On 06/03/2015 15:07, rickman wrote:
On 3/6/2015 2:46 AM, AndyW wrote:
On 05/03/2015 23:04, gareth wrote:
"Iain Young, G7III" wrote in message
...

An awful lot of evidence by citing off-the-shelf solutions for both
the hardware and the software of SDR.

It depends where you draw the line.
I have a DVB dongle that I use under linux.
I use pre-written drivers and a waterfall code module but the rest of
the code is self-written by me in c++ and python with some java 2D stuff
for the pretty front end and logging and analysis (largely because I
prefer the collections interface in Java over c++ for massive data
handling).

It is certainly homebrew because the amount of time and effort I spent
in writing to code (and time to learn python on codeacademy - good site
BTW) was probably longer than I have spent designing and building
hardware.

Your mileage may vary....

Andy


I didn't know about these things. Pretty amazing. A UHF/VHF tuner for
under $10 on eBay. Which one do you have?


There are a number of similar ones. This is the one I have:

http://www.ebay.co.uk/itm/RTL2832U-R...em566780 9155

You need to make or buy an antenna connector so you can use a BNC or
something sensible to connect to your antenna system. The supplied
antenna is pretty grim, I suppose you could use the connector an snip
the rather poor coax short and put a decent connector on it.

Depending on which OS you use, there are a number of existing programs
you can use with it to get a feel for it before you start developing
your own. Some people use them with R Pi's to make receive only iGates
or Internet Scanners etc. I think I even saw a webpage where someone had
used one as a spectrum analyser.

My understanding was that the idea of using them as SDRs came from the
USA but perhaps not.

On 3/6/2015 10:21 AM, Brian Reay wrote:
On 06/03/2015 15:07, rickman wrote:
On 3/6/2015 2:46 AM, AndyW wrote:
On 05/03/2015 23:04, gareth wrote:
"Iain Young, G7III" wrote in message
...

An awful lot of evidence by citing off-the-shelf solutions for both
the hardware and the software of SDR.

It depends where you draw the line.
I have a DVB dongle that I use under linux.
I use pre-written drivers and a waterfall code module but the rest of
the code is self-written by me in c++ and python with some java 2D stuff
for the pretty front end and logging and analysis (largely because I
prefer the collections interface in Java over c++ for massive data
handling).

It is certainly homebrew because the amount of time and effort I spent
in writing to code (and time to learn python on codeacademy - good site
BTW) was probably longer than I have spent designing and building
hardware.

Your mileage may vary....

Andy


I didn't know about these things. Pretty amazing. A UHF/VHF tuner for
under $10 on eBay. Which one do you have?


There are a number of similar ones. This is the one I have:

http://www.ebay.co.uk/itm/RTL2832U-R...em566780 9155


You need to make or buy an antenna connector so you can use a BNC or
something sensible to connect to your antenna system. The supplied
antenna is pretty grim, I suppose you could use the connector an snip
the rather poor coax short and put a decent connector on it.

Depending on which OS you use, there are a number of existing programs
you can use with it to get a feel for it before you start developing
your own. Some people use them with R Pi's to make receive only iGates
or Internet Scanners etc. I think I even saw a webpage where someone had
used one as a spectrum analyser.

My understanding was that the idea of using them as SDRs came from the
USA but perhaps not.

What do you use yours for?

--

Rick

On 06/03/15 15:29, rickman wrote:
On 3/6/2015 10:21 AM, Brian Reay wrote:
On 06/03/2015 15:07, rickman wrote:
On 3/6/2015 2:46 AM, AndyW wrote:
On 05/03/2015 23:04, gareth wrote:
"Iain Young, G7III" wrote in message
...

An awful lot of evidence by citing off-the-shelf solutions for both
the hardware and the software of SDR.

It depends where you draw the line.
I have a DVB dongle that I use under linux.
I use pre-written drivers and a waterfall code module but the rest of
the code is self-written by me in c++ and python with some java 2D
stuff
for the pretty front end and logging and analysis (largely because I
prefer the collections interface in Java over c++ for massive data
handling).

It is certainly homebrew because the amount of time and effort I spent
in writing to code (and time to learn python on codeacademy - good site
BTW) was probably longer than I have spent designing and building
hardware.

Your mileage may vary....

Andy


I didn't know about these things. Pretty amazing. A UHF/VHF tuner for
under $10 on eBay. Which one do you have?


There are a number of similar ones. This is the one I have:

http://www.ebay.co.uk/itm/RTL2832U-R...em566780 9155



You need to make or buy an antenna connector so you can use a BNC or
something sensible to connect to your antenna system. The supplied
antenna is pretty grim, I suppose you could use the connector an snip
the rather poor coax short and put a decent connector on it.

Depending on which OS you use, there are a number of existing programs
you can use with it to get a feel for it before you start developing
your own. Some people use them with R Pi's to make receive only iGates
or Internet Scanners etc. I think I even saw a webpage where someone had
used one as a spectrum analyser.

My understanding was that the idea of using them as SDRs came from the
USA but perhaps not.

What do you use yours for?


I've not used it much. I was curious and decided to try one. I don't
like radios you 'drive' from a keyboard or computer, I prefer the
traditional front panel.


The one exception is a PCR1000 which I use as a bit of test kit- with an
attenuator and suitable SW it makes a passable spectrum analyser. I may
try the RTL dongle out for this in time.

I do like the maths of SDRs etc. but actually using them holds little
attraction.


The same goes for modes like PSK etc.

I've no issue with others enjoying them, they just don't appeal to me.

On 06/03/2015 19:04, Brian Reay wrote:

I've not used it much. I was curious and decided to try one. I don't
like radios you 'drive' from a keyboard or computer, I prefer the
traditional front panel.

For a self- coded radio it should be a breeze to add your own 'dials and
knobs' front end.
I have to agree that inputting a number or clicking the sweep button is
not the same and turning a heavy tuning dial but it does produce a hell
of a lot more useful data than an older radio.

However - like MP3s and vinyl, they just don't have the same richness of
sound as a proper radio.

Andy

On 09/03/2015 08:28, AndyW wrote:
On 06/03/2015 19:04, Brian Reay wrote:

I've not used it much. I was curious and decided to try one. I don't
like radios you 'drive' from a keyboard or computer, I prefer the
traditional front panel.

For a self- coded radio it should be a breeze to add your own 'dials and
knobs' front end.
I have to agree that inputting a number or clicking the sweep button is
not the same and turning a heavy tuning dial but it does produce a hell
of a lot more useful data than an older radio.

Agreed but the attraction of SDRs is the 'tweakability' and, if you
build it all into a box with, say, a modest uP to handle the comms to
the dongle, drive a display, etc. etc. and run any other software of
course, 'tweaking', while still possible, is more of a faff. Not quite
the worst of both worlds but certainly heading that way.

Of course, others many like this approach, it is a matter of taste.

Likewise, having a control panel, or controls, which connect to the PC,
really doesn't appeal.

Occasionally, I operate a station in the US remotely but I find it a
'fiddle', I don't even care to do it locally. Again, others enjoy it,
each to his own, it just isn't something I enjoy. Just as I don't enjoy
reading books etc. from things like Kindles, although I am trying to get
used to that.

On Mon, 9 Mar 2015, Brian Reay wrote:

On 09/03/2015 08:28, AndyW wrote:
On 06/03/2015 19:04, Brian Reay wrote:

I've not used it much. I was curious and decided to try one. I don't
like radios you 'drive' from a keyboard or computer, I prefer the
traditional front panel.

For a self- coded radio it should be a breeze to add your own 'dials and
knobs' front end.
I have to agree that inputting a number or clicking the sweep button is
not the same and turning a heavy tuning dial but it does produce a hell
of a lot more useful data than an older radio.

Agreed but the attraction of SDRs is the 'tweakability' and, if you build it
all into a box with, say, a modest uP to handle the comms to the dongle,
drive a display, etc. etc. and run any other software of course, 'tweaking',
while still possible, is more of a faff. Not quite the worst of both worlds
but certainly heading that way.

But that is what's happening in commercial radios, it's just less a
visible process.

They hide the computer and software behind the panel, they lay on software
that interfaces the controls with that software. Done well, you can't
tell what's real and not. 20 years ago, it was probably software between
the panel and the radio internels, except software wasn't involved in
processing the signal. Now the software is doing so much more, and if it's
written well, still invisible.

I'd figure out what controls are necessary to be controls as we know them.
Certainly a tuning knob, maybe some other things. WIth software, you can
always reallocate them to some other function, so long as you have them
there. I recall complaints about menu based front panels, in test
equipment if not amateur radio equipment, where you can decide what
controls get primary status and such.

Michael

On 09/03/15 19:01, Michael Black wrote:
On Mon, 9 Mar 2015, Brian Reay wrote:

On 09/03/2015 08:28, AndyW wrote:
On 06/03/2015 19:04, Brian Reay wrote:

I've not used it much. I was curious and decided to try one. I don't
like radios you 'drive' from a keyboard or computer, I prefer the
traditional front panel.

For a self- coded radio it should be a breeze to add your own 'dials and
knobs' front end.
I have to agree that inputting a number or clicking the sweep button is
not the same and turning a heavy tuning dial but it does produce a hell
of a lot more useful data than an older radio.

Agreed but the attraction of SDRs is the 'tweakability' and, if you
build it all into a box with, say, a modest uP to handle the comms to
the dongle, drive a display, etc. etc. and run any other software of
course, 'tweaking', while still possible, is more of a faff. Not quite
the worst of both worlds but certainly heading that way.

But that is what's happening in commercial radios, it's just less a
visible process.



I appreciate that but that wasn't the point.

If I feel the urge to tinker with SDR SW then the obvious way is to
host it on a PC.

If I stick it in a box, I can 'tweak' it but it becomes more of a faff,
perfectly doable, but why make it a faff?

On 09/03/2015 13:22, Brian Reay wrote:

Agreed but the attraction of SDRs is the 'tweakability' and, if you
build it all into a box with, say, a modest uP to handle the comms to
the dongle, drive a display, etc. etc. and run any other software of
course, 'tweaking', while still possible, is more of a faff. Not quite
the worst of both worlds but certainly heading that way.

Of course, others many like this approach, it is a matter of taste.

Likewise, having a control panel, or controls, which connect to the PC,
really doesn't appeal.

Occasionally, I operate a station in the US remotely but I find it a
'fiddle', I don't even care to do it locally. Again, others enjoy it,
each to his own, it just isn't something I enjoy. Just as I don't enjoy
reading books etc. from things like Kindles, although I am trying to get
used to that.

Simple job to add a raspberry pi front end (especially since the Mk II
is out and considerably faster) with a touch-screen. A lot of coding is
required to connect them all together though.
Or add a cheap rooted android tablet like the Hudl Mk I which is
programmable in Java, there are SDR apps for android tablets, not the
best but remarkably portable and it makes a great 'signal sniffer'.
It would be a faff and probably cost more than buying one but then cost
is not the point of self-construction. God knows I spent a fortune and
about 2 inches of hairline in building quiz buzzers based on raspberry
pi, touch-screen and PS2 Buzz controllers. I could have just bought a
kit from Maplins for a tenth of the price and made it in an afternoon.

However there is still something wonderfully tactile about the weight
and inertia of turning a hefty dial that you will never get from a
touchscreen.

Andy

AndyW wrote:
On 09/03/2015 13:22, Brian Reay wrote:

Agreed but the attraction of SDRs is the 'tweakability' and, if you
build it all into a box with, say, a modest uP to handle the comms to
the dongle, drive a display, etc. etc. and run any other software of
course, 'tweaking', while still possible, is more of a faff. Not quite
the worst of both worlds but certainly heading that way.

Of course, others many like this approach, it is a matter of taste.

Likewise, having a control panel, or controls, which connect to the PC,
really doesn't appeal.

Occasionally, I operate a station in the US remotely but I find it a
'fiddle', I don't even care to do it locally. Again, others enjoy it,
each to his own, it just isn't something I enjoy. Just as I don't enjoy
reading books etc. from things like Kindles, although I am trying to get
used to that.

Simple job to add a raspberry pi front end (especially since the Mk II is
out and considerably faster) with a touch-screen. A lot of coding is
required to connect them all together though.
Or add a cheap rooted android tablet like the Hudl Mk I which is
programmable in Java, there are SDR apps for android tablets, not the
best but remarkably portable and it makes a great 'signal sniffer'.
It would be a faff and probably cost more than buying one but then cost
is not the point of self-construction. God knows I spent a fortune and
about 2 inches of hairline in building quiz buzzers based on raspberry
pi, touch-screen and PS2 Buzz controllers. I could have just bought a kit
from Maplins for a tenth of the price and made it in an afternoon.

However there is still something wonderfully tactile about the weight and
inertia of turning a hefty dial that you will never get from a touchscreen.

Andy

Actually, depending on how much existing code you wanted to use, you may be
surprised how little extra code you would need to write if you used if you
used a R Pi. There are packages to use the RTL with the RPi and others to
drive small displays. All you would need is to write something to interface
to your front panel, essentially replacing the keyboard function. Come to
think of it, that would be a way to reduce the faff in maintaining the
flexibility- if you had a front panel but could plug in a keyboard to
'tweak' you own SDR software (if you didn't use off the shelf SW).