> Hi gang,
>
> I'm looking to purchase or rent a spectrum analyzer. I do
> a lot of work installing a/v modulators (like thost at
> http://www.channelvision.com) and I need a way to see what affects
> my picture quality, like amplitude and bleed through from
> one channel to the next.
>
> I'm not sure what to look for in a spectrum analyzer. Are
> there any features that will be particularly useful for TV
> work?
>
> Thanks,
> Michael
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> "[PIC]:" PIC only "[EE]:" engineering "[OT]:" off topic "[AD]:" ad's

> > If he were asking for realtime digital filtering I would agree, but he
> > is only asking for a spectrum analyzer.  He can digitize a chunk, then
> > chew on it for a while before outputting the result and grabbing another
> > chunk.  I don't have an answer for him, but somewhere there must be some
> > FFT code for a PIC.
>
> This sounds like a job for the DSPics that are coming out.  Some DSPs (I'm
> not sure about the DSPics) have special support for doing the butterfly
> addressing for doing power of 2 FFTs.
>
>
> ********************************************************************
> Olin Lathrop, embedded systems consultant in Littleton Massachusetts

>> I would like to use a pic to function as an Audio Spectrum Analyzer, does
>> anyone know what Pic I could use or where I could find more info.
>
>What is your highest frequency, 20KHz?  Does it need to be real time, or can
>you sample a snapshot of the audio signal and do post processing on it?
>Does all the signal need to be sampled, or only occasionally?
>
>If it needs to be real time or you are expecting it to keep up with a
>continuous "audio" stream of reasonable bandwith, then a PIC isn't going to
>do it.  You will need a DSP.  Note that Microchip is coming out with the new
>dsPIC line, which is PIC-flavored DSPs.
>
>At best you can expect a PIC to sample a chunk of audio, go "off line" while
>is runs an FFT to find the frequencies in the chunk, output those somehow,
>then do the next chunk.  PICs and other general purpose microcontrollers are
>not well suited to this kind of task.
>
>
>********************************************************************
>Olin Lathrop, embedded systems consultant in Littleton Massachusetts
>(978) 742-9014, EraseMEolinembedinc.com, http://www.embedinc.com
>
>--
>http://www.piclist.com hint: PICList Posts must start with ONE topic:
>[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>
>

>At 08:56 PM 6/26/01 -0600, Dan wrote:
>>Ages ago....
>>
>>There was the Radio Shack Color Computer (AKA the "CoCo"), which ran at a
>>mere 1/4 of the
>>frequency of a common color burst crystal.  (a 6809 @ less than 1 Mhz!).
>>It had
>>an R2R resistor ladder style D/A converter and a single analog comparator
>>with which one could implement an A/D in software.  They sold a ROM cartridge
>>which contained an audio spectrum analyzer program. Does anyone else
>>remember this? I have a hard time believing that a clever programmer could
>>not achieve the same with a PIC (at 20Mhz + hardware A/D) today.
>
>The key to the whole audio spectrum analyzer question is the required
>bandwidth and the required frequency resolution.
>
>The RS Color Computer only measured up to 5KSPS as I recollect, and the
>microprocessor had an 8-bit hardware multiply.
>
>An FFT is an orthogonal transformation, so it would be possible to do a
>reasonable job with low accuracy fixed point arithmetic.
>
>The real killer is the memory needed for the job.
>

> > If he were asking for realtime digital filtering I would agree, but he
> > is only asking for a spectrum analyzer.  He can digitize a chunk, then
> > chew on it for a while before outputting the result and grabbing another
> > chunk.  I don't have an answer for him, but somewhere there must be some
> > FFT code for a PIC.
>
> This sounds like a job for the DSPics that are coming out.  Some DSPs (I'm
> not sure about the DSPics) have special support for doing the butterfly
> addressing for doing power of 2 FFTs.
>
>
> ********************************************************************
> Olin Lathrop, embedded systems consultant in Littleton Massachusetts
> (978) 742-9014, RemoveMEolinspam_OUTKILLspamembedinc.com, http://www.embedinc.com
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>
>

>
> So:
>
> 1. What bandwidth? If audio, one would assume 20Hz-20kHz would be
> necessary. This is tough to do as a 'continuum' on a PIC.
>
> 2. What resolution in frequency? If only 8-16 individual frequencies were
> needed (sort of like the LED bar graph spectrum displays), then fixed
> frequency transforms might be viable.
>
> 3. What accuracy is needed? If only 4-bits or so, then memory requirements
> are much easier. If 8-bits, you need an external memory.
>
> In summary, it should be possible to do a 32-, 64- or even 128-sample DFT
> on a PIC, if you're willing to tolerate a less than 8-bit resulting
> accuracy. The maximum sampling rate would probably be only 1-2 kSPS
> real-time, expandable if delays in reporting are allowed (1st record, then
> analyze).
>
> This kind of application is much better suited to a microcomputer with a
> larger address space and hardware 8-bit multiply at least. E.g., 8051,
> etc., or better.
>
> ================================================================
> Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: RemoveMEralKILLspamlcfltd.com
> Least Cost Formulations, Ltd.            URL: http://lcfltd.com/
> 824 Timberlake Drive                     Tel: 757-467-0954
> Virginia Beach, VA 23464-3239            Fax: 757-467-2947
>
> "Vere scire est per causas scire"
> ================================================================
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> Are you saying that we could not download this AN from Scenix?
>
> "dr. Imre Bartfai" gravada:
>
> > Ubicom has (at least, Scenix had) an AN dealing with this subject,
> > AFAIK. I got it, too. Unfortunately, it is not public as I should sign an
> > Undisclosure Agreement before. It is free from them, though.
> >
> > Regards,
> >
> > Imre
> >
>
> --
> http://www.piclist.com hint: The list server can filter out subtopics
> (like ads or off topics) for you. See http://www.piclist.com/#topics
>
>
>

>Hello Piclist,
>
>       I4m looking for a Spectrum analyzer software (freeware) where I can
>define a periodic
>       waveform.
>       Is to analyze harmonics in waveforms.
>
>       Thanks in advance,
>                         Gus
>
>
>--
>  Digiled                            EraseMEmailEraseMEdigiled.com
>
>--
>http://www.piclist.com hint: The list server can filter out subtopics
>(like ads or off topics) for you. See http://www.piclist.com/#topics

>>Hello Piclist,
>>
>>       I4m looking for a Spectrum analyzer software (freeware) where I can
>>define a periodic
>>       waveform.
>>       Is to analyze harmonics in waveforms.
>>
>>       Thanks in advance,
>>                         Gus
>>
>>
>>--
>>  Digiled                            @spam@mail@spam@spam_OUTdigiled.com
>>
>>--
>>http://www.piclist.com hint: The list server can filter out subtopics
>>(like ads or off topics) for you. See http://www.piclist.com/#topics

>Hello Mike,
>
>       Simply a simulator where I can define a perdiodic waveform and
>       it calculates the harmonic content of the signal...
>       It4s to evaluate a filter and a PWM signal.
>       Any ideas ?
>
>MH> I'm not entirely clear on what it is you're looking for, but here's
>MH> a page that has a lot of test equipment-like software, mostly
>MH> using the sound card for input.
>
>MH> http://www.dazyweblabs.com/shannonsoft/page3.html
>
>MH> Mike H.
>
> >>Hello Piclist,
> >>
> >>       I4m looking for a Spectrum analyzer software (freeware) where I
>can
> >>define a periodic
> >>       waveform.
> >>       Is to analyze harmonics in waveforms.
> >>
> >>       Thanks in advance,
> >>                         Gus

>Hi there, this is the third email which I'm sending to the list with
>this topic, the other two seems being lost somewhere...
>
>I'm interested in a refurbished, used (inexpensive) spectrum analyzer
>covering a
>0-6GHz range minimum (preferable with tracking generator), not very
>old, from an european seller.
>
>Any hints will be appreciated,
>Vasile
>
>  
>

>
> Hi there, this is the third email which I'm sending to the list with
> this topic, the other two seems being lost somewhere...
>
> I'm interested in a refurbished, used (inexpensive) spectrum analyzer
> covering a
> 0-6GHz range minimum (preferable with tracking generator), not very
> old, from an european seller.
>
> Any hints will be appreciated,
> Vasile
>

>
> WBR Dmitry.
>
>
> Vasile Surducan wrote:
> >
> > Hi there, this is the third email which I'm sending to the list with
> > this topic, the other two seems being lost somewhere...
> >
> > I'm interested in a refurbished, used (inexpensive) spectrum analyzer
> > covering a
> > 0-6GHz range minimum (preferable with tracking generator), not very
> > old, from an european seller.
> >
> > Any hints will be appreciated,
> > Vasile
> >
> > --

> Vasile Surducan <piclist9 <at> gmail.com> writes:
>
> >  Would work yes, but will be almost unuseless. The simple mixer must
> > be replaced with an IQ one, else would be necessary two or three IF
> > stages with all the problems. The biggest one will be the frequency
> > fluctuation in the audio side and the limited bandwith or distortion.
> > Also will be necessary a real VCO and not a white noise generator.
> >  There are many analyzers like this one on the web, the best one is
> > using a tuner
> > and claim to work ok till 2Ghz. I'm seeing every day  how works a good
> > spectrum analyzer (for it's 30 years old age) TEK492 and if that one
> > can't be used for fast signal analyses, all analyzers having the same
> > principle (unfortunately) can't.
> > So depends what do you need.
>
> I wrote:
>
> > > Finally an affordable solution for
> > > filter and amplifier design for homebrew UHF and microwave ?
> > >
> > > http://www.qsl.net/7n3wvm/Fil_Meas.html
> > >
> > > Peter
>
> Could you elaborate on this ? Why is an IQ mixer needed ?

> most needed thing is low (very low) phase noise of the carrier so the LO does
> not swamp the mixer and the audio after it (although I am unsure what happens
> with the phase noise in a direct conversion receiver when an actual signal is
> not present). The scheme is the same as used in DSB/CW direct conversion
> receivers, whose performance is rather good usually. Also using a noise source
> as input makes it possible to go to very high frequencies without the usual
> problems. No ? Also it is a very simple and inexpensive scheme. With a $10 mixer
> it could cover dc to 4GHz. If a stabilised Gunnplexer is used then microwave
> filter (and Gunn and varactor bias, by voltage, to match an existing filter or
> structure) tuning becomes possible. What am I missing ? Ok, dynamic range is
> probably 55dB or less (sound card dynamic range). With a good sound card and a
> preamplifier this could be 90-100dB. Many people already have such a good sound
> card. If the LO is replaced with a stepwise DSS or PLL then a spectrum can be
> taken with say 40kHz 'windows' from DC (almost) to 1GHz. The DSS could be
> controlled by a USB to parallel control for example.
>
> Peter
>
>

>Caught the YES 35th anniversary show on PBS tonight and went back in time.
>
>Back before MP3, iPod and ear buds there were people tweaking equalizers and watching bouncing
>LEDs on spectrum analyzers.
>
>To build a 8 or 16 channel spectrum analyzer would you go analog using bandpass filters into
>A/D into on perhaps a PIC 18F or 24F, or is it something that a dsPIC is a better fit for?
>
>The bandpass filters would (could?) take a fare chunk of board space but the firmware would be simpler.
>dsPIC would just suck the signal into a single input but require high power software to split it out inside?
>
>
>
>
>  
>

> > The math for a discrete FFT isn't too complicated, especially at low
> > resolutions. Try doing a little reading about it - it's fascinating
> > stuff.
>
> We did it on an MC6800 long long ago.
>
> The memory gives me Butterflies :-)
>
>
>
>
>         RM
>

>>The math for a discrete FFT isn't too complicated, especially at low
>>resolutions. Try doing a little reading about it - it's fascinating
>>stuff.
>>    
>>
>
>We did it on an MC6800 long long ago.
>
>The memory gives me Butterflies :-)
>
>
>
>
>        RM
>
>  
>

> Just to make an ideea about what a spectrum analyzer means
> (using multiple FI stages and no DDS or IQ arhitecture):
>
> http://www.hanssummers.com/electronics/equipment/spectrumanalyser/index.htm
>
> greetings,
> Vasile
>
> On 6/4/06, Rich Graziano <spamBeGonergrazia1EraseMErochester.rr.com> wrote:
>> Hi All:  Does anyone have a proven circuit for a spectrum analyzer for a
>> frequency range 20 Hz to 20 MHz:?  Something I could fit on a small PC
>> Card?
>> Rich

> Sean Breheny wrote:
>> Hi all,
>>
>> Can someone who is familiar with the Tek 492 spectrum analyzer please
>> email me offlist? I recently bought one on eBay and I am trying to
>> check it out before giving feedback. There are a couple of items which
>> seem like they may be quirks or problems, but the manual doesn't seem
>> to address them. I'd like to ask someone who is knowledgeable or
>> someone who can compare results with his own Tek 492. Email address is
>> shb7 AT cornell.edu
>>
>> Thanks very much in advance!
>>
>> Sean
>>
>
>    Try here:
>
>    http://groups.yahoo.com/group/TekScopes/
>
>    Mark Jordan
>

> So, in my huge amounts of free time I've been thinking that the one area
> of electronics I don't really have much experience is radio.
>
> I've been experimenting and having some fun, but I've convinced myself
> that something that might turn out to be a really fun and educational
> adventure is building a spectrum analyzer.
>
> There's not of google links out there to half finished or ancient
> projects.
>
> I'm not looking at creating laboratory grade equipment, just something
> that'll help me see that the circuits I'm building are actually doing.
>
> So, any suggestions?
>
> I'm not to concerned about the interface or display, that's the kind of
> stuff I've done before so I'd probably just take the easy way out and
> use a PC initially.
>
> My main area of concern is the actual RF stuff.
>
> I'd like the analyzer to at least cover up to about 1GHz (the 2.4GHz
> band would be nice (and very useful in the future) but I feel I might be
> overreaching there).
>
> Alot of projects use the tuners in VCRs for the RF front end. Any
> recommendations on something that might work well?
>
> Ideally if I could get a tuner to do most of the dirty work (something
> like feed it a voltage to select which frequency to tune, and output an
> RSSI signal to indicate signal strength) that would be a great way to
> start.
>
> Any suggestions? Anybody do something similar?
>
> Thanks for your ideas!
>
> TTYL
>

> On Tue, 2011-06-28 at 17:07 +0200, Ariel Rocholl wrote:
> > Hi Herbert,
> >
> > That is more or less what I did for RF Explorer, see
> > http://www.rf-explorer.com . Current versions are limited to narrow ISM
> > bands, but wider band models are coming in a few weeks, including a
> 2.4Ghz
> > and 240-960Mhz.
> >
> > The circuit is published on the "hacker's corner" wiki. You may get some
> > ideas out of it.
>
> Hello Ariel,
>
> neat, thanks!
>
> I've looked at other units that are kinda similar to that. Thing is, I
> don't really want to build something restricted to one band, I'd like
> something that covers a wide range.
>
> TTYL
>

> So, in my huge amounts of free time I've been thinking that the one area
> of electronics I don't really have much experience is radio.
>
> I've been experimenting and having some fun, but I've convinced myself
> that something that might turn out to be a really fun and educational
> adventure is building a spectrum analyzer.
>
> There's not of google links out there to half finished or ancient
> projects.
>
> I'm not looking at creating laboratory grade equipment, just something
> that'll help me see that the circuits I'm building are actually doing.
>
> So, any suggestions?
>
> I'm not to concerned about the interface or display, that's the kind of
> stuff I've done before so I'd probably just take the easy way out and
> use a PC initially.
>
> My main area of concern is the actual RF stuff.
>
> I'd like the analyzer to at least cover up to about 1GHz (the 2.4GHz
> band would be nice (and very useful in the future) but I feel I might be
> overreaching there).
>
> Alot of projects use the tuners in VCRs for the RF front end. Any
> recommendations on something that might work well?
>
> Ideally if I could get a tuner to do most of the dirty work (something
> like feed it a voltage to select which frequency to tune, and output an
> RSSI signal to indicate signal strength) that would be a great way to
> start.
>
> Any suggestions? Anybody do something similar?
>
> Thanks for your ideas!
>
> TTYL
>

> On Tue, 2011-06-28 at 11:44 -0400, Sean Breheny wrote:
>> One fairly common way to make a cheap spectrum analyzer for <1GHz is
>> to use a surplus TV tuner module, the kind which used to be on
>> computer analog TV input cards. These can be set up to take RF in,
>> give a single IF frequency out (often 45MHz or 10.7 MHz), and take a
>> tuning voltage input. These would allow you to tune from about 40MHz
>> to 1GHz. They also often have built-in AGC with a signal strength out
>> pin. You then can amplify the output, apply a much narrower filter,
>> and feed it to a log-amp detector IC. Then, the combination of the AGC
>> level out plus the output of the log amp would be your signal strength
>> in the BW of the narrow filter.
>>
>> I bought a few of these tuner modules on eBay for only a dollar or two
>> each just a few months ago. They came with documentation, too.
>
> Thats exactly the kind of thing I'd like to find! Any pointers? Willing
> to sell the ones you've got? :)
>
> How would I go about searching for something like that? The
> documentation would of course be key, don't want to try and figure
> pinouts of modules on my own?
>
> Thanks, TTYL
>

>
> So, in my huge amounts of free time I've been thinking that the one area
> of electronics I don't really have much experience is radio.
>
> I've been experimenting and having some fun, but I've convinced myself
> that something that might turn out to be a really fun and educational
> adventure is building a spectrum analyzer.
>
> There's not of google links out there to half finished or ancient
> projects.
>
> I'm not looking at creating laboratory grade equipment, just something
> that'll help me see that the circuits I'm building are actually doing.
>
> So, any suggestions?
>
> I'm not to concerned about the interface or display, that's the kind of
> stuff I've done before so I'd probably just take the easy way out and
> use a PC initially.
>
> My main area of concern is the actual RF stuff.
>
> I'd like the analyzer to at least cover up to about 1GHz (the 2.4GHz
> band would be nice (and very useful in the future) but I feel I might be
> overreaching there).
>
> Alot of projects use the tuners in VCRs for the RF front end. Any
> recommendations on something that might work well?
>
> Ideally if I could get a tuner to do most of the dirty work (something
> like feed it a voltage to select which frequency to tune, and output an
> RSSI signal to indicate signal strength) that would be a great way to
> start.
>
> Any suggestions? Anybody do something similar?
>
> Thanks for your ideas!
>
> TTYL
>

> On Tue, 2011-06-28 at 11:44 -0400, Sean Breheny wrote:
>> One fairly common way to make a cheap spectrum analyzer for <1GHz is
>> to use a surplus TV tuner module, the kind which used to be on
>> computer analog TV input cards. These can be set up to take RF in,
>> give a single IF frequency out (often 45MHz or 10.7 MHz), and take a
>> tuning voltage input. These would allow you to tune from about 40MHz
>> to 1GHz. They also often have built-in AGC with a signal strength out
>> pin. You then can amplify the output, apply a much narrower filter,
>> and feed it to a log-amp detector IC. Then, the combination of the AGC
>> level out plus the output of the log amp would be your signal strength
>> in the BW of the narrow filter.
>>
>> I bought a few of these tuner modules on eBay for only a dollar or two
>> each just a few months ago. They came with documentation, too.
>
> Thats exactly the kind of thing I'd like to find! Any pointers? Willing
> to sell the ones you've got? :)
>
> How would I go about searching for something like that? The
> documentation would of course be key, don't want to try and figure
> pinouts of modules on my own?
>
> Thanks, TTYL
>

> OK, I looked at what I have and it is less impressive than what I
> remember. Frequency range is only about 400 to 900 MHz. I have
> attempted to attach a GIF image which I was sent by the eBay seller
> when I bought them (qty 2). I also have a schematic but please ask me
> offlist if you want it as it is a little bit bigger file and I do not
> think that I should try to send it on-list.
>
> Also, I came across this archived discussion on this topic of spectrum
> analyzers from TV tuners:
>
> http://www.nitehawk.com/rasmit/sa_notes1.html
>
> The modules I have were made by Mitsumi, they have only one label on
> them which seems to say TIF4-A41. Also appears to have a date code of
> 8447 (47th week of 1984 I'd guess). These are probably not the best
> bet for this project as there are more modern ones available, some
> even with I2C-controlled digital tuning.
>
> I would be willing to sell them if you are still interested.
>
> Sean
>
>
> On Tue, Jun 28, 2011 at 11:49 AM, Herbert Graf <spam_OUThkgrafspam_OUTspam_OUTgmail.com> wrote:
>> On Tue, 2011-06-28 at 11:44 -0400, Sean Breheny wrote:
>>> One fairly common way to make a cheap spectrum analyzer for <1GHz is
>>> to use a surplus TV tuner module, the kind which used to be on
>>> computer analog TV input cards. These can be set up to take RF in,
>>> give a single IF frequency out (often 45MHz or 10.7 MHz), and take a
>>> tuning voltage input. These would allow you to tune from about 40MHz
>>> to 1GHz. They also often have built-in AGC with a signal strength out
>>> pin. You then can amplify the output, apply a much narrower filter,
>>> and feed it to a log-amp detector IC. Then, the combination of the AGC
>>> level out plus the output of the log amp would be your signal strength
>>> in the BW of the narrow filter.
>>>
>>> I bought a few of these tuner modules on eBay for only a dollar or two
>>> each just a few months ago. They came with documentation, too.
>>
>> Thats exactly the kind of thing I'd like to find! Any pointers? Willing
>> to sell the ones you've got? :)
>>
>> How would I go about searching for something like that? The
>> documentation would of course be key, don't want to try and figure
>> pinouts of modules on my own?
>>
>> Thanks, TTYL
>>

>>   Does anyone here know of any
>> good (free if possible) real time spectrum analyzer software for
>> Windows? I want to be able to view what audio is coming out of this
>> guitar interface.
>>      
> Mayhaps
>
> PC soundcard based:
>
>             http://www.techmind.org/audio/#specanaly
>
>           From:  http://www.techmind.org/audio/#intro
>
>
> Mod for DC response
> YMMV
> Caveat Emptor
>
>       http://blog.makezine.com/archive/2008/05/how-to-modify-a-pc-sound.html
>
> Related
>
>       http://www.edaboard.com/thread136601.html
>
> Zelscope $10
>
>      http://www.zelscope.com/
>
> TrueRTA
> Versions for $0
>
>     http://www.trueaudio.com/rta_abt1.htm
>
> Legion
>
>       http://www.dxzone.com/catalog/Software/Spectrum_analyzers/
>
> Virtins
> 21 day trial free
>
>          http://www.virtins.com/

> Hi all,
>
> I bought a cheap guitar-computer interface off of dealextreme:
>
> http://www.dealextreme.com/p/guitar-to-usb-interface-link-cable-for-pc-mac-recording-130cm-32874
>
> It works very well and GarageBand/Guitar Rig totally rock. Latency is
> minimal as well. I don't think I can notice it with the proper
> settings.
>
> Anyway, there seems to be a very high frequency hiss sound on certain
> amp models/configurations on both GarageBand and Guitar Rig (have yet
> to try logic studio) which makes me question whether or not the guitar
> interface is at fault. I want to do a spectrum analysis on the output
> of the thing and see what's going on. Does anyone here know of any
> good (free if possible) real time spectrum analyzer software for
> Windows? I want to be able to view what audio is coming out of this
> guitar interface.
>

> On Wed, Aug 10, 2011 at 5:45 PM, Robert Rolf <RemoveMERobert.RolfRemoveMEEraseMEualberta.ca>wrote:
>
>>  Or just change out the op amp in the existing amplifier for one with a
>> much better noise figure. One MEANT for low noise operation, rather than
>> cheapness.
>>
>> There are op amps designed specifically for ultra low noise audio
>> operations with low internal bias currents and low shot noise as a
>> result.  LT1115 comes to mind, AD8597 series, OPA827, etc.
>>
>> Saves a lot of time is all you do is swap out the noise maker for one
>> that isn't so intrinsically noisy.
>> Have you looked at what is in there currently? I'll bet its a general
>> purpose, super cheap, op amp.
>>
>
> LOL! So I opened up the device and it's using a PCM2902 (
> http://focus.ti.com/docs/prod/folders/print/pcm2902.html) inside. The
> opamp is an LMV824 quad opamp (http://www.national.com/pf/LM/LMV824.html)
>
> What do you guys think of the opamp? Is it suitable for this purpose? Is it
> a noisy opamp?
>
> What do you guys think of the LT1028 (I hear lots of people love this one
> for audio) and LT1115?
>
> The LMV824 noise spec is 24nV/rt(Hz) @ 1KHz
>
> The LT1028 is 0.85nV
>
> The LT1115 is 0.9nV
>
> So yeah, it's a pretty unsuitable opamp in the guitar interface box. Would
> it be possible that the noise spec on the LMEV824 is causing the noise
> problem? I was reading up on the noise spec calculations and how to use
> them, but I forgot. How /bad/ is 24nV/rt(Hz) for audio purposes?
>
> I would ideally like to use 4 of LT1028 opamps but they're expensive to buy
> 4 of. What other opamps would you guys recommend? 4-in-a-chip would be nice,
> but I would guess that quality is compromised for quantity for these opamps.
>

>Hello all,
>
>well, after a long delay, I've been able to dedicate a little time to my
>idle project: a home built spectrum analyzer based on a TV tuner front
>end.
>
>I've found what I believe the perfect tuner for me (mostly because it's
>something I have in my hands):
>
>http://www.datasheetarchive.com/indexdl/Datasheet-028/DSA00488547.pdf
>
>It's a Temic 4036 RF front end module. I found it on a WinTV PC TV tuner
>PCI card.
>
>It's a I2C based tuner, with single 5V power supply (has an onboard
>DC-DC to get the 33V needed by the tuner). I stuck the card in a PC,
>booted Ubuntu, attached a protocol analyzer (thank you beta version of
>the BitScope software, was a major time saver!) on the I2C pins, started
>TVTime and changed channels. The module is being programmed exactly as
>the datasheet says it should be!
>
>So, with that out of the way, what would be my next step?
>
>First off, the module outputs CVBS (at baseband), and something labelled
>IF2 (at 45.75 MHZ). Obviously I need an RSSI circuit. But do I first
>have to "tune" the output somehow?
>
>What I'm envisioning (and note, I no NOTHING about RF stuff, so this is
>very much a learning project for me) is using a second tuner (some sort
>of home built one chip thing with RSSI output perhaps?) that "tunes"
>somewhere in the CVBS output with a bandwidth of say 10kHz? So basically
>sweeping would be two steps, set the TV tuner to a channel, then sweep
>the second tuner across the ~4MHz bandwidth of the CVBS or IF output.
>Then step the TV tuner to the next range, and sweep the CVBS or IF
>output. Combined I could get everything I need.
>
>Does this sound at all reasonable or am I WAY out of wack here?
>
>Should use the CVBS or the IF output?
>
>Anybody have chip recommendations for how I might build the second
>tuner, one hopefully with an RSSI output?
>
>Is there a simpler way to what I'm after? What kind of resolution should
>I aim for?
>
>Thanks for any pointers!
>
>TTYL
>

> Have you checked out the "Poor Man's Spectrum Analyzer" at
> <http://www.science-workshop.com/> ?  They may have circuit blocks that are
> useful for you.
>
> Searching out "poor mans spectrum analyzer" yields lots of hits -
> some of those may also be useful.
>
> dwayne
>
>
> At 01:15 PM 5/24/2012, Herbert Graf wrote:
>> Hello all,
>>
>> well, after a long delay, I've been able to dedicate a little time to my
>> idle project: a home built spectrum analyzer based on a TV tuner front
>> end.
>>
>> I've found what I believe the perfect tuner for me (mostly because it's
>> something I have in my hands):
>>
>> www.datasheetarchive.com/indexdl/Datasheet-028/DSA00488547.pdf
>>
>> It's a Temic 4036 RF front end module. I found it on a WinTV PC TV tuner
>> PCI card.
>>
>> It's a I2C based tuner, with single 5V power supply (has an onboard
>> DC-DC to get the 33V needed by the tuner). I stuck the card in a PC,
>> booted Ubuntu, attached a protocol analyzer (thank you beta version of
>> the BitScope software, was a major time saver!) on the I2C pins, started
>> TVTime and changed channels. The module is being programmed exactly as
>> the datasheet says it should be!
>>
>> So, with that out of the way, what would be my next step?
>>
>> First off, the module outputs CVBS (at baseband), and something labelled
>> IF2 (at 45.75 MHZ). Obviously I need an RSSI circuit. But do I first
>> have to "tune" the output somehow?
>>
>> What I'm envisioning (and note, I no NOTHING about RF stuff, so this is
>> very much a learning project for me) is using a second tuner (some sort
>> of home built one chip thing with RSSI output perhaps?) that "tunes"
>> somewhere in the CVBS output with a bandwidth of say 10kHz? So basically
>> sweeping would be two steps, set the TV tuner to a channel, then sweep
>> the second tuner across the ~4MHz bandwidth of the CVBS or IF output.
>> Then step the TV tuner to the next range, and sweep the CVBS or IF
>> output. Combined I could get everything I need.
>>
>> Does this sound at all reasonable or am I WAY out of wack here?
>>
>> Should use the CVBS or the IF output?
>>
>> Anybody have chip recommendations for how I might build the second
>> tuner, one hopefully with an RSSI output?
>>
>> Is there a simpler way to what I'm after? What kind of resolution should
>> I aim for?
>>
>> Thanks for any pointers!
>>
>> TTYL
>>

> I have seen that before. That site seems to just offer for purchase the details, or parts.
>
> I will have a look to see what kind of hits "poor mans spectrum analyzer" gets me. Thanks for the pointer.
>
> TTYL
>
>
> On 2012-05-24, at 5:48 PM, Dwayne Reid wrote:
>
>> Have you checked out the "Poor Man's Spectrum Analyzer" at
>> <http://www.science-workshop.com/> ?  They may have circuit blocks that are
>> useful for you.
>>
>> Searching out "poor mans spectrum analyzer" yields lots of hits -
>> some of those may also be useful.
>>
>> dwayne
>>
>>
>> At 01:15 PM 5/24/2012, Herbert Graf wrote:
>>> Hello all,
>>>
>>> well, after a long delay, I've been able to dedicate a little time to my
>>> idle project: a home built spectrum analyzer based on a TV tuner front
>>> end.
>>>
>>> I've found what I believe the perfect tuner for me (mostly because it's
>>> something I have in my hands):
>>>
>>> www.datasheetarchive.com/indexdl/Datasheet-028/DSA00488547.pdf
>>>
>>> It's a Temic 4036 RF front end module. I found it on a WinTV PC TV tuner
>>> PCI card.
>>>
>>> It's a I2C based tuner, with single 5V power supply (has an onboard
>>> DC-DC to get the 33V needed by the tuner). I stuck the card in a PC,
>>> booted Ubuntu, attached a protocol analyzer (thank you beta version of
>>> the BitScope software, was a major time saver!) on the I2C pins, started
>>> TVTime and changed channels. The module is being programmed exactly as
>>> the datasheet says it should be!
>>>
>>> So, with that out of the way, what would be my next step?
>>>
>>> First off, the module outputs CVBS (at baseband), and something labelled
>>> IF2 (at 45.75 MHZ). Obviously I need an RSSI circuit. But do I first
>>> have to "tune" the output somehow?
>>>
>>> What I'm envisioning (and note, I no NOTHING about RF stuff, so this is
>>> very much a learning project for me) is using a second tuner (some sort
>>> of home built one chip thing with RSSI output perhaps?) that "tunes"
>>> somewhere in the CVBS output with a bandwidth of say 10kHz? So basically
>>> sweeping would be two steps, set the TV tuner to a channel, then sweep
>>> the second tuner across the ~4MHz bandwidth of the CVBS or IF output.
>>> Then step the TV tuner to the next range, and sweep the CVBS or IF
>>> output. Combined I could get everything I need.
>>>
>>> Does this sound at all reasonable or am I WAY out of wack here?
>>>
>>> Should use the CVBS or the IF output?
>>>
>>> Anybody have chip recommendations for how I might build the second
>>> tuner, one hopefully with an RSSI output?
>>>
>>> Is there a simpler way to what I'm after? What kind of resolution should
>>> I aim for?
>>>
>>> Thanks for any pointers!
>>>
>>> TTYL
>>>

> Of not much help (because I can't find mycopy), Electronics Australia
> (defunct) did a Spectrum Analyser project based on a TV tuner, I can't
> recall how the sweep component worked. I vaguely recall an early Elektor
> magazine (70's or 80's) also did one.
>
> Colin
> --
> cdb, @spam@colinSTOPspam@spam@btech-online.co.uk on 27/05/2012
>  
> Web presence: http://www.btech-online.co.uk  
>  
> Hosted by:  http://www.justhost.com.au
>  
>
> This email is to be considered private if addressed to a named  individual
> or Personnel Department, and public if addressed to a blog,  forum or news
> article.
>  
>
>

> Of not much help (because I can't find mycopy), Electronics Australia
> (defunct) did a Spectrum Analyser project based on a TV tuner, I can't
> recall how the sweep component worked. I vaguely recall an early Elektor
> magazine (70's or 80's) also did one.
>
> Colin
> --
> cdb, spamBeGonecolinbtech-online.co.uk on 27/05/2012
>
> Web presence: http://www.btech-online.co.uk
>
> Hosted by:  http://www.justhost.com.au
>
>
> This email is to be considered private if addressed to a named  individual
> or Personnel Department, and public if addressed to a blog,  forum or news
> article.
>
>
>
>