel with the 9 meg resistor which allows compensating for the input capacitance of the scope so that the scope's input capacitance doesn't form an low pass RC with the 9 meg resistor. Because of the high input impedance ( 1 meg on 1x and 10 meg on 10x) you can directly trace sigs in the radio using the scope and probe. If you don't want to see any DC offsets in AC sigs set the scope to AC, otherwise leave it DC coupled. Lou W7DZN ++++++++++++++++++++++++ Date: Mon, 05 Nov 2001 21:55:02 -0500 From: "Mark J. Dulcey" Subject: Re: [Elecraft] Signal Tracing Stuart Rohre wrote: > However, it is possible to get new 50 MHz > probes for $14.95, thus anyone with a scope can get a probe that will do > most amateur troubleshooting up to 6m quite reasonably. > > The probes available from Jameco Electronics catalog 213A, are $20.95 for 60 > MHz, rated to 600 VDC, with 5 foot cable. pg. 125 for example. I saw the > lower price in another catalog which has escaped my grasp. +++++++++++++++++++++ Date: Fri, 12 Jul 2002 19:07:53 -0400 To: elecraft at mailman.qth.net From: Dudley Chapman Subject: [Elecraft] Checking in with good news. A while ago I checked in for the first time with the status of my newly constructed K2 #2522. Everything was fine except I had no TX or RX on 10/12 meters. A few days later, Tom, N0SS, sent me his advice on just using a little wire and a cap as a signal injector to trace where signals disappear. I did that and quickly narrowed my problem down to the bandpass filter. On closer inspection, I found that a little piece of the plastic tuning tool had broken off and filled the small slot in the slug of one of the 10/12 meter bandpass filter inductors. So when I was attempting to adjust that particular slug, the remainder of the tool was not getting traction. DOH! I cleared the problem, tuned the filter, things came to life, and I got over 10 W on 10 and 12 meters. So that's my status update. Thanks, Tom. Since then, I put up a SuperLoop 80 from RadioWorks way out in my woods (cant figure out if this antenna is a crock or not, but it sure is a lot of wire in the air. That can't be bad, right?.). The top of it is at about 80 feet. Since the loop is about 400 ft from the house, I ran really classy BuryFlex coax and put an LDG RT-11 autotuner out at the antenna end of the run. Its powered with a sealed lead acid battery which is sitting in a cheap Walmart tackle box (for now, anyway). With my K2 autotuner set to CALS, all I need to do is change bands, push the K2 tune button and watch the swr fall at the far end of the feedline. Life is good. Its funny that I never before had much of an urge to crack pileups when I was running 100W or more. With the K2, however, its a great thrill to wade into a big pileup and outfox the big guns with my 10 watts and strategic use of XIT or split. It takes a while, but I haven't walked away from a pileup yet. Low power operation is really addicting. Way more fun than QRO, I have decided. We should tell more people about this. Thats all I have. Just checking in. 73's everyone. Dudley, WA1X /8 +++++++++++++++