centracom II patch feature

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miken8eqd
Posts: 18
Joined: Thu Dec 28, 2006 9:00 pm

centracom II patch feature

Post by miken8eqd »

Well,

I'm learning new things every day with my Centracom II console.

This console has a way to patch 2 or more radios together. I tried it on a couple of channels and it works - sort of.

i have a manual and would like to know if the audio levels are adjustable between modules when the patch is enabled. If the levels are adjustable, where would i look for the adjustments?

Most of the BIM's are B1422 and B1423 with the exception of one BLN6654D card.

thanks
mike w8vpc
Jim202
Posts: 3610
Joined: Sun Sep 09, 2001 4:00 pm

Re: centracom II patch feature

Post by Jim202 »

miken8eqd wrote:Well,

I'm learning new things every day with my Centracom II console.

This console has a way to patch 2 or more radios together. I tried it on a couple of channels and it works - sort of.

i have a manual and would like to know if the audio levels are adjustable between modules when the patch is enabled. If the levels are adjustable, where would i look for the adjustments?

Most of the BIM's are B1422 and B1423 with the exception of one BLN6654D card.

thanks
mike w8vpc



I think you will find that some of the radio techs do a poor job of aligning the audio levels on the radio circuits. There are a few good techs that know what they are doing, but I have run into a number of them that don't even know how to set up a TIMS unit correctly. The big problem is they don't know the difference between un-terminated and terminated when they make the measurements.

The other problem with the BIM cards is the output level adjustment pot is not easy to set. You just breath on it and the level changes a good amount. Plus these pots get dirty and who knows what the level will end up at. Generally it goes low. When this happens, the TX audio on that channel goes down.

Jim
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d119
Posts: 3532
Joined: Tue Mar 19, 2002 4:00 pm

Re: centracom II patch feature

Post by d119 »

Not to mention that there is a service bulletin related to patch audio being louder than dispatcher audio.

On top of that, the patch is VOX by default. It can be configured for COR, but requires additional equipment.

The long and the short of it is that half duplex to half duplex patches (radio to radio) DO NOT work very well on Centracom. It works much better with systems that have wireline on them (repeaters, comparators) and are full duplex, or in cases where a trunking system with a wireline to the console is involved.

Interop switches to a much better job of handling radio to radio patches, as they can ignore hang times, tones, etc. Centracom cannot.

I echo Jim's statement about techs not being TIMS-savvy. I always hook everything up as it will be in the final configuration, and then BRIDGE in with the TIMS to measure the levels.
miken8eqd
Posts: 18
Joined: Thu Dec 28, 2006 9:00 pm

Re: centracom II patch feature

Post by miken8eqd »

Thanks for the replies!

I suspect the issue was something to do with audio level adjustments. I was hoping there were adjustments for patch audio and how the patch function works.

TIMS = Transmission Impairment Measurement Set.

I should look up information about this piece of test equipment. Is there a procedure on how the adjustments are done?

again, thanks for the information!
Mke
Jim202
Posts: 3610
Joined: Sun Sep 09, 2001 4:00 pm

Re: centracom II patch feature

Post by Jim202 »

Part of the answer to making it work is what type of keying control your using. If it's tone control or E&M keying to the radio. I don't play with this model console so I have to back out and let the others that have more time under their belt help.

I will say that the simple way I have used in the past to adjust a tone remote control circuit is real simple. I use the TIMS in the bridged mode and measure the low level guard tone (LLGT), which is PTT with no audio from the mic on the console. In all the dispatch locations I have been to around the country, I have found the LLGT to be some place in the range of a -27 to a -35 db. Where it ends up really doesn't matter as long as the radio techs align all the channels the same and set the remote transmitters to it.

Using the LLGT to do alignments of the audio levels is easy and doesn't bug the users on the channel. The down side to it is that you can't set the transmitter deviation with it, but it can allow you to align everything else up to the transmitter.

Just some comments for what they are worth.

Jim
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