|Joined:||Mon, Mar 28th 2011, 02:08||Roles:||N/A||Moderates:||N/A|
|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.
Stan Kozlowitz AA5XO