MC2500 and MDC1200

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Spatch713
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MC2500 and MDC1200

Post by Spatch713 »

Ok for some background for you guys to help me, our EMS agency just moved into a brand new building. We had a nice commuincations setup installed which includes Low, high, and UHF CDM1250's. The UHF CDM is controlled by 6 MC1000's and one MC2500.

The problem is when we use a remote our transmissions are "clipped" at the begining of a transmission by the repeater. Every radio in the department has Post MDC signalling set up to overcome the repeaters delay in transmitting. The MDC feature is used for ID purposes as well as making people wait the correct amount of time to talk and be heard.

The repeater is a total whore of an install by our regional dispatch center. It's a UHF Tait crossbanded to a Purc low band. Our area is slowly switching to UHF and off of low band. I am certain the problem is caused by the crossband repeater setup. We have spoken with our dispatch center and they stated there is not much they can do because the setup itself induces a 300ms + delay caused by the hardware.

With that being said we need the remotes to key the CDM and send a Post MDC ID just like our mobiles and portables. I enabled the PTT ID on the CDM but the sidetone is not heard on the remotes?. How do I program this so that a user at the end of the remote can hear the PTT ID Sidetone?
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wavetar
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Post by wavetar »

I believe you mean "pre" MDC...post would indicate you're sending the MDC upon release of the PTT.

In order to hear the pre-MDC sidetone, you need to use 4-wire remotes. You are currently likely only using 2-wire...which works fine until you need some sort of feedback from the radio, such as an MDC sidetone or trunking talk permit tones.

The other possibility is you're using the 'handsfree' transmit button on the remotes, which of course cuts off the speaker in the remote to avoid feedback...just like a handsfree phone. You will only hear the sidetone in the handset.

Todd
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Spatch713
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Post by Spatch713 »

You are absolutely correct I mean PRE PTT ID. Thanks you for the correction. All of the remotes were wired with CAT-5 but I only noticed two wires going to the demark and then on to the tone remote adapters. Would you happen to know what I would have to do in order to get that audio I need?
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wavetar
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Post by wavetar »

Well, I know for the older C200 series tone remotes, they came as 2-wire (tx & rx on the same wire pair) by default, and you had to add a 'daughter' board to convert them to 4-wire (tx on one pair, rx on the other). I'm not positive on the MC1000, but could check tomorrow at work (if I remember to).

If they are 4-wire capable, you simply need to run another pair of wires between the tone remote interface box to the remotes, terminating them at the 'L2' connections in each tone remote.

There are jumper settings inside the tone remote interface box to switch it from 2 to 4-wire operation. Once the jumpers are moved, you can still run 2-wire remotes on it (at least, the older TNA200 tone remote adaptor worked that way).

The MC2500 you can choose 4-wire in the programming options...so you could have that one giving you the sidetone if nothing else in the meantime.

Todd
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Spatch713
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Post by Spatch713 »

Excellent, thank you for the quick reply.

The wire that is already run from the demark to the tone remote adapters, has the extra wires left in place. They are twisted together and out of the way. Looks like the big work is on the tone remote adapter. The programming of the MC2500 will have to be done by our vendor.

The other remotes on the control station are MC1000's do they need any programming changes or jumper added/deleted?
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wavetar
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Post by wavetar »

Spatch713 wrote: The other remotes on the control station are MC1000's do they need any programming changes or jumper added/deleted?
As I said, I'm unsure whether the MC1000 is '4-wire ready' out of the box or not. I can check tomorrow at work, as we do have a few installation/user manuals around for them.

Todd
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