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What spec is most related to the ability of a tuner to pick up, clearly, FM stations. I don't mean picking up a station three states away but fairly local to the state.
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In addition to the very good list that mkmelt supplied, I also look at capture ratio. It expresses how well a tuner can separate two stations on the same frequency. Not too common a problem, but it can occur if you are between cities. We used to have problems here in Cleveland with a Detroit station on the same frequency.I find that in the modern era with the air full of "stuff" from cell phones. cordless phones, pagers, planes, digital noise, etc. The tuners from a lot of the 70's receivers are not up to the job. I tried several and ended up with an Onkyo Integra T-4087, which is clean as a whistle. My main problem here is multipath, owing to the city water tower being 180 degrees away from the antenna of our local good music station.
Remember that a good, directional antenna mounted as high as possible is the best solution. An average tuner with a good antenna will outperform a great tuner with a crappy antenna.
Thanks Jerry.I thought about Capture Ratio after I created my original post. For many years capture ratio was typically spec'd at 2db , then sometime in the late 70s manufacturers started to quote their equipment as being capable of having a capture ratio of 1db. A few manufacturers of super class tuners would specify their tuners as capable of having a capture ratio of 0.5db.
Regardless of all these impressive tuner specifications, if you are equidistant between two cities that had FM stations competing on the same frequency, unless you have a directional antenna you are pretty much scrod.
I assume you want to listen in stereo. The tuner specs I usually pay attention to include:Sensitivity for 50db stereo quieting: (expressed in the more modern dbf units, 34-37dbf is typical, here lower is better)
Adjacent Channel (200KHz separation of signals) Selectivity: (8-15 db is typical, higher is better. Usually only important if you are trying to listen to a weak station that is one assigned channel frequency (200KHz)away from an equally strong or stronger station.)
Alternate Channel (400KHz separation of signals) Selectivity: (50-70 db is typical, higher is better. Some tuners feature switchable wide/normal, and narrow intermediate frequency (i.f.) tuning stages that are able to boost selectivity performance, but usually at the expense of slightly higher total harmonic distortion (THD).)
AM Rejection: (80db, 100db is not unusual, higher is better, this spec is a good, but not perfect, indication of a tuner's ability to reject multipath interference (reflections of FM signals bouncing off mountains, overhead airplanes, tall structures.)
Maximum Stereo S/N: (Assumes a very strong signal. 60-80db, 70 db is typical, higher is better.)
Stereo Separation: (Usually stated for multiple frequencies such as 100Hz, 1KHz, 4KHz, 10KHz.) Midband separation can easily exceed 40db, usually the spec for 10KHz will be much lower. Anything over 15db should be enough to provide the necessary auditory cues to localize the sound of specific instruments in the stereo sound field.)
Frequency Response: Most tuners are going to quote similar frequency responses, typically from a low of 20Hz or 30Hz to 15KHz at the upper end, +/- 1db.
Total Harmonic Distortion: 0.1 - 0.5%, measured distortion is usually lower at the midband, slightly higher for the uppermost tested frequency(10khz). Lower is better.
Thanks, I've been trying to make sense of these numbers for a long time. Once in a while I like to compare tuners in receivers to see if they could compare with seperate tuners units.
Here is an informative link.
..The rejection sensitivies define how well the tuner can keep one local station from being distorted by another strong station on a nearby band. I'll leave it to others to define what is good and what is excellent in this regard...but they should at least be greater than 50db,65db respectively...S/N ratio once full limiting is reached (i.e. with a strong signal) can range from 60db up to 75db or 80db. In general, solid state and later tuners will have higher S/N's. However, anything over 65db is generally adds inaudible noise at normal listening levels. Above the level, the audio qualities of the tuner itself (like any hi-fi component) become more important.
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