I'm trying to fix a problem with a MX-850 and an MRF-250. Heres the problem. Every two or three times you hit a certain button, the MRF will send it to the DirecTV HR20 twice. IE, hit "list" once, and the dvr page comes up for a split second, then disappears. Or if number two is pressed, 22 will show up. Each button is only pressed once, and about half the time the MRF sends the IR twice. This is only happening with the DirecTV HR20, the reciever and dvd player work flawlessly. Does anyone know whats going on with this, or if theres a fix for it?

Oh yeah, and I tried the DirecTV remote and it works fine.

i've come across that problem, not too long ago. I changed the mrf-250 for used mrf-300 & adjusted the ir output, it fixed the problem for me.

or i you can just move the placement of the ir on the mrf-250.

Remove the antenna from the MRF-250.

hang the emitter from the top of the hr20
so that it sits one inch away from the front
if that doesn't work try spinning the emitter around
so that only the little dot faces the hr20
there is always a sweet spot somewhere in all that

THANK YOU!!!

I have the Ir transmitter 2 inches away and have a piece of black electrical tape with a pinhole over the sensor window.

Even the closed caption macro for the HR20 is 100% accurate with my MRF-200! Wouldn't it be nice if Directv just had a single button for it.

Sounds like the IR output was too high...unfortunately the MRF-250 isn't adjustable. Placing it further away will help...also you can add a resistor in line to lower the output.

If I have the MRF-200, do you have a value in mind for the resistance?

Sometimes LEDs are driven by a constant current driver and adding a series resistance would only make the driver put out more voltage to compensate for the resistance. Do you have any idea if this is the case? (Now would be just the time for a very nice HTM guru to pop in). If that is the case, it might make sense to have a parallel resistance or series / parallel.

I have seen the resistance idea tossed around, but never heard what a good value would be.

Another trick that sometimes works is placing a piece of scotch tape between the eye on the box and the emitter.

That's possble for displays, but have you ever seen a remote control product where the money is spent to add the parts needed for constant current? What I've seen have always been products where resistors can be added to lower the current.

Incidentally, a Xantech's high output current is the bus with a 100 ohm resistor in series with it. The low output current is the bus with 470 ohms in series with it. And all this stuff is pretty similar in output voltages, so these resistance ranges are representative.

If I wanted to pin down LED current to a sat receiver with that problem, I'd get a 1000 ohm pot and wire it in series. Once I had the pot at a value that worked flawlessly, I'd measure the pot and replace it with a resistor of the closest value. A pot might not work for too long at these currents, but be designed for less.