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- Whimsical Doorbell in Nuts and Bolts Oct 2005 is Very Nice — Parallax Forums

- Whimsical Doorbell in Nuts and Bolts Oct 2005 is Very Nice

MrdavidjenkinsMrdavidjenkins Posts: 49
edited 2005-12-09 15:09 in General Discussion
Remote Alert Project idea.

I am very happy with the radio transmitter and receiver kit that·I purchased from italiano34@hotmail.com for the project "Whimsical Doorbell' in the October issue of Nuts and Bolts.· If you remember, the project building folk art doorbell ringer with a wireless connection to a remote receiver.· On one of the projects I am working on I need to monitor a process and alert someone remotely.· The Kit I purchased from Andy is very useful and will do everything I need at a reasonable price ($50)

Here is a link to the article:

http://www.nutsvolts.com/toc_Pages/oct05toc.htm

He has been really helpful and quick in responding.· I expect that I will be buying a few more from him as I need them.

Comments

  • Beau SchwabeBeau Schwabe Posts: 6,568
    edited 2005-11-16 15:31
    Mrdavidjenkins,

    Not to be picky, but for 434MHz, a 9.36 inch antenna does not seem optimal.


    Wavelength = velocity(speed of light in meters) / frequency (Hz)

    .691 meters = 300Mm / 434MHz

    .691 meters * 39.37 = 27.2 inches ' Convert meters to inches


    Full wave = 27.2 inches
    1/2 wave = 13.6 inches
    1/4 wave = 6.8 inches
    1/8 wave = 3.4 inches

    Most likely you would use a 1/4 wave or 1/8 wave antenna.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Beau Schwabe

    IC Layout Engineer
    Parallax, Inc.
  • MrdavidjenkinsMrdavidjenkins Posts: 49
    edited 2005-11-16 16:29
    Wow - I will try what you suggest. Thanks for the advice
  • MrdavidjenkinsMrdavidjenkins Posts: 49
    edited 2005-12-09 15:09
    Good Morning,

    I did not change the antennae length, but I got some pretty great results. I was hoping for 100 ft range, but I got about 300 ft with a strong signal. This was in a open warehouse like environment with 2 concrete walls separating. This is a very nice product and was really useful in an application where I needed a remote allert. Recommended!

    Dave
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