MTR3000 in wideband

[dal]

My client who is 2000 miles from here, claims that his new MTR3000 is delivering distorted TX audio. (Analog conventional) He is trying to run it in wideband mode (25kHz channels). He says he is putting audio in on the 2-wire terminals of the line card. He says his audio level is 0 dBm. I am wondering if his particular MTR3000 has a problem that prevents it from reaching the full 5kHz deviation.Has anyone run across this problem? I am waiting to hear if it is OK on narrowband (12.5kHz)

[Bill_G]

I haven't played with them yet, but I'll ask the guys that have. I suspect it needs to have the tx wireline adjusted. 0 in is rather hot. Normal expected tx / in is -13db. Normal expected rx / out is 0db (with full deviation), -6db for avg voice. Hard to say where the factory set the levels on the new station.

[d119]

I agree - He's overdriving the wireline card.

We haven't experienced any issues like this with any of the MTR 3000's we've put in service...

[dal]

Hallo Bill and d119, I take it then that you have run an MTR3000 in WB mode, and were able to get at least 60% RSD (3kHz) without clipping? The client is expecting 5kHz deviation, and is probably overdriving the linecard trying to get it.
I don't have the SW yet so I am still in the dark.

[Bill_G]

Unless they hooked it up wrong, or were driving their old station hot to compensate for problems it was having, they should have been able to plug-n-play. That said, since you don't have the rss, you apparently did not program or align it during installation, and therefore you do not have a baseline performance record. So, it is hard to speculate what is happening without a report from a tech on site.

[dal]

The units that were removed were Mastr2's, which they claim worked fine. The next step may be to have them ship an MTR3000 to us, with a codeplug, and we would purchase the CPS. Then with our ancient R2670 and TIMS we could prove or disprove what their techs are saying. As you might guess we are consultants. But I personally have programmed/aligned Mastr3's and Tait TB8100's so testing the MTR should not be too difficult I hope.
Thanks for the help.

[Bill_G]

Why don't their techs just do the alignment on site? The customer will be maintaining the equipment. They should purchase the cps.

As stated earlier, 0db in is very hot and should be turned down to -10db or so. The assumption is the customer uses telco leased line circuits that will be driven with a max 0db input at the head end and arrive at the far end station with at least 10db loss. If they are using a loss-less system like a microwave, or very short lines within a building, then they should turn the head end down to -10db out to prevent overdriving the input. Then they should run the tx wireline alignment procedure with the cps. Follow the instructions on the screen. It walks you through it.

If you decide to go with Plan A - shipping it back to Portland OR for eval - we can make some tech time available to assist either in our shop or at yours. You can contact me by PM or email.

[dal]

It appears that the customer does have the CPS....I will email you.
thanks