From: jim grey (jwg@acd4.acd.com)
Subject: Re: Tuner Recommendations?
Organization: /u/jwg/.organization
Date: Fri, 8 Jan 1993 14:56:47 GMT


In article <1993Jan7.113516.892@lmpsbbs.comm.mot.com>
solomon@becks.comm.mot.com (James Solomon) writes:
   Please send me your tuner recommendations: both positive and
   negative.  Here are some specifiics:

   1) $200-$300 is preferrable.  Max = $500.  2) AM is mandatory.  I
   listen to AM radio from other cities at night.  As such, it is
   important that the AM section have good sensitivity and
   selectivity.  3) AM *STEREO* is nice but optional.  4) If it's not
   obvious: FM stereo is mandatory.  5) In case this matters: I have a
   DENON PMA-1060 Integrated Amp which drives Infinity RS Kappa-7's.

   Thanks for your time and suggestions.  Please Email all responses.
   --
   Jim Solomon (solomon@comm.mot.com)
   Disclaimer:  It's my fault, not Motorola's.

I replied to Jim via email, but thought others here might be
interested in this article I got from rec.radio.broadcasting.

jim grey jwg@acd4.acd.com

-------------------------------------------

I found the review below posted on the Fidonet shortwave echo.  I
thought it might be of interest here:

*****************************************

>Msg#:53692 *SHORTWAVE*
>10/30/92 11:13:00
>From: AL QUAGLIERI
  To: ALL
>Subj: DENON SUPERTUNER
>Edited excerpts from From RADIO WORLD, 21 October 1992:
 
TUNER TESTS OUT "SUPER" by Len Feldman
 
At long last, the NAB-commissioned "Super Tuner" has been produced by
Denon and is available for purchase by interested radio stations - or
for that matter by consumers.
 
FEATURES The Denon TU-680NAB is, first and foremost, a superb AM/FM
stereo tuner, incorporating the universally approved stereo FM system
as well as the Motorola-developed C-QUAM system for stereo AM. Two
settings of bandwidth are available for both the FM and AM bands.  The
tuner also incorporates a noise-gating circuit that significantly
reduces interference on the AM band from externally generated
electrical noise, such as that from fluorescent lights, electric
motors, and the like. When using the FM band, noise reduction in the
form of an MPX filter can be switched on.
 
Up to 30 channels of either AM or FM can be stored in memory for
instant recall by number. A remote control, capable of handling
virtually all the control functions of the tuner, is supplied.  The
remote also features a "Preset Scan" button that is not duplicated on
the tuner's front panel. A separate AM loopstick as well as an FM
indoor antenna and the usual twin audio shielded pin-plug cable also
come with the product. The AM frequency band available on this tuner
extends from 520 kHz to 1710 kHz, in conformance with the expanded AM
frequency band recently authorized by the FCC.
 
TEST RESULTS, FM 50 dB quieting in mono with input signals of only
15.3 dBf Stereo muting below 40 dBf In mono, THD plus noise at mid
frequencies 0.057 percent,
     increasing to 0.085 percent at 100 Hz and just over 1 percent at
     6 kHz.
In stereo, THD plus noise at mid frequencies measured just over
     0.1 percent, increasing to 0.17 percent at 100 Hz and 0.16
     percent at 6 kHz.
In both mono and stereo, lowest THD plus noise was attained with
     little more than a 50 dBf signal strength.
Stereo separation reached nearly 50 dB at 1 kHz and maintaining
     nearly that at 100 Hz. At 10 kHz, separation remained greater
     than 30 dB.
Second harmonic distortion 0.1 percent
 
TEST RESULTS, AM Wideband selectivity 60 dB, narrowband selectivity 77
dB Image rejection 85 dB AM suppression 60 dB Capture ratio 1.2 dB IF
rejection in excess of 100 dB claimed Distortion plus noise varied
with frequency, using modulation
     levels of 90 percent. At 1 kHz, THD plus noise measured 1.2
     percent in wideband, 1.4 percent in narrowband.
Actual harmonic distortion under 1.0 percent Ultimate s/n ratio with
strong signals: 55 dB mono Stereo separation at midfrequencies 24.3
dB.
 
SUBJECTIVE TEST We hooked up an ordinary indoor dipole antenna to the
FM antenna terminal and oriented the dipole towards the west, in the
direction of most of the transmitter antennas in our metropolitan
area. Under those conditions, we were able to receive no less that 53
acceptable signals in mono. That's nearly a half dozen more than we
usually receive with typical "hi-fi" tuners and receivers we have
tested over the last several years. Switching to the "Auto" tune more
(thereby activating stereo circuitry), we logged some 43 acceptably
noise-free stereo signals on the FM band.
 
Orienting the supplied AM loopstick for best reception, we then
switched to the AM band and were able to log 26 acceptable signals.
There was little difference in the logged signal count when we
switched from the "Auto" tuning mode to the "Manual" mode. A few of
the stations exhibited less interference when we switched to the
narrowband mode, but even under those conditions, audio fidelity was
better than we have heard from an AM tuner in many years. (Back in the
1940s and 1950s, AM receivers - then in the majority - sounded a lot
better than most of them do today.  The Denon TU-680NAB is a happy
exception to that rule.)
     
Perhaps the most startling revelation occurred when we tuned a
classical music station on the FM band that also simulcasts on the AM
band. The stations were WQXR-FM (at 96.3 MHz) and WQXR-AM (1560 kHz).
This enabled us to switch back and forth between AM and FM while
listening to the same program material. We know you're going to find
this hard to believe, but to our ears (and to those of several
visitors to the lab while these tests were ongoing), the audio quality
of the AM transmission seemed actually better than that heard when
tuned to the FM band.
 
Denon deserves to be congratulated for this effort. The TU-680NAB may
well inspire other audio equipment manufacturers to follow a similar
course in designing future tuners and receivers.  ---
 * Origin: Radio FREQS' SCHENECTADY, NY (518) 377-7127 (1:267/103)

-- _______________________________Mike
_Schuster________________________________ NY Pub. Access
UNIX/Internet: schuster@panix.com | 70346.1745@CompuServe.COM The
Portal (R) System: schuster@shell.portal.com | MCI Mail,GEnie:
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