I think that’s right if the only issue is your own transmit signal bouncing back from the antenna junction and traveling along the exterior of the feedline. But for receiving, I think a choke at each end of the feedline is important unless you’re in an exceptionally low noise location. K9YC recommends putting a choke at the antenna end of the feedline, and I’ve found it makes quite a difference in the amount of local noise on the received signal. If I understand it right, the outside of the feedline picks up the noise signal and carries it to the antenna junction, from where it gets mixed in with the desired signal.
Art Delibert, KB3FJO Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10 From: Rob Atkinson<mailto:[email protected]> Sent: Friday, September 15, 2017 12:34 PM To: [email protected]<mailto:[email protected]> Subject: Topband: RF choke/balun If you have enough radials at or below ground you won't need a common mode choke. You don't say if your inverted L will have an elevated ground system or not. If the ground system consists of 60 or more radials you can probably put a matching network out and the feedpoint and forget about fooling around with common mode chokes and all that. The RF current on the exterior of your feed line will be so small it won't matter. 73 Rob K5UJ _________________ Topband Reflector Archives - https://eur02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.contesting.com%2F_topband&data=02%7C01%7CK7OX%40msn.com%7C90d25689d0e24f27303908d4fc57a3f7%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636410900726688609&sdata=QPoWjPSW%2BxOAG0peN9NV01fTIyJxcsBaE82h8l7CtBY%3D&reserved=0 _________________ Topband Reflector Archives - http://www.contesting.com/_topband
