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Temporary Opportunity - Analog TV Broadcast Setup in the DR

Posted: Thu Apr 27, 2017 5:13 pm
by alvarodecamps

I have no engineering experience, I am the manager of 2 TV stations and a Radio station in Santo Domingo, Dominican Republic. After speaking to several engineers in my country, I have decided to look for help online and see if there is a viable solution to our problem. We are considering the possibility of inaugurating Channel 6 in Dominican Republic after 15+ years being off the air.

The problem first arose because of interference between channel 5 (76-82 MHZ) and channel 6 (82-88 MHZ). According to what I have managed to find out; in order to have the two channels operating without interference we had to transmit from nearby locations and with similar potency. Long story short, we invested in two 60 KW Toshiba transmitters in 1999 with some special filters that allowed us to go on air. For about 9 months we covered half of the country, but after struggling to keep the channel functioning because of poor programming content we turned off the transmitters.

Channel 5 has done everything in their power to keep us from turning on any transmitters on our assigned frequency because they say it's not possible to have the two analog channels coexist. Since 2002 they have been hijacking our sound carrier - 87.7 FM where they transmit the audio of the their channel to make sure we have interference if we decide to power on the signal.

DR is not ready for digital television for 5+ years and we would like to know if there is a way to have channel 6 coexist with channel 5. There must be used transmitters at good prices that we can acquire and buy the necessary equipment, or maybe some way to salvage the transmitters. Im happy to share more information about the situation with someone interested in helping.

We have a new management with the energy and desire to launch the channel with a new format. Please let me know if there are any suggestions.

Re: Temporary Opportunity - Analog TV Broadcast Setup in the DR

Posted: Fri Apr 28, 2017 10:11 am
by Shane
Is there no other channel available? In the US prior to the switch to digital television, two stations were never assigned to adjacent channels in the same market, and to the co-channel (i.e.: two channel 6's for example) there would generally be at least 200 miles separation between transmitter sites. You know the channel frequencies so I assume you also know that channels 4 & 5 are not adjacent - at least up here in the US. There is 4 MHz of space between those two. Also channels 6 & 7 are not adjacent. So if 4 or 7 were available, perhaps you could move to one of those. With either of these you would not be adjacent to the channel 5 station.

Of course, if they are determined to keep you off the air, they will just set up an audio carrier on whatever channel you pop up on. Whatever authority regulates broadcasting in your country would probably have to fix that.

To illustrate the "no-adjacent channel" rule here, the analog VHF stations channel assignments in Greater New York City were 2,4,5,7,9,11,& 13. Greater Philadelphia, which is about 110 miles away had 3,6,10 & 12 with channel 8 being assigned to a smaller city west of Philadelphia; Washington and Baltimore I think were like New York except split up between the two cities. I don't remember which city had which channels but they are close enough to be one market for technical purposes. Washington and Baltimore are over 200 miles from New York City so they could be co-channel with New York stations.

Re: Temporary Opportunity - Analog TV Broadcast Setup in the DR

Posted: Fri Apr 28, 2017 3:36 pm
by alvarodecamps
Hi Shane thank you for your response. There is no other channel available.

Channels 2,4,5,7,9,11,13 are all occupied. But I recently learned that channel 2 will be moved to channel 10 and will have a special antenna with a filter that will allow it to coexist with 9 and 11. I'm wondering what filter and what setup might this be.