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

[Wayne Burdick]

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 outputs that could be used to slew a C-tuning motor up and down with suitable buffering. I’ll write the code for that if/when it’s needed. 

Wayne
N6KR

----
elecraft.com

> On Jan 22, 2019, at 7:43 PM, Bill Johnson <k9yeq at live.com> wrote:
> 
> 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 close to my body, but there may be studies that dispute that.  I am still alive after 12 months constant exposure to agent orange.  No problem.  What was I writing about? :_)  
> 
> (Emoji added in case the sarcasm was missed.)
> 
> 73,
> Bill
> K9YEQ
> 
> https://wrj-tech.com/
> 
> -----Original Message-----
> From: elecraft-bounces at mailman.qth.net <elecraft-bounces at mailman.qth.net> On Behalf Of Wayne Burdick
> Sent: Tuesday, January 22, 2019 2:57 PM
> To: Elecraft <elecraft at mailman.qth.net>
> Cc: KX3 <KX3 at 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
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