Good FM Noise floor

[radionut81]

Hi folks - I've been doing some rewiring and regrounding on our switcher (360 systems am-16B). Our airchain goes from our scott ss32 to a broadcast tools acs 8.2 to the 360 switcher then routes to the omnia3 turbo and out to the tower site on our moseley 6010. THE BEST I CAN GET for a noise floor with no audio coming out of the scott is -78 to -80. Is that acceptable or not. It's been a bear fighting the 360's tendency for ground loops (the building doesn't have the best ground in the world to begin with)...just curious what some other station's noise floors are (we're in a small market and I don't have a good pool to compare to).

Thanks..

 

[ChiefCheese]

> Hi folks - I've been doing some rewiring and regrounding on
> our switcher (360 systems am-16B). Our airchain goes from
> our scott ss32 to a broadcast tools acs 8.2 to the 360
> switcher then routes to the omnia3 turbo and out to the
> tower site on our moseley 6010. THE BEST I CAN GET for a
> noise floor with no audio coming out of the scott is -78 to
> -80. Is that acceptable or not. It's been a bear fighting
> the 360's tendency for ground loops (the building doesn't
> have the best ground in the world to begin with)...just
> curious what some other station's noise floors are (we're in
> a small market and I don't have a good pool to compare to).
>
> Thanks..
>
Had an AM16B once and it was noisy...as you moved from input 1 to 16 it either got quieter or noisier, I can't remember. We ended up outboarding the power xfmr on it and that helped a lot.

The noise floor you mention isn't bad. What is your limit of headroom? +20? +24? If +20, for example, then you're looking at a dynamic range of about 100 dB. Not too shabby.

 

[taylorengineer]

> Hi folks - I've been doing some rewiring and regrounding on
> our switcher (360 systems am-16B). Our airchain goes from
> our scott ss32 to a broadcast tools acs 8.2 to the 360
> switcher then routes to the omnia3 turbo and out to the
> tower site on our moseley 6010. THE BEST I CAN GET for a
> noise floor with no audio coming out of the scott is -78 to
> -80. Is that acceptable or not. It's been a bear fighting
> the 360's tendency for ground loops (the building doesn't
> have the best ground in the world to begin with)...just
> curious what some other station's noise floors are (we're in
> a small market and I don't have a good pool to compare to).
>
> Thanks..
>
Good Gawd man.....there was a time when you got a -60 noise spec and people thought you sat at the right hand of God himself!!
-80 is not bad....if your talking about the entire air chain. Your a dadgum guru!

 

[Chuck]

> The noise floor you mention isn't bad. What is your limit
> of headroom? +20? +24? If +20, for example, then you're
> looking at a dynamic range of about 100 dB. Not too shabby.
>
Keep in mind that a typical consumer cassette recorder is only in the mid 40's, and a really good one is in the low 50's. People seem to think that is acceptable. 80 db is more than adequate for your purposes. We are desensitized to SN figures these days, largely due to advertising hype. Many people will tell you that anything less than 100 db is awful, but most of the compamies that tout incredible specs do so by weighting their figures. That's polite for "lying like a rug." But it does sell products.

 

[JohnnyElectron]

Re: Great FM Noise floor

Most people won't notice, unless they're using the Fanfare FTA-100 tuner, which has the lowest noise floor on FM that I've ever heard. The AM (AMAX) tuner is 'smokin' too. The FTA-100 is a great tuner for translators too.
JP