ARRL

Register Account

Login Help

aa5xo

Joined: Mon, Mar 28th 2011, 02:08 Roles: N/A Moderates: N/A

Latest Posts

Topic Author Posted On
Using Coax From Old Sat. dish W1FL on 28/1/12
First of all, old coax is usually bad because of water seeping into it. Check it out with a RF/SWR Analyzer such as the MFJ-269. You have to make sure the coax is good. You can measure the loss directly with the SWR Analyzer. Leave the coax open at the far end, connect the MFJ-269 to the near-end, Move the menu to coax-loss and measure at the appropriate frequency.

Secondly, connecting four coax cables in parallel reduces the input impedance to 1/4th of one cable. Maybe for a vertical, that would be a good thing. However, if the input impedance to the antenna is truly 50 ohms, feeding the antenna with 75 ohm coax is perfectly fine.

73,
Stan Kozlowitz AA5XO

Back to Top

EXPLORE ARRL

Instragram     Facebook     Twitter     YouTube     LinkedIn