N9EWO tests 3 Chinese Portables |
Tecsun
PL-660 Tecsun PL-680 (notes) Tecsun PL-880 |
Be
sure and view the comparison chart located on the bottom of this
page
HUGE
thanks to "John C." and "Hal H." as without these folks, this
page would NOT
be here.
General Quality Control Note : As covered around the internet with ALL 3 of the models of these Chinese portables reviewed below, quality control can vary greatly. With the PL-680 test sample (manufactured in May 2017), it was plagued with so many QC issues that made a "100 % proper" test not possible. It also had old firmware which did not allow the calibration of the MW and SW bands to be tested.
Dave N9EWO
Tecsun PL-660
(N9EWO Photo)
N9EWO
Review : TECSUN PL-660
Firmware Version Tested: Unknown
Country of Manufacture: China
Approx. Serial Number of Test Sample (manufactured in March of 2014) :
396201403019xx
GOOD : Dual Up Conversion design . Decent SW/MW
sensitivity (whip or external antenna), especially when the synchronous
detector that includes selectable sideband,
is used. Generally good ergonomics including excellent direct
keyboard entry operation. LW and AirBand frequency coverage (not
tested). Clean and open audio (even if sounding a bit shrill).
Buttons have good tactile feel (see con). Unique 2 speed tuning
selector that works well (Fast OR Slow modes only, not both on at
once). 2 well-chosen bandwidth filters (for AM mode signals). 2
event timer and sleep functions. 2000 total memory channels. ATS
(Auto Tuning Storage) that also operates on SW. 24 hour clock,
display separate from frequency. SSB mode is average for price
point and usable, includes a SSB fine tune control (see con). 2
step attenuator switch. LCD is large and well laid out (see con). FM
Stereo
indicator and selector. Built in ni-mh recharge circuit. Includes
unregulated AC adapter, padded carrying case and 4 low capacity
ni-mh rechargeable batteries.
BAD : Very weak MW / SW / FM signals get cut off with
the soft muting circuit and this ill conceived idea cannot be switched
off (using the Sync detector helps
to tamp this bug, but not always). FM performance only so-so
and adjacent channel rejection is fair. SSB and the fine tune
control operate strangely and SSB audio contains
“buzzy” audio traits that makes for strained use.
Frequency display off (on FM about 50 kHz high / SW up to 5 KHz off), a
real issue
with weak signals being received properly (see text for adjustment
tweak). Sync detector equally symmetrically off (but can be slightly
off tuned). Auto tuning
speed selection (fast and slow together) makes for difficult
operation (thank goodness this is can be switched off) .5-step signal
strength indicator pins on even the
weakest of signals. No frequency slewing buttons. Limited dynamic
range more so with external antenna’s at night (curable with
the 2 step attenuator). FM whip antenna is still active when
external jack is used (not an issue on SW). MW not supported on
external antenna jack. Buttons are small and some are recessed to
make matters even worse. LCD backlight is dim and no way for
continuous operation even when connected to the AC Adapter. Single step
tone control is just a high cut off filter. Cabinet quality
fair and encoder / volume knobs feel low quality. Battery cover
not hinged. No line audio output jack (see text). Confusing
“Chinglish” owner’s manual. Included AC adapter
cable too short. Power jack uses un-standard NEGATIVE tip.
The PL-660 works
generally very well and usable Sync Detection (over the PL-880....arf
!). No line record output either, which is huge drawback for
us. Good news is the headphone output is so clean one can
CAREFULLY connect this to a “line input” on a recorder
or computer and get fairly good results (just watch the volume
control not to get too loud).
We have the dreaded soft muting circuit where very weak signals can get
cut off. If the sync is used on the MW and SW bands it can help the
situation, sometimes greatly. The FM band sensitivity was only
average on our test sample and can’t separate station as
well either. So if you need above average FM Broadcast, this is
not the set for you.
SSB while it does better than the PL-880 (massive distortion /
clipping), is still not the greatest. Here we have a
“buzzy” trait and also some clipping in the audio on
really strong signals once in awhile. It's hard to tune and
another strange background "whoosh" sound that varies
with rotation of the fine tune control (an AGC bug?). Thank
goodness it does use the more standard 4 AA battery operation and
includes a non-switching and unregulated AC adapter (WARNING :
Set uses a negative tip on the power jack !!). This AC adapter
works well but the cable is too short however (only 4 feet long).
One cannot keep the back light on "full time" even with
the AC adapter in use (which is just plain stupid). Dynamic range
is also limited with external antenna’s at night, so
overloads say on 41~49 meters , but again can be tamed using the
2-step attenuator switch.
Sync detector works well even if the center point was off a bit
with the test sample (so switching between USB and LSB Sync does
not sound the same). It does have a pretty narrow lock in range (maybe
1 kHz either side maximum). But this allows for a tweak on either
side of the signal to allow for a crisper audio response. When
used it can greatly help with weak signal reception. It really
does decrease fading distortion and adjacent channel interference
well. The 2 bandwidth filters get the job done nicely and are
electronically selected on the front panel. There are no side-mounted
mechanical switches to have to fiddle with. It rarely looses lock
even on the weakest of signals (something we can’t say about
the old Sony ICF-SW7600GR, which has a lousy Sync in comparison. See
here for my insight on the ICF-SW7600GR portable .
Tecsun's PL-660 is a nice set for the money spent (provided
you don’t receive a dreaded Tecsun-Degen dud, or other bugs, eham link
here).
It is sold in Black and Silver cabinet colors. On a final note
our early 2014 test sample never experienced the SSB or MW drift
as reported elsewhere (it's SSB is rock stable for hours on end).
Also the variable sensitivity bug reported elsewhere was another
one that never cropped up with our later production sample .
FM Calibration Adjustment (Not Tested) : Kaito Electronics reports this hidden function to calibrate the FM frequency (if it's off) with the PL-660 or PL-680.
"Re-calibrating FM, radio needs to be on and set to FM band. Tune to the desired frequency/station you wish to listen to, press "SYNC" for about 3 seconds back light will flash. Tune up until the frequency/station sounds more clear press "1" to confirm re-calibration. If done correctly the correct frequency/station will be displayed on the display. Keep the battery in for all the time." (this probably means that when the batteries are replaced this needs to be done again ??)
Note
: On LATER PL-660 samples the AIR band button can be used (using the
same procedure as above) to calibrate the SW band filters if they are
not centered with any given sample. WIDE and NARROW filters are
independently set. Appears these settings are retained in EEPROM and
can be put back to factory default by just entering the calibrate mode
(AIR or SYNC button) without pressing the "1" confirm key.
Dave N9EWO
© N9EWO, all
rights reserved
Ver 2.8
Tecsun PL-880
(N9EWO Photo)
N9EWO
Review : TECSUN PL-880
Firmware Version Tested: 8820
Country of Manufacture: China
Approx. Serial Number of #1 (defective) Test Sample: 426201312004xx
(The defective sample was even slightly less sensitive on SW than
the replacement below)
Approx. Serial Number of #2 Test Sample (manufactured in December 2013)
: 426201312005xx
GOOD : Dual Up Conversion analog design that
also includes a DSP IF (Si4735) for the decent IF bandwidth filtering.
Outstanding super clean MW / SW / FM audio quality with it’s
sealed active and passive speaker system (see con). 2-step
attenuator switch. Generally good ergonomics including excellent
direct keyboard entry. 2 knob fast and slow tuning (allows for
super fine tuning on SSB, a rarity on portables in this price
category). All keys have very good tactile response. Display
button allows for clock to be displayed independently from
frequency display. Line Output jack (see con). LCD backlight can
be easily switched on full time. Signal Strength / SNR digital
display is decent (after one gets used to it). ATS (auto tuning
system) that also works on SW. 3050 total memory channels. 1
event timer and sleep function. LW band coverage (not tested).
Built in auto Lithium battery charger. A slew of un-documented adjustments for
operation tweaks (do a internet search). Stereo-mono
indicator and
selector. Attractive metal speaker grill and long “snooze
bar” on top. Includes a zippered carrying case and one 18650
lithium ion battery.
BAD : Audio may be considered too
“bassy” by some (is not selectable). A single-step tone
control is nothing more than a simple high cut switch. General
whip and overall sensitivity is not so hot (however
using a better external antenna makes it reasonably good).
Limited dynamic range when external antenna’s in use more so
at night (curable with the 2 step attenuator). Very weak MW / SW
signals tend to get swamped out in the AGC. No frequency slewing
(up-down buttons). Line audio output is bit too hot (high level),
but not to any distortion levels. The “unofficial”
Synchronous Detector is useless (more distortion and warble than
signal). With our test sample SSB modes were are awash with
distortion, makes SSB modes also totally useless. Battery cover
not hinged. SW bandwidth always defaults to 5 kHz when first
selected (in VF mode). Limited "wider" SSB mode
bandwidths. MW not supported on external antenna jack. Flimsy
whip antenna (top segments are easily bent). Uses an
untraditional 18650 Lithium Ion battery for power, standard
AA’s operation is not possible. Power input (charging and
operation) is via a 5-volt (at 500ma) mini-USB power supply,
locating a suitable NON-switching AC adapter is difficult (and
NOT included).
"....and
the winner is ??..." __
Looking for a low cost in this size with decent MW / SW Broadcasting traits ?? Our pick out of these three is the Tecsun PL-660. Even with the PL-880's fantastic audio with MW / SW AM mode signals and FM , the rest of it was a fast downhill slide. SSB is OK and usable on the PL-660 / PL-680, but it has a "buzzy" trait in the audio . How bad can you make a set sound with SSB signals ?? The PL-880 sample we used in our tests has to be one of the worst (portable or desktop) sets for SSB we have ever encountered . It's SW whip sensitivity was poor in our tests too. However the PL-660 / PL-680's FM performance is not the greatest either (but OK). Also see our Sangean ATS-909X review here, but later samples have reported serious (unacceptable?) issues. Dave N9EWO