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

When I was in College at Kansas State, I had a random length long wire out the window and up into some trees from the basement apartment. I used a simple coil and cap with alligator clips to make a LCD tuner on a piece of pine. What made it work was the copper pipe water inlet two feet from the

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

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

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

10+ years ago, we built a HF loop inside a coat. I can’t really tell you the application but the loop was made of copper braid and put between the liner and the outer shell of the coat. It was tuned with a simple L match with a LED to indicate peak power. We operated it on the 80, 60 and 40m

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

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

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 Who was that guy at the HFPack get-together at HARA a few Daytons ago, that was running A

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

Years back QST had an article that showed a home made 2 meter "filter" made in a garbage can,   they ran low power and placed a hot dog inside,  closed the lid and applied RF,   the hot dog was BBQed in short order, Perhaps with QRP one could put a sandwhich in one pocket and coffee in another

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

h the backpack on? KD4IZ Jack Spitznagel FM19oo -Original Message- From: David Gilbert Sent: Wednesday, January 23, 2019 00:04 To: elecraft@mailman.qth.net Subject: Re: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna? Here's another idea. Run a wire inside your shir

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

about? :_) (Emoji added in case the sarcasm was missed.) 73, Bill K9YEQ https://wrj-tech.com/ -Original Message- From: elecraft-boun...@mailman.qth.net On Behalf Of Wayne Burdick Sent: Tuesday, January 22, 2019 2:57 PM To: Elecraft Cc: KX3 Subject: [Elecraft] Urban stealth HF

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 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?

nal Message- > From: elecraft-boun...@mailman.qth.net On > Behalf Of Wayne Burdick > Sent: Tuesday, January 22, 2019 2:57 PM > To: Elecraft > Cc: KX3 > Subject: [Elecraft] Urban stealth HF: Inside-the-backpack loop antenna? > > I’ve engaged in plenty of ultralight HF pack oper

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

: elecraft-boun...@mailman.qth.net On Behalf Of Wayne Burdick Sent: Tuesday, January 22, 2019 2:57 PM To: Elecraft Cc: KX3 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

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

: 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

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?

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

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] 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

[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