I thought it would be good to start a new thread on the keyless entry issue, since I've got some new data to contribute to the discussion.
Before we get on with my new information, here's a quick recap on the prior discussion:
- When the Empeg is playing or is in standby, keyless-entry systems are reduced in range.
- When the Empeg has fallen out of Sleep mode and is in full-power-off mode, keyless systems work normally.
- When the Empeg is unplugged from the dash, keyless systems work normally.
- It doesn't seem to be power-draw related.
- It only happens in some cars. The amount of range reduction varies from car to car and from installation to installation. Sometimes it is mild, sometimes it is very severe.
The evidence so far points to RF interference, of course. And I don't see any way that Empeg could do any better about reducing it. They are already within FCC specs and are not obligated to solve the problem for the car manufacturers. The best work-around I've seen so far is to reduce the sleep-timeout value to 5 seconds. That way, when you turn off the ignition, by the time you exit the car and try to lock it, the empeg is no longer interfering. This is fine, to me, and I don't see any need for Empeg to worry about the issue.
But I noticed something very odd today and want to discuss it. One thing that's going to come up in the discussion is the fact that I'm alpha-testing one of the tuner modules, so let's just get that out of the way first. By the way, the tuner module works like a charm, it's awesome and it gets great reception. It's significantly better than the tuner in the Mark1.
Anyway, here's my chronology:
- I have, over the last year, had either the Mk1 or the Mk2 installed in my Accord at all times. The keyless entry system has worked mostly fine the whole time.
- After the RF interference thread came up on the BBS, I investigated and determined that my keyless range was reduced by a few yards when the empeg was on standby. But I still had plenty of range and was not worried about it.
- One of the things about the Honda is that it's a PITA to run cables to the amps in the trunk. So I cheated on my install and ran the audio cables in the same tunnel as the power cables.
- Needless to say, there was a bit of inductive noise in the system. The long RCA-cable run was acting like an antenna, and picking up RF interference from the power cables running alongside it. The noise was very faint, but I could barely hear it when the engine was revving and the player was in the silent part between songs. It seemed to be ordinary alternator whine combined with other car electrical system noise (A/C fan, etc.). It was not internal "computer" sounds from the empeg, it was the car's noises. It didn't seem to be a ground loop or anything wrong with the empeg/amps.
- So I made a pact with myself: When I get a tuner module, I do whatever it takes to re-route the RCA cables differently.
- I got the tuner, and I did the re-routing. Spent several hours that evening ripping out the RCA cables and re-routing them through the center tunnel instead of the driver's side.
- Initial tests indicate the inductive noise is gone. Cables are fully routed, but during these tests, the dash is disassembled and Empeg is sitting on passenger seat. It sounds great this way. No noise with engine revs.
- Then I re-assemble the dash, with the tuner installed as well. Everything is in its final place.
- Inductive noise is BACK! Although it has a totally different character and seems to be echoing a different set of the car's electrical system noise. It still increases with engine revs, but now more of the A/C fan noise is in there, too.
- The only thing I can figure is that the wires bunched up behind the docking sleeve are communicating RF interference at that location. So I reach into the dash with everything mostly still assembled, and I fiddle with the wires a bit. Moving them gently in small amounts, I can make the inductive noise go away. Note that this is not a loose wire problem as far as I can tell, it really sounds/behaves like an RF problem.
- I fiddle with the behind-the-sleeve wire layout until I am satisfied with the results. One of the things that SEEMED to help was to take the three "dangling" unused connections: Serial, Aux-in, and Mic-in, and dangle them somewhere away from the RCA cables and other wiring.
- Then I go out for a spin today, and what do I notice? I CAN'T UNLOCK THE DOOR unless I'm standing right next to the car. I now have the keyless entry bug!!!
I think that wire re-arranging has a significant impact on the keyless entry systems. In the same way that wire re-arranging can get rid of the inductive noise in the RCA cables, it can affect other components as well.
I am also wondering if the
unconnected items (mic/aux/serial) could be acting as
broadcast antennas? Or could the tuner module be giving off some new RF of its own? Remember that the tuner module, in my car, is getting
great reception.
Any insights?
___________
Tony Fabris
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