STL Questions

Thank you for reading my post. I have some STL questions regarding my new LPFM. Before just trying the "Trial and Error" route, I'd like to hear your expert suggestions regarding my STL questions. My Transmitter Site (2300') is 8 miles from my temporary studios (1500'). Unfortunately, the STL path from my temporary studios to the transmitter site is blocked. So RF STL isn't an option. The transmitter site does have power and POTS, however it is so remote I doubt that I'd be able to get any data services over the existing POTS line. So, I'm considering the following. Installing Satellite Internet at the transmitter site to be used as STL (Ku Band, DISH Network). Just the thought of Satellite Internet makes me very nervous. Here in SoCal the majority of the days are sunny. However, during the Winter there are some occassional storms that would have the potential to knock out my satellite internet connection during heavy downpours. DISH doesn't guarantee their service. So, it's a "you get what you get" thing. Since I have no backup STL, if something happens to the satellite, I'll be off the air. Another option I have would be to locate a location that has a line of sight shot to the transmitter site. Bring my audio over the internet to that location, then go RF STL the rest of the way. If I go internet, or partial internet, I'm planning on using the BARIX codecs. I'd process my audio before encoding it with the Instreamer. One of the BARIX decoders has balanced outputs. My question is, is that audio going to be suitable to feed my transmitter with .... without additional audio processing at the transmitter site? My processor (Omnia 3FM) has several outputs I can use (Analog, Digital, Composite). My Transmitter is a BW Broadcast TX-300 V2. Any suggestions that you might have would be greatly appreciated.

Regards,

Bill Walton - KJ6EO
KZNQ FM 101.5 (Santa Clarita, CA)
http://www.live365.com/stations/kznqfm

Wow, that's quite an HAAT for a LPFM transmitter site. What's your TPO, 1 watt?

Anyway... Better than satellite Internet (which sucks), I'd go with the 4G-LTE route. Verizon has a nice little router with 4 Ethernet spigots and with an external yagi antenna, works much more reliably than satellite, cheaper too. Verizonwireless.com sells the router and I purchased the external antennas and coax from Amazon.com. Just search for 4G LTE antennas. Depending on how much bandwidth you use and assuming you purchase the router ($200), go with the month-to-month plan ($35+taxes) and 2Gb Internet bandwidth, you should be good to go.

Hi Kelly - There is a 4,000 foot hill behind my site that brings my HAAT way down. I'm currently permitted for 50 watts (eligible for 100). Yes, I'm gonna have a whopping coverage area from that site. I've already had my Engineer do the L/R calcs and they are impressive.

If I remember correctly, there is a wireless signal at the site. However, I'm gonna need about 45GB per month to accomodate a 128K 44khz MP3 stream running 24 hours a day. Just to check the quality of the stream, I'm gonna drive my audio chain with my cell phone. It'll be interesting to hear what it sounds like. Thanks for your suggestions!

I use two barix units for the STL for KVSH-LP. I would never put the processing at the studio and run it over the Barix in the MP3 mode. I use two NanoStation M units from Ubiquiti https://www.ubnt.com/airmax/nanostationm/ for my STL.
The units I use cost $85 per end. Our link is inly 1.4 miles and it is just an extension of the network at the studio. With this link set up I have it running in the PCM 16bit mode and the Optimd is at the transmitter. The digital out from the Optimod feeds the main Harris Digit transmitter and the composite feeds the back up BW transmitter. The BW units we both have are great because they have that built in processor you can use if your main fails.

But I don't process the audio before the barix unit, kinda gutsy but it's been OK. I also have flashed the Barix boxes with the Studio Transmitter Firmware and it works great. The Ubiquity units were so cheap that there is a redundant pair with it's own barix decoder. So at the transmitter there are two ubiquity radio's (glorified WI-fi) each feeding it's own Barix decoder hooked to a silence switcher so that if one link fails it switches to the other link.

Could you possibly use a Ubiquity radio link to complete the path to your Transmitter from a location where you can get cheap internet? I also use Exede satellite for back up ISP at my house. I know you could get one of there systems to work for under $100 a month.

I would really concider putting the Omnia at the transmitter. If you feed the Omnia into the Barix at the studio using MP3 it will not sound as good and give you tight control of the modulation like having the Omnia at the Transmitter. Likewise using the BW as a final limiter with the Omnia still at the studio. To get the full potential out of the Omnia it needs to be at the transmitter. Feed the Barix with a Gentle AGC at the studio.

Sure you cannot use a normal 950MHz non compressed STL path? Personally, I hate running ANY compressed rate audio into an audio processor....the closer you can get to normal WAV 44.1k/16bit audio, the better....If you can only run composite 950, I would go processor at the studio...otherwise, I would run L/R discrete to the processor and put it at the xmtr site....I hate hearing any compressed rate STL...Even the Moseley 6000 series makes my ears hurt

I'm with the rest of the group, uncompressed is best! If you can get POTS at the site you may ask your provider about a T-1. They tend to be available in more remote areas when Internet is not. You would then need a Interplex or similar to go on either end and get your uncompressed audio across.
As to backup, I would encourage you to put an backup audio PC or audio payout devices at the site that can be switched to if the link fails. Deva Broadcast and a few others make audio fail over switches that have MP3 back up as well.

I am not sure of the LPFM rules but could you lease a HD2 or 3 channel from one of the local reliable FM stations? If they are making money they might not charge for a tax break.

Your suggestions and expert advice are appreciated. This STL problem is a nagging sore that refuses to heal. I've never tried sending processed audio over Barix codecs. My Engineer told me that my STL path is blocked by a mountain range between my temporary studios and the transmitter site. Using Binoculars, I can see the transmitter site from my Kids Elementary School just up the street though. My Kids have gone there since Kindergarden so I know most of the staff. Once I get my lease signed for the transmitter site, I'm thinking of talking to the school to see if I could bend their arm and put my STL transmitter there. It is a bit of a haul for an STL (8 miles), I might have to use the larger higher gain antennas. Would 10 watts be enough to go 8 miles on 950Mhz. I'd have to figure out how to get my audio over to the School. That might not be that big of a problem seeing that broadband internet is already there. I do plan to put a backup PC at the transmitter site. It's an exact copy of the server I use at the Studios. I'll post more info as soon as it is available.

10 Watts is overkill. You will be OK with a few watts. The antennae will give you gain. You will need to use 6 ft antennae.

ditto, 10 is WAY to much. But a couple of 6 foot dishes would be great, at less than 10 miles you might even be able to get away with 4'. If you don't have a large hill in the way from your studio to the school, and you can see the site from the school then I would think going right from the studio would work. Maybe we should have asked this before but it sounds like me your transmit side must be to low if you are having this many problems. How tall is your STL tower at the studio?

kj6eo said:

Your suggestions and expert advice are appreciated. This STL problem is a nagging sore that refuses to heal. I've never tried sending processed audio over Barix codecs. My Engineer told me that my STL path is blocked by a mountain range between my temporary studios and the transmitter site. Using Binoculars, I can see the transmitter site from my Kids Elementary School just up the street though. My Kids have gone there since Kindergarden so I know most of the staff. Once I get my lease signed for the transmitter site, I'm thinking of talking to the school to see if I could bend their arm and put my STL transmitter there. It is a bit of a haul for an STL (8 miles), I might have to use the larger higher gain antennas. Would 10 watts be enough to go 8 miles on 950Mhz. I'd have to figure out how to get my audio over to the School. That might not be that big of a problem seeing that broadband internet is already there. I do plan to put a backup PC at the transmitter site. It's an exact copy of the server I use at the Studios. I'll post more info as soon as it is available.

Click to expand...

New 950MHz STLs are limited to +40dbW ERP....but for an 8 mile path, depending on the transmit dish the SBE Freq Coordinator will allow. you should be able to make that with 10 watts easily. A Scala Paraflector would work IF allowed.

Check with your local SBE Frequency Coordinator (www.sbe.org) Howard Fine, [email protected], and give him the xmit and rcv coordinates and see what they can recommend channel and antenna wise. Then file for the STL with the FCC and you'll be good to go AND no delay on the STL if you go with an uncompressed version.

Good luck and let us know how it goes

8 miles with analog composite STL is a piece of cake, and the previous poster is correct. We have a ten mile hop with a bad connector at the Tx with an output of maybe 2 watts, and it works.

Go IP to the school, put the stereo generator at the school, offer the school district regular promotional messages, use Scala paraflectors and a 950 link.

Unfortunately ... there's no path from the school. See below:

RF does not read.....I bet a 950 STL would make it...I've done farther with less and worse!

I appreciate all of your responses and suggestions. My Neighbor across the street owns a small hilltop behind his house. Using binoculars, I can see the transmitter site from up there. On top of the hill there is a 25' telephone pole with nothing mounted on it. I have a full scale wireless signal from my house up there (I have an external wireless antenna). For a test, I could just run an extension cord up there from my Neighbors house I guess. I could send the audio across the street to the pole via wireless (maybe a couple of Barix codecs). The Barix codecs are unbalanced. Is it possible to send composite audio through them? An adaptor maybe? How would it sound?