I know that telcos used to provide STL service over T1 using “Program Channel Units” in a D4 channel bank. AM links were typically 5 kHz channel units occupying 2 slots (128 kbps), FM links were typically 15 kHz channel units occupying 6 slots (384 kbps), double that for stereo.
From: Chuck McCown Sent: Thursday, February 18, 2016 3:03 PM To: af@afmug.com Subject: Re: [AFMUG] Colocating with fm radio station Some of the FM music stations take a satellite feed for the music and then insert their local content only over the STL. So that is a great backup. Perhaps the TV networks do it that way too now. But the actual broadcast transmitter sites I have personally worked on, rely upon a single microwave link to get the signal to the mountain top. Or in the case of AM broadcasters, they used to use a couple of copper telephone loops. KSL in Salt Lake City was on open wire for many years. When they went to the underground copper they complained about the loss of audio quality. I think they split the audio bandwidth over two loops. But my direct experience is years old. Probably everything is different now. From: Chuck McCown Sent: Thursday, February 18, 2016 1:59 PM To: af@afmug.com Subject: Re: [AFMUG] Colocating with fm radio station The broadcast stations I have worked around have no backup. Dead air. From: TJ Trout Sent: Thursday, February 18, 2016 1:55 PM To: af@afmug.com Subject: Re: [AFMUG] Colocating with fm radio station What do they do when the STL fails? Do they have a way to get some generic stuff playing while it's fixed? On Thu, Feb 18, 2016 at 12:50 PM, Chuck McCown <ch...@wbmfg.com> wrote: The public internet yes, but if you have pretty good control over the route then it should not be a problem. Many times the traffic is like a two hop distance. If your upstream provider peers with the station provider I can’t see a big problem. Or better yet, your upstream provider serves the station studio or whatever the other end is... From: Daniel White Sent: Thursday, February 18, 2016 1:47 PM To: af@afmug.com Subject: Re: [AFMUG] Colocating with fm radio station I won’t claim to be an expert by any means on STL links. I’ve engineered backhaul links for broadcast guys though so I know a bit about the requirements. IMHO it’s a bad idea to put STL traffic on the internet. Packet loss, jitter, latency are all very important metrics. Capacity is low… maybe 2Mbps tops for HD audio (I guess it could be more depending on how many stations are transmitting from that antenna). Give them a dedicated link. Telos/Axia and Whetstone are the two encoder manufacturers I’ve run across. Jeff Holdenrid at DoubleRadius would be a great contact if you’re looking for ways to make the STL work. Thank you, Daniel White afmu...@gmail.com Cell: +1 (303) 746-3590 Skype: danieldwhite Social: LinkedIn: Twitter From: Af [mailto:af-boun...@afmug.com] On Behalf Of Joseph Marsh Sent: Thursday, February 18, 2016 11:52 AM To: af@afmug.com Subject: Re: [AFMUG] Colocating with fm radio station If someone has any info on the STL links. Send me a message off list. I wanna know everything possible about it On Feb 18, 2016 12:37 PM, "Joseph Marsh" <josephmarsh2...@gmail.com> wrote: Josh He has 6000 watts on the main transmitter On Feb 18, 2016 12:22 PM, "Josh Luthman" <j...@imaginenetworksllc.com> wrote: You could be OK. Definitely not a "will be" especially with unknown power. Also keep in mind you're supposed to lower the power when climbing on the tower. Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Thu, Feb 18, 2016 at 1:21 PM, Joseph Marsh <josephmarsh2...@gmail.com> wrote: So if I do shielded cat 5 I should be okay correct? On Feb 18, 2016 11:55 AM, "George Skorup" <geo...@cbcast.com> wrote: We're on a very similar site. We're running 100Mb and GigE links with no issues. However, external surge suppressors on the tower near the radios did give us errors, so we had to take them out... and pray. On 2/18/2016 11:38 AM, Joseph Marsh wrote: The transmitter is 6000 watts 350 ft tall. We are going up at 125ft On Feb 18, 2016 11:29 AM, "Joseph Marsh" <josephmarsh2...@gmail.com> wrote: You bet I'll be on the other side of tower with cat 5. It's a privately. Owned tower so I got leeway to do what I need On Feb 18, 2016 11:25 AM, "Chuck McCown" <ch...@wbmfg.com> wrote: Metallic liquidtight flexible conduit with shielded cat5 inside. Stay away from the driven elements as far as you can. Some use ferrite cores on the cable too. Can’t hurt. From: Joseph Marsh Sent: Thursday, February 18, 2016 10:09 AM To: af@afmug.com Subject: Re: [AFMUG] Colocating with fm radio station He told us but can't remember off hand I got one hell of a deal just had to give him internet for a stl box so he can do away with a 900 mhz. Ptp system On Feb 18, 2016 11:00 AM, "Josh Luthman" <j...@imaginenetworksllc.com> wrote: Far as possible. How much power is the FM station? Definitely use shielded cable. Josh Luthman Office: 937-552-2340 Direct: 937-552-2343 1100 Wayne St Suite 1337 Troy, OH 45373 On Thu, Feb 18, 2016 at 11:54 AM, Joseph Marsh <josephmarsh2...@gmail.com> wrote: How far do I need to be from the fm transmitter to be safe with cambium and ubnt. Equipment This email has been sent from a virus-free computer protected by Avast. www.avast.com
