gizmomkr Posted September 9, 2010 Share Posted September 9, 2010 Just thought I would share -I bought an "ELE FM Transmitter" / CZH-05b off E-bay. I paid about 60.00 total. It took a solid two weeks to get here.I cant quite figure out why, but the power cord it came with doesnt quite work - I suspect the barrel connector is slightly larger or smaller than the dc jack on the PCB. They feel like a good fit... but it only works when I apply a small amount of pressure to one side. Solder joints to the PCB look good.... I had plenty of other 12v DC supplies around, and it worked fine after I ditched the cheap junk power cord. anyhow thats not why I posted...I'm actually really happy with it. Its not a Ramsey, and I'm not mutch to judge sound quality, but I think its great for the price I paid.Verry basic design, the signal is crisp and clear, and I get a great range out of it. With stock antenna , in a back bedroom of my home I got about 2 blocks with no static. It claims ot be 1/2 watt.No RDS, nothing fancy - but a good cheap transmitter with great range Attached files Link to comment Share on other sites More sharing options...
Scott T Posted September 9, 2010 Share Posted September 9, 2010 The thing you must watch for dirty harmonics. A 1/2 watt is a lot of power for only 2 blocks.The EDM (the one I have)is switchable between 10 mw and 100 mw. I get about 1/2 mile at 100mw and a little over 1/4 mile at 10mw.You must be careful not to interfer with any other bands outside the fm range (harmonics)The borning stuff ... A harmonic of a wave is a component frequency of the signal that is an integer multiple of the fundamental frequency, i.e. if the fundamental frequency is f, the harmonics have frequencies 2f, 3f, 4f, . . . etc. The harmonics have the property that they are all periodic at the fundamental frequency, therefore the sum of harmonics is also periodic at that frequency. Harmonic frequencies are equally spaced by the width of the fundamental frequency and can be found by repeatedly adding that frequency. For example, if the fundamental frequency is 25 Hz, the frequencies of the harmonics are: 50 Hz, 75 Hz, 100 Hz, etc. Link to comment Share on other sites More sharing options...
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