Tunabananas at 10:21, 11 November 2017

2017-11-11T10:21:51Z

← Older revision		Revision as of 03:21, 11 November 2017
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	The antenna will depend on the frequency range we choose for the transmitter. No work has been done on this yet, but the cost should be kept as low as possible.		The antenna will depend on the frequency range we choose for the transmitter. No work has been done on this yet, but the cost should be kept as low as possible.

			[[Category:DisasterRadio]]

Juul: Created page with "= Prototypes = == Transmitter == The first transmitter prototype is using the USRP1 with the WBX daughterboard. We've been testing on 500 mhz. === Antenna === We're using ..."

2013-09-14T00:43:54Z

Created page with "= Prototypes = == Transmitter == The first transmitter prototype is using the USRP1 with the WBX daughterboard. We've been testing on 500 mhz. === Antenna === We're using ..."

New page

= Prototypes =

== Transmitter ==

The first transmitter prototype is using the USRP1 with the WBX daughterboard. We've been testing on 500 mhz.

=== Antenna ===

We're using a "christmas tree"-type pcb antenna from Ettus Research.

== Receiver ==

The receiver prototype is the Elonics E4000 which is a $12 (from china) RTL-SDR device.

=== Receiver antenna ===

We're using the antenna that came with the Elonics E4000 which is fine for short distances.

= Final radio hardware =

== Transmitter ==

Work is currently in progress to design a cheap radio transmitter that plugs into USB. We're trying to keep the price under $150. We have a few design ideas that need to be added to this wiki. A quick overview of current proposed designs:

Something that takes USB input and spits it out through a 200-500 MSPS DAC. This would limit us to 100-250 mhz (probably realistically more like 50-125 mhz, as you don't want to cut it too the Nyquist limit), but would probably be pretty cheap. This could probably be implemented with a cheap FPGA as the only IC and would be really cheap.

We could also do something that isn't a fully general purpose SDR, using e.g. the [http://www.analog.com/en/rfif-components/modulatorsdemodulators/adl5385/products/product.html ADL5385] (30 mhz to 2.2 ghz QAM modulator that takes an I/Q input signal) and the [http://www.analog.com/en/rfif-components/pll-synthesizersvcos/adf4351/products/product.html ADF4351] (35 mhz to 4.4ghz voltage controlled oscillitor). Analog Devices already has a free reference design using these devices. This would mean that the modulation scheme is limited to QAM, but the signal would likely be of high quality and the transmission frequency and power could be varied to a high degree.

=== Amplifier ===

A transmission amplifier will be needed to make a mesh work with only a few of the nodes capable of transmission. We haven't done any work on this yet.

=== Antenna ===

No work on this yet.

== Receiver ==

We will almost certainly use the Elonics E4000 as the final receiver as well.

=== Antenna ===

The antenna will depend on the frequency range we choose for the transmitter. No work has been done on this yet, but the cost should be kept as low as possible.

DisasterRadio/SDR hardware - Revision history

Tunabananas at 10:21, 11 November 2017

Juul: Created page with "= Prototypes = == Transmitter == The first transmitter prototype is using the USRP1 with the WBX daughterboard. We've been testing on 500 mhz. === Antenna === We're using ..."