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aa5xo

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

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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

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