One of the keys to the performance level of Ryder's receiver would seem be a textbook-level signal path: filtering - limiting - demodulation. You actually don't see that very often in tuners (the odd Revox comes to mind), as most commercial samples (especially Japanese) tend to use limiter-amplifiers with plenty of gain in the midst of filtering, presumably favoring quieting over IF linearity. Selectivity at higher signal levels is much degraded as a result.
BTW, I wouldn't recommend biasing the VCO tuning diodes with a plain 100k, that certainly won't be too good for phase noise.
BTW, I wouldn't recommend biasing the VCO tuning diodes with a plain 100k, that certainly won't be too good for phase noise.
Hi sgrossklass,
i think your right, IF bandwidth and linearity is not the focus of so many tuners. Those that do have special attention in this area of the tuner sound amazing.
Anyway not to digress too much from the post… Ryder's tuner design was amazing in 2000 but today we are somewhere else with DSP and a digital path from RF to stereo demodulator.
Today something like this (http://k-ns.jp/fpga.html) kills them all in all measurable parameters relevant to FM tuners… Use google translate and click on the various embedded sub-links to see some specifics…
Accuphase two latest models T-1000 and T-1100 use this sort of technology. no contest.
this same kit was once available as a diy module for folks to experiment.
http://homepage3.nifty.com/RadioGaGa/FM
/paba
i think your right, IF bandwidth and linearity is not the focus of so many tuners. Those that do have special attention in this area of the tuner sound amazing.
Anyway not to digress too much from the post… Ryder's tuner design was amazing in 2000 but today we are somewhere else with DSP and a digital path from RF to stereo demodulator.
Today something like this (http://k-ns.jp/fpga.html) kills them all in all measurable parameters relevant to FM tuners… Use google translate and click on the various embedded sub-links to see some specifics…
Accuphase two latest models T-1000 and T-1100 use this sort of technology. no contest.
this same kit was once available as a diy module for folks to experiment.
http://homepage3.nifty.com/RadioGaGa/FM
/paba
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Hi Patrick,
yes by default that module is set to japan band 76-90, but I think I recall it was just a firmware mode, to get 88-108 and different de-emphasis. It was a few years back just google "FPGA FM stereo tuner" and you will land on several japanese builders web sites then with google translate you can get most of it.
One or two places sell a finished tuner based on the module, maybe they will build you one for your market with power transformer, band and de-emphasis corrected for market. It is worth sending an email. The module is a few years old now.
I have so many tuners but I would be tempted by this one. Just don;t have the time to build it myself.
/paba
yes by default that module is set to japan band 76-90, but I think I recall it was just a firmware mode, to get 88-108 and different de-emphasis. It was a few years back just google "FPGA FM stereo tuner" and you will land on several japanese builders web sites then with google translate you can get most of it.
One or two places sell a finished tuner based on the module, maybe they will build you one for your market with power transformer, band and de-emphasis corrected for market. It is worth sending an email. The module is a few years old now.
I have so many tuners but I would be tempted by this one. Just don;t have the time to build it myself.
/paba
One can buy a fully finished one here for 70k Yen.
????
But you knew already.
For those who want to read about the development process and the different DIY builds :
FPGA FMƒXƒeƒŒƒI¥ƒ`ƒ…�[ƒi
Full Coverage FPGA FM Stereo Tuner
Full Coverage”łւ̃Aƒbƒvƒf�[ƒg
FPGA FMƒXƒeƒŒƒI�Eƒ`ƒ…�[ƒi�[‚Ì�»�ì “dŽq�H�ì‚Ì�¬•”‰®/ƒEƒFƒuƒŠƒuƒ�ƒO
Patrick
????
But you knew already.
For those who want to read about the development process and the different DIY builds :
FPGA FMƒXƒeƒŒƒI¥ƒ`ƒ…�[ƒi
Full Coverage FPGA FM Stereo Tuner
Full Coverage”łւ̃Aƒbƒvƒf�[ƒg
FPGA FMƒXƒeƒŒƒI�Eƒ`ƒ…�[ƒi�[‚Ì�»�ì “dŽq�H�ì‚Ì�¬•”‰®/ƒEƒFƒuƒŠƒuƒ�ƒO
Patrick
Cheaper DSP based FM radio
Few days back I ordered this $10 FM radio board, completely shocked by its performance. Especially audio quality from this little radio is un-believable. I just hung 6ft wire, and its receiving most stations, putting my other analog FM tuners to shame both in adjacent channel rejection and sound quality. Now I believe I'm hearing the true sound quality FM stations transmit.
This board is based on the Quintic DSP FM chip QN8035. Its just 10 pin IC, takes the FM RF input and gives the Left + Right audio. No other inductors, IFTs, capacitors, varicaps, MPX filters etc. All done in digital domain, power of DSP processing, un-believable.
DSP & PLL Digital Stereo FM Radio Receiver Module 87-108MHz With Serial Control Sale-Banggood.com
Few days back I ordered this $10 FM radio board, completely shocked by its performance. Especially audio quality from this little radio is un-believable. I just hung 6ft wire, and its receiving most stations, putting my other analog FM tuners to shame both in adjacent channel rejection and sound quality. Now I believe I'm hearing the true sound quality FM stations transmit.
This board is based on the Quintic DSP FM chip QN8035. Its just 10 pin IC, takes the FM RF input and gives the Left + Right audio. No other inductors, IFTs, capacitors, varicaps, MPX filters etc. All done in digital domain, power of DSP processing, un-believable.
DSP & PLL Digital Stereo FM Radio Receiver Module 87-108MHz With Serial Control Sale-Banggood.com
All parts are from this circuit are here, so let's start.
1st difficulty seems to be the connections from the tiny TDA7021, TDA7040, LM386 to the IC-sockets. I found some 0.8mm cable and will try today.
1st difficulty seems to be the connections from the tiny TDA7021, TDA7040, LM386 to the IC-sockets. I found some 0.8mm cable and will try today.
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Slightly OT, but Europe has been turning towards DAB for many years. A number of EU countries have since had second thoughts, and are delaying sthe switch....... except Norway which are pushing ahead. The first region to close FM is where I live, - year from now. What is the status elsewhere??
Luxman T-400, Kenwood KT-880 (even though its digital tuning, every thing else is analog only, no DSP processing). What surprises me is the sound quality of this new FM tuner I feel on a strong station its close to CD quality.
Thanks
Thanks for posting this link. I always like to discover new audio sources - even if the format is long in the tooth.
But hey, FM still has it's 'aging' followers. And being digital just sweetens the deal even more. I ordered one! Hum... now let me see how I can incorporate this little gem into one my next projects...Rick
In the UK the authorities were hoping to switch off FM in 2015, but then realised that this would be very unpopular and 2015 was an election year. Current status is "wait and see". There is talk of FM switchoff when digital listening (mainly internet and via digital TV) reaches 50%. This could mean switching off the most popular method of receiving broadcasts (FM), in favour of the least popular (DAB). It would be a brave politician who does this! The authorities here don't seem to have noticed that almost everywhere else which tried DAB has dropped it, either for DAB+ or something else or nothing.AuroraB said:
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