22 May
2007
22 May
'07
8:36 p.m.
----- Original Message ----- From: "kc6uqh" kc6uqh@cox.net To: "Mike Miller" mmiller@nctc.com; amsat-bb@amsat.org Sent: Tuesday, May 22, 2007 7:46 AM Subject: [amsat-bb] Re: 75 ohm CATV Cable on 70 cm
I have used the 1/2 " hardline type with disk type dielecrtric for several years. A 1/4 wave of brass hobby tubing driven over the copper center conductor and soldered at both ends solves the 50/75 transition problem.
Art, KC6UQH
Hi Art, KC6UQH
If the diameter of your 1/4 electrical wave long of brass hobby tubing driven over the copper center conductor changes the impedance of this cable section from 75 ohm to SQR( 50 * 75) = 61 ohm it is a good idea.
Best 73" de
i8CVS Domenico