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RF Amplifier — Parallax Forums

RF Amplifier

ArchiverArchiver Posts: 46,084
edited 2004-01-19 14:10 in General Discussion
Hello All

To some this might not be a stamp question, but please hear me out, I need help.

I bought a RC truck for my son, I have modified the motor driver to handle a 12V
battery ( was 7.2V ). With the extra power the range seems a little short. I was
wandering if any one knows If there is a RF amplifier that I could add to the
truck? There is no room in the remote but there is allot of room in the truck.

Also I have been looking for a charger that will do a fast charge. There are two
batteries. 12V 4 amp/Hr lead acid, & TYCO 7.2V NiCad. I want to make a charger
that I plug into the truck. I was going to use two chargers in one box to do
both batteries.

Thanks for any info

[noparse][[/noparse]Non-text portions of this message have been removed]

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-01-17 16:15
    Anthony,

    My guess is that the motors running at a higher voltage is creating more
    noise, and so shortning the range. It might be possible to install some .1
    and .01 uF filter caps and clean up the noise.

    Is the receiver voltage regulated? If not, the RX module may be protesting
    due to high voltage. Check the voltage on the receiver module (not the
    input, but on the board at the RF chip. You can find the RF chip by
    following the antenna trace. It isn't easy to amplify RF and keep a clean
    signal. What frequency does the unit run at?

    Another thing you might try, run the motors off the new battery pack and run
    the RF receiver from a seperate battery pack, like some "AA", at the
    original voltage.

    Hope this helps,

    Jonathan

    www.madlabs.info

    Original Message
    From: "Anthony Conti" <aconti@s...>
    To: <basicstamps@yahoogroups.com>
    Sent: Friday, January 16, 2004 8:54 PM
    Subject: [noparse][[/noparse]basicstamps] RF Amplifier


    > Hello All
    >
    > To some this might not be a stamp question, but please hear me out, I need
    help.
    >
    > I bought a RC truck for my son, I have modified the motor driver to handle
    a 12V battery ( was 7.2V ). With the extra power the range seems a little
    short. I was wandering if any one knows If there is a RF amplifier that I
    could add to the truck? There is no room in the remote but there is allot of
    room in the truck.
    >
    > Also I have been looking for a charger that will do a fast charge. There
    are two batteries. 12V 4 amp/Hr lead acid, & TYCO 7.2V NiCad. I want to make
    a charger that I plug into the truck. I was going to use two chargers in one
    box to do both batteries.
    >
    > Thanks for any info
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    >
    > Yahoo! Groups Links
    >
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    >
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    >
    > Your use of Yahoo! Groups is subject to:
    > http://docs.yahoo.com/info/terms/
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-01-19 14:10
    What you seem to be looking for is an RF pre-amp. This is not difficult to
    build and you can find plans and information in the Amateur Radio Handbook
    from www.arrl.com. Most libraries also carry this book or similar
    publications. This amp would fit between the antenna and receiver in the
    truck and should improve range a bit. If the receiver has sufficient gain
    already, you may not see much improvement. Consider a better (resonant)
    antenna before adding a pre-amp and you might get the results you need for
    the cost of a bit of wire. Antenna designs are also in the handbook and
    other publications available at the same site.

    jim
    http://www.geocities.com/jimforkin2003/


    Original Message
    From: Anthony Conti [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=SCzor5nJXSW7tFi360lMFNOhG8zLEtMtHjGaCk1auY2Z64j0Mix7XBfQ6IFT1-noV_fHO63p8Loz285i]aconti@s...[/url
    Sent: Friday, January 16, 2004 11:55 PM
    To: basicstamps@yahoogroups.com
    Subject: [noparse][[/noparse]basicstamps] RF Amplifier


    Hello All

    To some this might not be a stamp question, but please hear me out, I need
    help.

    I bought a RC truck for my son, I have modified the motor driver to handle a
    12V battery ( was 7.2V ). With the extra power the range seems a little
    short. I was wandering if any one knows If there is a RF amplifier that I
    could add to the truck? There is no room in the remote but there is allot of
    room in the truck.

    Also I have been looking for a charger that will do a fast charge. There are
    two batteries. 12V 4 amp/Hr lead acid, & TYCO 7.2V NiCad. I want to make a
    charger that I plug into the truck. I was going to use two chargers in one
    box to do both batteries.

    Thanks for any info

    [noparse][[/noparse]Non-text portions of this message have been removed]


    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.


    Yahoo! Groups Links

    To visit your group on the web, go to:
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