ICOM 746 installation in 2002 Fleetwood Discovery

Discussion in 'On the Road' started by KD2HTG, Sep 11, 2020.

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  1. KD2HTG

    KD2HTG Ham Member QRZ Page

    Hello everyone,

    This is my first posting on the QRZ forum.

    I have installed an ICOM 746 in the rear of my motorhome, using the ICOM cable directly to the house batteries. The antenna is an Eagle One Vertical which is mounted on the ladder. The ground braid is wrapped around a rug of the ladder and goes to a clean contact on the chassis of the motorhome from the stud on the antenna for a counterpoise. I have an air choke with three fair-rite 241 - 52 toroid cores with 6 turns of the coax at the antenna feed point. The radio works well both transmit and receive. The ICOM internal tuner tunes the SWR well on several bands.

    Here is the PROBLEM: When I transmit 50 watts to 100 watts on 40 meters the black water, gray water, and fresh water indicator lights flash in modulation with my voice. When I disconnect the tank leads from the indicator panel at the indicator panel there is no flashing. I have put ferrites on the leads at the indicator panel and they still blink. Sometimes, the lights blink on 20 meters but mostly 40.

    I pulled the connectors AT the black and gray water tanks with the connector "connected" at the indicator panel and they still blink. I cannot find a connector to disconnect the fresh water tank at the sensors, so that could still be providing the blinking lights when the other two tanks are disconnected. There are three different sets of sensors, one for each tank.

    I think that either the sensors themselves, or the cabling to the indicator panel is picking up the RF from the antenna. With an oil can dummy load at the antenna feed point ,and at the radio, no lights blink, so it seems as if it is the energy from the antenna that blinks the lights.

    This might be a minor difficulty as I am not having the problems others have mentioned, with the awning going out or the fans activating. Has anyone else had a similar problem and, please, how did you fix it?

    Thank you for your replies

  2. KD2HTG

    KD2HTG Ham Member QRZ Page

    No one has encountered anything like this before?

  3. K3SZ

    K3SZ Ham Member QRZ Page

    Have you tried putting some .01 uF caps across the tank leads at the indicator panel end?
  4. KD2HTG

    KD2HTG Ham Member QRZ Page

    No I have not, but I will. Thanks
  5. N1IPU

    N1IPU Premium Subscriber QRZ Page

    Rule #1, Ground everything on mobiles with flat braid. Even the Exhaust.

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