Hi Alan,
Where I live, the temperature extremes inside my attic are not so bad.
If you look at devices such as the Kinetic SBS 3, you will see that Ethernet ports are
becoming quite normal on SDR gear these days. This not only allows you to minimise the
cable run to the antenna (important at 1090MHz) but also to use the device from anywhere
with an adequate network connection to it.
http://www.kinetic-avionics.com/
A 500 foot drum of RG-6 may only cost $32 at Home Depot, but you would need over 30,000
such drums to reach the closest Home Depot from my home. Quite an outlay when we already
have the wealth of a global telecommunications industry at our fingertips and begging to
be used!
My main reason for doing this however, is really to make a better radio than the RTL
dongle provides on it's own. I am interested in front end filtering and an LNA and
want to use the rPi to control this. You could still run 500' of lossy co-ax to the
antenna if you wanted to... :-)
I could buy a Funcube Pro+ Dongle for £150 instead, but where is the fun in that?
Simon
----- Original Message -----
From: "Alan Corey" <alancorey(a)yahoo.com>
To: osmocom-sdr(a)lists.osmocom.org
Sent: Friday, 10 May, 2013 03:39:55 GMT +00:00 GMT Britain, Ireland, Portugal
Subject: Re: Raspberry Pi based remote SDR head
To no one in particular: The usefulness of doing this escapes me. Sure you'd want to
put the receiver up high, but in an attic? There are all kinds of temperature extremes up
there, from very hot most of the year to below freezing in colder climates in the winter.
Something like a 1-transistor preamp feeding some RG-6 seems like a more practical
solution. You can buy 500 feet of RG-6 for about $32 at Home Depot and good low-noise
transistors are available under $1. You just need enough gain to offset the cable loss
and RG-6 is pretty good.
Alan
-----
Radio Astronomy - the ultimate DX
--- On Thu, 5/2/13, Simon PurplePlaNET <simon(a)purpleplanet.org> wrote:
From: Simon PurplePlaNET <simon(a)purpleplanet.org>
Subject: Raspberry Pi based remote SDR head
To: osmocom-sdr(a)lists.osmocom.org
Date: Thursday, May 2, 2013, 7:57 PM
Hi folks,
I've been messing around with rtl_tcp and an RTL2832 device on a Raspberry Pi and want
to add a bank of front end filters and a LNA that can be controlled by the GPIO.
I want to allow manual control of the signal path via a web page hosted on the Pi, but
also want to be able to have the filters selected automatically based on the frequency
that the RTL device is tuned to.
I noticed that rtl_tcp helpfully echos the frequency changes to the console, so I wrote a
simple shell script to gather this data and control the GPIO.
Somebody may have already done this and there is probably a better way to achieve it but,
if this would be of any use to you, please feel free to copy and use as you wish.
http://www.purpleplanet.org/?q=rtl-robot
Cheers,
Simon