bt amp grounding
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Dear wils5150,
Disclaimer - Even the “perfect” solution can fail.
On the pre-Rushmore EG we recommend the high current ground from the amplifier be attached to the top triple-tree clamp. Also, we recommend that the amp, head unit and other audio components “star ground” to the same point. Prior to ’06 radio ground was located on the top clamp. In 06 radio ground runs through a 50A Packard connector and back under the seat to a 1/4” stud that MoCo calls the “quiet ground” (where most of the lower power items on the bike form a star ground. A few inches away is another 1/4” stud where the high-current objects connect. Over the fifteen years we have been doing electronics for Harley’s we have seen more issues from the introduction of the connector and the longer ground than issues from the top triple tree ground.
(It’s also worth noting that bars are set in rubber isolators, and to provide the ground for the handlebar switches the top triple-tree location is still the rule.)
On the pre-Rushmore RG we recommend one of the four radio box studs - this location is more convenient, but can be more problematic because the studs are pressed in and the neck box is powder coated and uses through bolts. (Because this served as the radio ground (among others), I believe that ground integrity issues were more-or-less solved at the factory because the radio (or other circuits) would not perform properly.) Anyway the radio box stud(s) on the RG *usually* get the job done.
The issue with long, high current grounds (like a wire back to the battery) is that if the wire is small enough and the current high enough, a voltage can be generated which can cause noise in sensitive portions of the network - like the low level circuit which is then amplified, usually several orders of magnitude (40X is not unusual.) Long grounds are also conducive to ground loops - another source (or sink) of noise due to electro-magnetic fields. Mix in rubber tire earth ground isolation and oh boy!
Anyhow please call and we can get you a replacement set of voltage supply leads. I’m keen to learn how the B+ line chafed and where it occurred.
Regards,
-MM
====================================
Celebrating fifteen (15) years in business. Happy Birthday Biketronics!
Dear wils5150,
Disclaimer - Even the “perfect” solution can fail.
On the pre-Rushmore EG we recommend the high current ground from the amplifier be attached to the top triple-tree clamp. Also, we recommend that the amp, head unit and other audio components “star ground” to the same point. Prior to ’06 radio ground was located on the top clamp. In 06 radio ground runs through a 50A Packard connector and back under the seat to a 1/4” stud that MoCo calls the “quiet ground” (where most of the lower power items on the bike form a star ground. A few inches away is another 1/4” stud where the high-current objects connect. Over the fifteen years we have been doing electronics for Harley’s we have seen more issues from the introduction of the connector and the longer ground than issues from the top triple tree ground.
(It’s also worth noting that bars are set in rubber isolators, and to provide the ground for the handlebar switches the top triple-tree location is still the rule.)
On the pre-Rushmore RG we recommend one of the four radio box studs - this location is more convenient, but can be more problematic because the studs are pressed in and the neck box is powder coated and uses through bolts. (Because this served as the radio ground (among others), I believe that ground integrity issues were more-or-less solved at the factory because the radio (or other circuits) would not perform properly.) Anyway the radio box stud(s) on the RG *usually* get the job done.
The issue with long, high current grounds (like a wire back to the battery) is that if the wire is small enough and the current high enough, a voltage can be generated which can cause noise in sensitive portions of the network - like the low level circuit which is then amplified, usually several orders of magnitude (40X is not unusual.) Long grounds are also conducive to ground loops - another source (or sink) of noise due to electro-magnetic fields. Mix in rubber tire earth ground isolation and oh boy!
Anyhow please call and we can get you a replacement set of voltage supply leads. I’m keen to learn how the B+ line chafed and where it occurred.
Regards,
-MM
====================================
Celebrating fifteen (15) years in business. Happy Birthday Biketronics!
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