Batboard

OK here is the picture. You have a BIM card in a CEB used to connect to a telco remote control line.
You also have a tone remote on the telco line. If the BIM card is in a patch on a trunking system, you
can hear the LLGT (low level guard tone 2175 Hz) on the patched trunking talkgroup if the tone remote keys up.

The LLGT is not loud, but you know it is there on the patched outbound trunking talkgroup. Is there a
way of removing the LLGT from feeding through on the patch?

I was under the impression that there was some sort of 2175 notch filters in the TX audio path of the patch,
but it looks like I may be wrong. Anyone else had to deal with this situation?

Jim

You hear it over the air, or at the console? I'll assume at the console. In a 4W system, someone may not have installed the 2175 notch in the rx audio path. BIM cards are always 4W internally even if only used as 2W to the station. Review the jumpers on that BIM.

Bill_G wrote:You hear it over the air, or at the console? I'll assume at the console. In a 4W system, someone may not have installed the 2175 notch in the rx audio path. BIM cards are always 4W internally even if only used as 2W to the station. Review the jumpers on that BIM.

That is the question on how to get the notch filter to be active in the audio path going to the next talkgroup in the system.
I have 2 talkgroups patched together and on one side of the patch, there is a tone remote console in the TX mode. It is
from this source that the 2175 is being heard over the trunking radio. The tone remote is talking to a user on the trunking
system.

The audio is heard on the outgoing path of the trunking system patch. Don't care about the console at this time. I believe
they always have a built in notch filter active.

Jim

Okay. So, it's being heard over the air suggesting the tone remote adapter is missing the notch filter. But, it sounds fine when used stand alone? You only hear the llgt when you establish a cross patch? I'd check some levels and the freq of the llgt just in case it is getting translated someplace falling outside the notch filter skirts. I've had 2175 become 2180 through a bad mux.