My system was installed by a "professional" installer,
who I have since determined was kind of an amateur. I
should have shopped for an installer myself, rather than
allowing my general contractor to do it. But that's water
under the bridge, and a way of explaining why I, a consumer,
am now faced with fixing my system's problems, which I've
been suffering with for a couple of years now.

I have an MX-850 which uses an RFX-150 to relay RF signals
to a pair of MRF-250's.


Everything in my system is controlled by RF, except for
the TV, which is IR. The component stack is in a bedroom
closet, out of line-of-sight from the remote. The RFX-150
is positioned high in the bedroom closet, above the component
stack.

Everything works fine, at all times, EXCEPT my ReplayTV
5500, which often, and randomly, fails to respond to the
MX-850. It responds perfectly, however, to its own remote,
if I walk into the closet and point it at the Replay,
and responds perfectly to the MX-850 if I enable IR on
the MX-850, and walk into the closet and point the MX-850
at it.

When the ReplayTV is failing to respond, its misbehavior
can last for a minute, or an hour. Occasionally a command
will get through to it; I have to press buttons on the
remote repeatedly during these episodes to get a single
command to register. Other times, it works just fine.


I did not at first think the problem was radio inteference,
because all my other components work just fine; if it
was radio interference, I figured, it would affect all
the components equally.

Rather, since this doesn't happen with any of the other
components in my system, I assumed it was a ReplayTV-specific
problem (or a problem specifically with communicating
with the ReplayTV). I tried many things: I replaced
the circuit board in the ReplayTV that contains the infrared
sensor. I adjusted, in both directions, the intensity
of the signal being sent by the MRF through the IR-blaster
to the Replay. (Maybe it's saturating? Maybe it's not
strong enough? Maybe if I fed it wet instead of dry food?)
I tried a different MRF unit. I tried a different IR
blaster cable. I even tried a different MX-850 and a
different RFX-150. I tried re-programming the codes into
the MX-850, using the Replay's remote. I tried positioning
the MRF unit in front of the component stack and using
the built-in flashers, rather than the IR blasters. Nothing
worked.


Having finally encountered this thread (and having run
out of things to swap out), I am of course suspecting
RF interference. (I feel like I've ruled out or swapped
out everything else!) This would account for the total
randomness of the occurrence of the problem...and I notice
that (duh) the little RF indicator light on the RFX-150
flickers (dimly) from time to time when I'm not using
the remote. (It lights very strongly, of course, when
I *am* using the remote.)

I've turned the sensitivity of the RFX-150 as low as it
goes (it's only about 15 feet away from where I sit when
using the remote), and folded its antenna in, in an attempt
to reduce its sensitivity to unwanted interference. That
seems to have eliminated the dim flickering of its RF
light (at least so far...it's been a couple of hours)
and the Replay seems to be responding well...though I've
had this experience of jubilation before, only to be followed
by disappointment as the intermittent problem returns.

My fear is that this won't work, and that the problem
will return, and I'm trying to decide, if it does, whether
to continue to bark up this RF interference tree, trying
ferrite cores and changing the routing of my wires, and
moving the RFX-150 farther from the components, etc.

But it only makes sense to follow that route if it's true
that there could be a reason that the interference is
affecting only the ReplayTV and not my other components;
is it possible, for example, that the ReplayTV's receptor
or circuitry is more sensitive to imperfect, interfered-with
signals than the receptors of other components? I can't
help but think that, absent something like that, it's
totally non-logical for communications with the Replay,
but not my other components, to be affected by RF interference,
and I am reluctant to embark on a course of RF interference
elimination (which seems very trial-and-error-based) if
simple logic says that because all my other components
work just fine, that can't be the problem. I'd appreciate
any thoughts you guys might have on this.