P25RX P25 Phase 1/2/DMR Receiver With Bluetooth Audio Support

btt

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So, only shipping to the U.S?
Any chance of including Canada?
Sorry, not at the current time, but maybe at a future date.

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The support this past week has been amazing. Thank you all! Page 19 of this thread really helped! I will be working hard to get more units available as soon as I can. The current version of the software / firmware on the website (0907_0118) appears to be a good candidate for the new "stable" version. Thank you to everyone who has been testing and reporting the issues they find so they can be resolved.
 

cmjonesinc

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I am so glad I got in "back in the day" lol. This is a GREAT product, and so glad to see a homegrown product supported the way it is. Take note folks, this is the future of scanning/monitoring. Not a bad one either.
As soon as I saw that you initially liked it I knew that it had to be pretty solid. I've been nothing but impressed so far. I've been loaning mine out to try and stoke up some interest.
 

kinglou0

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This is a GREAT product, and so glad to see a homegrown product supported the way it is. Take note folks, this is the future of scanning/monitoring. Not a bad one either.
And.....
Most importantly, this product is entirely a one man operation. btt designed it, had it built, does the final assembly/testing and is now providing excellent support along with a wealth of features for an extremely reasonable price.

As a community, we should be ashamed of ourselves. Imagine what other products could pop up if everyone started thinking outside the box and told Uniden/Whistler to take a hike?

The choice is clear in my mind. Support guys like btt. Who knows where the P25RX might end up given btt's rapid progress on various features and protocols?
 

footage

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I plan to order one. But I'm wondering whether anyone is working successfully with a MacBook air or a very, very slow HP netbook.
 

KC1UA

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Another fun thing to do with this great little receiver....for the past 3 days we have had one whopper of a tropospheric band opening here on the east coast of New England. During this opening numerous P25 control channels on VHF and UHF have been discovered. It's great to be able to plug them right into the P25RX and let it do the rest. Sitting on Cape Cod and listening to the Virginia STARS statewide system using the P25RX is kinda neat, as an example.
 

Chance

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I just discovered this project. Absolutely amazing and I commend you on bringing a product to market.

I don't mean to be a killjoy but it is the elephant in the room. Licensing.....

The configuration software is open source. But what about the firmware? If parts are utilizing libraries that fall under the GNU license, you could be forced to share the improvements made. MIT license, such as SDRTrunk, is fine to use in closed-source, but should at least be attributed to in the user manual.

And the bigger question. DVSI. They have an active patent on AMBE+2. Are you using a DVSI chip to route the decoding through?

It's all fun and games, for the most part, when people are playing with SDR's while blatantly violating patents as long as no money is involved. The second you start selling a product, you will surely be on someone's radar.

There may creative be ways to keep them of your back if you are just selling the hardware and the firmware is acquired some place else.
 
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btt

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The choice is clear in my mind. Support guys like btt.
Thanks kinglou0!,

I appreciate the support from everyone since the beginning and especially the first week of this month! Now, I can keep working on this full-ime for at least another month.

The thread seems like it slowed down quite a bit...

Just thought I should mention, I don't think the community should "be ashamed" or "tell the big corps to take a hike". The P25RX is just another option out there. I'm having fun, I hope you guys are having fun, but I'm certainly not getting rich from this. I'm just trying to pay my modest monthly bills while working for myself, nothing more.

Patents only last 20 years at the most before expiring... I don't have anything else to say about this subject and I really hope the thread doesn't go down this path.
 

Chance

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They should, but they don't. US7634399B2 - Voice transcoder - Google Patents On 11-07-2025, you will be in the clear on AMBE+

To put it bluntly, it is your ass on the line. Trying to provide for yourself and/or family could end up landing you in a mountain of legal bills.

You're not answering the other GNU/MIT questions. So I will assume you wrote every bit of code yourself and no other authors need any credit.

No further discussion needed. Any which way you had me hooked on message one. And I hope everything works out for you.

Patents only last 20 years at the most before expiring... I don't have anything else to say about this subject and I really hope the thread doesn't go down this path.
 

btt

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One feature of the new software/firmware that I would like to mention is the "reference frequency estimate". Assuming that you are monitoring a P25 control channel, you can make the assumption that the frequency being transmitted by the system is very accurately controlled. We can use this information to build up an estimate of the reference frequency in the P25RX. After approximately 1.5 minutes of monitoring P25, the constellation view will show a color-coded line with "Estimated Reference Frequency". The color represents how much difference there is between the estimated frequency and the currently programmed reference frequency. Getting the reference frequency close is important for optimal performance. It not only determines initial operating frequency (before automatic frequency correction), but it is also a reference for the ADC re-sampling rate. After you let the receiver warm up and monitor the P25 control channel for a while, you can use the reference estimate to program the reference frequency on the P25RX Configuration tab. See the attached image for where to find the estimate.

ref_freq_estimate.png
 
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rgchristy

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I apologize in advance if this is a dumb question/suggestion. I noticed that you mentioned that you were looking to increase your sales. The other day I was on rtl-sdr.com and noticed that they posted a roundup of software designed radios. It ranged from the $20 dongles to the AOR AR-2300 and into some equipment that cost $70,000. You might want to consider contacting them to see if you can get mentioned or have them do a review of your P25RX.

Their categories are:
GENERAL USE SOFTWARE DEFINED RADIOS
MODIFIED RTL-SDRS
HF HAM RADIO SOFTWARE DEFINED RADIOS

It's just a thought. Hopefully, it might help you.

Take Care,
Rich
 

cg

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After using the receiver for a few days on a P25 P2 Simulcast system, I am happy with the results. I have had a couple issues pop up and some suggestions for making use easier.
Issues:
- system locked up while sitting and running. I don't think I did anything but not sure. I noticed the LEDS were both blinking long-short-short. Unplugging/plugging back in radio did not make any difference. I rebooted and while waiting for it to start, I pressed and held the blue button. It then was able to start normally.
- On the Talkgroup Editor tab, there are issues with Sorting. If I click a column header, it sorts the entries first by Enabled or not and then by the column that was clicked. However, it seems that the lines in the memory don't just change, just the display. For example, if I click TGRP to sort them by number and then click Disable Selected, a different line that the highlighted one is unchecked. Also, after sorting, deleting picks an unselected group as well.

Things I would like to see/suggestions:
- I would like to see the ability to create per call audio files rather than one single file that is edited.
- I have a system that uses the State licenses so nothing can be imported from the FCC database. Rather than add each site manually, if the program could add the Neighbors into the Database as it sees them, it would help.
- RID Display, Alias, logging options for radios.
- Import systems from text. I have ProScan files, DSDPlus files, SDRTrunk files, and UniTrunker files not to mention the RR database. I can get the information into predefined text files from these sources if the program would allow importing.

Thanks for your time
chris
 

btt

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.....You might want to consider contacting them to see if you can get mentioned or have them do a review of your P25RX.
I have had a couple issues pop up and some suggestions for making use easier....
Thank you both for the feedback and suggestions. I appreciate it!

- system locked up while sitting and running. I don't think I did anything but not sure. I noticed the LEDS were both blinking long-short-short.
This indicates that flash memory was corrupted. You were correct to press the button to recover. The only thing that could cause this while it is sitting there operating (that I can think of) is if "auto flash" and/or "auto disable encrypted" are enabled on the talk group editor tab. Obviously it should not cause corruption, but flash corruption shouldn't happen unless flash memory is being written to. I will be looking into trying to reproducing this issue and getting it resolved. This issue has also happened occasionally during firmware updates (not very often). If this happens, press the button to get past the error indication. In this case, the configuration and talk group flash will be reset to default.
 
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