audio dipping

[Stafball]

Hello every one i have a question on transmitting on fm the audio keeps dipping in volume and dropping out then back in again for more then a second at times and power also drops .this is with professional tx and link also btw ..what can this be ?would the FM Pre-Emphasis and De-Emphasis its mono tx lpr for community radio think link is 48mhz dont know what the tx is tho as its on a different site i never installed the stuff i just helped wire up the decks and herd them talking about the issues

Any help much appreciated tips advice etc...i know it is not really pirate related but hey pirates know best lol

[Albert H]

You'll probably find that the link transmit end is equipped with an audio limiter. If this is overdriven, the audio could dip more than it should!

One station I worked on had a hand-held OB microphone, and handling noise - which was mostly sub-sonic - would dip the audio. I cured it by including a high-pass filter in the microphone audio circuit and also filtering the microphone compressor "sidechain" feed, so that very low frequency sounds wouldn't affect the audio we wanted to convey.

[reverend]

If it's just the audio that's dipping then Albert is most probably correct. Badly set up limiters are a pain for that kind of thing.

You mentioned that the 'power' was dropping too. This sounds like a TX fault, and may be caused by a safety cut out that could be triggered by overheating or poor antenna SWR.

[Stafball]

CHEERS guys the limiter is digital and has built in audio processing unit i have passed this information on thanks again