Question concerning RF signal testing

[kd6532]

I am designing an automated mailbox system that, after sensing an
object in the mailbox, will send an RF signal from the mailbox to a
receiver inside the home. To do so I am using a 555 timer to generate
the tone, and on the receiving end, I am using a LM567 tone detector to
detect this tone (probably with an output filter capacitor to "clean
up" the signal). I want to make sure the correct signal is being
received, and I was hoping someone could give me some insight (info, or
even just point me in the right direction with like a book or website).
I also would love to find out more about testing procedures to ensure
the right signal is being received. Thanks for your time, and any
advice is welcomed and appreciated.

Kris

[horseshoe7]

Post by kd6532
I am designing an automated mailbox system that, after sensing an
object in the mailbox, will send an RF signal from the mailbox to a
receiver inside the home. To do so I am using a 555 timer to generate
the tone, and on the receiving end, I am using a LM567 tone detector to
detect this tone (probably with an output filter capacitor to "clean
up" the signal). I want to make sure the correct signal is being
received, and I was hoping someone could give me some insight (info, or
even just point me in the right direction with like a book or website).
I also would love to find out more about testing procedures to ensure
the right signal is being received. Thanks for your time, and any
advice is welcomed and appreciated.
Kris

[horseshoe7]

Post by kd6532
I am designing an automated mailbox system that, after sensing an
object in the mailbox, will send an RF signal from the mailbox to a
receiver inside the home. To do so I am using a 555 timer to generate
the tone, and on the receiving end, I am using a LM567 tone detector to
detect this tone (probably with an output filter capacitor to "clean
up" the signal). I want to make sure the correct signal is being
received, and I was hoping someone could give me some insight (info, or
even just point me in the right direction with like a book or website).
I also would love to find out more about testing procedures to ensure
the right signal is being received. Thanks for your time, and any
advice is welcomed and appreciated.

If you are interested in staying with the unlicensed personal radio
services, you may be better off going with MURS than FRS, as digital
experimentation is basically verboten on FRS.

Check out:

http://www.cmlmicro.com/Products/Index.htm

and

http://groups.yahoo.com/group/MURS-OPEN

Also, in the long run, you might be better off getting your ham
license:

http://www.arrl.org

Post by kd6532
Kris

- Stewart (N0MHS)

[mryan]

A simpler way to go is just rig a garage door opener transmitter to the
mailbox. Place the receiver unit in hour house with a buzzer or other
announciator. You can get these transmitter/receiver pairs most anywhere -
even at Home Depot and they have digital coding to prevent falsing. If you
need more range, attach a bigger antenna to the receiver.

Post by kd6532
I am designing an automated mailbox system that, after sensing an
object in the mailbox, will send an RF signal from the mailbox to a
receiver inside the home. To do so I am using a 555 timer to generate
the tone, and on the receiving end, I am using a LM567 tone detector to
detect this tone (probably with an output filter capacitor to "clean
up" the signal). I want to make sure the correct signal is being
received, and I was hoping someone could give me some insight (info, or
even just point me in the right direction with like a book or website).
I also would love to find out more about testing procedures to ensure
the right signal is being received. Thanks for your time, and any
advice is welcomed and appreciated.
Kris

[horseshoe7]

Post by mryan
A simpler way to go is just rig a garage door opener transmitter to the
mailbox. Place the receiver unit in hour house with a buzzer or other
announciator. You can get these transmitter/receiver pairs most anywhere -
even at Home Depot and they have digital coding to prevent falsing. If you
need more range, attach a bigger antenna to the receiver.

Yes... or a motion detector driving a light or bell... these very
inexpensive devices were designed for this very application - and
perfectly legal Part 15 devices.

You are right - no need to re-invent the wheel.

- Stewart

[Phil Stripling]

Post by mryan
A simpler way to go is just rig a garage door opener transmitter to the
mailbox.

:-> Every time the garage door goes up or down, go check the mail.