Batboard

Our agency has been experiencing a chronic problem of low console audio. The audio is only low from any of the four console positions, with the repeat audio from mobiles and portables being very acceptable. The console is connected to the repeater via. a 4 wire, wireline control using a leased circuit from the local teleco. and terminated at a DIU at the repeater site. Our local radio service vendor has check the line levels on two ocassions and reports that the level is within acceptable parameters. i.e. leaves the CEB at 0db and is received at the DIU at -8db. Does the DIU have adjustments for the line level?

This situation is frustating as the volume level needed to hear the dispatcher is set high and then when a field unit broadcasts, their audio is too high (loud). This low audio only occurs on our channel as the audio level from the console on other channels is acceptable. i.e. Sheriff, PD, other agencies.

Any insights would be greatly appreciated.

Bab

Not trying to confuse the issue here, but by any chance have you tried a local mic on the radio at the
repeater site? If the local mic audio sounds low, then the radio has the deviation set low.

If the local mic sounds good, then the problem probably lies in the remote line input audio at the radio
needs to be adjusted.

You said the repeated audio sounds good, so the transmitter deviation is probably OK. I would have
the radio geeks look at the line input adjustment at the radio.

Jim

bbrantner wrote:Our agency has been experiencing a chronic problem of low console audio. The audio is only low from any of the four console positions, with the repeat audio from mobiles and portables being very acceptable. The console is connected to the repeater via. a 4 wire, wireline control using a leased circuit from the local teleco. and terminated at a DIU at the repeater site. Our local radio service vendor has check the line levels on two ocassions and reports that the level is within acceptable parameters. i.e. leaves the CEB at 0db and is received at the DIU at -8db. Does the DIU have adjustments for the line level?

This situation is frustating as the volume level needed to hear the dispatcher is set high and then when a field unit broadcasts, their audio is too high (loud). This low audio only occurs on our channel as the audio level from the console on other channels is acceptable. i.e. Sheriff, PD, other agencies.

Any insights would be greatly appreciated.

Bab

"...terminated at a DIU at the repeater site..."

The repeater is a Quantar?

Console transmit audio is low in digital mode, analog mode, or both?

Is the console CCII?

If CCII, are you using the Centracom signaling link or TRC?

Thanks for the replies.

The station is a Quantar and operates in analog mode with tone remote keying from the console.

The line level was increased at the BIM card in an attempt to increase the console level, this had little effect on voice audio (didn't increase much). However, the BIM level was adjusted back to it's original setting as the increase caused paging tones to be too hot, which resulted in pagers not decoding.

For a lack of a better description of my problem, I would have to describe it as low voice units, low modulation from the console. It also doesn't seem to matter how hard the dispatcher drives the mic. This particular channel is always low.

Thanks again for any insight.

Bruce

Level setting seems to be a lost art.

Many of todays products have AGC and are designed to work acceptably over a wide range of levels. Nonetheless, what is needed here is someone with DIU & Quantar expertise along with some test equipment.

There are adjustments in the DIU and Quantar that will allow the configuration to be optimized so that it works well.

One thing I would recommend is to not enable "Analog Repeater Boost" in the Quantar channel programming. That's kind of a throw-back to Micor days. You might not notice the effect if every user was over-the-air [no wireline] but the 6dB increase in all repeated transmissions could result in the console audio being low by comparison - even if it is otherwise normal.

You need a qualified person on this because you may have more problems then you know from your description so far.

CoM