cowboy,
Well, imagine that you've ordered a few of these HR-34s for your customer. Yopu've been told your order is at the top of the list, but about fifty have been ordered by various installers. You hear that yours have have arrived at the distributor, but they are going to take a couple of days to test them out and play with them.

See why they'd just ship them out instead of playing with them? They are in business to deliver the goods to you first, play with them if they have enough of them.

And would you want an open box at full price?



On second and third thought, these probably won't work.

This is similar to the first IR product ever brought to market, Xantech's Xtra Link. A coaxial cable that goes from one product to another carries the IR signal, which varies between zero volts and either five or twelve volts, depending on the system.

Here's what's wrong with that in today's system:
*That was intended for use where a modulated signal, usually channel 3 from a satellite receiver that is now obsolete, goes to a TV at some distance from the satellite receiver. The piece you link to goes near the TV, and a separate piece goes near the satellite receiver and extracts the IR signal from the cable. Since new satellite receivers don't have modulated outputs, that makes this obsolete.

*Unless you use a ZeeVee modulator. That's awful pricy for one TV.

*Some people tried using these things with a coax that carries the satellite signal. Since a satellite receiver outputs either 13 volts or 18 volts to determine polarity selection, you can't use this device, which sends a signal varying between zero and 12. The 13 or 18 would swamp it out.


Finally, on a whole other topic, maybe this input isn't working because it's not seeing a high enough voltage.

See, sensor outputs go from zero to five volts and can supply quite a bit of current. An LED, though, only wants to see about 5 milliamps, so there's a resistor, often in the 470 ohm range, between the IR sensor and the IR LED. This resistor is built into every LED output circuit.

That means that if you connect a signal intended for an LED, the internal resistance of the satellite receiver's circuit might cut down the voltage below a usable level. If this is the case, you'd take the signal not from an LED output, but directly from the sensor output. This is sometimes called IR HIGH or something else to define it as "not for an LED."