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| Thread ID: 71115 | 2006-07-27 01:18:00 | Hot water cyclinder:How does it work and how much power.... | lance4k (4644) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 473907 | 2006-08-04 04:40:00 | Billy: I knew all that. I thought you might have found some better way. Terry: There's a lot of grunt close up. But you need quite a lot to catch it. The CCIR graph says that a 1kW transmitter will have a field of 110 dBu at 1 km. That's approximately 300 mV/m. 2YA has 54dBW -- 250 kW, giving 4.74 V/m at 1 km. (The CCIR figure is for a "short monopole 1/8 wavelength, whereas the Titahi Bay tower is 220 m, closer to half a wavelength, so the numbers should be bigger). A half wave dipole in that field would produce close to 800 volts at the centre. If you match the load, you'll get about 2.2 kW in it. But the halfwave dipole needs to be vertical. And it would pay to raise the bottem end well above the earth. Someone might notice this thing. The wavelength is 529 m. The energy density is about 0.6 W/m^2 . A 10 m high whip might collect 60 watts. At 26 km, over salt water, the fields should be about 30 dB lower. That's still a strong signal. |
Graham L (2) | ||
| 473908 | 2006-08-04 05:10:00 | Perhaps some enterprising soul could construct a boat to cross Cook Straight from Titahi Bay, powered by 2YA? :rolleyes: | Terry Porritt (14) | ||
| 473909 | 2006-08-04 05:20:00 | There is another 250 kW RNZ transmitter (on 657) kHz , plus a 48dBW one on 783 at Titahi Bay, so you should be able to get nearly three times the power. But it's inverse square ... before long you would be rowing. (Or swimming anyway, the wind would topple you) | Graham L (2) | ||
| 473910 | 2006-08-04 05:22:00 | Lance, HWC's are expensive to run period. Short showers, maybe share baths? if you are using a whole heap more power for some reason, maybe the TS is US (easy to check) If you aren't confident get a sparky, also loose connections can be a problem. If you really want to save money solar will pay for its self, depending on usage rather quickly. Or on demand gas system is pretty good and may be able to hook up the hob for more savings if you haven't already - they use a bit of power as well. Cheers Kelem |
Kelem (10339) | ||
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