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| Thread ID: 84878 | 2007-11-21 19:11:00 | Commuity FM radio station | curly (6655) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 613769 | 2007-11-21 19:11:00 | I only just discovered a real neat music only 24x7 FM station broadcasting from Tee Tree Point, near Whangarei. As we are out and about of the farm all day, we were wondering if it was possible to feed the audio output from our FM tuner into a small FM transmitter I read about in an overseas electronics mag and listen to the station while on the move within our property. Any thoughts. We would only need a range of 200 to 300 metres for most of the day, after that we would probably be out of range of our small FM repeater. But most of all - would this be legal, or are we up for a Radio Licence to operate the "station". Your thoughts please. |
curly (6655) | ||
| 613770 | 2007-11-21 22:30:00 | 200-300m is doable without a license, as long as you don't transmit over the power limits for the class. | Erayd (23) | ||
| 613771 | 2007-11-22 03:37:00 | OK thanks for reply, will look into it a bit more. | curly (6655) | ||
| 613772 | 2007-11-22 03:45:00 | I'm lost here! Why not just tune it in direct on the radio you take out on the farm? I'll lay odds the signal strength from Ti Tree point will be better than you can readily generate yourself, AFAIK there's not much equipment around to buy for higher power re-transmission. Cheers Billy 8-{) |
Billy T (70) | ||
| 613773 | 2007-11-22 22:15:00 | A community FM station won't be using a 5 or 15 kW transmitter, rather about half a watt, so the field strength won't be great at any range. So using a decent antenna on the house receiver then feeding a retransmitter is likely to give a better signal out on the farm. |
Graham L (2) | ||
| 613774 | 2007-11-23 04:19:00 | A community FM station won't be using a 5 or 15 kW transmitter, rather about half a watt, so the field strength won't be great at any range. So using a decent antenna on the house receiver then feeding a retransmitter is likely to give a better signal out on the farm. That's as may be in a perfect world Graham, but few domestic FM receivers are connected to an external antenna. I'm aware of the low power levels used, but any community Tx has to have sufficient power for cheapie boomboxes and car stereos to get the message so coverage is unlikely to be an issue. If it is acceptable at the homestead it is unlikely to fade on the range, unless it is all downhill and gullies away from the house. It is overkill to suggest rebroadcasting, I'd recommend a site check with the portable radio first and maybe save a lot of time and effort, it's only 200-300 metres to walk or drive. Besides that, few local transmitters run quite as low as 500mW and the range of the myriad such services in Auckland is surprisingly good. I pick up low power transmitters in Devonport from several kilometres away into the rear of a log periodic antenna and it is not line of sight. Cheers Billy 8-{) |
Billy T (70) | ||
| 613775 | 2007-11-23 04:19:00 | Thats exactly what I am hoping for. Already tried a little hand held, but it was useless. The house does have a dedicated FM antenna. | curly (6655) | ||
| 613776 | 2007-11-24 23:53:00 | I'm surprised to hear that "few" community stations have "as low as 500 mW" Billy . That's the maximum (e . i . r . p) allowed by the licence (www . rsm . govt . nz/cms/licensing/types-of-licence/broadcasting) they operate under . . . . (4) The maximum peak radiated power must not exceed – 3 dBW (500 mW) e . i . r . p . (5) Notwithstanding the provisions of (4), the field strength must not exceed 112dBuV/m based on a measurement bandwidth of 100 kHz and a reference distance of 10 metres . (6) Transmitter carrier stability (frequency tolerance) must be maintained within +/– 5kHz . (7) External controls for the adjustment of the transmitter power are not permitted . . . . [gurl-lpfmbc-2 . pdf] You won't need a licence (or rather, you will be operating under another "General User Radio Licence) curly, as long as you buy a set from a reputable outlet . The "C-tick" is an indication that equipment complies with NZ regulations . Electronics shops like DSE will have a selection: try "fm transmitter" in their web site searches . Make it clear that you need more coverage than just inside a house (or car) . The RSM web site is not a nice one to find things in --- lots of dead links, and bad indexing . :( |
Graham L (2) | ||
| 613777 | 2007-11-25 00:11:00 | i was involved in building a repeater setup many years ago (tv) . one BIG problem with a repeater setup is finding a spare frequency to work with without interfering with anyone else (assuming you change the frequency, most repeaters don't which makes it harder again) . theres been a few repeaters around which the inspectors found and removed (confiscated) due to interference to everyone else . the power required to get a small handheld to receive needs to be quiet good which will probably require a licence . the interference range (unless confined by hills) will be in the 5 mile range easy enough . |
tweak'e (69) | ||
| 613778 | 2007-11-25 00:23:00 | That's the Regs Graham, but there's any number of transmitters available with variable output, they even sell them on TM for heavens sakes. In today's world of notional compliance, ensured by imposing a suitable fee and stamping a piece of paper, there's zero chance of being pinged for running 750-1000mW provided you are careful about how you do it. There's local transmitters around here that override commercial stations in some areas and I doubt that the concentration of transmitters in Whangarei would be such that a few extra ergs up the coax would ever be noticed. Cheers Billy 8-{) |
Billy T (70) | ||
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