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If so, can the coaxial signal be maintained without degradation (think inserting a transmitter in the middle of a coaxial connection to relay that signal wirelessly without actually interrupting the original coaxial path)?

Can it send this information to multiple (up to 7) devices (Android and IOS) without its signal being degraded from sharing between them?

Any ideas as to what module would I look for to do this? (maybe on DX.com?)

At the core I would like to know if this idea is even possible. It would be gravy to figure out how I'd go about doing this and what parts I'd need.

Thanks to anyone who can help!

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  • \$\begingroup\$ Don't have time for a full answer, but whether or not it will work is determined by the frequency of the Coax signal and the frequency of the Bluetooth transceiver. Coax is typically an analog signal, so it would have to be converted to digital for transmission over Bluetooth. Once it is in the air, it can be received by as many units are in range, just so long as they can individually "shake hands" with the transmitter to establish a connection. \$\endgroup\$ – Kurt E. Clothier May 4 '13 at 2:58
  • \$\begingroup\$ Thanks so much for helping me. I am completely new to all of this and found this awesome website while trying to research my question on google. So to be clear, they make bluetooth receivers that work only at certain frequencies? The signal would likely be around 20hz I believe. Digital to analog converters are pretty commonplace, is there be a certain class of one I would need to use? \$\endgroup\$ – Kel May 4 '13 at 3:10
  • \$\begingroup\$ A 20hz signal seems very, very slow. What exactly is being transmitted? It's not that BLuetooth only transmits a certain frequency, although it does have a "carrier" frequency, what I mean is that the Bluetooth module will have maximum signal frequency that it can transmit known as a baud rate. \$\endgroup\$ – Kurt E. Clothier May 4 '13 at 5:04
  • \$\begingroup\$ Instead of asking about a specific solution to an "unknown" problem you present the "target" of what you are trying to achieve. This does two things (1) bigger liklihood of a better answer and (2) potential answerers are equipped with better knowledge. \$\endgroup\$ – Andy aka May 4 '13 at 19:42
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(Expanding on Kurt E Clothier's comment ...)

As often, the answer should be "it depends", in this case on the nature of the signal that's being transmitted via the coax cable. If the original signal is an analog type signal this type of transmission would involve several steps:

  1. Conversion of the analog signal into digital byte stream using an analog-to-digital converter (=ADC), most likely with a little bit of pre-amplification of the signal.
  2. Packaging and transmission of the digital signal via the Bluetooth transmitter to the Bluetooth receivers.
  3. Back-conversion of the received digital signal into an analog signal using a digital-to-analog converter (=DAC), again followed by some signal conditioning.

As you can imagine, these steps all take some time. The ADC can only convert the analog signal to digital bytes a finite number of times per second (the so-called sampling rate). Similarly, the Bluetooth radios (transmitter and receivers) can only transmit a finite number of bits/bytes per second. Lastly, the DAC can only convert so many samples per second back into analog form. Therefore, if your original signal doesn't change very quickly (the 20 Hz you mention would not be considered quick at all), all the steps have enough time to complete. If it is changing more quickly, there simply isn't enough time to complete the different steps.

Another thing that follows from the description above is that with each conversion between analog and digital domain, the signal will be altered just a little bit. Both your ADC and your DAC have limited "resolution" (e.g. 8-bit, 10-bit, 16-bit ...), with higher resolution meaning that the ADC can produce a more fine-grained representation of the signal (see Quantization. Again, it depends on the nature of your original signal whether the small alterations done during the conversion steps are tolerable or not.

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