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N9EWO Review :
TIVDIO V-115 / Retekess V115
 Audiomax / Kaimeda SRW-710S
VRrobot  WC-710S
Portable Radio - MP3 Player
 "Off Air Recorder"



N9EWO's findings on the "Low Cost " TIVDIO V-115 DSP Portable Receiver / MP3 player and "off air" recorder.
It does NOT use the Silicon Labs
Si473x receiver DSP receiver IC (here it's the AKC6951/6955/ M6951/M6955).
NOTE : PC Board Markings Were Different Between the 2 Test Samples (see below).

N9EWO's Review on the TIVDIO V-115.
It is also sold as the
Retekess V115, VRrobot WC-710S , Audiomax and Kaimeda SRW-710S.
(2 Samples were tested for this report)

Model : TIVDIO V-115 Portable DSP Receiver and MP3 Player / Recorder
Country Of Manufacture : China
Firmware Version Tested (both samples) : V1.2
Serial Number (approx.) of Test Sample # 1 : 1707T1152014xx (Manufactured in July 2017 ?)
Serial Number (approx.) of Test Sample # 2 : None (missing)
PC Board Marking (First Sample)  : SWR-710 2014.11.20
PC Board Marking (Second Sample) : SWR-710S 2017-4-20

PRO :

- Uses the DSP Receiver IC AKC6951/6955 Instead of the Silicon Labs Si473x
- 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 (Separate Memory Channels for MW / SW and FM) (see con)
- Electronic Volume Control Allows for Fine Very Low Adjustments for Decent Night Time Use
Up 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 text)
- 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 (see con)
- Uses Common BL-5C Lithium Ion Battery (most new samples include a 1000 mah capacity battery)
- Includes a Short 2.2 Foot Micro USB Cable and BC-5L Battery (our test samples came with a 1000 mah)
- Click "Locking Type" Micro SD card slot
- Extremely Low Cost "Bargain"

CON :

- Weak Signal Reception Hampered By Circuit Noise And Other Spurious Signals (All Bands Including FM)
- 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 Location)
- Limited Dynamic Range (SW Signal Overloading with Too Long Of Clipped On External Antenna)
- MW Sensitivity Only Fair (Has Short Loopstick Antenna, See Internal Picture below.)
- 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)
- Headphone Jack Audio Output is "Shrill" and Hard On The Brain after while
- Indifferent Battery "Charger" Indication (see text)
- MP3 Player Has No Shuffle Mode
- No AA Battery use possible
- Uses the "Radio" non-standard MICRO-USB Jack
- Microprocessor / Firmware "Bug-A-Boos" (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 antenna)
- No Carrying Case or USB Charger Included
- Poor "Chinglish" Owners Manual That is Also Printed on Very Thin paper in Tiny Fonts


FM / SW Receive Performance Decent / MW only Fair / MW Breakthrough on SW / Uses AKC DSP Radio Receiver IC

FM and SW sensitivity is most usable (decent). Not any worse than any other pocket set. With the improved AGC when compared to the Degen DE1126 or DE1128H 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 like 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 wire with a gator clip to attach to the telescopic whip handy.

The V-115 uses the AKC DSP Radio Receiver IC (not the Si473x as seen in 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.

We 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). 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 annoyance in the pie. If you do not use the V-115 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.

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.

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

SW 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 fast order.

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 has a Auto Store feature for memory channels. It is activated by pressing and HOLDING the MP3 PLAY button. WARNING (BE CAREFUL) : It will rewrite all previous memory channels. Unlike the Tecsun's ETM function using a special bank of memory channels, there is no such feature on the V-115.

All memory channels stored are sorted in "frequency order" like it our not. There is no way to get around this. 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 however.

There is actually frequency (up-down button tuning) "slewing" , but only 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).


Battery "Charging" 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.

Important Update :  When we used a PC 2.0 USB port to charge the depleted battery in the 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 up to 12 hours total ??).

We never came down to what is going on here with this very strange variability and is very strange !

Now a step back on what to use to charge it with ? No battery charger is included. It also uses the less "radio" standard "micro-USB" type jack (includes a very short 2.2 foot USB cable). The manual indicates to use a 5 V USB charger rated between 500 to 1000 ma (1A) of current. As covered above I would NOT recommend using a PC to charge it with. We feel this suggested current rating needs to be respected with the simple battery charge circuit in the V-115 (see internal pictures below). This is also warned about in the manual ! Using say a 2 Amp rating USB charger could very well damage the battery and or radio ?? Better safe then sorry as they say.

I will NOT be held responsible for any info that is listed here
ALL DONE AT YOUR OWN RISK !

Excellent Built In MP3 "Off Air" Recorder

As it is with some Degen manufactured models over the years (the DE1121, DE1126 and DE1128 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 records in true MP3. It has 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.

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 used 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.

V-115 Undocumented MP3 Feature (To Delete Files)
One 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, select ROOT
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.

The MP3 player has the typical EQ settings, but sadly it has no shuffle mode. 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 hit 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 indifferent).

Sorry there is no alarm, timer or clock function on the V-115.
What do you expect for a <$ 25. all in one device like the V-115 ? It does have a "Sleep Timer" (up to 90 minutes). This is accessed in the menu's.

"Record Set" kbps
(as marked on a file)
 Sample Rate
 (as shown on external PC program)

 Simple Record 
64 kbps
22050 hz
Quality Record
96 kbps
44100 hz
Super Record
128 kbps
44100 hz
The 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 either sample (see text)  (N9EWO Chart)


Buggy Firmware / Is there a Microprocessor Reset ?

In regards to the record feature (with both test samples), in testing we 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 "toggle use" 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 BOTH test samples, so points to a firmware bug ??
 
Other "firmware" bugs experienced in testing included (NOTE : The issues 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 work again).

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 bass response.

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 "shrill" sounding 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.

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 extremely disappointing with the 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 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". So 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 in stereo.

Our Conclusion : Decent  "Low Cost" Pocket Set !! (but Buyer Beware)

For what it is, the lightweight 7.2 ounce near pocket TIVDIO V-115 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 pocket sets 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 Wave (but 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 V-115. We need to stress again with the 2 test samples the battery charger indicator worked weirdly (again please see review text above as this is extremely important for proper operation).

Dave N9EWO
N9EWO, all rights reserved
Ver 7.2


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) :

TRRS #1332 - TIVDIO Shortwave Radios - Reception Tests (shows the MW Bleed into the SW Band Issue)



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