Retekess / TIVDIO V115
Audiomax / Kaimeda SRW-710S
Portable Radio - MP3 Player
"Off Air Recorder"
findings on the "Low Cost " Retekess V115 DSP Portable Receiver / MP3
and "off air" recorder.
It does NOT use the Silicon Labs Si473x
receiver DSP receiver IC (here it's the
NOTE : PC Board Markings Were Different Between the 3 Test Samples (see
N9EWO's Review on the Retekess V115 (old marking TIVDIO V-115).
It is also sold as the HanRongDa K-603, VRrobot WC-710S , Audiomax
,Kaimeda SRW-710S and others.
(3 Samples were tested for this report)
TIVDIO V-115 Portable DSP Receiver and MP3 Player / Recorder
Of Manufacture : China
Versions Tested (sample #1 and #2 : V1.2 , sample #3 : V1.4)
Number (approx.) of Test Sample # 1 : 1707T1152014xx (Manufactured in
Serial Number (approx.) of Test Sample # 2 : None (missing)
Number (approx.) of Test Sample # 3 : 1908T11511002xx (Manufactured in
(NOTE : Test sample 3 was marked as the Retekess V115)
PC Board Marking (First Sample) : SWR-710 2014.11.20
PC Board Marking (Second Sample) : SWR-710S 2017-4-20
Marking (Third Sample) : SWR-710SU 2019-3-16
- Uses the DSP Receiver IC AKC6951/6955 Instead of the Silicon Labs
- Direct Keyboard Entry For Frequency and MP3 Files
- 9 SW "Band" Presets
- All Buttons Have Very Good Tactile Response (uses separate Tac
Switches unlike the cheaper TIVDIO V111 model)
- Large Easy to See LCD that is readable even without backlight In use
- SW and FM Sensitivity OK Average Even With It's Limited 15 inch
Telescopic Antenna (which swivels and rotates)
- SW Selectivity Wide Enough For Decent Audio (Unlike the narrow Degen
DSP Pocket Sets)
- AGC Much Improved Over Most Si473X Based Receivers (Except for the tested Tecsun PL-380)
- Audio Quality (with Internal Speaker) Excellent For Size with It's
Powerful Additional Amplifier and Micro "Sub-Woofer" (see con)
- Audio Mute Function
- FM Stereo With Headphones (Records In FM Stereo As Well)
- Memory Channels Auto Sort in Frequency Order with Firmware 1.3 /
Firmware 1.4 allows for user Memory Chanel Selection
- Separate Memory
Channels for MW / SW and FM) (see con)
- Electronic Volume Control Allows for Fine Very Low Adjustments for
Decent Night Time Use
To a 90 Minute Sleep Timer (Adjusted in Menu's)
- Scan and Seek Function that includes Auto Memory Store Feature
- Excellent Built In "Off-Air" MP3 Recorder With 3 Quality Levels (see
- Tilt Stand Attached on Carrying Strap (remember the Sony ICF-SW1)
- Lock Button (does not lock power button)
- MP3 Player That Works Properly With No Skipping or Other Gremlins
- Uses Common BL-5C Lithium Ion Battery (most new samples include a
mah capacity battery)
- Includes a Short 2.2 Foot Micro USB
- Click "Locking Type" Micro SD card slot
Player Shuffle Mode (undocumented,see text)
- Extremely Low Cost "Bargain"
- Weak Signal Reception Hampered By Circuit Noise And Other Spurious
Signals (All Bands Including FM). NOTE : Intensity varies with sample.
- Local AM (MW) Break Through Into entire SW Band With Both Test
Samples (using attached whip antenna)
- Reported To Have SW Bleed Through Issues In Area's With Local Strong
FM Broadcast Stations (NOTE : We Did Not Experience This At Our Testing
- Limited Dynamic Range (SW Signal Overloading with Too Long Of Clipped
On External Antenna)
- MW Sensitivity Only Fair (Has Short Loopstick Antenna, See Internal
- No Tuning Knob
- No SSB Mode
- No Frequency Slewing Tuning Once a Memory Channel is Entered
- No Signal Strength Indicator
- No External Antenna Jack
- Somewhat Limited Short Wave Coverage. SW Starts at a Weird 4750 kHz
and goes up to 21.850 kHz (no Gaps)
- Only Way to Store Memory Channels Are In Frequency Order (Auto
Sorting), corrected with firmware 1.4 (see text)
- Headphone Jack Audio Output is "Shrill" and Hard On The Brain
- Indifferent Battery
"Charger" Indication (see text)
- No AA Battery use possible
- Uses the "Radio" non-standard MICRO-USB
- Microprocessor / Firmware "Bug-A-Boos" with 1.2 firmware (see text)
- Odd 5v Charge Current Adapter Requirement (500 to 1000 ma current
output rating ONLY)
- Whip Antenna at a Short 15 Inches and Is flimsy (sample # 2 arrived with broken whip
- No Carrying Case or USB Charger Included
- Poor "Chinglish" 4 page "Owners Manual" That is Also Printed on Very
paper in Tiny Fonts (Booklet version with later production)
FM / SW
Receive Performance Decent / MW only Fair / MW Breakthrough on SW /
Uses AKC DSP Radio Receiver IC
and SW sensitivity is most usable (decent). Not any worse than any
set. With the improved AGC when compared to the Degen
its a royal treat (not that it perfect here either, but much less
cutting in and out). However the whip antenna is only at a short 15
inches long. Connecting a short wire to the whip antenna can help
greatly to improve reception. As it usually goes with low cost sets
this, one needs to keep the wire governed as it will launch into
overload if too long and especially at night (mishmash of audio like
being in busy court
room). But most owners will want to have a SHORT insulated thin
with a gator clip to attach to the telescopic whip handy.
The V-115 / V115 uses the AKC DSP Radio Receiver IC (not the Si473x as
most Degen DSP receivers like this). The ONLY near pocket set where the
Si473x has been properly interfaced in our testing over the years has
been with the Tecsun PL-380.
MW band is OK for local and powerful regional stations, but here is
where the tested Tecsun PL-380 kicked it's behind
!! It has a very short loopstick
antenna (see internal photo's below) and it shows.
experienced local AM (MW) "Break Through" with received with SW Band
signals on both test samples using the attached whip antenna (test
sample # 2 was a bit worse, but test sample #3 was improved). This bug
did not appear all the time with the 1000
watt MW station at the
test location (at 5 miles away), but when it did was just another
the pie. If you do not use the V-115 / V115 near ANY MW transmitters
this should not be an issue. See the links section at the bottom of
this review for a "You Tube" Video that shows this.
The downside to the V-115's weak signal sensitivity is it's noise
floor is awash with Microprocessor and other spurious noises (all
bands). Not that
this is going to effect receiving the strong signals it was designed
for too much (it doesn't). Plain and simple this low cost marvel is not
meant for DX'ing weak stations. If one places a hand or finger near the
LCD, this noise increases. Just as with the MW breakthrough issue, test
sample # 2 was bit worse here. We found the Intensity of the self
inflicted noise varies a bit with any given sample.
LCD is large considering it's 4.7
x 3.1 x 0.9 inch cabinet size. It also has a light background so it can
be seen fairly easy without it's backlight on (as far as you have some
halfway decent ambient light available). With many LCD's these days you
just can't do this.
Frequency Coverage / FM Is In Stereo
Coverage starts at 4750 kHz and goes up to 21.850 kHz (no Gaps). FM
Broadcast is from 87.0 to 108.0 MHz . Medium Wave Broadcast is from 520
to 1710 kHz. There are 9 Short Wave band pre-sets that start at the low
end of those bands and is most welcomed to start the scan function.
FM is in Stereo with headphones and also records to the Micro SD Card
in Stereo. There is no "Stereo" indication on the LCD.
Tuning / Memories / Scanning
Direct frequency keyboard entry is provided. It's super easy too
as one just taps in the frequency with no other buttons before required
and hit PLAY (enter). Tuning steps on SW are 5 kHz, sorry you are not
able to even cheat using the keypad to achieve say 1 kHz steps. It will
just round it off to the nearest 5 kHz frequency. MW step can be set at
9 or 10 kHz in the menu's. FM broadcast is in the usual 100 kHz steps.
Alas the keypad is in a 2 row layout, but one gets the used to this in
Are 100 memory channels available (however this is a bit of mystery, we
did not test this) ? Each band (FM / SW and MW) has
it's own bank of memories.
The V-115 / V115 has a Auto Store feature for memory channels. It is
by pressing and HOLDING the MP3 PLAY button. WARNING (BE
CAREFUL) : It will rewrite
all previous memory channels. Unlike the Tecsun's ETM function
special bank of memory channels, there is no such feature provided here.
All memory channels stored are sorted in "frequency order" like it or
not (Update : Firmware 1.2, this memory entry bug was fixed with 1.4
see text at the bottom of this review). This can be an advantage or a
drawback depending how you like it. There is no way to tune a memory
channel either. You can start a band scan from that memory channel
There is actually frequency (up-down button tuning) "slewing", but
until you enter a memory channel. Then those buttons turn into a memory
channel up-down only. No encoder knob tuning is provided. Also missing
is SSB mode and a external antenna jack (but at this price point that
can be expected).
Indicator Indifferent / Very Strange Charger Requirements
The 4 step (actually it's 5, the fifth one being a "flashing" empty
one) battery "consumption" metering seem to be fairly
accurate and useful to see how much juice is LEFT in the BL-5C battery.
It does automatically shut off the device "after the last flashing
indication" to protect the battery from over discharge.
(all firmware versions including later 1.4) :
When we used a PC 2.0 USB port to charge the depleted battery in the
V115 / V-115, it’s 4 bar indicator showed a full charge in about 2 minutes
(which of course is NOT accurate). The charging indicator became more
accurate after we used a low cost standalone 1000 ma USB charger
(uncertain how much more accurate however). These
can be purchased in just about every drug / department store on the
planet that carries cell phone accessories. Just be sure it’s rated at
1000 mah (1A) and nothing above that. One is still advised to leave the
radio on the charger even after the full battery indication to
be sure it receives a full charge (perhaps say 6 to 8 hours total ??).
We never came down to what is going on here with this very strange
Now a step
back on what to use to charge it with ? No battery charger is included.
also uses the less "radio" standard "micro-USB" type jack (includes a
very short 2.2
foot USB cable). The manual strongly indicates to use a 5 V USB charger
between 500 to 1000 ma (1A) of current.
feel this suggested current rating needs to be respected with the
simple battery charge circuit in the V-115 / V115 (see internal
below). This is also warned about in
the manual !
Using say a 2 Amp or over rating USB charger could very
well damage the
battery and or radio ? Better safe then sorry as they say, you sure do
not want any fires if a overheated battery blows up ! So indeed heed
Built In MP3 "Off Air" Recorder / Player has "Shuffle Mode"
I will NOT be held
responsible for any info that is listed here
ALL DONE AT YOUR OWN RISK !
As it is with some Degen manufactured models over the years (the
to name 3 as we have tested) the V-115 has a
nifty built in "off air" recorder. It of course writes the file to the
micro SD card which is NOT included. Unlike the Degen DE1126/1127 and
DE1128H models that
record in a strange WAV format , the V-115 / V115 records in true MP3.
3 quality selections to boot. If you use the best "Super Record"
setting, it's most decent and no artifacts were noticed (except on very
weak signals), nor were any
dropouts or other gremlins. Pause function is also available. The
lesser 2 settings are usable, but why bother. As this report was
complied, we have not tested with any 1 hour + length recordings as
one file. There is built in microphone for voice recordings (and works
well) and a "Line In" jack to record external audio from another source
(not tested). Be sure and read the "Buggy Firmware" note next with
important information on the record feature (with firmware 1.2).
NOTE : We used a 16 GB micro SD card in testing. No card is included
with the device. Unknown how large
of card will work in the V-115 (32 GB> ?). The Micro SD Card Slot
is of the desirable "click" in type. "Off Air" Recorded files appear in
the radio generated "FMRECORD"
directory. Yes, a TF card and micro SD card are one in the same.
Playback of "Off Air" recorded files is done by using the 0 (zero) key.
|V-115 Undocumented MP3 Functions
Files (from Adi) :
normally can’t delete MP3 files that are on the the TF (micro-sd) card,
only internal recordings can be deleted with the DEL button.
But Adi Informed us of a way you can, here's how :
1) When in MP3 listening mode , press/hold PLAY until menu shows,
2) Press PLAY and navigate to the file you want to delete with
the |<< or >>|
3) Press the VOLUME – DOWN, then a delete message pop will
appear, confirm with PLAY.
To Select "Shuffle Mode" (from
Omer E.) :
'Menu' button, it doubles as a 'Repeat' button, as indicated by the
imprinted symbol as well on the radio. The mode is shown on the
display, and it cycles through (A), (1), (F), and (R). As you can
imagine, (R) is for 'Random'."
: With our firmware 1.2 test samples.
One sample had the Random (R)
selection while the earlier sample did NOT. So this feature appears to
have been added with later 1.2 samples only (and of course firmware
1.4 all samples). The R selection needed to be
toggled every time the set was powered up (does not remember it).
The MP3 player has the typical EQ settings, and it even has a very
handy shuffle mode, but this is not properly documented in the manual
(see update in yellow block above).
Omer E. from Canada informs us
(as verified). Many thanks Omer on this great discovery. I was thinking
that (R) was for just for repeat. :
"Both of my radios
support a 'Shuffle' mode. First one is Firmware 1.2, and the second one
1.4. The documentation and
the info on their web site has missed this completely, but if you
quick-press the 'Menu' button, it doubles as a 'Repeat' button, as
indicated by the imprinted symbol as well on the radio. The mode is
shown on the display, and it cycles through (A), (1), (F), and (R). As
you can imagine, (R) is for 'Random'."
One can access the file structure for direct access to a file by
holding down the PLAY button when in MP3 player mode. The direct entry
keypad can also be used to enter the file (track) number.
User Tip : When
you are finished listening to the MP3 player, always a good idea and
the Play / Pause button BEFORE you turn it off or switch to radio
operation. This way it will be sure and continue at that point when you
return to MP3 play operation,
otherwise it will "sometimes"start back at file number 001 (this is
Sorry there is no alarm, timer or clock function on the V-115. What do you expect for around $ 25. all in
device like the V115 / V-115 ? It does have a "Sleep Timer" (up to 90
minutes). This is accessed in the menu's.
(as marked on a file)
(as shown on external PC program)
| Simple Record
The V115 / V-115 gives
for decent MP3 Record Quality in "Super Record" setting (128 kbps
44100 Sample Rate).
However these settings did not jive out of the box with test
samples # 1 and 2 [firmware V1.2]. Reinserting the battery
made this bug go away (Super Record then gave you 128 kbps, not 64
kbps), good news is
this issue was cleared up with firmware version 1.4. (see
text below) (N9EWO Chart)
Buggy Firmware / Is there a Microprocessor
to the record feature (with test samples 1 and 2, firmware V1.2), in
discovered it was required to
toggle ALL "Record Set" settings, (use the recorder a few times in each
setting), THEN reinsert the battery after, in order to get the quality
setting to jive with the actual
kbps. For example : Simple Record was 128 kbps at first. Once the
of all 3 settings was done and battery pulled and reinserted after
(just for second) it was OK after, so the “Super Record” was
finally at 128 kbps as marked. It's a very strange bug, and if you
leave the battery out for awhile it needs to be done again. This issue
was experienced with test sample 1 and 2,
(UPDATE : After
testing sample #3,. this issue has been TOTALLY fixed in firmware 1.4)
"firmware" bugs experienced in testing included [firmware V1.2] (NOTE :
below were only detected after an "auto store" function was completed) :
- Very intermittently we experienced
erroneous Memory data (these
normally disappear with a loop around).
- Also when it’s having this fit,
we were also unable to see memory Channels over 09.
- Sometimes it would not accept ANY
manual memory channel entries (after some fiddling it would suddenly
These issues appear to have been TOTALLY fixed in firmware 1.4)
So a few disconcerting "bug-a-boos" do lurk (were the 2 test samples
semi-defective ?). Good news is it never totally locked up in testing.
We are unaware of any microprocessor reset procedure with the receiver
as this report was being compiled.
Audio Quality and Painful Headphone / EarBud Use
Audio quality from the V-115's internal speaker is just outstanding for
it's size. Not only does it have a beefy 4 ohm / 3 watt speaker and
separate loud audio amplifier IC just for the speaker output, it also
has a rear mounted passive micro "sub-woofer" which greatly increases
However what emits from the headphone output (jack) is
another story. Here it uses the raw audio output right from the DSP
chip's audio amplifier. It's very
and was painful to listen to for any length of time with most phones /
earbuds with the test sample. It also cannot produce any bass response
with headphones (breaks up with a file that contains any real bass in
it.). With MP3 listening we were able to
somewhat offset the shrill sound with it's EQ settings (try "classic"),
but is still no great
shakes even after that.
This shrill headphone audio issue has remained "no changes" with later
To top that off there have been an excessive
amount of reports where an owner only has audio in one ear (see the
green block below for details, Craig Menning discovered the reason why
(in green block below). But lets face it, listening
via a pair
of phones was disappointing with the V115 / V-115 (harsh) even when
all is well.
WARNING : One
more comment with headphone listening, be sure and turn DOWN the volume
BEFORE you return back to
speaker listening. Otherwise
It will be excessively LOUD if you do not !!
You Say You Only Get
audio from one earphone or earbud on your V115 / V-115 ?
Proper headphone / earbud operation depends on the diameter of the
reduced portion of the tip on the phone plug. "Works fine with some
phones, but not with others".
appears is the reason why some only get one channel,
and it has to do with the headphone jack and headphone / earbud plug
being used. The V-115 indeed receives FM Stereo and also records to the
Micro SD card
Sample #3, "firmware 1.4" Improvements
With test sample #3 that contained 1.4 firmware, there
were a number of bugs that were fixed over 1.2 including :
- Memory entry now allows user to select channel where it is to be
entered. Once the number 5 "Memo" key is pressed it will then ask what
channel number where it is to be entered using the keypad. Hit the
usual "Play" (enter) key after to accept. So no more auto frequency
sort with the memory channels.
- Other strange Memory bugs covered above have also appeared to have
been cleared up. No more unstable events were noted.
- The "record quality" setting located in the menu now takes properly
from the start. Before it was floating around it 3 settings until you
provoked it at bit with battery re-installs (see text above).
- Owners manual came with test sample #3 was in a booklet form in
various languages vs. the 4 page single sheet English instructions
(this could be considered as a plus or minus). Same Chinglish babble in
some parts of it's Chinese translation.
Other parts of the set remains unchanged including the "NOT accurate
battery charging indication". So continue to charge as indicated in
this review text (and still ONLY use a EXTERNAL USB charger rated
between 500 to 1000 ma output as indicated in the manual). The manual
now has this text added after the indicator says full charge (say what
!): "Suggested to continue to charge
for 1 to 2 hours to guarantee the lithium battery reaches maximum
charging capacity". They also give some expected charging
times not given in the other older manuals.
Conclusion : Decent "Low Cost" Pocket Set !! (but Buyer
what it is, the lightweight 7.2 ounce near pocket TIVDIO V-115 /
Retekess V115 receiver
is a sheer bargain and is just plain fun. Always excellent to see a SW
receiver that include a built in "off air" recorder for capturing
signals for the archive. However don't expect to
receive a $ 100. receiver for $ 25. either. But the receiver
performance is improved over the Degen Si473x "Off Air" record
we have tested over the years (say the tested Degen DE1125 / DE1126
etc.). Wider SW Bandwidth and AGC are more usable
as where with the Degen
pocket sets it was a total disaster on Short
not that it's perfect here either). The Tecsun PL-380 is
still the better performer, however it does not have a built in "Off
Air" MP3 recorder / player either.
One needs to keep in mind the possible "local station" MW or FM
breakthrough on SW, poor
headphone audio, self-generated circuit noise and disconcerting
firmware bugs that do lurk
with the older 1.2 firmware V-115 samples. We need to stress again with all 3 test samples the
indicator worked weirdly (again please see review text above as
this is extremely important for proper operation).
© N9EWO, all rights
V-115 Internal Photo - PC Board Rear (Board
Rev 2014-11-20). This
and the V-111 both use the AKC6951/6955 DSP Receiver IC.
The speaker is in a sealed compartment, plus a rubber covered
"Micro-Woofer" port on the rear cabinet.
This clearly helped the audio quality through it's internal speaker. (N7TQM Photo's /
N9EWO Photo Edit)
V-115 Internal Photo - PC Board Front.
Uses real individual "Tac" switches (not those inferior raw membrane
ones). (N7TQM Photo's /
N9EWO Photo Edit)
Links and other Information (all subject to
change without notice) :
Page (with usual reviews)
Owners Manual from
Manufactures Web Site / Latest Book Version (NOTE : This can be a VERY
You Tube Video's :
TRRS #1332 You Tube Video- TIVDIO
Shortwave Radio Reception Tests (shows the MW
Bleed into the SW Band Issue)
Video Review: Tivdio V-115 Radio Lets You
Record Airchecks On the Go
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