The team

Northern Virginia FM & TV DXing

The writer of this blog (FM DXing) also contributes an occasional technical article on FM tuner electronics to David’s long distance FM radio blog.

3 Responses to The team

  1. Rinus Jansen says:
    August 11, 2015 at 7:25 pm

    Hi David
    Just to let u know that 50 (80) kHz and 110 kHz ceramic filters are available from Kent Electronics
    in Holland 10.7MT and 10.7MHY

    Reply
  2. KPL says:
    August 10, 2016 at 12:43 am

    David, you mention at ‘Tin Can Bay Volunteer Coast Guard’ the use of a vehicle with an ‘amplified Shark Fin’. Are you 100% sure that the Shark Fin functioned as the FM radio aerial?
    My experience (in Europe) is that original Shark-Fins are only used for GPS and phone. Cars with them usually have the FM/AM antennas printed on the back window with the demister (or sometimes printed on rear side windows). I know there are aftermarket sharkfins to replace ‘Beesting’ FM/AM antennas available, with greatly reduced reception.
    One way to test where on the car the FM (or AM) aerial is is to tune in a weak station, and move about a handheld device that is known to cause some interference (a TV remote control interferes with AM on an adjacent receiver when any button is pressed, a Tablet etc would likely interfere with FM) and see where there is maximum interference,

    Reply
    • fmdxing says:
      August 19, 2016 at 5:13 pm

      Thanks for your comments, Kieran.

      The factory radio used at Tin Can Bay is made by Harman Becker Automotive Systems GmbH. The parent company making the car is Volkswagen Aktiengesellschaft. My educated guess is that one these two companies manufacture the shark fin antenna. The AM/FM reception is provided by either (a) the shark fin or (b) an invisible rear windscreen antenna. I believe it is the shark fin, as I looked up the car manufacturer’s part number for the antenna.

      Obviously with hire vehicles – particularly 4WDs I’ve found that’s often impossible. I agree that it is certainly possible in those instances that a shark fin antenna may not be ‘what the car is using’ for AM/FM reception.

      Are original factory shark fin antennas only used for GPS & phone?

      I have certainly seen car manufacturers (or their third party manufacturers) employing shark fin antennas for combined cellular, navigational & broadcast band reception. This seems to be a relatively recent development.

      How do you test where the antenna is on the vehicle?

      You have provided very good advice. In particular, testing with a tablet (for example) to see whether it causes FM interference to accurately determine the exact location of the FM antenna.

      I would add… One way to test whether a FRONT windscreen antenna is in use is to use the windscreen wipers whilst listening to FM. In my car (which uses a front windscreen antenna) running the wipers on an empty FM channel using the factory radio (made by Robert Bosch Car Multimedia GmbH) causes audible interference over the white noise as the wipers turn.

      Reply

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