I am looking at building an egg beater to work the birds. Problem is I don't know where I can find 100ohm coax.
Jerry, K5OE built a number of DIY versions, a decade ago.http://wb5rmg.somenet.net/k5oe/
Dale is correct, RG-62/U is readily available at 93 ohms Z.
RG-62/U is the standard coaxial cable used by IBM as part of their System Network Architecture (SNA) from 1970s to 1990s. The cable is used between the IBM 3274/3174 terminal controller and the IBM 3270 terminals used with IBM mainframes (360 series).
MILLIONS of miles of this coax cable were installed from mid-1970s to mid-1990s in computer data centers, and then slowly removed for UTP cabling since 1995. My last surplus RG-62/U was given to Jerry, K5OE in late 1990s.http://wb5rmg.somenet.net/k5oe/Texas_Potato_Masher_2.html
Pres, N8UG at The Wireman; Joel at RF Connections; and Digi-Key sell it by the foot.http://media.digikey.com/pdf/Data%20Sheets/General%20Cable%20PDFs/RG_62U_Type.pdf
If it is feasible, would it be as simple as adding 25% to the length or would it be more complicated than that?
Sigh. Learning the Basics (Radio, AC Theory, Electronics) is important ... It's complicated when you don't.