Panoramic spectrum analysis

[DManzaluni]

There used to be a really cool tuner made by Sequerra which I saw in
the 1970s which had this amazing feature on a built-in scope. None of
the other tuners made at that time which had scopes in them seemed to
have that function (I actually bought a Marantz ST600, though for the
AMAZING sound, not the scope)

Does anyone know why this technology died a death? Surely this could
be useful now, as well as being useful for broadband signal detection,
showing signal strength as well as how stable the signal is? Or has
the concept of having a scope in a tuner died a death for some
reason? Surely it should be easier now with the prevalence of LCDs
being used for everything in sight?

Or are there any WiFi applications which can simulate this function?

 

[William Sommerwerck]

There used to be a really cool tuner made by Sequerra which I saw in
the 1970s which had this amazing feature on a built-in scope. None of
the other tuners made at that time which had scopes in them seemed to
have that function. (I actually bought a Marantz ST600, though for the
AMAZING sound, not the scope.)

Does anyone know why this technology died a death?

It adds to the tuner's cost without providing a feature most users need.

Surely this could be useful now, as well as being useful for broadband
signal detection, showing signal strength as well as how stable the
signal is?

You can buy an inexpensive WiFi detector at RatShack and elsewhere.

Or has the concept of having a scope in a tuner died a death for some
reason?

See above.

FM is no longer a significant program source for many listeners, especially
with the decline in classical and jazz stations.

 

[DManzaluni]

On Mar 28, 9:38 am, "William Sommerwerck" <grizzledgee...@comcast.net>
wrote:

There used to be a really cool tuner made by Sequerra which I saw in
the 1970s which had this amazing feature on a built-in scope. None of
the other tuners made at that time which had scopes in them seemed to
have that function. (I actually bought a Marantz ST600, though for the
AMAZING sound, not the scope.)
Does anyone know why this technology died a death?

It adds to the tuner's cost without providing a feature most users need.

Surely this could be useful now, as well as being useful for broadband
signal detection, showing signal strength as well as how stable the
signal is?

You can buy an inexpensive WiFi detector at RatShack and elsewhere.

I would like it for diagnostic purposes, to see when (and by how much)
my cable company's signal drops off, as well as which nearby WiFi
signals are experiencing similar problems. I use RCN and their signal
wavers around like mad. No app l know of can show any of this: Most
of them are dependent on the beacon to show just whether there is
anything there or not and how strong it is when it is beaconing. I
wonder if what I am asking for is a practical impossibility? Surely
routers are transmitting all the time even if the beacon only
transmits at certain intervals. It would b interesting to see an app
like this show things like packet loss etc.

Or has the concept of having a scope in a tuner died a death for some
reason?

See above.

FM is no longer a significant program source for many listeners, especially
with the decline in classical and jazz stations.

Dont take your point: In my area there are plenty of classical choices
and with a knob tuner, it is interesting to see where the stations are
and how strong they are, though this signal strength business doesnt
seem to be as important as it is with WiFi.

 

[CJT]

DManzaluni wrote:

On Mar 28, 9:38 am, "William Sommerwerck" <grizzledgee...@comcast.net
wrote:
snip
FM is no longer a significant program source for many listeners, especially
with the decline in classical and jazz stations.


Dont take your point: In my area there are plenty of classical choices
and with a knob tuner, it is interesting to see where the stations are
and how strong they are, though this signal strength business doesnt
seem to be as important as it is with WiFi.

Where, pray tell, are classical stations that numerous?

--
The e-mail address in our reply-to line is reversed in an attempt to
minimize spam. Our true address is of the form che...@prodigy.net.

 

[William Sommerwerck]

FM is no longer a significant program source for many listeners,
especially with the decline in classical and jazz stations.

Dont take your point: In my area there are plenty of classical choices
and with a knob tuner, it is interesting to see where the stations are
and how strong they are, though this signal strength business doesnt
seem to be as important as it is with WiFi.

You're fortunate, but for the country as a whole, classical and jazz are in
a decline. And tuners are made to sell throughout a country, not just in one
area.

 

[msg]

DManzaluni wrote:

On Mar 28, 9:38 am, "William Sommerwerck" <grizzledgee...@comcast.net
wrote:

<snip>

Surely this could be useful now, as well as being useful for broadband
signal detection, showing signal strength as well as how stable the
signal is?

You can buy an inexpensive WiFi detector at RatShack and elsewhere.

Those are not spectrum analyzers. I am interested in talking with anyone
who has purchased the Airsleuth spectrum analyzer, which is uses HomeRF2
NICs, to learn about installation details you encounter. Details of the
product are here:

http://www.NutsAboutNets.com/performance-wifi/main/downloads-wifi-spectrumanalyzer.htm

If you are serious about doing some signal and spectrum monitoring in the WiFi
bands, this may be a useful choice. I have the hardware but am interested in
hearing of the installation experience another user encounters with either the
Airsleuth-Pro or Airsleuth-Lite product.

Michael

 

[Jeff Liebermann]

On Sat, 28 Mar 2009 12:55:40 -0600, msg <msg@_cybertheque.org_> wrote:

Those are not spectrum analyzers. I am interested in talking with anyone
who has purchased the Airsleuth spectrum analyzer, which is uses HomeRF2
NICs, to learn about installation details you encounter. Details of the
product are here:
http://www.NutsAboutNets.com/performance-wifi/main/downloads-wifi-spectrumanalyzer.htm

(404. Page not found) Try instead:
<http://www.nutsaboutnets.com/performance-wifi/products/product-airsleuth-wifi-spectrum-analyzer.htm>

Moderately expensive Wi-Fi spectrum analyzers are common:
<http://www.metageek.net> (Wi-Spy)
<http://www.bvsystems.com> (Bumblebee)
<http://www.airmagnet.com/products/spectrum_analyzer/>
There are also some based on a Proxim FHSS PCMCIA card (which doesn't
work using XP or Vista).

You can also build your own:
<http://www.wireless.org.au/~jhecker/specan/>
<http://www.nitehawk.com/rasmit/sa50.html>
Note that you really don't need to build or buy a spectrum analyzer
that covers from 0.1 to 6GHz to see Wi-Fi. You only need something
that works up to perhaps 500MHz. Precede that with a local
oscillator, mixer (downconverter), preamp, and filter, to cover the
desired frequency range. In other words, buy the complicated IF and
display section and build your own front end. There will be some
mixing artifacts, but they're fairly easy to detect. If you want
better results (i.e. better dynamic range fewer spurs), a real
spectrum analyzer is far more useful. Fluke, Tek, Agilent, Anaritsu,
etc all make portable devices in the $3,000 and up price range.

As for the demise of classical music FM stations, in the Monterey Bay
area, we have KBOQ:
<http://www.kbach.com>
In the SF Bay area, there is KDFC:
<http://www.kdfc.com>
Some of the college stations play classical music, but not full time.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Jeff Liebermann]

On Sat, 28 Mar 2009 06:17:02 -0700 (PDT), DManzaluni
<dmanzaluni@googlemail.com> wrote:

There used to be a really cool tuner made by Sequerra which I saw in
the 1970s which had this amazing feature on a built-in scope.

The magic buzzword is "panadapter". Search Google for lots of hits.
For fairly narrowband applications, it's sometimes called a
"waterfall" display.

The feature is found on some AOR scanners. All the SDR (software
defined radio) tuners have panadapters in software. For example:
<http://www.rfspace.com/SDR-IQ.html> (see photos)
Any synthesized receiver that covers the FM band can have this
feature, but you need direct access to the frequency control and IF
output. The panadapter sweeps the frequency range, and displays the
detected signal strength versus frequency on an x-y display.


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[David Nebenzahl]

On 3/29/2009 8:45 AM Jeff Liebermann spake thus:

As for the demise of classical music FM stations, in the Monterey Bay
area, we have KBOQ:
http://www.kbach.com
In the SF Bay area, there is KDFC:
http://www.kdfc.com

.... which is only a faint shadow of its former self, now playing nothing
but "easy listening" classical pieces and war horses.

When I moved here, not only were there 2 FM classical stations, but KDFC
broadcast in *AM* as well (there were a couple of other classical AM
stations as well). So I'd say classical music radio is in a rather steep
decline.


--
Made From Pears: Pretty good chance that the product is at least
mostly pears.
Made With Pears: Pretty good chance that pears will be detectable in
the product.
Contains Pears: One pear seed per multiple tons of product.

(with apologies to Dorothy L. Sayers)