If one were to use multiple FM transmitters, in this case Decade, how does one avoid internet latency from one transmitter to another. Depending on the ISP, the source and other factors, I have heard as much as ten seconds. Here in my little town I run OTR from ABN on a Barix box. A friend also runs the same programming on his Part 15 FM using a Barix and the same ISP. There is about 5 seconds difference.
I feel I should answer this question because this is how my station was operated and since that is the case, I probably have the best answer for you.
Although WXTZ 87.9 Norwich used 8 Decade transmitters located in 8 different locations around Norwich Connecticut, they were planted in various large apartment buildings.
Did those signals over-lap each other? The answer to that is no.
That is because the buildings we favored, were not located close enough to each other for an over-lap to take place.
Now, if our transmitters were allowed a power output of 1 Watt, there stands a very good chance those signals would over-lap each other at some point or another.
I was NOT associated with this person's station operations, but I do know of a guy who bought the Ramsey FM transmitter kit, it had a tuning coil for channel selection (model number is unknown). He bought a 1 watt Ramsey amplifier kit and had the FM transmitter wired to it. He used a 1/4 wave dipole built using ribbon wire for television antenna connections built into a PVC pipe looking like a letter "T" he used it as a vertical antenna placed 60 feet in the air. He used 90.7MHz or perhaps it was 91.7MHz I can't remember now, but he used the 88.1 to 91.9MH section of the FM band.
His signal reached 2 1/2 miles. I witnessed this myself on my own FM car radio receiver. He was located on a high elevation.
Yes, the FCC did shut him down, he got a visit from them. This took place over 12 years ago, but all they did was tell him to shut it down.
So as you can see, 1 watt can cover 2 1/2 miles in a city location.
I can not be 100% positive that this is the case, but he showed me on a VHS video tape, how the local Hartford Connecticut television station WFSB TV channel 3 came to his house to do a Dan Kane eyewitness news report on this guys radio station. I believe, that WFSB contacted the FCC about this station after they aired the article as a news story. Mind you, the owner whose name I'll keep private, was the one who called WFSB thinking he was going to get free publicity for his station. WFSB did not air the article under the accusations of a pirate station, they did it as publicity for this type of entertainment. But it is my personal guess, once that article hit the airwaves, someone decided to report him to the FCC.
Bruce.
Adding an update here. During any experiments that I am aware of, we did not experience any signs of delay.
I do understand what you are asking, can the speed of the stream be different in different locations and cause a slight delay between feeds?
It sounds very possible. But then again, in our case, all the receivers were on the same system, which was on Comcast cable TV modems. The best I can offer you an answer, I do not believe anyone noticed any difference at each of the locations.
Your question has prompted me to ask our transmitter owners if they noticed anything odd with the stream we were sending them. To the best of their ability to answer this question, they said no, they did not notice a delay different from another owner's feed.
Perhaps, things would have been different if it was possible to receive all 8 transmitters at the same time, which is impossible to do under todays conditions. Because there was not enough RF power to get two separate signals to cross each other and they were too far apart in mileage to hear more then one signal at the same time.
I am sure though, there would have had to been some kind of co-channel heterodyne noise evident where the carriers would mix together, but none of our transmitters were close enough to witness that issue.
Bruce.
If you use the Internet to feed your transmitters, you will eventually get latency (or delay). Packets get lost and after a while, you'll notice the internet fed station many seconds behind one that is fed directly. I know I experience that, anyway. Even when I listen to my station over the Internet in my home (I have several Internet Radios), I see a delay, and it can be 10-15 seconds or more).
Now, if you have multiple transmitters all on the same network, with no intervening nodes between you, then maybe there wouldn't be a problem. But that would be difficult to determine, I would think, unless you're located really close to each other.