17 Jul
2003
17 Jul
'03
10:09 p.m.
I wouldn't use a simple on/off IR signal. I'm talking about a modulated/
decoded signal. Sunlight will not affect that. An RF link is far more
susceptible to RF interference than an IR signal (if the IR receiver is
properly shielded, and most come already shielded). If the front end of
an RF receiver becomes saturated, it is even more susceptible. Until
now, I've never heard of a TV being activated by RF through the IR
electronics. I won't say it can't happen, but I would not give it very
good odds.
-Bryan
ghldbrd(a)ccp.com wrote:
I'd think a bit about IR, because of the
following:
My neighbor complained that my ham gear was turning her television set on.
IR control was being triggered by sunlight wafting in through drapes and
blinds, and happened to hit the right pulse sequence to turn on the set.
I've heard that is not unusual.
Being "outside", you might have something like that key up your
transmitter when you don't want it to. I'd stick with a hardwire PTT
switch of some sort.
Gary Hildebrand WA7KKP
>I second the motion! Use an IR link! Use of a frequency selective IR
>Tx/Rx system will prevent unwanted keying of your transmitter, and if it
>is anything like the ones I have built, the reflected signal will be
>enough to make it work (no need to be line of sight).
>
>Using RF to create a link is asking for trouble, not to mention a lot
>more work. Check FCC regs, this is considered remote transmitter
>control. If you choose to go RF, use a coded transmitter similar to a
>remote entry key, not a PL based one, since even that is susceptible to
>interference. Holtek makes a few Tx/Rx chips with digital coding. You
>can buy the chips at digikey.com. (But don't use them! Go IR!)
>
>-Bryan