MicroP25RX

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btt

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If you were following the BTT: Open-source thread, then you probably saw the reference to the new hardware currently being developed. For lack of a better name, I'm referring to this new hardware as the MicroP25RX for now (it is approximately the size of a Bic lighter). As I mentioned earlier, the digital board is currently being tested and firmware being developed with an IF-tap from a P25RX-II providing an analog signal to the 12-bit ADC on the the new processor. As mentioned earlier, the analog boards were already ordered. I received some photos of the the analog board partial-assemblies (passives installed). They look good! They have shipped. Developing firmware on the new board is awesome! With the emulated Ethernet network interface, and 40x bandwidth increase, monitoring the effects of changes to any aspect of the firmware is now visually-possible/real-time. After I gained confidence in the new board/MCU, I ordered 15 more for a total of 25. I should have enough of everything on the way to build 25, with the exception of the outer pcb panels that will form the RF shield, button interface, display/Wio-terminal-batterypack interface?, battery holder, etc. I have ideas for multiple products emerging from this development including the multi-receiver system idea that FreqNout shared. Stay tuned for more information. I uploaded a video last night demonstrating the performance while receiving a local simulcast system @ -96 to -90 dBm signals. Note that the PC is only being used to display information. The A/D conversion, down-conversion, decimation, re-sampling, demodulation, decoding, voice-audio-synthesis, and streaming over IP/UDP to multiple ports is being performed stand-alone on the new digital board.
 

btt

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Outstanding!

I know it is probably too early in the game, what is the target pricing?

HH
It depends on where we go with the final details/options, but I am currently shooting for $199 to $249 for the basic recevier (digital board + analog board + cover panels/RF-sheilds (buttons, silk screen, AA battery holder)). I'm open to design changes at this point, so it might change.
 

FreqNout

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Great work @btt!

There really is a need for a low cost entry level P25 receiver.

Future 'add on' features to a basic model would allow for a design your own 'system'.
 
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KevinC

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I may be jumping way ahead, but any plans on incorporating the dual band (7/800) in this model? Even at $299 that would be a steal and I’d sign up for one….I’ll even beta test one for you. ;)
 

brndnstffrd

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I may be jumping way ahead, but any plans on incorporating the dual band (7/800) in this model? Even at $299 that would be a steal and I’d sign up for one….I’ll even beta test one for you. ;)
Same. Have been following very eagerly since Todd started dropping bits of info.
 
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btt

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I may be jumping way ahead, but any plans on incorporating the dual band (7/800) in this model? Even at $299 that would be a steal and I’d sign up for one….I’ll even beta test one for you. ;)
I wasn't planning on this to start with because of the relative size increase, but I started to think the same thing today. I'm starting to think that one version of this new design with a switched, dual-filter (cell tower downlinks in both bands completely attenuated) on the front-end and an option for a board that is a plug-in-to-the-back of a Wio-terminal / battery pack. It would be a pretty nice package for very low cost with subscriber-like RF performance. As Goldmyne99 mentioned, the Wio-terminal would add the possibility of Bluetooth back in. Please give feedback if this is where you would like to see this go. If you would rather see this go toward a single-band-per-receiver, multi-receiver, system with an option for up to 4 receivers per package, then please respond as well (I have been thinking about how to implement this and have a solution) It may be that these are both valid products to develop. I think they are.
 

FreqNout

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If you would rather see this go toward a single-band-per-receiver, multi-receiver, system with an option for up to 4 receivers per package, then please respond as well (I have been thinking about how to implement this and have a solution) It may be that these are both valid products to develop
The linked Multi RX system. None exist now. It would offer high performance opportunities for multiple channel decodes at the same time rather just buying another stand alone scanner. It is new concept in design. Push the envelope!
 

btt

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The linked Multi RX system. None exist now. It would offer high performance opportunities for multiple channel decodes at the same time rather just buying another stand alone scanner. It is new concept in design. Push the envelope!
What I'm thinking for this approach, would a USB hub controller based pcb that would allow a single digital upstream board to communicate with 4 downstream receivers in a single package. Up to 4 receiver boards would be able to plug into a vertically pcb-mounted USB plug (male) connectors. The host/upstream digital board would also have an Ethernet interface. The fully populated system should be able to easily fit in your hand. The enclosure would have 4 SMA connectors and a single 100Mbit Ethernet connector exposed . Power could be a DC plug or POE. The Ethernet interface would have the benefit that all operating systems would be compatible without any hassles.
 

KevinC

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I wasn't planning on this to start with because of the relative size increase, but I started to think the same thing today. I'm starting to think that one version of this new design with a switched, dual-filter (cell tower downlinks in both bands completely attenuated) on the front-end and an option for a board that is a plug-in-to-the-back of a Wio-terminal / battery pack. It would be a pretty nice package for very low cost with subscriber-like RF performance. As Goldmyne99 mentioned, the Wio-terminal would add the possibility of Bluetooth back in. Please give feedback if this is where you would like to see this go. If you would rather see this go toward a single-band-per-receiver, multi-receiver, system with an option for up to 4 receivers per package, then please respond as well (I have been thinking about how to implement this and have a solution) It may be that these are both valid products to develop. I think they are.

Thinking about traveling, a very large system in my state uses 700, 800 and VHF. So the 4 receiver version would be needed for that.

I personally like the dual filter idea as that would suit my local needs just fine as well as most other buyers.

If you could offer both that would be awesome, but that’s a lot of R&D time plus having to support two different designs.

Isn’t being in business for yourself fun?:p
 

btt

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Forgot to mention, but there have been what I think are significant improvements to the audio since the video I posted earlier. I implemented most of these changes on the P25RX-II in the latest testing( multi-mode scanning) release. Let me know via email if you think it is better. If so, I will implement on the other firmware versions for the P25RX/P25RX-II.
 

FreqNout

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I'm starting to think that one version of this new design with a switched, dual-filter (cell tower downlinks in both bands completely attenuated) on the front-end and an option for a board that is a plug-in-to-the-back of a Wio-terminal / battery pack.
The MicroP25RX with a snap on Wio Terminal for display/control would be a super cool hand held option.
 

brndnstffrd

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I can see a usage scenario for both. The portable 7/800 mhz receiver would be great for use in a vehicle/portable, especially tied to a screen such as the WIO terminal. One of these would be a no-brainer for me, especially at the proposed price-point.

The multi-receiver would be great for home use. I could definitely see myself having at least 2 7/800 mhz units for monitoring on my state system, then adding more down the road as $ allows. This is an attractive option since it would be scalable, instead of dropping the $6-800 all at once like you must do with an SDS or Unication, you can start off small and add to it as funds allow. Want to save a few $$? No problem, buy the rest later or maybe not at all if your needs don't require them. Don't need UHF? No problem. Want to double up in a band? No problem. This really has the potential to be a game-changer, especially since this is the only device I am aware of that will follow multiple talkpaths simultaneously.
 

dispatchgeek

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I’m not in the cool kids club here, but I’d love to see a 7/800 that mates to the WIO terminal. Our state system is going pretty heavy on combination 700/800 MHz sites. It would hamstring me quite a bit to either have two receivers or only have either 700 or 800 MHz.

I would greatly consider a dual 700/800 mated to a WIO to go permanently in my vehicle.

I wasn't planning on this to start with because of the relative size increase, but I started to think the same thing today. I'm starting to think that one version of this new design with a switched, dual-filter (cell tower downlinks in both bands completely attenuated) on the front-end and an option for a board that is a plug-in-to-the-back of a Wio-terminal / battery pack. It would be a pretty nice package for very low cost with subscriber-like RF performance. As Goldmyne99 mentioned, the Wio-terminal would add the possibility of Bluetooth back in. Please give feedback if this is where you would like to see this go. If you would rather see this go toward a single-band-per-receiver, multi-receiver, system with an option for up to 4 receivers per package, then please respond as well (I have been thinking about how to implement this and have a solution) It may be that these are both valid products to develop. I think they are.
 
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radio3353

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I like the multi-receiver options. Please have an audio line out or USB out jack so I can feed audio into my PC. Thanks.
 
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mikenet

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I’d love to throw a multi-RX system in a weather-proof box at the antenna(s), and just run cheap ethernet w/PoE back to the LAN. Or a WiFi bridge in a home environment.

With single-band front ends would make quite the monitoring setup. Extra points if you provide IF-out (even if narrow-ish) in that scenario for those who want to poke around with SDR in a better-than-dongle setup.
 

freqseeker

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I would like to see single band receivers. Subscriber quality is important to me. Scanners have always been mediocre at best. If you own a Uniden SDS series scanner look at the filter settings they had to add to make it usable.
I know that a lot of systems combine 700 and 800 frequencies, and can see it would be good to use one receiver. I prefer quality over quantity.
I don't look at this project as a budget alternative, but rather a very high quality receiver system.
I like the idea of adding to the system as budget permits. I look forward to the progress.
 

RFI-EMI-GUY

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I would love to buy one of these. I have basically one system 700/800 that I listen to and it is in an urban environment so RF filtering is a must. I would use portable/mobile when out and about. Size is a consideration as it would get a lot of use with an earpiece.
 
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