Sangean HDT-1
			  Versions 1.2F and 1.4F


Important Problems

1. Severe intermod may occur on FM when transmitters are nearby.

2. AM response does not follow standard NRSC deemphasis and can sound shrill. [1.4F]

3. The AM low end rolls off below 200 Hz. [1.2F]

4. There is no way to force analog reception of HD Radio signals.

5. There is no way to dim the LCD or turn it completely off in standby.

6. The clock resets if power is removed. In itself, this is just inconvenient.
But in a bedroom, power must be removed to kill the display in order to sleep.
Since no one is going to reset the clock each time he turns on the tuner, the
clock always displays the wrong time in a bedroom.

7. FM deemphasis error peaks at +2 dB. The error is audible when comparing the
HDT-1 to a tuner with accurate deemphasis. [1.4F is flatter but droops to -3.3
dB at 15 kHz]

8. There is no way to disable the automatic stereo channel blend or the
high-frequency noise filter.

9. Loss of signal for more than a few seconds retunes HD-2 to HD-1.

10. Bugs may occur when the DSP firmware is not updated along with the Atmel.


Lesser Issues

1. AM deemphasis deviates from the standard NRSC curve greatly at high
frequencies.
 
2. For very weak signals the AM synchronous detector is not always in lock
when the tuner unmutes, occasionally loses lock during a selective fade, and
will not lock when the signal on the adjacent channel is strong.

3. The extended-info selection is lost when tuning to a new frequency. The
display reverts to regular info.

4. Extended-info parameters are not in most-used order.

5. It should not be necessary to press PRESET to recall a frequency. Any press
of a digit shorter than 2 seconds should call up the station. [1.2F]

6. The distinction between a memory being empty (press 2 seconds to store) or
full (5 seconds to overwrite) is unnecessary. The memories will eventually all
fill. Just store the memory after 2 seconds, overwriting whatever's there, and
be done with it. [1.2F]

7. Pressing the final 0 when entering AM frequencies isn't necessary since all
U.S. frequencies end in 0.

8. 0.1-MHz steps on FM slow automatic tuning and make manual tuning awkward.

9. When tuning manually, the tuner steps through multicast channels even when
not attempting to lock to HD. This slows tuning and upsets the two-push
cadence necessitated by 0.1-MHz tuning steps.

10. The tuner has no stereo indicator. This would be especially useful on AM.

11. SSI always indicates maximum except for weak signals.

12. The audio output level is excessively high. At 1.5 V, it is 8 dB above the
component tuner standard of 600 mV. This makes it difficult to compare the
HDT-1 with other tuners and awkward to integrate with existing stereo systems.
[1.2F]

13. The clock is not synchronized with the line frequency. Eventually the time
becomes inaccurate.

14. AM tracking is off as much as 30 kHz and 3 dB at midband. [1.4F is worse]

15. The tuner does not retain the last station tuned when power is removed.

16. When power is restored, the tuner comes up in standby. This makes it
impossible to power up an entire stereo system with a single switch.

17. The polarized power plug does not fit the unpolarized AC outlets on older
stereo equipment.

18. The stereo channel blend and noise-filter thresholds change after cycling power.

19. Intermod occurs on AM with nearby transmitters, mostly noticeable between
stations.

20. Although probably not audible, FM stereo distortion is rather high.

21. The LCD font is rather primitive (e.g., raised descenders).

22. The frequency-scan rate is slow. [1.4F]

23. The CNR value is truncated rather than rounded. [1.2F]

24. SSI drops when there is audio near 15 kHz on FM and varies wildly with any
modulation on AM. The display is ambiguous at best on FM and useless on AM.

25. Occasional clicks are audible on AM. They are infrequent and not loud, but
annoying when they occur. They coincide with discrete AGC level changes.

26. The AM varactor drive backsteps at 840, 930, and 1340 kHz. [1.2F]

27. Rapid keypresses are lost. [1.4F]


Updated June 24, 2008
Brian Beezley