I want to buy an FM tuner (hopefully an NAD). When I look at a Denon FM tuner in a supermarket, I thought there must be nothing important in the box, why it is so expensive. So what are the important criteria here? If I bought it, I would surely upgrade the component and the circuit.
I can’t imagine the most important and expensive parts in a radio! Antenna? Variable condensator? (Trimmable) coils? Amplifying IC? Or simply the features? What I care about is the sound! Any idea?
I can’t imagine the most important and expensive parts in a radio! Antenna? Variable condensator? (Trimmable) coils? Amplifying IC? Or simply the features? What I care about is the sound! Any idea?
I've been reading alot on this very subject and may be able to help. The first two things you need to do is to determine if your broadcast area is relatively crowded and if your emphasis is on pulloing in stations or having good sound. Once you have the answers to those questions, I have some recommendations.
A variable capacitor has been replaced by capacitance diodes long time ago, 15-20 years...?Jay said:
I wonder also if there is any need for a very good radio. In Sweden has the commercial stations AWFUL sound quality, compressed and very modulated. The state radio has only one channel with some fidelity. The other ones have also compressed dynamics but have decent modulation.
<B>Nania</B>,
Good sound is all I need, and only FM. I don’t think that a standard FM tuner may not be able to handle “crowded” stations to an acceptable degree. Or, I can always set the inductance, for example, to allow for my favorite stations to be pulled in, can’t I?
But, is there any parameter to reflect the capability above? If turning on the radio is the only way to find out this capability, I don’t think that the seller provides adequate antenna if available (Well, I guess this will be a big problem).
<B>Peranders</B>,
What is capacitance diode?? Whatever it is, I don’t think that a good variable condensator (I mean the one from metal housing) can be outperformed by… diodes??
With radio I can hear the most recent popular songs, which I can use as a reference to buy a CD. And a wide variation of music option. With my CDP, I can only feed one CD at a time. As far as I can remember, the radio signal quality is very good in my country. Especially at night.
Good sound is all I need, and only FM. I don’t think that a standard FM tuner may not be able to handle “crowded” stations to an acceptable degree. Or, I can always set the inductance, for example, to allow for my favorite stations to be pulled in, can’t I?
But, is there any parameter to reflect the capability above? If turning on the radio is the only way to find out this capability, I don’t think that the seller provides adequate antenna if available (Well, I guess this will be a big problem).
<B>Peranders</B>,
What is capacitance diode?? Whatever it is, I don’t think that a good variable condensator (I mean the one from metal housing) can be outperformed by… diodes??
With radio I can hear the most recent popular songs, which I can use as a reference to buy a CD. And a wide variation of music option. With my CDP, I can only feed one CD at a time. As far as I can remember, the radio signal quality is very good in my country. Especially at night.
Jay
Short answer to this statement is: No! Depending on the nature of the tuning capacitor and whether the filters are inductors or Murata chips (more likely) your attempts to tweak a tuner will probably result in making it worse overall. Do you have a good spectrum analyzer available to you (you'll be working in RF you know)? Doing alignments in the IF on a good used piece and maybe some parts upgrades will result in a much better bang for buck than anything you can find for $2500 nowadays. I would say your best bet is to look into the used market. There is alot of very good undervalued product that looks real nice too. Don't look at anything with less than 4 FM tuning capacitors and stay away from boutique stuff. Oh, and moderators should probably move this thread to the Analogue section where I think it belongs.
I don't know how they are today, but older Onkyo tuners are outstanding -- certainly have a leg up on the concurrent NADs (i've owned both).
And on another note, what are you typing to get this -- windows specific i'm guessing -- character that i'm guessing is supposed to be a single quote? (see pic)
dave
And on another note, what are you typing to get this -- windows specific i'm guessing -- character that i'm guessing is supposed to be a single quote? (see pic)
dave
Attachments
A tuner has to handle a very large dynamic range from the strong signal of a nearby station to the weak signal of a far-off station. Moreover, it has to do this without distortion. The solution is to have automatic gain control that decreases the gain for the stronger station. However, when you tune to the weaker station, the gain must rise. If the RF selectivity of the front end is unable to reject the stronger station, the overload causes spurious harmonics of that station to appear. The tell-tale sign of this is that a poorer tuner appears to pick up more stations, when actually, it is picking up the same station up and down the dial. The VHF/FM broadcast band is too narrow for the fault to become apparent in this way, but the problem remains. The best way to improve RF selectivity is to have many ganged tuned circuits, but 5 gang variable capacitors are expensive, so varicap diodes began to be used in the 70s. Unfortunately, varicap diodes are not ideal capacitors, and it is difficult to make a tuner with varicap diodes that is as good as one with real air-spaced variable capacitors or variable inductors.
The other issue with overload/intermodulation is that the ideal gain device in the front end and IF strip should be capable of swinging large voltages without distortion.
The upshot of all this is that the final generation of valve tuners had very good RF performance. They aren't quite as quiet, and they don't have quite the sensitivity of a good modern tuner, but they are still very good. Their decoders are usually terrible, but there are aftermarket kits available.
The other issue with overload/intermodulation is that the ideal gain device in the front end and IF strip should be capable of swinging large voltages without distortion.
The upshot of all this is that the final generation of valve tuners had very good RF performance. They aren't quite as quiet, and they don't have quite the sensitivity of a good modern tuner, but they are still very good. Their decoders are usually terrible, but there are aftermarket kits available.
Wow, thanks for the helps, pals…
And tvi, those links are great! I like the DIY page at www.fmtuner.com.
And as I have thought (nania was right), whichever tuner I choose, I will be able to upgrade the performance dramatically by parts upgrade (especially the filter). So, the physical look of the tuner will be my first consideration.
With many other specs, I don't think that they will be available as a label on the tuner body. And of course, the seller won't be able to answer if I ask. So, knowing the top FM tuners will be helpful (but I don't have a membership to the yahoo site nania gave me), unfortunately I don't think that I can find them easily in my country.
I have been looking for NAD tuner without success. I hope that this tuner uses OPA OP-Amp, so that I can replace it with a better one.
<B>Dave</B>,
You may be a Macintosh fanatic. But you should not blame Windows for every problem you have!
I wrote the text on MS Words before pasting to the text box. MS Words recognizes 3 types of quotes (straight, curly, and the inclined one). As far as I can remember, the double quotes causing the problem is the one "inclined". I think it is ASCII #147/148 in Latin I character entities.
And tvi, those links are great! I like the DIY page at www.fmtuner.com.
And as I have thought (nania was right), whichever tuner I choose, I will be able to upgrade the performance dramatically by parts upgrade (especially the filter). So, the physical look of the tuner will be my first consideration.
With many other specs, I don't think that they will be available as a label on the tuner body. And of course, the seller won't be able to answer if I ask. So, knowing the top FM tuners will be helpful (but I don't have a membership to the yahoo site nania gave me), unfortunately I don't think that I can find them easily in my country.
I have been looking for NAD tuner without success. I hope that this tuner uses OPA OP-Amp, so that I can replace it with a better one.
<B>Dave</B>,
You may be a Macintosh fanatic. But you should not blame Windows for every problem you have!
I wrote the text on MS Words before pasting to the text box. MS Words recognizes 3 types of quotes (straight, curly, and the inclined one). As far as I can remember, the double quotes causing the problem is the one "inclined". I think it is ASCII #147/148 in Latin I character entities.
Jay said:
Curly quotes... i have been using them on the Mac since 1985. Usually the default is to off but Microsoft alway seems to turn everything on (one of the reasons for ALOT of the world's virus attacks). Any ASCII above 127 used on the internet is going to break on someone's computer somewhere (i am quite cautios not to use any of these platform specific characters), it would be nice if there was a standard character set, it could make alot of these posts richer.
dave
ie (if, on some platform where these screw up -- it would be interesting to see a snapshot)
curly quotes ÔÕ, ÒÓ
degress ¡
bullets ¥
omega <font face="symbol">W</font>
n, m dash Ð Ñ
mu µ
Let me ask you: How are tuners tuned since 20 years back? Yes, capacitance diodes!Jay said:
This is a diode which has higher capacitance than a normal one (but you can use a normal one also). You bias the diode backwards (plus on cathode), then you will get a capacitance which vary with the voltage. I have a capacitance diode in my vinyl amp (Denon PRA-1200). The diode creates a stepless capacitor from 200-500 pF.
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