Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

Hook it up to your KPA1500 and you've got whole house illumination! Martin, HS0ZED On 23/01/2019 13:11, Wayne Burdick wrote: Up the power to 100 W and you’ve got a personal heating appliance. Awesome. “Without RF, life itself would be impossible.” Wayne elecraft.com On Jan 22,

Re: [Elecraft] Urban Stealth

This thread brings back memories of an antenna I once used mobile for a weekend.  I was headed to a hamfest in Phoenix from Tucson back when two-meter AM was still in vogue.  Should give you and idea of time-frame.  I owned a Heathkit "Twoer" and a 1956 Corvette (wish I had this back---the

Re: [Elecraft] K2 VCO Alignment T5 L30

Tom, welcome to the club.   I think anyone who has put together a K2 has such stories.   In my case I had installed U4 backwards and did not notice it as the chip has a very pronounced 'dimple' on one end which (for some reason) made me overlook the notch on the other end.    I spent a week

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

Up the power to 100 W and you’ve got a personal heating appliance. Awesome. “Without RF, life itself would be impossible.” Wayne elecraft.com > On Jan 22, 2019, at 9:04 PM, David Gilbert wrote: > > > > Here's another idea. > > Run a wire inside your shirt from one cuff across your

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

Here's another idea. Run a wire inside your shirt from one cuff across your back and down to the other cuff.  Wrap loading coils around each arm just above the elbow.  Feed the "dipole" in the center at the back of your neck. I did a quick model (assuming your arms are held straight out)

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

Thanks for the amazing response and great ideas. If someone wants to build a backpack loop antenna for 20 m sooner than I can, I promise to extensively field test it for you. If it works, it could become an Elecraft product. (AL1? :) The KXIO2 option for the KX2 includes two open-drain

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

The back pack frame would be the antenna? Low power is the game. I am not concerned. In the Vietnam era, I was in a station where we had ~5 10KW transmitters using wave guide at ~1.9Ghz and while there were very large dishes, the exposure was there. I would never worry about HF at 10 watts

[Elecraft] 2019 Visalia Top Band Dinner

Announcing the Top Band Dinner at the 2019 Visalia International DX Convention. Buffet Dinner. Pre-Assigned seating. Door Prizes. $42/person. Program: "Snapshot: VK9XG to North America on 160m," Chris Duckling, G3SVL and "KH1/KH7Z Top Band From Baker Island" George Wallner, AA7JV For the most

Re: [Elecraft] Urban Stealth

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

Re: [Elecraft] K2 VCO Alignment T5 L30

Don Et Al, So, It is with some embarrassment, and much relief, that I can report it was operator error and my BFO is now working perfectly. I got home from work and was getting ready to do some continuity checks to all the circuits surrounding and including U11, but decided I better check all the

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop

On 1/22/2019 6:03 PM, Edward R Cole wrote: > "Shades of WWII spy movies" with the german's sniffing RF with rotating > loops on top of a small van! That system - called the Finch loop in the US - was used by most if not all radio enforcement administrations world-wide in some version or other

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop

"Shades of WWII spy movies" with the german's sniffing RF with rotating loops on top of a small van! Great idea! Better Rx antennas, of course. I have plans to make a 6 or 8 foot loop out of some old 1/2 inch heliax cable (1/2 inch copper shield) to try on 630m for Rx. One foot loop on

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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/ There are also articles more recently (2018) on

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

For N1MM, use the up and down arrow keys to get close in S 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 __ Elecraft mailing list Home:

Re: [Elecraft] Elecraft Digest, Vol 177, Issue 36

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 >

Re: [Elecraft] [KX3] Urban stealth HF: Inside-the-backpack loop antenna?

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

[Elecraft] Ferrite Rod? (was: Urban stealth HF...)

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

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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 Date: 22/01/2019 22:09 (GMT+00:00) To: K9MA Cc: elecraft@mailman.qth.net

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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

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 …

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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,

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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 __ Elecraft mailing list Home:

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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,

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

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 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

Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna?

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

Re: [Elecraft] [KX3] Urban stealth HF: Inside-the-backpack loop antenna?

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.

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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 __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help:

[Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

"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

[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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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 __

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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...

Re: [Elecraft] [KX3] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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.

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

[Elecraft] Zero Beat / CWT / Auto Spot

> > 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 -

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

-- 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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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] K2, K1, W1, and other stuff for Sale

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

Re: [Elecraft] K3 SWR Anomaly

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.

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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.

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

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

Re: [Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

Wayne, thanks for this historical description. I have used these tools myself a lot over the years. They are one reason I have purchased my K3, K3S and KX3(however sold to purchase K3S). Now, one thing you missed... when you’re working a big pileup and you feel you just can’t get through,

Re: [Elecraft] New K2 Build

Oh, No! Say it isn't so, Don! Sorry to hear this news. It's been about a generation of your supporting hams with their legacy Elecraft radi!os through builds, upgrades, and repairs. I'm glad I got my K2 A-to-B upgrade from you before this decision. I wish you many more years of helpful

[Elecraft] Auto-spot, tuning aids, and the arcane history of CW pitch-matching

A history of CW pitch matching would seem to be incomplete without a mention of the BFO (Beat Frequency Oscillator). When I started operating CW I had separate TX and RX. TX was homebrew and the RX was an AR-88D.A common technique for tuning a CW station was to set the BFO to zero offset,