Decoding P25 on a Windows Tablet

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thegriff

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I picked up a $100 Windows tablet this afternoon in the hopes I could migrate my SDR "scanner" away from a mini-tower thereby saving some electricity. I'm using Unitrunker, SDR# and DSD+. I've tried both the two dongle approach and a single dongle approach as well as a two dongle with one being run through rtl_tcp on a Raspberry PI.

I'm really happy and a bit amazed to report that the tablet is running the software packages better than either of two older PCs I've been working with. CPU utilization is reasonable and the decodes are at least equal to what I get using a PC.

I believe my decode issues have to do with being mid-way between two simulcast towers as I've had decode issues since day one, even after using DSDTune.

I had never tried the single dongle approach previously and I'm quite impressed with how well that works. It also gets around what I perceive as a deficiency in how Unitrunker switches to a higher priority call if found. I'll be at least trying to setup another dongle to monitor another local system to see if the little tablet can handle that load.

So far I've not even used this thing as a tablet! It's been sitting on my desktop with a USB wireless keyboard attached. I get the micro HDMI cable tomorrow so I can hook it up to a monitor.

FWIW I'm using the Winbook TW-802 from Micro Center. They currently have it for $99.99 in stores with the 801 model going for $119.99. Supposedly the 801 is a bit better due to a USB-3 port and support for higher capacity SD cards. I didn't have a need for either and had heard reports of the 802's screen being better so I opted to spend the $20 on a case. Both come with Office 365 Personal for a year.

I am truly impressed by this little tablet and can't get over how well it runs SDR# and DSD+. I knew Unitrunker would work but still impressed with that program in general.
 

Your_account

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I have an Windows Tablet to but that creapy shhttt Product have only one USB Connector who is used for recharge. When i use an Y Cable with an PowerSupply the Tablet loose Power to...
My tablet is nice for Websurfing on Train or when i visit a Friend but not for SDR.
(The Windows have also a Bug. There is no way to turn the Display off. The Tablet run with Display or the disconnect the Wifi/ BT Connection and no ADSB will be send home that sucks!)
 

thegriff

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I should have mentioned the tablet I purchased has a full size USB connector in addition to the microUSB charging connector.

From what I've read about the display turn off issue the easiest work around is to prohibit display sleep but instead set a blank screensaver. That should allow the tablet to remain on but blank the screen.
 

Your_account

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the display is black but the backlight is on so it consume more unleash power...
I need an small ADSB Sharer for Airport and Air Show Events.
A Pi are an nice one but i need also an Filter + LNA but the are not "boxed".
I dont know why nobody build an ADSB Dongle with an LNA and Filter on a single Board.
 

jaspence

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Win 8.1 tablet

These are amazing for their cost, but you can't expect a full computer for $100 to $150. The micro USB on mine does not allow charging while a dongle is used. I use a powered hub which allows me to run a wireless keyboard/mouse and a dongle without drawing excessive power from the tablet battery. The keyboard/mouse combo (Logitech K400r) makes it much easier to use when trying to tap on small text. I bought my tablet to use for programming my HT while traveling, and it works great
 

moonbounce

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I am very surprised that you can run DSD+ and Unitrunker or SDR# and DSD+ on one GB of ram? Do you use a VB Cable to send the signal to DSD+ from either of the other two programs. I see the processor of the tablet is a quad core, but one gig of ram to me would be it's downfall. Kinda like driving a Ferrari but you can't use more than first and second gear.:)
 

EricCottrell

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Hello,

I was looking at the Winbook tablets. The advantage is a separate USB port and charging port. The 801 is listed on the Microcenter website as having DDR2 memory, but the spec sheet for the processor shows DDR3L. It appears the 802 has an updated processor with the same specifications and has USB 2.0 instead of USB 3.0.

I got a deal about a year ago on a Dell Venue 8. I used it with my Elad FDM-S2 and WinRadio G305e. Dell recently released a dongle that allows using USB devices and charging at the same time. I got one and it works great.
Dell Micro USB Dongle for Data and Charging : Tablets & Mobile Accessories | Dell

I noticed 3rd-party adapters for various tablets that will allow USB and charging at the same time.

There is a problem using the Elad FDM-S2 with some USB 3.0 ports due to driver issues, so the 802 would be a good choice.

One downside is the small 8" screen. Sometimes spin buttons and other controls are too small for my fat fingers and I have to use a Stylus.

73 Eric
 

thegriff

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I am very surprised that you can run DSD+ and Unitrunker or SDR# and DSD+ on one GB of ram? Do you use a VB Cable to send the signal to DSD+ from either of the other two programs. I see the processor of the tablet is a quad core, but one gig of ram to me would be it's downfall. Kinda like driving a Ferrari but you can't use more than first and second gear.:)
The tablet I have has 2GB and it runs everything perfectly. I am using VB Cable to get audio between SDR#, Unitrunker and DSD+.

I've been mostly running a single dongle configuration for my experiments as I've found it works really well. I also have a dongle in a closet hanging off a Raspberry PI. When I use it as the source I can be anywhere in the house decoding signal.

I'm not sure exactly what my final configuration will look like. I had been running two dongles but I'm not sure I see the need any longer. I do believe I'll eventually hang everything off of an Intel Compute Stick once they are out since they'll have similar specs.
 

lynzoid

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Excuse me, but the guy who mentioned Winbook TW802 here is a freaking genius!
Amazing piece of hardware, cheap, nicely made, fast (!), reliable, good battery, and (of course) runs 2 RTL-SDR sticks simultaneously with 2048msps range set on both in Unitrunker AND decodes digital audio with DSDPlus at the same freaking time. Running on battery!
Oh yes, that was a sound piece of advise.
Thank you guys!
 

sibbley

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Excuse me, but the guy who mentioned Winbook TW802 here is a freaking genius!
You got that right! Just got my TW802 last night and was up and running in about 30 minutes. I need a mouse though, my fingers are too big for the sliders in SDR#.

I'm going to have to try the powered usb hub like jaspence mentioned to use a keyboard, mouse, and the dongle.
 

lynzoid

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I got a cheap chinese minikeyboard with integrated trackball. Bluetooth. No extra wires. Works amazingly. I also bought griffin power knob. Not arrived yet, but planning to use it as a tuning knob in sharp.
 

sibbley

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I got a cheap chinese minikeyboard with integrated trackball. Bluetooth. No extra wires. Works amazingly. I also bought griffin power knob. Not arrived yet, but planning to use it as a tuning knob in sharp.
I forgot the TW802 has Bluetooth. I'll have to check into that. Thanks...
 

Bmacs

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Lynzoid,

How do you hook up two dongles with one USB port? I have tried a powered hub with RTL dongles and it doesn't work... What specific HW are you using?

Thanks,

Bill

Excuse me, but the guy who mentioned Winbook TW802 here is a freaking genius!
Amazing piece of hardware, cheap, nicely made, fast (!), reliable, good battery, and (of course) runs 2 RTL-SDR sticks simultaneously with 2048msps range set on both in Unitrunker AND decodes digital audio with DSDPlus at the same freaking time. Running on battery!
Oh yes, that was a sound piece of advise.
Thank you guys!
 

lynzoid

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Not using any powered hub. TW's power more than enough to drive 2 sticks.
What i have is cheapest usb2.0 hub (mine is blue, 4 ports, BITES written on it). First one that got my eye ergonomically.
Works great.
I may get you a picture of my hub, but it really was first one i liked on display. May have been just lucky i guess :)
 

sibbley

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Lynzoid,

How do you hook up two dongles with one USB port? I have tried a powered hub with RTL dongles and it doesn't work... What specific HW are you using?

Thanks,

Bill
I've been using a powered hub today. I read something here on the forums about installing the drivers for the dongles separately. Plug in one dongle, install the driver and plug in the second and install the driver. Worked for me. I had sdr# and dsd+ running with their own dongle.
 

lynzoid

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Ideally you need to reprogram each stick's eeprom's serial so they are discernable.
Usually all sticks have same 0000001 serial. You need linux and rtl_eeprom util. Search RR, there was my post about it.
 

Bmacs

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Sibbley,

I changed the serial numbers on all of my dongles - reloaded the drivers for each one,,, still no go with the two different USB hubs I own. Can you tell me the brand/model of the one you are using?

Thanks,

Bill

I've been using a powered hub today. I read something here on the forums about installing the drivers for the dongles separately. Plug in one dongle, install the driver and plug in the second and install the driver. Worked for me. I had sdr# and dsd+ running with their own dongle.
 

KA2ZEY

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I've been using a TW100 and I'm making use of the microUSB with an adapter. So I'm able to run 2 RTL sticks without hub. Of course, I can't charge the thing but that's ok. I leave it plugged in when not charging.
 

sibbley

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Sibbley,

I changed the serial numbers on all of my dongles - reloaded the drivers for each one,,, still no go with the two different USB hubs I own. Can you tell me the brand/model of the one you are using?

Thanks,

Bill
D-Link Model DUB-H7 7 port USB 2.0 Hub. I've had this thing for a few years. Both dongles are NooElec R820T2 SDR & DVB-T NESDR Mini 2.
 
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