[bars] Physically small 440 antenna?

[William Smith]

Andy,

Good idea, and I can 3D print the insulator part that goes on an aluminum channel, so metalworking, 3D printing, Amazon, NanoVNA, and an excuse to dig out my mobile rig, got all the bases covered!

Maybe I'll document it for the newsletter.  I'll have plenty of spare time with the new puppy arriving.  8*)

#itsAllAboutTheJourney

73, Willie N1JBJ

> On Sep 30, 2022, at 3:05 PM, Andy Wallace <soldersmoke01 at gmail.com> wrote:
> 
> Willie, trying to use a ground plane antenna on other than a vehicle or othee large plane of metal is problematic. 
> 
> I cobbled up a quick vertical dual band dipole inside my cellar stairs for 2m and 70cm and it works ok. It uses a barrier strip and a couple metal scraps (coathangers would work). 
> 
> | 
> | 
> |
> |  |
> |-| <—-to center cond
> 
> |-| <—-to shield
> |  |
> |
> |
> |
> 
> ASCII art is tough but think of it as two asymmetrical U shapes fed at the center by coax heading out horizontally. It’s like a multiband fan dipole. The 2 and .70 elements are fed at the same time. 
> 
> If you only want 70cm it’s even simpler. It’s just a half wave dipole turned 90 degrees. 
> 
> 468/(443 MHz) = 1 foot, 0.7 inches. Each leg is less than 7”. Surely you have room for that. You could even use copper tape stuck to the window. 
> 
> Got scrap coax? Strip a little over eight inches off and spread the braid and center conductor at right angles and see how it performs. Just make sure the coax exits perpendicular. 
> 
> Cut things long and trim (if you have an swr meter). 
> 
> Good luck. Don’t overcomplicate it!
> Andy
> KA1GTT