Good thinking, Grant. How about the metal frame for a backpack? Unobtrusive, lightweight, and an intregal part of the backpack. Brilliant! Cheers Norm vk5gi McLaren Vale South Australia
Sent from my iPad > On 23 Jan 2019, at 12:21 pm, elecraft-requ...@mailman.qth.net wrote: > > Send Elecraft mailing list submissions to > elecraft@mailman.qth.net > > To subscribe or unsubscribe via the World Wide Web, visit > http://mailman.qth.net/mailman/listinfo/elecraft > or, via email, send a message with subject or body 'help' to > elecraft-requ...@mailman.qth.net > > You can reach the person managing the list at > elecraft-ow...@mailman.qth.net > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Elecraft digest..." > > > Today's Topics: > > 1. Re: Urban stealth HF: Inside-the-backpack loop antenna? > (Grant Youngman) > 2. Re: Urban stealth HF: Inside-the-backpack loop antenna? (K9MA) > 3. Re: Urban stealth HF: Inside-the-backpack loop antenna? > (Clay Autery) > 4. Re: Urban stealth HF: Inside-the-backpack loop antenna? > (Grant Youngman) > 5. Re: Urban stealth HF: Inside-the-backpack loop antenna? (K9MA) > 6. Re: Urban stealth HF: Inside-the-backpack loop antenna? (turnbull) > 7. Ferrite Rod? (was: Urban stealth HF...) (Steve Sergeant) > 8. Re: [KX3] Urban stealth HF: Inside-the-backpack loop antenna? > (Rich Arland) > 9. Re: Elecraft Digest, Vol 177, Issue 36 (Thaire Bryant) > 10. Re: Auto-spot, tuning aids, and the arcane history of CW > pitch-matching (Robert Rennard) > 11. Re: Auto-spot, tuning aids, and the arcane history of CW > pitch-matching (Bill Frantz) > 12. Re: Urban stealth HF: Inside-the-backpack loop antenna? (kevinr) > 13. Re: Auto-spot, tuning aids, and the arcane history of CW > pitch-matching (Joan) > 14. Re: Urban stealth HF: Inside-the-backpack loop antenna? > (Michael Chowning) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 22 Jan 2019 16:46:03 -0500 > From: Grant Youngman <ghyoung...@gmail.com> > To: Wayne Burdick <n...@elecraft.com> > Cc: Elecraft <elecraft@mailman.qth.net>, KX3 <k...@yahoogroups.com> > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <066c8920-e8ff-4d53-8366-f1cb675f4...@gmail.com> > Content-Type: text/plain; charset=utf-8 > > The problem is loop diameter. Efficiency on 20m of a 12? diameter loop would > be on the order of 5%. Forget it entirely on 40m .. essentially a dummy load > that would take around 1200 pf to resonate. On 17m efficiency would go up to > around 11%. > > I use a loop portable all the time (Alexloop, W4OP) and they work well. > They?re both about 3 ft in diameter. The Alexloop is light enough to be > carried around hand held ... the W4OP needs a table top or tripod. > > Grant NQ5T > > Sent from my iPhone > >> On Jan 22, 2019, at 3:57 PM, Wayne Burdick <n...@elecraft.com> wrote: >> >> >> >> So, just for grins, I?d like to try something completely incognerdo: no >> visible antenna. A small remotely tuned loop (say 12? diameter) would seem >> to be the best choice, as it would fit entirely inside a small backpack. It >> could have modest efficiency while not requiring a counterpoise wire. Rigid >> 1? copper pipe formed in a square would be convenient to deploy. >> >> The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, >> of course. OTOH, we?re talking about HF. A cellphone by your ear is >> probably worse. >> >> Any other antenna suggestions? >> >> Wayne >> > > > ------------------------------ > > Message: 2 > Date: Tue, 22 Jan 2019 15:51:00 -0600 > From: K9MA <k...@sdellington.us> > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <9ef9fe8c-52c4-318e-bb94-0c4022983...@sdellington.us> > Content-Type: text/plain; charset=utf-8; format=flowed > >> On 1/22/2019 15:46, Grant Youngman wrote: >> The problem is loop diameter. > > It doesn't have to be round. > > 73, > > Scott K9MA > > > -- > Scott K9MA > > k...@sdellington.us > > > > ------------------------------ > > Message: 3 > Date: Tue, 22 Jan 2019 16:01:56 -0600 > From: Clay Autery <k...@montac.com> > To: Elecraft <elecraft@mailman.qth.net> > Cc: KX3 <k...@yahoogroups.com> > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <mailman.5376.1548208292.22883.elecr...@mailman.qth.net> > Content-Type: text/plain; charset=utf-8 > > Consider integrating the loop into a purpose built/modified backpack...? or > the frame. > You can get a larger enclosed area, maintain easier use of the pack's volume > without jacking up the loop, and better insure the loop geometry doesn't > change as you pack/move/use it. > With a little creativity, yiu could also integrate some variable tuning into > the design with access by hand if you place the adjusrable parts in the right > location... > If you do switch in/out parts, it could be just a switch setup on the torso > strap... > If QRP, I'd try to use the frame or an extension thereof... > Even the flexible plastic stiffeners in some frames could be used to carry a > loop wire. > Good luck! > 73, > ClayKY5G > > > Sent from my Verizon, Samsung Galaxy smartphone > -------- Original message --------From: Wayne Burdick <n...@elecraft.com> > Date: 1/22/19 14:57 (GMT-06:00) To: Elecraft <elecraft@mailman.qth.net> Cc: > KX3 <k...@yahoogroups.com> Subject: [Elecraft] Urban stealth HF: > Inside-the-backpack loop antenna? > I?ve engaged in plenty of ultralight HF pack operation, with a KX2, AX1 > antenna and a dragged counterpoise. In wide open spaces it?s a blast. But > urban settings with dogs, wire-eating cacti and overzealous Neighborhood > Watchers can distract from one?s radio experience. > > So, just for grins, I?d like to try something completely incognerdo: no > visible antenna. A small remotely tuned loop (say 12? diameter) would seem to > be the best choice, as it would fit entirely inside a small backpack. It > could have? modest efficiency while not requiring a counterpoise wire. Rigid > 1? copper pipe formed in a square would be convenient to deploy. > > The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, of > course.? OTOH, we?re talking about HF. A cellphone by your ear is probably > worse. > > Any other antenna suggestions? > > Wayne > N6KR > > > > ---- > elecraft.com > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k...@montac.com > > ------------------------------ > > Message: 4 > Date: Tue, 22 Jan 2019 17:09:56 -0500 > From: Grant Youngman <ghyoung...@gmail.com> > To: K9MA <k...@sdellington.us> > Cc: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <2505c114-46db-4ecc-b5b3-2020e74ae...@gmail.com> > Content-Type: text/plain; charset=utf-8 > > Yes, it does not have to be round. The actual measurement of interest is > Circumference of whatever shape it is (e.g, the total length of the > radiator). A 12? loop or square, or whatever, is still going to have a very > low efficiency at this size point. But closer to rounder is better ? > > Grant NQ5T > K3 #2091 KX3 #8342 > >> On Jan 22, 2019, at 4:51 PM, K9MA <k...@sdellington.us> wrote: >> >> On 1/22/2019 15:46, Grant Youngman wrote: >>> The problem is loop diameter. >> >> It doesn't have to be round. >> >> 73, >> >> Scott K9MA >> >> >> -- > > > > ------------------------------ > > Message: 5 > Date: Tue, 22 Jan 2019 16:17:12 -0600 > From: K9MA <k...@sdellington.us> > To: Grant Youngman <ghyoung...@gmail.com> > Cc: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <545c324a-10cf-613a-030d-31ba07b6d...@sdellington.us> > Content-Type: text/plain; charset=utf-8; format=flowed > > There's undoubtedly a trade-off between rounder and longer. I was > thinking of a typical more or less rectangular backpack, which would > have a circumference much larger than a 12 inch circle. A typical > backpacking pack could accommodate a circumference of about 88 inches, > more than twice that of a 12 inch round loop. Granted, such a large pack > wouldn't exactly be inconspicuous on an urban hiking trail, but you > could always put some rocks in it, and pretend you're training for a > Grand Canyon hike. > > 73, > Scott K9MA > >> On 1/22/2019 16:09, Grant Youngman wrote: >> Yes, it does not have to be round. ?The actual measurement of interest >> is Circumference of whatever shape it is (e.g, the total length of the >> radiator). ?A 12? loop or square, or whatever, ?is still going to have >> a very low efficiency at this size point. ?But closer to rounder is >> better ? >> >> Grant NQ5T >> K3 #2091 KX3 #8342 >> >>> On Jan 22, 2019, at 4:51 PM, K9MA <k...@sdellington.us >>> <mailto:k...@sdellington.us>> wrote: >>> >>>> On 1/22/2019 15:46, Grant Youngman wrote: >>>> The problem is loop diameter. >>> >>> It doesn't have to be round. >>> >>> 73, >>> >>> Scott K9MA >>> >>> >>> -- >> > > -- > Scott K9MA > > k...@sdellington.us > > > > ------------------------------ > > Message: 6 > Date: Tue, 22 Jan 2019 22:24:49 +0000 > From: turnbull <turnb...@net1.ie> > To: Grant Youngman <ghyoung...@gmail.com>, K9MA <k...@sdellington.us> > Cc: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <5c479834.1c69fb81.e4b5a.f...@mx.google.com> > Content-Type: text/plain; charset=utf-8 > > Why not a collapsible Alexloop mag loop which fits in your back pack and will > be nore efficient.? ? 73 Doug EI2CN > > > Sent from my Samsung Galaxy smartphone. > -------- Original message --------From: Grant Youngman <ghyoung...@gmail.com> > Date: 22/01/2019 22:09 (GMT+00:00) To: K9MA <k...@sdellington.us> Cc: > elecraft@mailman.qth.net Subject: Re: [Elecraft] Urban stealth HF: > Inside-the-backpack loop antenna? > Yes, it does not have to be round.? The actual measurement of interest is > Circumference of whatever shape it is (e.g, the total length of the > radiator).? A 12? loop or square, or whatever,? is still going to have a very > low efficiency at this size point.? But closer to rounder is better ? > > Grant NQ5T > K3 #2091 KX3 #8342 > >> On Jan 22, 2019, at 4:51 PM, K9MA <k...@sdellington.us> wrote: >> >> On 1/22/2019 15:46, Grant Youngman wrote: >>> The problem is loop diameter. >> >> It doesn't have to be round. >> >> 73, >> >> Scott K9MA >> >> >> -- > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to turnb...@net1.ie > > ------------------------------ > > Message: 7 > Date: Tue, 22 Jan 2019 14:26:34 -0800 > From: Steve Sergeant <steve...@effable.com> > To: elecraft@mailman.qth.net > Subject: [Elecraft] Ferrite Rod? (was: Urban stealth HF...) > Message-ID: <63af7962-16c6-c0bd-b849-6779599a9...@effable.com> > Content-Type: text/plain; charset=utf-8 > > Just as a way-out idea: How about a large ferrite rod on the end of a > walking staff, on top of a backpack, or hidden inside a top-hat? > > [ https://sites.google.com/site/g3xbmqrp3/antennas/ferrite_tx ] > >> On 1/22/19 12:57 PM, Wayne Burdick wrote: >> So, just for grins, I?d like to try something completely incognerdo: no >> visible antenna. A small remotely tuned loop (say 12? diameter) would seem >> to be the best choice, as it would fit entirely inside a small backpack. It >> could have modest efficiency while not requiring a counterpoise wire. Rigid >> 1? copper pipe formed in a square would be convenient to deploy. >> >> The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, >> of course. OTOH, we?re talking about HF. A cellphone by your ear is >> probably worse. >> >> Any other antenna suggestions? >> >> Wayne >> N6KR > > > > ------------------------------ > > Message: 8 > Date: Tue, 22 Jan 2019 22:59:32 +0000 > From: Rich Arland <k...@live.com> > To: Mark Goldberg <marklgoldb...@gmail.com>, Michael Blake > <k9...@mac.com> > Cc: Elecraft Reflector <elecraft@mailman.qth.net> > Subject: Re: [Elecraft] [KX3] Urban stealth HF: Inside-the-backpack > loop antenna? > Message-ID: > > <dm5pr12mb1899ce0fbed7cea6e540862cf6...@dm5pr12mb1899.namprd12.prod.outlook.com> > > Content-Type: text/plain; charset="iso-8859-1" > > Ref: Homless......let's not forget the ever present shopping cart! Get a BIG > one. It can be used as a counter poise in place of a set of radials or a drag > wire. One could also try loading the shopping cart and using it as an antenna > since the wheels are composed of a non-conductive set of wheels so the cart > would be above ground. > > Just sayin' > > Vy 73 es gud DX! > > Rich Arland K7SZ WPE7BYR > Radio/electronics archaeologist > Author: The ARRL's Low Power Communicatoions > Bent Dipole Ranch, Dacula, GA > http://commobunker.blogspot.com/ > > > > ________________________________ > From: elecraft-boun...@mailman.qth.net <elecraft-boun...@mailman.qth.net> on > behalf of Michael Blake via Elecraft <elecraft@mailman.qth.net> > Sent: Tuesday, January 22, 2019 4:40 PM > To: Mark Goldberg > Cc: Elecraft Reflector; KX3 > Subject: Re: [Elecraft] [KX3] Urban stealth HF: Inside-the-backpack loop > antenna? > > Mark (W7MLG), It is scary how perfectly sane and normal your suggestions > sound to me :) > > Very 73 - Mike - K9JRI > > > > > > > >> On Jan 22, 2019, at 4:32 PM, Mark Goldberg <marklgoldb...@gmail.com> wrote: >> >> I would expect any high Q antenna like a loop would be detuned by any >> movement or any metal you pass by. One more reason to support automatic >> mobile screwdriver / mag loop antenna tuning on the KX series. >> A flag on a backpack would be more or less ignored. Just put a flag on the >> top of the AX1. Counterpoise is an issue though. Maybe a short one down >> your leg? >> >> Now, if you dressed as a homeless or otherwise distressed person, lots of >> weird things are possible, tinfoil hat with a big flag, dragged wire >> disguised as one of those fake animals on a leash, etc. The weirder, the >> more people will ignore you. >> >> Hopefully taken in the spirit of which it is posted. >> >> 73, >> >> Mark >> W7MLG >> >> >> On Tue, Jan 22, 2019 at 1:57 PM Wayne Burdick n...@elecraft.com [KX3] < >> kx3-nore...@yahoogroups.com> wrote: >> > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k...@live.com > > > ------------------------------ > > Message: 9 > Date: Tue, 22 Jan 2019 18:11:18 -0500 > From: Thaire Bryant <tbry...@myfairpoint.net> > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Elecraft Digest, Vol 177, Issue 36 > Message-ID: <8de822e3-cf74-460b-8a93-28352e1d1...@myfairpoint.net> > Content-Type: text/plain; charset=utf-8 > > Ed, I?d like the K1. > > Thaire. W2APF > >> On Jan 22, 2019, at 16:41, elecraft-requ...@mailman.qth.net wrote: >> >> Send Elecraft mailing list submissions to >> elecraft@mailman.qth.net >> >> To subscribe or unsubscribe via the World Wide Web, visit >> http://mailman.qth.net/mailman/listinfo/elecraft >> or, via email, send a message with subject or body 'help' to >> elecraft-requ...@mailman.qth.net >> >> You can reach the person managing the list at >> elecraft-ow...@mailman.qth.net >> >> When replying, please edit your Subject line so it is more specific >> than "Re: Contents of Elecraft digest..." >> >> >> Today's Topics: >> >> 1. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Mike Harris) >> 2. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (David Gilbert) >> 3. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (K9MA) >> 4. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (K9MA) >> 5. Re: K3 SWR Anomaly (N8LP) >> 6. K2, K1, W1, and other stuff for Sale (Dauer, Edward) >> 7. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Chris Cox, N0UK) >> 8. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Chris Cox, N0UK) >> 9. Zero Beat / CWT / Auto Spot (Jim Clymer) >> 10. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Bob McGraw K4TAX) >> 11. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Don Wilhelm) >> 12. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (rv6amark) >> 13. Re: [KX3] Auto-spot, tuning aids, and the arcane history of >> CW pitch-matching (Howard Hoyt) >> 14. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Dave New, N8SBE) >> 15. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Dave New, N8SBE) >> 16. Urban stealth HF: Inside-the-backpack loop antenna? >> (Wayne Burdick) >> 17. Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Andy Durbin) >> 18. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (Wes) >> 19. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (ab2tc) >> 20. Re: [KX3] Urban stealth HF: Inside-the-backpack loop antenna? >> (Mark Goldberg) >> 21. Re: Urban stealth HF: Inside-the-backpack loop antenna? >> (Steve Sergeant) >> 22. Re: [KX3] Urban stealth HF: Inside-the-backpack loop antenna? >> (Michael Blake) >> 23. Re: Auto-spot, tuning aids, and the arcane history of CW >> pitch-matching (K9MA) >> >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Tue, 22 Jan 2019 13:28:28 -0300 >> From: Mike Harris <mike.har...@horizon.co.fk> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <99139b11-a047-0f9d-6981-4a1da3335...@horizon.co.fk> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> Yet another trick learnt by hard experience given away for free :-( >> >> Regards, >> >> Mike VP8NO >> >>> On 22/01/2019 11:14, Nr4c wrote: >>> Now, one thing you missed... when you?re working a big pileup and you feel >>> you just can?t get through, it may be that all your ?buddies? are doing the >>> same thing, using Auto-Spot! >>> >>> Now turn on XIT and set it to 12-20 Hz either way. Now your signal will be >>> just a little different from all the others and you have a better chance of >>> being heard. >>> >>> Sent from my iPhone >>> ...nr4c. bill >> >> >> ------------------------------ >> >> Message: 2 >> Date: Tue, 22 Jan 2019 09:59:04 -0700 >> From: David Gilbert <xda...@cis-broadband.com> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <d2e5fba7-83ea-6bfd-cbd8-d81db7261...@cis-broadband.com> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> >> Wayne, you forgot clicking on the DX Cluster spot.? ;) >> >> I'm being facetious, of course, but the practice of simply clicking on a >> cluster spot does point out a problem with zero beating by any means ... >> if every calling station is zero beat the station calling CQ isn't going >> to copy anyone. >> >> Zero beat isn't always a good thing. >> >> 73, >> Dave? AB7E >> >> >>> On 1/21/2019 10:09 PM, Wayne Burdick wrote: >>> Elecraft's auto-spot and CWT features -- available on the K3/K3S/KX2/KX3 -- >>> are very useful tools for CW operators, especially those not experienced in >>> pitch-matching. Here's a bit of history on where these features came from >>> and how they work. >>> >>> >>> CW Spotting History >>> >>> When a station finishes a CQ in CW mode, the operator faces the challenge >>> of copying someone who's calling back. Callers may be weak or obscured by >>> QRM; the op can usually deal with both problems by narrowing the filter >>> passband. However, callers may also be off frequency. A calling station may >>> be using a wide filter passband themselves, not attempting to carefully >>> match their VFO frequency to that of the CQing station. The result may be >>> no QSO, even when propagation is excellent. >>> >>> In the Days of Yore, a frequency offset between stations didn't always >>> matter. Sometimes both stations used crystal-controlled transmitters, so >>> operators had to patient tune around after calling CQ. >>> >>> As a 14-year-old novice I embraced this operating style for a year or so, >>> armed with a dozen or so crusty FT-243 crystals for my Heath HW-16. I >>> nearly wore out the socket swapping them in and out. After calling CQ, it >>> was not unusual to find a caller 30 or more kHz away! (Away from "where" >>> was a poorly answered question, as my Hallicrafters receiver dial wasn't >>> exactly digital.) >>> >>> Fortunately I soon acquired an outboard VFO, a life-changing addition to my >>> station. Jealous friends doubled up on their paper routes to pay for their >>> own. Girls suddenly paid more attention to me. >>> >>> These days virtually everyone has a VFO, along with the expectation that >>> they won't have to tune theirs very far, if at all, to tune you in. Not >>> only that, they're stable and well calibrated, not like the beasts we had >>> to skillfully tame. Progress! >>> >>> >>> Manual Spotting (SPOT switch) >>> >>> Once I had a VFO I quickly learned to do *manual* pitch matching. Older >>> rigs did't provide a way to do that explicitly, so you'd improvise. >>> Basically, you had to coerce a very weak signal out of your own >>> transmitter, say by turning on only the driver, then tune the transmit VFO >>> until you could hear your signal on your own receiver -- superimposed on >>> the calling station, at the same pitch. This is what we call spotting. >>> >>> Of course spotting is a lot more convenient these days, as many rigs >>> include a SPOT switch. This function is easy for a modern transceiver >>> designer to add, because the radio's firmware is quite capable of turning >>> on only the CW sidetone without transmitting. >>> >>> That is the purpose of the SPOT switch on all Elecraft transceivers. Tap >>> SPOT, and you'll hear your sidetone pitch. Most people can do a good job of >>> adjusting the VFO such that the CQing station's pitch matches that of the >>> SPOT tone. This ensures that when you call them, you'll be close to their >>> own frequency. >>> >>> >>> Tuning Aids: Filtering (APF), PLL (NE567), and Spectral (CWT) >>> >>> Since not everyone has an inherent musical ear, various hardware-enhanced >>> means of tuning in CW signals have been developed. >>> >>> The simplest method is to just narrow your receiver passband so much that, >>> if you can hear a station calling CQ at all, you're guaranteed to be "right >>> on top of him." This assumes that your transceiver enforces alignment >>> between its transmit and receive pitch...true of all Elecraft gear. >>> >>> Narrow filtering has gone through decades of evolution. Some filters were >>> based on op-amps (active filters), while others were based on LC filtering, >>> conscripting humongous toroidal cores scavenged from telco equipment. I >>> acquired my stash of these from a haphazard mound of old switching racks, >>> decaying in an abandoned aircraft hanger on the Bermuda U.S. Navy base. >>> (That irresistible junk pile was also a mother load of TO5 transistors, >>> multi-pound electrolytic capacitors, and tetanus, but that's another >>> story.) Typically the toroids were 88 millihenries -- a huge value for a >>> high-Q inductor, permitting resonance in the low audio range. >>> >>> Later, such filters migrated to digital signal processing, in the form of >>> switched-capacitor ICs or DSPs. You can still buy these switched-capacitor >>> chips, like the MF10, from various sources. It's instructive to roll your >>> own tunable filter, just for fun. >>> >>> Whether passive or active, the goal of filtering is typically to achieve a >>> narrow passband, say 250 Hz or less. With DSP, nearly perfect filters with >>> "brick wall" passbands can be created. But these have the disadvantage of >>> ringing like a bell when pinged by a CW signal or noise, making copy >>> difficult. >>> >>> One solution incorporated into the K-line and KX-line is the Audio Peaking >>> Filter (APF), which provides a 30-Hz bandwidth at -3 dB, but broad skirts, >>> preventing ringing from occurring. As our customers will attest, APF works >>> like magic on weak signals obscured by noise. >>> >>> Another forerunner to DSP techniques was the audio phase-locked-loop, using >>> inexpensive ICs like the legendary LM567. When locked on a signal that >>> matched its center frequency, the circuit would turn on an LED, alerting >>> the operator that the VFO was now properly tuned. >>> >>> With the DSPs in our K-line and KX-line radios, we can provide a much more >>> powerful tool: CWT, or "CW Tuning Aid." When enabled, CWT turns the upper >>> portion of the rig's S-meter into something of a mini spectrum analyzer. >>> The pitch of the strongest signal in the passband is analyzed by the DSP, >>> then represented as a single segment of the bar graph. For CWT-enhanced >>> manual spotting, the operator simply tunes the VFO slowly until the center >>> CWT segment is flashing along with the keyed signal. >>> >>> Manual tuning with CWT can also be used in FSK-D and PSK-D modes as >>> described in the owner's manual. >>> >>> >>> Closing the Loop: Auto-Spotting (SPOT + CWT) >>> >>> The Elecraft K3/K3S/KX2/KX3 take CW tuning another step forward by >>> providing a way to *automatically* retune the VFO frequency to match that >>> of a received signal. How does this work? >>> >>> When CWT is turned on, firmware treats the SPOT switch as AUTO-SPOT. The >>> DSP analyzes the incoming signal, and with a bit of processing, determines >>> its exact audio pitch. From there all that's needed is a bit of math to >>> offset the VFO to match this pitch to the CW sidetone. >>> >>> There's another subtlety, though. Since a CW signal is generally being >>> keyed on and off, the CWT algorithm has to ensure that it doesn't "take >>> off," chasing a signal that's not there. To avoid this, we keep track of >>> the energy in the passband, and slew the VFO incrementally over an average >>> of about 0.5 second, moving only when the target signal is present. >>> >>> >>> How to Use Auto-Spot >>> >>> I encourage you to give the auto-spot feature a try. It's best to start >>> with a fairly narrow passband, say 400-600 Hz; narrower if there's a lot of >>> QRM. Find a signal, turn on CWT, then tap SPOT to tune it in. A second tap >>> of SPOT may get even closer, especially if there's a lot of band noise. >>> >>> Auto-spot can also be used in Elecraft's PSK-D mode, i.e. for PSK31/PSK63. >>> As with CW mode, just turn on CWT, tune in a prospective signal, and tap >>> SPOT. Since PSK auto-decoding requires very accurate tuning, it's best to >>> set the filter bandwidth to 50 Hz, then let auto-spot dial things in down >>> to the last 2 or 3 Hz. If you have text decode turned on, you should start >>> seeing text characters scroll by after auto-tuning has completed. Tapping a >>> second time or fine-tuning the VFO a bit in 1 Hz steps may improve copy. >>> >>> 73, >>> Wayne >>> N6KR >>> >>> >>> >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to xda...@cis-broadband.com >>> >> >> >> >> ------------------------------ >> >> Message: 3 >> Date: Tue, 22 Jan 2019 11:11:30 -0600 >> From: K9MA <k...@sdellington.us> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <a15e08d5-8fb7-8063-a447-7936dfdd6...@sdellington.us> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> Back in my college days at W9YT, we had a Drake line, separate >> transmitter and receivers. When searching and pouncing in a contest, you >> had to spot the transmitter before every contact. Spotting required >> turning one of the rotary switches on the transmitter, a cumbersome >> process. Imagine doing that a couple thousand times in a weekend. At >> some point, we came up with the idea to hook a foot switch up to do the >> spotting, which made it much easier, and save a lot of wear and tear on >> the rotary switch, not to mention the operator's wrist. >> >> In those days, 40-50 years ago, transceivers just didn't work well on >> CW, so almost all CW operators used separate transmitters and receivers. >> Some, like the Drake line, could transceive, but had the same problem on >> CW. Transceivers didn't account for the BFO offset, and there was no RIT >> or XIT. If you called another station in transceive mode, you would be >> 700 Hz or so off frequency. Two transceivers pretty much couldn't work >> each other at all. Sometime while I was inactive in the late 70's and >> 80's, that problem was solved, and we no longer had to spot before every >> contact. I think that solution had to wait for frequency synthesis, as >> it otherwise would have required additional (expensive) crystals. Does >> anyone know of a non-synthesized transceiver that didn't have the CW >> offset problem? >> >> 73, >> Scott K9MA >> >> >>> On 1/21/2019 23:09, Wayne Burdick wrote: >>> Elecraft's auto-spot and CWT features -- available on the K3/K3S/KX2/KX3 -- >>> are very useful tools for CW operators, especially those not experienced in >>> pitch-matching. Here's a bit of history on where these features came from >>> and how they work. >> >> >> -- >> Scott K9MA >> >> k...@sdellington.us >> >> >> >> ------------------------------ >> >> Message: 4 >> Date: Tue, 22 Jan 2019 11:14:27 -0600 >> From: K9MA <k...@sdellington.us> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <5df178e8-5d66-fb3f-b731-d6a036568...@sdellington.us> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >>> On 1/22/2019 10:59, David Gilbert wrote: >>> >>> Wayne, you forgot clicking on the DX Cluster spot. ;) >> >> Everyone zero beat was, I think, a bigger problem before skimmers. >> Skimmer spots often seem to be quite a ways off frequency, probably >> because their SDR receivers aren't all that stable. Some may be in >> unheated buildings, too. >> >> 73, >> >> Scott K9MA >> >> -- >> Scott K9MA >> >> k...@sdellington.us >> >> >> >> ------------------------------ >> >> Message: 5 >> Date: Tue, 22 Jan 2019 11:13:25 -0700 (MST) >> From: N8LP <n...@telepostinc.com> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] K3 SWR Anomaly >> Message-ID: <1548180805579-0.p...@n2.nabble.com> >> Content-Type: text/plain; charset=us-ascii >> >> This may be out of left field, but I seem to recall from the deep recesses of >> my memory that there were some issues regarding an IF trap in the output of >> the K3. It could be that one of the components in the trap has changed and >> it now affects 40m. I don't know if newer K3s even have this circuit. Just >> thinking out loud. >> >> Larry N8LP >> >> >> >> >> >> -- >> Sent from: http://elecraft.365791.n2.nabble.com/ >> >> >> ------------------------------ >> >> Message: 6 >> Date: Tue, 22 Jan 2019 18:15:19 +0000 >> From: "Dauer, Edward" <eda...@law.du.edu> >> To: "elecraft@mailman.qth.net" <elecraft@mailman.qth.net> >> Subject: [Elecraft] K2, K1, W1, and other stuff for Sale >> Message-ID: <eb637be8-8cd0-4576-b41d-a1f01a9a5...@law.du.edu> >> Content-Type: text/plain; charset="utf-8" >> >> Selling principal home, no further need for seven HF transceivers. So the >> following are for sale. Terms for each are: No pay Pal, shipment on >> receipt of payment, seller packs, and buyer pays actual shipment cost from >> Denver, CONUS only and selling to licensed hams only. All items unless >> otherwise noted are in excellent cosmetic and electrical condition. >> Nonsmoking environment, never used out of doors or in mobile / portable >> operations. >> >> I have two heavy dimpled main tuning knobs for the K2s. Original cost $90 >> (as I remember it), option to buy for $50 each with purchase of a K2. Most >> interconnecting cables for K2s are also available at no additional cost. >> >> K2/10 (s/n 7637) with KNB2, KAF2, KAT2, KIO2, KBT2 (with battery), and >> optional heavy dimple knob. $900. >> >> K2/10 (s/n 7687) with KNB2, KSB2, KAF2, KPA100, and KAT100-1 in matching low >> profile enclosure, with tilt stand. $1,300. >> >> K2/10 (s/n 7739) and KAT100/KPA100 in EC-2 enclosure (?twins? >> configuration). K2 includes KNB2, KSB2, KAT2, KAF2, KIO2. $1,550. >> >> K1 (s/n 3440) 17 and 30 meters, with KAT1 internal ATU, KNB1 noise blanker, >> and KBT1 internal battery adapter. Includes extra cover and speaker (not >> used when cover with ATU is installed.) Tuned and aligned by Alan Wilcox. >> $350. >> >> Elecraft W1 Power Meter in acrylic case w/stand. $70 >> >> KD1JV Triband Transceiver and external ATU (Kit built, never tested.) $100 >> >> Pico Keyer condition unknown. Free to whomever buys the first K2 or K1. >> >> >> Ted, KN1CBR >> >> >> >> Edward A. Dauer >> Dean Emeritus and Professor Emeritus of Law >> University of Denver >> >> >> ------------------------------ >> >> Message: 7 >> Date: Tue, 22 Jan 2019 12:54:36 -0600 (CST) >> From: "Chris Cox, N0UK" <chr...@chris.org> >> To: K9MA <k...@sdellington.us> >> Cc: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <pine.lnx.4.64.1901221252100.27...@xsvr1.chris.org> >> Content-Type: TEXT/PLAIN; charset=US-ASCII >> >> The transceive problem didn't seem to exist on any older non-synthesized >> transceiver that I have used, including FT-101 series, TS-520/820 and >> later, KW Electronics KW-2000E. these were all '70s era transceivers. >> >> -- >> 73 Chris Cox, N0UK, G4JEC >> chr...@chris.org >> >> >> >> ------------------------------ >> >> Message: 8 >> Date: Tue, 22 Jan 2019 12:51:50 -0600 (CST) >> From: "Chris Cox, N0UK" <chr...@chris.org> >> To: K9MA <k...@sdellington.us> >> Cc: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <pine.lnx.4.64.1901221251260.27...@xsvr1.chris.org> >> Content-Type: TEXT/PLAIN; charset=US-ASCII >> >> >> >> -- >> 73 Chris Cox, N0UK, G4JEC >> chr...@chris.org >> >>> On Tue, 22 Jan 2019, K9MA wrote: >>> >>> transmitter before every contact. Spotting required turning one of the >>> rotary >>> switches on the transmitter, a cumbersome process. Imagine doing that a >>> couple >>> thousand times in a weekend. At some point, we came up with the idea to >>> hook a >>> foot switch up to do the spotting, which made it much easier, and save a lot >>> of wear and tear on the rotary switch, not to mention the operator's wrist. >>> >>> In those days, 40-50 years ago, transceivers just didn't work well on CW, so >>> almost all CW operators used separate transmitters and receivers. Some, like >>> the Drake line, could transceive, but had the same problem on CW. >>> Transceivers >>> didn't account for the BFO offset, and there was no RIT or XIT. If you >>> called >>> another station in transceive mode, you would be 700 Hz or so off frequency. >>> Two transceivers pretty much couldn't work each other at all. Sometime >>> while I >>> was inactive in the late 70's and 80's, that problem was solved, and we no >>> longer had to spot before every contact. I think that solution had to wait >>> for >>> frequency synthesis, as it otherwise would have required additional >>> (expensive) crystals. Does anyone know of a non-synthesized transceiver that >>> didn't have the CW offset problem? >>> >>> 73, >>> Scott K9MA >>> >>> >>>> On 1/21/2019 23:09, Wayne Burdick wrote: >>>> Elecraft's auto-spot and CWT features -- available on the K3/K3S/KX2/KX3 -- >>>> are very useful tools for CW operators, especially those not experienced in >>>> pitch-matching. Here's a bit of history on where these features came from >>>> and how they work. >>> >>> >>> -- >>> Scott K9MA >>> >>> k...@sdellington.us >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to chr...@chris.org >>> >> >> >> ------------------------------ >> >> Message: 9 >> Date: Tue, 22 Jan 2019 14:27:25 -0500 >> From: Jim Clymer <ws6x....@gmail.com> >> To: elecraft@mailman.qth.net >> Subject: [Elecraft] Zero Beat / CWT / Auto Spot >> Message-ID: >> <CAENrfz=2XpPoe8T9iJNbq2PwQUun3yPQ6r+DrGRA2B7=mwo...@mail.gmail.com> >> Content-Type: text/plain; charset="UTF-8" >> >>> >>> Anyone who has ever had the privilege of being on the receiving end of a >>> huge CW pileup has a new appreciation for the tone deaf and those who never >>> learned to use CWT. (And the savvy pileup busters who >> >> intentionally avoid zero beat.) Of course there is always the W5 - dead >>> zero beat - who is so loud you don't hear anyone else no matter how far off >>> frequency! >> >> Jim - WS6X >> >>> >> Date: Mon, 21 Jan 2019 21:09:44 -0800 >>> From: Wayne Burdick <n...@elecraft.com> >>> To: Elecraft Reflector <elecraft@mailman.qth.net> >>> Subject: [Elecraft] Auto-spot, tuning aids, and the arcane history >>> of CW pitch-matching >>> >>> CW Spotting History >>> Tuning Aids: Filtering (APF), PLL (NE567), and Spectral (CWT) >>> How to Use Auto-Spot >>> >>> >> >> >> ------------------------------ >> >> Message: 10 >> Date: Tue, 22 Jan 2019 14:14:00 -0600 >> From: Bob McGraw K4TAX <rmcg...@blomand.net> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <fc86b438-6051-f1fd-7e3b-07a4f2d69...@blomand.net> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> Another trick which works well.?? Tune to a WWV frequency in CW mode.? >> Press SPOT and the radio will jump on the exact carrier frequency.?? The >> SPOT function can pull on to the WWV frequency as far away as about 100 >> Hz.? Once the radio has? resolved SPOT, the readout / display is the >> frequency of WWV +/- the error in Hz. Thus the readout of 9.999.992 is >> indicating being 8 Hz low. >> >> From a cold start, FP being 19?C, I find? -8 Hz error on 10 MHz WWV.? >> After about 15 minutes the FP is 25?C and the error is -1 Hz.? I've >> tweaked the REF CAL such that after 1/2 hr. in receive tuning to WWV >> from both higher and lower will produce a reading of 10.000.000.?? Will >> all stations pse QNZ? QNN. >> >> 73 >> >> Bob, K4TAX >> >> >> >> >> ------------------------------ >> >> Message: 11 >> Date: Tue, 22 Jan 2019 15:19:54 -0500 >> From: Don Wilhelm <donw...@embarqmail.com> >> To: "Chris Cox, N0UK" <chr...@chris.org> >> Cc: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <48f3e257-a765-e853-62c6-d20e06109...@embarqmail.com> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> In that era, SSB capable transceivers often offset the BFO by using a >> different BFO crystal for CW transmit or CW receive - but that technique >> slaved you to one sideband and one CW pitch. >> There were other ways of doing the offset as well, but it was usually >> done by shifting the BFO frequency. >> >> 73, >> Don W3FPR >> >>> On 1/22/2019 1:54 PM, Chris Cox, N0UK wrote: >>> The transceive problem didn't seem to exist on any older non-synthesized >>> transceiver that I have used, including FT-101 series, TS-520/820 and >>> later, KW Electronics KW-2000E. these were all '70s era transceivers. >>> >>> -- >>> 73 Chris Cox, N0UK, G4JEC >>> chr...@chris.org >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to donw...@embarqmail.com >>> >> >> >> ------------------------------ >> >> Message: 12 >> Date: Tue, 22 Jan 2019 12:26:40 -0800 >> From: rv6amark <rv6am...@yahoo.com> >> To: K9MA <k...@sdellington.us>, elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <mailman.5342.1548193282.22883.elecr...@mailman.qth.net> >> Content-Type: text/plain; charset=utf-8 >> >> Re:? "Does anyone know of a non-synthesized transceiver that didn't have the >> CW offset problem?" >> >> My TenTec 540 doesn't have that problem, but my much older TenTec PM-3A >> does.? If my memory is correct, the Heathkit HW8 has the problem, but they >> fixed it in the HW9 with a small capacitor that switches in and out for >> RX/TX to shift the VFO. >> >> There are others. >> >> Mark >> KE6BB >> >> >> >> Sent via the Samsung Galaxy Tab E, an AT&T 4G LTE tablet >> -------- Original message --------From: K9MA <k...@sdellington.us> Date: >> 1/22/19 9:11 AM (GMT-08:00) To: elecraft@mailman.qth.net Subject: Re: >> [Elecraft] Auto-spot, tuning aids, >> ? and the arcane history of CW pitch-matching >> Back in my college days at W9YT, we had a Drake line, separate >> transmitter and receivers. When searching and pouncing in a contest, you >> had to spot the transmitter before every contact. Spotting required >> turning one of the rotary switches on the transmitter, a cumbersome >> process. Imagine doing that a couple thousand times in a weekend. At >> some point, we came up with the idea to hook a foot switch up to do the >> spotting, which made it much easier, and save a lot of wear and tear on >> the rotary switch, not to mention the operator's wrist. >> >> In those days, 40-50 years ago, transceivers just didn't work well on >> CW, so almost all CW operators used separate transmitters and receivers. >> Some, like the Drake line, could transceive, but had the same problem on >> CW. Transceivers didn't account for the BFO offset, and there was no RIT >> or XIT. If you called another station in transceive mode, you would be >> 700 Hz or so off frequency. Two transceivers pretty much couldn't work >> each other at all. Sometime while I was inactive in the late 70's and >> 80's, that problem was solved, and we no longer had to spot before every >> contact. I think that solution had to wait for frequency synthesis, as >> it otherwise would have required additional (expensive) crystals. Does >> anyone know of a non-synthesized transceiver that didn't have the CW >> offset problem? >> >> 73, >> Scott K9MA >> >> >>> On 1/21/2019 23:09, Wayne Burdick wrote: >>> Elecraft's auto-spot and CWT features -- available on the K3/K3S/KX2/KX3 -- >>> are very useful tools for CW operators, especially those not experienced in >>> pitch-matching. Here's a bit of history on where these features came from >>> and how they work. >> >> >> -- >> Scott? K9MA >> >> k...@sdellington.us >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to rv6am...@yahoo.com >> >> ------------------------------ >> >> Message: 13 >> Date: Tue, 22 Jan 2019 15:27:03 -0500 >> From: Howard Hoyt <hh...@mebtel.net> >> To: Mel Snyder <ct_digital_pho...@yahoo.com>, Wayne Burdick >> <n...@elecraft.com> >> Cc: Elecraft Reflector <elecraft@mailman.qth.net>, >> "k...@yahoogroups.com" <k...@yahoogroups.com> >> Subject: Re: [Elecraft] [KX3] Auto-spot, tuning aids, and the arcane >> history of CW pitch-matching >> Message-ID: <90b12bb3-b6c7-5d34-e454-3e842f7e3...@mebtel.net> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> Hi Mel, >> >> I experienced the same reading Wayne's highly informative post!! >> >> I started off in 1970 with a homebrew 6L6/807 xtal xmtr with maybe 12 >> xtals and a Hallicrafters S-38 which gave me hundreds of mesmerizing >> hours in my parents basement.? That rig gave me my first huge shock as >> well, so it is indeed memorable.? What idiot thought it was a good idea >> to put the 500 V B+ connection on an unguarded terminal strip on the >> back panel?? Wait, that was me... >> >> Still, I thought I was in heaven until my high school club bought a >> Drake R-4B/T-4XB which blew me away and I ended up owning a pair in the >> early 1980s and still love the Drake twins to this day. However they >> have been gathering dust since I got my K3, which is the best rig >> overall I have used to date, and love my KX3 in the car and on travel. >> >> Although it works well, I don't use Auto Spot is because it scrambles my >> feeble brain as to where I am tuned; I am just not used to a rig >> changing frequency without me intentionally doing it.? Perhaps this is a >> mental artifact of heavy contesting, where I am loathe to leave a good >> RUN frequency, indeed I often lock VFO A so I don't accidentally bump >> the VFO A knob. >> >> Cheers & 73, >> Howie / WA4PSC >> >> >>> On 1/22/2019 1:51 PM, Mel Snyder ct_digital_pho...@yahoo.com [KX3] wrote: >>> >>> Wow, this is *great,* Wayne! Thanks. I am away from home, but will be >>> interested to test the auto-spot when I get home. >>> >>> >>> A wonderful trip down memory lane. While you were swapping crystals >>> with your HW-16, I was a few years ahead of you as KN3AFW, swapping >>> them first into my home-brew 6AG7-6L6 rig, and then, a borrowed Eico 720. >>> >>> I still own a lovely Johnson Ranger II, and an SB-301 Heathkit >>> receiver with the original 500Hz filter, the combination of which >>> require your explained tuning the VFO to the note of the received >>> signal. But both are on my list to sell, along with my HW-9 and >>> FT-707, inasmuch with my KX3 for good band conditions and my >>> inherited/restored TS-940S when they?re poor, they are all surplus >>> space-consumers. >>> >>> Every time I turn on my KX3, I am in awe of how far ham radio has >>> progressed in the past 61 years since I was licensed. Like taking a >>> cell call on my Apple Watch, it?s beyond anything I dreamed of as a >>> kid back then. So glad I stopped by the Elecraft exhibit at the 2014 >>> Hartford ARRL convention, and was taken by the enthusiasm of KX3 users >>> that gathered there - and decided to join the cult. >>> >>> Mel, W3PYF >>> >>> >>> >>>> On Jan 22, 2019, at 12:09 AM, Wayne Burdick n...@elecraft.com >>>> <mailto:n...@elecraft.com> [KX3] <kx3-nore...@yahoogroups.com >>>> <mailto:kx3-nore...@yahoogroups.com>> wrote: >>>> >>>> Elecraft's auto-spot and CWT features -- available on the >>>> K3/K3S/KX2/KX3 -- are very useful tools for CW operators, especially >>>> those not experienced in pitch-matching. Here's a bit of history on >>>> where these features came from and how they work. >>>> >>>> CW Spotting History >>>> >>>> When a station finishes a CQ in CW mode, the operator faces the >>>> challenge of copying someone who's calling back. Callers may be weak >>>> or obscured by QRM; the op can usually deal with both problems by >>>> narrowing the filter passband. However, callers may also be off >>>> frequency. A calling station may be using a wide filter passband >>>> themselves, not attempting to carefully match their VFO frequency to >>>> that of the CQing station. The result may be no QSO, even when >>>> propagation is excellent. >>>> >>>> In the Days of Yore, a frequency offset between stations didn't >>>> always matter. Sometimes both stations used crystal-controlled >>>> transmitters, so operators had to patient tune around after calling CQ. >>>> >>>> As a 14-year-old novice I embraced this operating style for a year or >>>> so, armed with a dozen or so crusty FT-243 crystals for my Heath >>>> HW-16. I nearly wore out the socket swapping them in and out. After >>>> calling CQ, it was not unusual to find a caller 30 or more kHz away! >>>> (Away from "where" was a poorly answered question, as my >>>> Hallicrafters receiver dial wasn't exactly digital.) >>>> >>>> Fortunately I soon acquired an outboard VFO, a life-changing addition >>>> to my station. Jealous friends doubled up on their paper routes to >>>> pay for their own. Girls suddenly paid more attention to me. >>>> >>>> These days virtually everyone has a VFO, along with the expectation >>>> that they won't have to tune theirs very far, if at all, to tune you >>>> in. Not only that, they're stable and well calibrated, not like the >>>> beasts we had to skillfully tame. Progress! >>>> >>>> Manual Spotting (SPOT switch) >>>> >>>> Once I had a VFO I quickly learned to do *manual* pitch matching. >>>> Older rigs did't provide a way to do that explicitly, so you'd >>>> improvise. Basically, you had to coerce a very weak signal out of >>>> your own transmitter, say by turning on only the driver, then tune >>>> the transmit VFO until you could hear your signal on your own >>>> receiver -- superimposed on the calling station, at the same pitch. >>>> This is what we call spotting. >>>> >>>> Of course spotting is a lot more convenient these days, as many rigs >>>> include a SPOT switch. This function is easy for a modern transceiver >>>> designer to add, because the radio's firmware is quite capable of >>>> turning on only the CW sidetone without transmitting. >>>> >>>> That is the purpose of the SPOT switch on all Elecraft transceivers. >>>> Tap SPOT, and you'll hear your sidetone pitch. Most people can do a >>>> good job of adjusting the VFO such that the CQing station's pitch >>>> matches that of the SPOT tone. This ensures that when you call them, >>>> you'll be close to their own frequency. >>>> >>>> Tuning Aids: Filtering (APF), PLL (NE567), and Spectral (CWT) >>>> >>>> Since not everyone has an inherent musical ear, various >>>> hardware-enhanced means of tuning in CW signals have been developed. >>>> >>>> The simplest method is to just narrow your receiver passband so much >>>> that, if you can hear a station calling CQ at all, you're guaranteed >>>> to be "right on top of him." This assumes that your transceiver >>>> enforces alignment between its transmit and receive pitch...true of >>>> all Elecraft gear. >>>> >>>> Narrow filtering has gone through decades of evolution. Some filters >>>> were based on op-amps (active filters), while others were based on LC >>>> filtering, conscripting humongous toroidal cores scavenged from telco >>>> equipment. I acquired my stash of these from a haphazard mound of old >>>> switching racks, decaying in an abandoned aircraft hanger on the >>>> Bermuda U.S. Navy base. (That irresistible junk pile was also a >>>> mother load of TO5 transistors, multi-pound electrolytic capacitors, >>>> and tetanus, but that's another story.) Typically the toroids were 88 >>>> millihenries -- a huge value for a high-Q inductor, permitting >>>> resonance in the low audio range. >>>> >>>> Later, such filters migrated to digital signal processing, in the >>>> form of switched-capacitor ICs or DSPs. You can still buy these >>>> switched-capacitor chips, like the MF10, from various sources. It's >>>> instructive to roll your own tunable filter, just for fun. >>>> >>>> Whether passive or active, the goal of filtering is typically to >>>> achieve a narrow passband, say 250 Hz or less. With DSP, nearly >>>> perfect filters with "brick wall" passbands can be created. But these >>>> have the disadvantage of ringing like a bell when pinged by a CW >>>> signal or noise, making copy difficult. >>>> >>>> One solution incorporated into the K-line and KX-line is the Audio >>>> Peaking Filter (APF), which provides a 30-Hz bandwidth at -3 dB, but >>>> broad skirts, preventing ringing from occurring. As our customers >>>> will attest, APF works like magic on weak signals obscured by noise. >>>> >>>> Another forerunner to DSP techniques was the audio phase-locked-loop, >>>> using inexpensive ICs like the legendary LM567. When locked on a >>>> signal that matched its center frequency, the circuit would turn on >>>> an LED, alerting the operator that the VFO was now properly tuned. >>>> >>>> With the DSPs in our K-line and KX-line radios, we can provide a much >>>> more powerful tool: CWT, or "CW Tuning Aid." When enabled, CWT turns >>>> the upper portion of the rig's S-meter into something of a mini >>>> spectrum analyzer. The pitch of the strongest signal in the passband >>>> is analyzed by the DSP, then represented as a single segment of the >>>> bar graph. For CWT-enhanced manual spotting, the operator simply >>>> tunes the VFO slowly until the center CWT segment is flashing along >>>> with the keyed signal. >>>> >>>> Manual tuning with CWT can also be used in FSK-D and PSK-D modes as >>>> described in the owner's manual.. >>>> >>>> Closing the Loop: Auto-Spotting (SPOT + CWT) >>>> >>>> The Elecraft K3/K3S/KX2/KX3 take CW tuning another step forward by >>>> providing a way to *automatically* retune the VFO frequency to match >>>> that of a received signal. How does this work? >>>> >>>> When CWT is turned on, firmware treats the SPOT switch as AUTO-SPOT. >>>> The DSP analyzes the incoming signal, and with a bit of processing, >>>> determines its exact audio pitch. From there all that's needed is a >>>> bit of math to offset the VFO to match this pitch to the CW sidetone. >>>> >>>> There's another subtlety, though. Since a CW signal is generally >>>> being keyed on and off, the CWT algorithm has to ensure that it >>>> doesn't "take off," chasing a signal that's not there. To avoid this, >>>> we keep track of the energy in the passband, and slew the VFO >>>> incrementally over an average of about 0.5 second, moving only when >>>> the target signal is present. >>>> >>>> How to Use Auto-Spot >>>> >>>> I encourage you to give the auto-spot feature a try. It's best to >>>> start with a fairly narrow passband, say 400-600 Hz; narrower if >>>> there's a lot of QRM. Find a signal, turn on CWT, then tap SPOT to >>>> tune it in. A second tap of SPOT may get even closer, especially if >>>> there's a lot of band noise. >>>> >>>> Auto-spot can also be used in Elecraft's PSK-D mode, i.e. for >>>> PSK31/PSK63. As with CW mode, just turn on CWT, tune in a prospective >>>> signal, and tap SPOT. Since PSK auto-decoding requires very accurate >>>> tuning, it's best to set the filter bandwidth to 50 Hz, then let >>>> auto-spot dial things in down to the last 2 or 3 Hz. If you have text >>>> decode turned on, you should start seeing text characters scroll by >>>> after auto-tuning has completed. Tapping a second time or fine-tuning >>>> the VFO a bit in 1 Hz steps may improve copy. >>>> >>>> 73, >>>> Wayne >>>> N6KR >>>> >>> >>> __._,_.___ >>> ------------------------------------------------------------------------ >>> Posted by: Mel Snyder <ct_digital_pho...@yahoo.com> >>> ------------------------------------------------------------------------ >>> Reply via web post >>> <https://groups.yahoo.com/neo/groups/KX3/conversations/messages/65003;_ylc=X3oDMTJyOGZ0NTd0BF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARtc2dJZAM2NTAwMwRzZWMDZnRyBHNsawNycGx5BHN0aW1lAzE1NDgxODMyMDE-?act=reply&messageNum=65003> >>> >>> ? Reply to sender >>> <mailto:ct_digital_pho...@yahoo.com?subject=Re%3A%20%5BKX3%5D%20Auto-spot%2C%20tuning%20aids%2C%20and%20the%20arcane%20history%20of%20CW%20pitch-matching> >>> >>> ? Reply to group >>> <mailto:k...@yahoogroups.com?subject=Re%3A%20%5BKX3%5D%20Auto-spot%2C%20tuning%20aids%2C%20and%20the%20arcane%20history%20of%20CW%20pitch-matching> >>> >>> ? Start a New Topic >>> <https://groups.yahoo.com/neo/groups/KX3/conversations/newtopic;_ylc=X3oDMTJmZW5odm5zBF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNudHBjBHN0aW1lAzE1NDgxODMyMDE-> >>> >>> ? Messages in this topic >>> <https://groups.yahoo.com/neo/groups/KX3/conversations/topics/65002;_ylc=X3oDMTM3ajhnNzRwBF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARtc2dJZAM2NTAwMwRzZWMDZnRyBHNsawN2dHBjBHN0aW1lAzE1NDgxODMyMDEEdHBjSWQDNjUwMDI-> >>> >>> (2) >>> >>> ------------------------------------------------------------------------ >>> Have you tried the highest rated email app? <https://yho.com/1wwmgg> >>> With 4.5 stars in iTunes, the Yahoo Mail app is the highest rated >>> email app on the market. What are you waiting for? Now you can access >>> all your inboxes (Gmail, Outlook, AOL and more) in one place. Never >>> delete an email again with 1000GB of free cloud storage. >>> ------------------------------------------------------------------------ >>> Visit Your Group >>> <https://groups.yahoo.com/neo/groups/KX3/info;_ylc=X3oDMTJmcDMzNTc0BF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDdnRsBHNsawN2Z2hwBHN0aW1lAzE1NDgxODMyMDE-> >>> >>> >>> >>> Yahoo! Groups >>> <https://groups.yahoo.com/neo;_ylc=X3oDMTJlaGZwbzdlBF9TAzk3NDc2NTkwBGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTU0ODE4MzIwMQ--> >>> >>> >>> ? Privacy >>> <https://info.yahoo.com/privacy/us/yahoo/groups/details.html> ? >>> Unsubscribe >>> <mailto:kx3-unsubscr...@yahoogroups.com?subject=Unsubscribe> ? Terms >>> of Use <https://info.yahoo.com/legal/us/yahoo/utos/terms/> >>> >>> SPONSORED LINKS >>> . >>> >>> __,_._,___ >> >> >> ------------------------------ >> >> Message: 14 >> Date: Tue, 22 Jan 2019 13:45:13 -0700 >> From: "Dave New, N8SBE" <n8...@arrl.net> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: >> >> <20190122134513.1fa1e31b6b6b329ecc65be958babcc1f.2b096db9da....@email09.godaddy.com> >> >> Content-Type: text/plain; charset="utf-8" >> >> When I upgraded from my K3 to a K3s, I took the opportunity to order a >> 10 MHz Ref In option. >> >> I finally got around to hooking it up to a Leo Bodnar GPS receiver I >> picked up at Dayton a year ago, and now the K3s is rock solid spot on >> frequency. >> >> Don't know how i did without it all these years... >> >> 73, >> >> -- Dave, N8SBE >> >> -------- Original Message -------- >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> From: Bob McGraw K4TAX <rmcg...@blomand.net> >> Date: Tue, January 22, 2019 3:14 pm >> To: elecraft@mailman.qth.net >> >> Another trick which works well. Tune to a WWV frequency in CW mode. >> Press SPOT and the radio will jump on the exact carrier frequency. The >> SPOT function can pull on to the WWV frequency as far away as about 100 >> Hz. Once the radio has resolved SPOT, the readout / display is the >> frequency of WWV +/- the error in Hz. Thus the readout of 9.999.992 is >> indicating being 8 Hz low. >> >> From a cold start, FP being 19?C, I find -8 Hz error on 10 MHz WWV. >> After about 15 minutes the FP is 25?C and the error is -1 Hz. I've >> tweaked the REF CAL such that after 1/2 hr. in receive tuning to WWV >> from both higher and lower will produce a reading of 10.000.000. Will >> all stations pse QNZ QNN. >> >> 73 >> >> Bob, K4TAX >> >> >> >> >> >> ------------------------------ >> >> Message: 15 >> Date: Tue, 22 Jan 2019 13:47:04 -0700 >> From: "Dave New, N8SBE" <n8...@arrl.net> >> To: "Elecraft Reflector" <elecraft@mailman.qth.net> >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: >> >> <20190122134704.1fa1e31b6b6b329ecc65be958babcc1f.b1b5d245eb....@email09.godaddy.com> >> >> Content-Type: text/plain; charset="utf-8" >> >> I'm a great fan of using the auto-spot feature, and love to show it off >> to all shack visitors, as an example of yet another reason they need to >> upgrade to Elecraft, from whatever boat anchor they are still using... >> >> 73, >> >> -- Dave, N8SBE >> >> >> ------------------------------ >> >> Message: 16 >> Date: Tue, 22 Jan 2019 12:57:16 -0800 >> From: Wayne Burdick <n...@elecraft.com> >> To: Elecraft <elecraft@mailman.qth.net> >> Cc: KX3 <k...@yahoogroups.com> >> Subject: [Elecraft] Urban stealth HF: Inside-the-backpack loop >> antenna? >> Message-ID: <5eb8dddd-c0f1-42c4-b2f9-45ec3bd54...@elecraft.com> >> Content-Type: text/plain; charset=utf-8 >> >> I?ve engaged in plenty of ultralight HF pack operation, with a KX2, AX1 >> antenna and a dragged counterpoise. In wide open spaces it?s a blast. But >> urban settings with dogs, wire-eating cacti and overzealous Neighborhood >> Watchers can distract from one?s radio experience. >> >> So, just for grins, I?d like to try something completely incognerdo: no >> visible antenna. A small remotely tuned loop (say 12? diameter) would seem >> to be the best choice, as it would fit entirely inside a small backpack. It >> could have modest efficiency while not requiring a counterpoise wire. Rigid >> 1? copper pipe formed in a square would be convenient to deploy. >> >> The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, >> of course. OTOH, we?re talking about HF. A cellphone by your ear is >> probably worse. >> >> Any other antenna suggestions? >> >> Wayne >> N6KR >> >> >> >> ---- >> elecraft.com >> >> ------------------------------ >> >> Message: 17 >> Date: Tue, 22 Jan 2019 20:57:26 +0000 >> From: Andy Durbin <a.dur...@msn.com> >> To: "elecraft@mailman.qth.net" <elecraft@mailman.qth.net> >> Subject: [Elecraft] Auto-spot, tuning aids, and the arcane history of >> CW pitch-matching >> Message-ID: >> >> <mw2pr16mb2362cffbbc02b413c6216e618c...@mw2pr16mb2362.namprd16.prod.outlook.com> >> >> Content-Type: text/plain; charset="iso-8859-1" >> >> "Find a signal, turn on CWT, then tap SPOT to tune it in. A second tap of >> SPOT may get even closer, especially if there's a lot of band noise." >> >> and >> >> "I'm a great fan of using the auto-spot feature, and love to show it off to >> all shack visitors, as an example of yet another reason they need to upgrade >> to Elecraft," >> >> I must be missing something. How is this 2 step activated spot feature >> better than a single press of Kenwood's CWT? I often use CWT on my TS-590S >> but almost always with a spit or XIT offset (I didn't know that was a >> secret). >> >> Andy, k3wyc >> >> >> ------------------------------ >> >> Message: 18 >> Date: Tue, 22 Jan 2019 14:01:33 -0700 >> From: Wes <wes_n...@triconet.org> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <619ac274-ad1e-282d-8b1e-0b37685b0...@triconet.org> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >> Are you serious? >> >> Wes? N7WS >> >>> On 1/22/2019 1:45 PM, Dave New, N8SBE wrote: >>> Don't know how i did without it all these years... >>> >>> 73, >>> >>> -- Dave, N8SBE >>> >> >> >> >> ------------------------------ >> >> Message: 19 >> Date: Tue, 22 Jan 2019 14:01:52 -0700 (MST) >> From: ab2tc <ab...@arrl.net> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <1548190912091-0.p...@n2.nabble.com> >> Content-Type: text/plain; charset=us-ascii >> >> Hi all, >> >> Agreed; the problem can easily be solved in analog radios without frequency >> synthesis by offsetting the BFO frequency by those 700Hz or so in transmit. >> In down conversion machines with a single IF in the 8-9MHz range that could >> easily be done by pulling the BFO crystal. The Drake TR4 undoubtedly worked >> this way. I bought my first transceiver in 1969 (I think), a Yaesu FT-200, I >> think it was called in the US. In Europe it was sold as Sommerkamp FT-250. >> As the Drake TR4 it was down conversion with a single 9MHz IF and worked CW >> by pulling the BFO crystal into the passband of the 9MHz crystal filter on >> transmit. >> >> Another technical solution, which was used in the Collins KWM2 (and probably >> KWM1) was to keep the balanced (de)modulator balanced and inject an audio >> tone into it on transmit. Clearly the spectral purity of the CW signal would >> be less than ideal in this case, but I am not sure if FCC type approval was >> needed in those days. Nor am I sure what the the FCC spec for "inband" (read >> close in) spurs would be. >> >> AB2TC - Knut >> >> >> n0uk wrote >>> The transceive problem didn't seem to exist on any older non-synthesized >>> transceiver that I have used, including FT-101 series, TS-520/820 and >>> later, KW Electronics KW-2000E. these were all '70s era transceivers. >>> >>> >>> >>> -- >>> 73 Chris Cox, N0UK, G4JEC >> >>> chrisc@ >> >>> >>> _ >>> <snip> >> >> >> >> >> >> -- >> Sent from: http://elecraft.365791.n2.nabble.com/ >> >> >> ------------------------------ >> >> Message: 20 >> Date: Tue, 22 Jan 2019 14:32:47 -0700 >> From: Mark Goldberg <marklgoldb...@gmail.com> >> To: Wayne Burdick <n...@elecraft.com> >> Cc: Elecraft <elecraft@mailman.qth.net>, KX3 <k...@yahoogroups.com> >> Subject: Re: [Elecraft] [KX3] Urban stealth HF: Inside-the-backpack >> loop antenna? >> Message-ID: >> <CAKn+a3tdcK4Gk+SLSuyEP+2CR+nFK+qRtnVZWecrf0qDoh=c...@mail.gmail.com> >> Content-Type: text/plain; charset="UTF-8" >> >> I would expect any high Q antenna like a loop would be detuned by any >> movement or any metal you pass by. One more reason to support automatic >> mobile screwdriver / mag loop antenna tuning on the KX series. >> A flag on a backpack would be more or less ignored. Just put a flag on the >> top of the AX1. Counterpoise is an issue though. Maybe a short one down >> your leg? >> >> Now, if you dressed as a homeless or otherwise distressed person, lots of >> weird things are possible, tinfoil hat with a big flag, dragged wire >> disguised as one of those fake animals on a leash, etc. The weirder, the >> more people will ignore you. >> >> Hopefully taken in the spirit of which it is posted. >> >> 73, >> >> Mark >> W7MLG >> >> >> On Tue, Jan 22, 2019 at 1:57 PM Wayne Burdick n...@elecraft.com [KX3] < >> kx3-nore...@yahoogroups.com> wrote: >> >>> >>> >>> I?ve engaged in plenty of ultralight HF pack operation, with a KX2, AX1 >>> antenna and a dragged counterpoise. In wide open spaces it?s a blast. But >>> urban settings with dogs, wire-eating cacti and overzealous Neighborhood >>> Watchers can distract from one?s radio experience. >>> >>> So, just for grins, I?d like to try something completely incognerdo: no >>> visible antenna. A small remotely tuned loop (say 12? diameter) would seem >>> to be the best choice, as it would fit entirely inside a small backpack. It >>> could have modest efficiency while not requiring a counterpoise wire. >>> Rigid 1? copper pipe formed in a square would be convenient to deploy. >>> >>> The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, >>> of course. OTOH, we?re talking about HF. A cellphone by your ear is >>> probably worse. >>> >>> Any other antenna suggestions? >>> >>> Wayne >>> N6KR >>> >>> >>> >>> ---- >>> elecraft.com >>> >>> __._,_.___ >>> ------------------------------ >>> Posted by: Wayne Burdick <n...@elecraft.com> >>> ------------------------------ >>> Reply via web post >>> <https://groups.yahoo.com/neo/groups/KX3/conversations/messages/65005;_ylc=X3oDMTJyOWdpcW0yBF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARtc2dJZAM2NTAwNQRzZWMDZnRyBHNsawNycGx5BHN0aW1lAzE1NDgxOTA2NDA-?act=reply&messageNum=65005> >>> ? Reply to sender >>> <n...@elecraft.com?subject=Re%3A%20Urban%20stealth%20HF%3A%20Inside-the-backpack%20loop%20antenna%3F> >>> ? Reply to group >>> <k...@yahoogroups.com?subject=Re%3A%20Urban%20stealth%20HF%3A%20Inside-the-backpack%20loop%20antenna%3F> >>> ? Start a New Topic >>> <https://groups.yahoo.com/neo/groups/KX3/conversations/newtopic;_ylc=X3oDMTJmZW4xYXF1BF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNudHBjBHN0aW1lAzE1NDgxOTA2NDA-> >>> ? Messages in this topic >>> <https://groups.yahoo.com/neo/groups/KX3/conversations/topics/65005;_ylc=X3oDMTM3cGU2OTN1BF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARtc2dJZAM2NTAwNQRzZWMDZnRyBHNsawN2dHBjBHN0aW1lAzE1NDgxOTA2NDAEdHBjSWQDNjUwMDU-> >>> (1) >>> ------------------------------ >>> Have you tried the highest rated email app? <https://yho.com/1wwmgg> >>> With 4.5 stars in iTunes, the Yahoo Mail app is the highest rated email >>> app on the market. What are you waiting for? Now you can access all your >>> inboxes (Gmail, Outlook, AOL and more) in one place. Never delete an email >>> again with 1000GB of free cloud storage. >>> ------------------------------ >>> Visit Your Group >>> <https://groups.yahoo.com/neo/groups/KX3/info;_ylc=X3oDMTJmcmZybjN1BF9TAzk3MzU5NzE0BGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDdnRsBHNsawN2Z2hwBHN0aW1lAzE1NDgxOTA2NDA-> >>> >>> >>> [image: Yahoo! Groups] >>> <https://groups.yahoo.com/neo;_ylc=X3oDMTJlZDVicHB1BF9TAzk3NDc2NTkwBGdycElkAzc0NTIwOTQ3BGdycHNwSWQDMTcwNTA2MzEwOARzZWMDZnRyBHNsawNnZnAEc3RpbWUDMTU0ODE5MDY0MA--> >>> ? Privacy <https://info.yahoo.com/privacy/us/yahoo/groups/details.html> ? >>> Unsubscribe <kx3-unsubscr...@yahoogroups.com?subject=Unsubscribe> ? Terms >>> of Use <https://info.yahoo.com/legal/us/yahoo/utos/terms/> >>> >>> SPONSORED LINKS >>> . >>> >>> __,_._,___ >>> >> >> >> ------------------------------ >> >> Message: 21 >> Date: Tue, 22 Jan 2019 13:38:35 -0800 >> From: Steve Sergeant <steve...@effable.com> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop >> antenna? >> Message-ID: <63fb5351-46b5-0d73-e53d-ba852f654...@effable.com> >> Content-Type: text/plain; charset=utf-8 >> >>> On 1/22/19 12:57 PM, Wayne Burdick wrote: >>> A small remotely tuned loop (say 12? diameter) would seem to be the best >>> choice, as it would fit entirely inside a small backpack. It could have >>> modest efficiency while not requiring a counterpoise wire. Rigid 1? copper >>> pipe formed in a square would be convenient to deploy. >> >> [Deletia] >> >>> Any other antenna suggestions? >> >> I tried a 52ft 26ga wire J-pole/Zep on the line of a 5ft parafoil kite, >> with 50ft of kite line above the antenna, and another 50' of RG-174 >> between the antenna and the radio. >> >> I'll grant that this is not as invisible as your idea. But I felt >> reasonably inconspicuous working SSB with cell-phone type earbuds >> (w/mic), and the KX2 in an open waist-pack, out in an open field of a >> large city park. People just thought I was on a phone call while flying >> the kite. It helped that there were several other kite-fliers in the >> park that day. >> >> It was not a particularly good day for propagation, but I did work Las >> Vegas and Spokane from Silicon Valley with under 10W on 20m. >> >> >> >> >> ------------------------------ >> >> Message: 22 >> Date: Tue, 22 Jan 2019 16:40:04 -0500 >> From: Michael Blake <k9...@mac.com> >> To: Mark Goldberg <marklgoldb...@gmail.com> >> Cc: Elecraft Reflector <elecraft@mailman.qth.net>, KX3 >> <k...@yahoogroups.com> >> Subject: Re: [Elecraft] [KX3] Urban stealth HF: Inside-the-backpack >> loop antenna? >> Message-ID: <53ccb8bd-bff8-46cc-83ac-0f0a12d89...@mac.com> >> Content-Type: text/plain; charset=us-ascii >> >> Mark (W7MLG), It is scary how perfectly sane and normal your suggestions >> sound to me :) >> >> Very 73 - Mike - K9JRI >> >> >> >> >> >> >> >>> On Jan 22, 2019, at 4:32 PM, Mark Goldberg <marklgoldb...@gmail.com> wrote: >>> >>> I would expect any high Q antenna like a loop would be detuned by any >>> movement or any metal you pass by. One more reason to support automatic >>> mobile screwdriver / mag loop antenna tuning on the KX series. >>> A flag on a backpack would be more or less ignored. Just put a flag on the >>> top of the AX1. Counterpoise is an issue though. Maybe a short one down >>> your leg? >>> >>> Now, if you dressed as a homeless or otherwise distressed person, lots of >>> weird things are possible, tinfoil hat with a big flag, dragged wire >>> disguised as one of those fake animals on a leash, etc. The weirder, the >>> more people will ignore you. >>> >>> Hopefully taken in the spirit of which it is posted. >>> >>> 73, >>> >>> Mark >>> W7MLG >>> >>> >>> On Tue, Jan 22, 2019 at 1:57 PM Wayne Burdick n...@elecraft.com [KX3] < >>> kx3-nore...@yahoogroups.com> wrote: >>> >> >> >> >> ------------------------------ >> >> Message: 23 >> Date: Tue, 22 Jan 2019 15:41:14 -0600 >> From: K9MA <k...@sdellington.us> >> To: elecraft@mailman.qth.net >> Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history >> of CW pitch-matching >> Message-ID: <089118fa-b031-7b6d-b2b6-c31ff6dda...@sdellington.us> >> Content-Type: text/plain; charset=utf-8; format=flowed >> >>> On 1/22/2019 14:14, Bob McGraw K4TAX wrote: >>> Another trick which works well.?? Tune to a WWV frequency in CW mode. >>> Press SPOT and the radio will jump on the exact carrier frequency. >> >> You can do the same thing, of course, by listening to the beat between >> the sidetone and the carrier. I was able to get 3 Hz closer that way, >> within the 1 Hz tuning resolution. 3 Hz is close enough, though. >> >> When listening for the beats, you have to match the volume of the >> sidetone and carrier, or you won't hear them. You don't need a musical >> ear, just a functioning one. >> >> 73, >> >> Scott K9MA >> >> -- >> Scott K9MA >> >> k...@sdellington.us >> >> >> >> ------------------------------ >> >> _______________________________________________ >> Elecraft mailing list >> Post to: Elecraft@mailman.qth.net >> http://mailman.qth.net/mailman/listinfo/elecraft >> You must be a subscriber to post. >> Elecraft web page: http://www.elecraft.com >> >> End of Elecraft Digest, Vol 177, Issue 36 >> ***************************************** >> > > > > ------------------------------ > > Message: 10 > Date: Tue, 22 Jan 2019 17:26:41 -0600 > From: Robert Rennard <n...@rocketmail.com> > To: "elecraft@mailman.qth.net" <elecraft@mailman.qth.net> > Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history > of CW pitch-matching > Message-ID: <mailman.5377.1548208292.22883.elecr...@mailman.qth.net> > Content-Type: text/plain; charset="utf-8" > > For N1MM, use the up and down arrow keys to get close in S&P operation and > then press F11 to zero beat - > > F11 Z B,{CATA1ASC SWT42;} > > If it is a dense pile, a little XIT offset is a big help. > > 73, > > Bob R > > > ------------------------------ > > Message: 11 > Date: Tue, 22 Jan 2019 17:06:17 -0800 > From: Bill Frantz <fra...@pwpconsult.com> > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history > of CW pitch-matching > Message-ID: > <r480Ps-10142i-4AB5EDB7CF8240999297737DB768C61B@Williams-MacBook-Pro.local> > > Content-Type: text/plain; charset=UTF-8; format=flowed > > I must admit, most of my CW tuning is done with the P3/SVGA and > getting the pitch "right" in my earphones. (With RTTY, I can get > very close to the correct pitch by ear. Then I used the crossed > loop tuning aid for the final few Hz.) > > 73 Bill AE6JV > > --------------------------------------------------------------------------- > Bill Frantz | "I wish there was a knob on the TV to turn > up the > 408-356-8506 | intelligence. There's a knob called > "brightness", but > www.pwpconsult.com | it doesn't work. -- Gallagher > > > > ------------------------------ > > Message: 12 > Date: Tue, 22 Jan 2019 17:17:03 -0800 > From: kevinr <kev...@coho.net> > To: elecraft@mailman.qth.net > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <9db6ea37-d5a6-ffdf-33ce-59a4795bf...@coho.net> > Content-Type: text/plain; charset=utf-8; format=flowed > > There may be other options.? A serpentine pattern fed at the center > could give you enough length for a 10 m or larger dipole. I've seen > serpentine F antennas on printed circuit boards.? I've also seen spiral > patterns used so I know they work to some extent. > > If a dipole cut for 14 MHz is ~ 400 inches long it would take 11 up and > down segments of 36" each to stuff it inside your pack. I'm sure the > serpentine factor will change the length needed but with a bit of > tweaking this could work. > > Or feed it at one end for a 40 meter monopole (a counterpoise could be > woven into the pack). > > ?? 73 & GL, > > ?????? Kevin.? KD5ONS > > - > > >> On 1/22/19 12:57 PM, Wayne Burdick wrote: >> I?ve engaged in plenty of ultralight HF pack operation, with a KX2, AX1 >> antenna and a dragged counterpoise. In wide open spaces it?s a blast. But >> urban settings with dogs, wire-eating cacti and overzealous Neighborhood >> Watchers can distract from one?s radio experience. >> >> So, just for grins, I?d like to try something completely incognerdo: no >> visible antenna. A small remotely tuned loop (say 12? diameter) would seem >> to be the best choice, as it would fit entirely inside a small backpack. It >> could have modest efficiency while not requiring a counterpoise wire. Rigid >> 1? copper pipe formed in a square would be convenient to deploy. >> >> The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, >> of course. OTOH, we?re talking about HF. A cellphone by your ear is >> probably worse. >> >> Any other antenna suggestions? >> >> Wayne >> N6KR >> >> >> >> ---- >> elecraft.com >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to kev...@coho.net > > > ------------------------------ > > Message: 13 > Date: Tue, 22 Jan 2019 17:19:52 -0800 > From: Joan <joanpat...@me.com> > To: Wayne Burdick <n...@elecraft.com> > Cc: Elecraft Reflector <elecraft@mailman.qth.net>, > "k...@yahoogroups.com" <k...@yahoogroups.com> > Subject: Re: [Elecraft] Auto-spot, tuning aids, and the arcane history > of CW pitch-matching > Message-ID: <2d8bae14-eacc-4c2b-b053-1379bdf9b...@me.com> > Content-Type: text/plain; charset=utf-8 > > Thanks, Wayne! This is one of the best entries into these threads I?ve ever > read. And, yes, I've experimented with Auto Spot in CWT mode. > > And: > ?the Audio Peaking Filter (APF), ?provides a 30-Hz bandwidth at -3 dB, > but broad skirts, preventing ringing from occurring. As our customers will > attest, APF works like magic on weak signals obscured by noise?? To which I > also attest! ^_^ > > And, the VFO and IF passband tracking exactly on the user setable CW sidetone > (A 440, in my case) is one of the main things which made me fall in love with > Elecraft. > > 72 de KX2CW .. > ~Joan > > Darmok and Jalad at Tanagra, said Piglet. > Shaka, when the walls fell, said Pooh. > >> On Jan 21, 2019, at 21:09, Wayne Burdick <n...@elecraft.com> wrote: >> >> Elecraft's auto-spot and CWT features -- available on the K3/K3S/KX2/KX3 -- >> are very useful tools for CW operators, especially those not experienced in >> pitch-matching. Here's a bit of history on where these features came from >> and how they work. >> >> >> CW Spotting History >> >> When a station finishes a CQ in CW mode, the operator faces the challenge of >> copying someone who's calling back. Callers may be weak or obscured by QRM; >> the op can usually deal with both problems by narrowing the filter passband. >> However, callers may also be off frequency. A calling station may be using a >> wide filter passband themselves, not attempting to carefully match their VFO >> frequency to that of the CQing station. The result may be no QSO, even when >> propagation is excellent. >> >> In the Days of Yore, a frequency offset between stations didn't always >> matter. Sometimes both stations used crystal-controlled transmitters, so >> operators had to patient tune around after calling CQ. >> >> As a 14-year-old novice I embraced this operating style for a year or so, >> armed with a dozen or so crusty FT-243 crystals for my Heath HW-16. I nearly >> wore out the socket swapping them in and out. After calling CQ, it was not >> unusual to find a caller 30 or more kHz away! (Away from "where" was a >> poorly answered question, as my Hallicrafters receiver dial wasn't exactly >> digital.) >> >> Fortunately I soon acquired an outboard VFO, a life-changing addition to my >> station. Jealous friends doubled up on their paper routes to pay for their >> own. Girls suddenly paid more attention to me. >> >> These days virtually everyone has a VFO, along with the expectation that >> they won't have to tune theirs very far, if at all, to tune you in. Not only >> that, they're stable and well calibrated, not like the beasts we had to >> skillfully tame. Progress! >> >> >> Manual Spotting (SPOT switch) >> >> Once I had a VFO I quickly learned to do *manual* pitch matching. Older rigs >> did't provide a way to do that explicitly, so you'd improvise. Basically, >> you had to coerce a very weak signal out of your own transmitter, say by >> turning on only the driver, then tune the transmit VFO until you could hear >> your signal on your own receiver -- superimposed on the calling station, at >> the same pitch. This is what we call spotting. >> >> Of course spotting is a lot more convenient these days, as many rigs include >> a SPOT switch. This function is easy for a modern transceiver designer to >> add, because the radio's firmware is quite capable of turning on only the CW >> sidetone without transmitting. >> >> That is the purpose of the SPOT switch on all Elecraft transceivers. Tap >> SPOT, and you'll hear your sidetone pitch. Most people can do a good job of >> adjusting the VFO such that the CQing station's pitch matches that of the >> SPOT tone. This ensures that when you call them, you'll be close to their >> own frequency. >> >> >> Tuning Aids: Filtering (APF), PLL (NE567), and Spectral (CWT) >> >> Since not everyone has an inherent musical ear, various hardware-enhanced >> means of tuning in CW signals have been developed. >> >> The simplest method is to just narrow your receiver passband so much that, >> if you can hear a station calling CQ at all, you're guaranteed to be "right >> on top of him." This assumes that your transceiver enforces alignment >> between its transmit and receive pitch...true of all Elecraft gear. >> >> Narrow filtering has gone through decades of evolution. Some filters were >> based on op-amps (active filters), while others were based on LC filtering, >> conscripting humongous toroidal cores scavenged from telco equipment. I >> acquired my stash of these from a haphazard mound of old switching racks, >> decaying in an abandoned aircraft hanger on the Bermuda U.S. Navy base. >> (That irresistible junk pile was also a mother load of TO5 transistors, >> multi-pound electrolytic capacitors, and tetanus, but that's another story.) >> Typically the toroids were 88 millihenries -- a huge value for a high-Q >> inductor, permitting resonance in the low audio range. >> >> Later, such filters migrated to digital signal processing, in the form of >> switched-capacitor ICs or DSPs. You can still buy these switched-capacitor >> chips, like the MF10, from various sources. It's instructive to roll your >> own tunable filter, just for fun. >> >> Whether passive or active, the goal of filtering is typically to achieve a >> narrow passband, say 250 Hz or less. With DSP, nearly perfect filters with >> "brick wall" passbands can be created. But these have the disadvantage of >> ringing like a bell when pinged by a CW signal or noise, making copy >> difficult. >> >> One solution incorporated into the K-line and KX-line is the Audio Peaking >> Filter (APF), which provides a 30-Hz bandwidth at -3 dB, but broad skirts, >> preventing ringing from occurring. As our customers will attest, APF works >> like magic on weak signals obscured by noise. >> >> Another forerunner to DSP techniques was the audio phase-locked-loop, using >> inexpensive ICs like the legendary LM567. When locked on a signal that >> matched its center frequency, the circuit would turn on an LED, alerting the >> operator that the VFO was now properly tuned. >> >> With the DSPs in our K-line and KX-line radios, we can provide a much more >> powerful tool: CWT, or "CW Tuning Aid." When enabled, CWT turns the upper >> portion of the rig's S-meter into something of a mini spectrum analyzer. The >> pitch of the strongest signal in the passband is analyzed by the DSP, then >> represented as a single segment of the bar graph. For CWT-enhanced manual >> spotting, the operator simply tunes the VFO slowly until the center CWT >> segment is flashing along with the keyed signal. >> >> Manual tuning with CWT can also be used in FSK-D and PSK-D modes as >> described in the owner's manual. >> >> >> Closing the Loop: Auto-Spotting (SPOT + CWT) >> >> The Elecraft K3/K3S/KX2/KX3 take CW tuning another step forward by providing >> a way to *automatically* retune the VFO frequency to match that of a >> received signal. How does this work? >> >> When CWT is turned on, firmware treats the SPOT switch as AUTO-SPOT. The DSP >> analyzes the incoming signal, and with a bit of processing, determines its >> exact audio pitch. From there all that's needed is a bit of math to offset >> the VFO to match this pitch to the CW sidetone. >> >> There's another subtlety, though. Since a CW signal is generally being keyed >> on and off, the CWT algorithm has to ensure that it doesn't "take off," >> chasing a signal that's not there. To avoid this, we keep track of the >> energy in the passband, and slew the VFO incrementally over an average of >> about 0.5 second, moving only when the target signal is present. >> >> >> How to Use Auto-Spot >> >> I encourage you to give the auto-spot feature a try. It's best to start with >> a fairly narrow passband, say 400-600 Hz; narrower if there's a lot of QRM. >> Find a signal, turn on CWT, then tap SPOT to tune it in. A second tap of >> SPOT may get even closer, especially if there's a lot of band noise. >> >> Auto-spot can also be used in Elecraft's PSK-D mode, i.e. for PSK31/PSK63. >> As with CW mode, just turn on CWT, tune in a prospective signal, and tap >> SPOT. Since PSK auto-decoding requires very accurate tuning, it's best to >> set the filter bandwidth to 50 Hz, then let auto-spot dial things in down to >> the last 2 or 3 Hz. If you have text decode turned on, you should start >> seeing text characters scroll by after auto-tuning has completed. Tapping a >> second time or fine-tuning the VFO a bit in 1 Hz steps may improve copy. >> >> 73, >> Wayne >> N6KR >> >> >> >> >> > > > ------------------------------ > > Message: 14 > Date: Tue, 22 Jan 2019 19:51:01 -0600 > From: Michael Chowning <mike.chown...@mgccc.org> > To: Wayne Burdick <n...@elecraft.com> > Cc: Elecraft <elecraft@mailman.qth.net>, KX3 <k...@yahoogroups.com> > Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop > antenna? > Message-ID: <d6d06f5a-5117-4639-afc6-dc22e8f85...@mgccc.org> > Content-Type: text/plain; charset=utf-8 > > Just for grins, look into this link, from Ohio State University from back in > 2011! > https://news.osu.edu/antennas-in-your-clothes--new-design-could-pave-the-way/ > <https://news.osu.edu/antennas-in-your-clothes--new-design-could-pave-the-way/> > There are also articles more recently (2018) on electronics in one?s clothes, > and computers in one?s clothes in this website?s news as well. > Mike, N8TTR > >> On Jan 22, 2019, at 2:57 PM, Wayne Burdick <n...@elecraft.com> wrote: >> >> I?ve engaged in plenty of ultralight HF pack operation, with a KX2, AX1 >> antenna and a dragged counterpoise. In wide open spaces it?s a blast. But >> urban settings with dogs, wire-eating cacti and overzealous Neighborhood >> Watchers can distract from one?s radio experience. >> >> So, just for grins, I?d like to try something completely incognerdo: no >> visible antenna. A small remotely tuned loop (say 12? diameter) would seem >> to be the best choice, as it would fit entirely inside a small backpack. It >> could have modest efficiency while not requiring a counterpoise wire. Rigid >> 1? copper pipe formed in a square would be convenient to deploy. >> >> The loop would be only 6 to 8? from soft tissue, so you?d want to run QRP, >> of course. OTOH, we?re talking about HF. A cellphone by your ear is >> probably worse. >> >> Any other antenna suggestions? >> >> Wayne >> N6KR >> >> >> >> ---- >> elecraft.com >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to mike.chown...@mgccc.org > > > > ------------------------------ > > _______________________________________________ > Elecraft mailing list > Post to: Elecraft@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/elecraft > You must be a subscriber to post. > Elecraft web page: http://www.elecraft.com > > End of Elecraft Digest, Vol 177, Issue 37 > ***************************************** ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
