Thanks: re gain setting. I am having on all my receivers interference on 700mhz trunking systems, I believe, from adjacent strong signals from Firstnet; my SDR shows very high signals, which look TDMA'ish in the First Net assigned frequency band adjacent to 769 MHZ. I'm wondering if reduced gain would reduce the offending signal problem and will test.
P25RX P25 Phase 1/2/DMR Receiver With Bluetooth Audio Support
- Thread starter btt
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New testing version available 2020-09-17_1056.
$ rfgain 0
invalid rf gain. setting agc to automatic.
RF Gains:
0 to enable automatic gain control
-1,8,14,20,23,26,29,32,35,38,41,44,47 dB
If this doesn't help, you might try an external 10dB attenuator for close-in adjacent channel blockers.
I wish it worked with SYNC but in reality, I probably won't use it with SYNC often. It's got some quirks but it does work very well overall and gets better with every software release... I highly recommend it....
I have read all 22 pages of posts so far and downloaded the software, very impressive. If you were able to put in AES and ADP (RC4) multikey support for users with known keys (as talked about in the first few pages of the thread) to use as a remote receiver I would be 100% sold. Great product, lightning-fast with your responses your company is on fire.
Is this hardware based on some sort of SDR chipset?
BlueTail Technlogies
BlueTail Technologies specializes in the design and manufacturing of RF electronics. Our premier product is the stand-Alone P25RX Digital Police Receiver with Bluetooth Audio Support. The P25RX is not an old school police scanner! The P25RX uses a P25 Phase-1 Control Channel to automatically...bluetailtechnologies.com
Open-source Configuration software
Wow thanks for the very rapid software feature update. Didn't clear up my interference problem, but I appreciate the effort. I'll talk with my good friend rf engineer about DIY filter options.
Overall, I really like the P25RX. Very neat device, easy setup. Works as well as my BC436 as far as I can tell. Superb ease of F/W updates and very nice database import of frequencies/systems based on location. Synced with my favorite bluetooth speaker and my truck (2019 Frontier pro4x rockford fosgate factory audio).
I did notice a minor bug in my area wherein zipcode search in the region of 70503 for 700 mhz has the LWIN Scott site incorrectly as labeled Lafayette. The Lafayette site frequencies do not properly populate (only get about 3 of them) in the search, and none of them is the control channel. Of course the software is flexible enough I can just enter it directly.
Only real challenge is that which affects all my receivers. I live in 70503 area and monitor LWIN. On all my receivers which include: cheap dongles, AirSpy, and now P25RX, there is marked and intermittent degradation of P25 reception (both voice and control channel), from what I believe is adjacent interference from Firstnet. This intermittent degradation of P25 reception and sometimes total dropout of decoding occurs the closer you get to a cell site. It knocks out all of the above radios about 1/4 mile away, and is noticable aggravating to about 1/2 a mile or so. Again, all these receivers are similarly affected. From the elevated location of my 3rd floor office which has clear line of site to two cell towers under 1/2 mile, none of my receivers can decode, but they work in the interior of this steel/concrete/brick office building in a windowless room. Seems like this interference has worsened over time. I hadn't fired up my airspy in a while and checked it on unitrunker. Very strong signal to the Scott Lwin control channel but decode was dropping out, presumably again due to the same interference. Guess I need filtration.
Back to P25 rx, again I love this thing. Despite my whining about a local problem, it works as well as any of my other devices throughout my commute, which means it works the vast majority of the way; its only small areas that are dead. It interfaces with my truck's audio system nicely and I'm getting 15 character alphatags displayed. I'm not sure what the trailing 3 characters are, which consist of a colon, letter and number like, ":H9" I look forward to testing it some Phase II systems when I find myself in range of them. I don't know what this is supposed to be; the trailing characters.
I am delighted with my purchase and again
T H A N K S! to the developer.
Overall, I really like the P25RX. Very neat device, easy setup. Works as well as my BC436 as far as I can tell. Superb ease of F/W updates and very nice database import of frequencies/systems based on location. Synced with my favorite bluetooth speaker and my truck (2019 Frontier pro4x rockford fosgate factory audio).
I did notice a minor bug in my area wherein zipcode search in the region of 70503 for 700 mhz has the LWIN Scott site incorrectly as labeled Lafayette. The Lafayette site frequencies do not properly populate (only get about 3 of them) in the search, and none of them is the control channel. Of course the software is flexible enough I can just enter it directly.
Only real challenge is that which affects all my receivers. I live in 70503 area and monitor LWIN. On all my receivers which include: cheap dongles, AirSpy, and now P25RX, there is marked and intermittent degradation of P25 reception (both voice and control channel), from what I believe is adjacent interference from Firstnet. This intermittent degradation of P25 reception and sometimes total dropout of decoding occurs the closer you get to a cell site. It knocks out all of the above radios about 1/4 mile away, and is noticable aggravating to about 1/2 a mile or so. Again, all these receivers are similarly affected. From the elevated location of my 3rd floor office which has clear line of site to two cell towers under 1/2 mile, none of my receivers can decode, but they work in the interior of this steel/concrete/brick office building in a windowless room. Seems like this interference has worsened over time. I hadn't fired up my airspy in a while and checked it on unitrunker. Very strong signal to the Scott Lwin control channel but decode was dropping out, presumably again due to the same interference. Guess I need filtration.
Back to P25 rx, again I love this thing. Despite my whining about a local problem, it works as well as any of my other devices throughout my commute, which means it works the vast majority of the way; its only small areas that are dead. It interfaces with my truck's audio system nicely and I'm getting 15 character alphatags displayed. I'm not sure what the trailing 3 characters are, which consist of a colon, letter and number like, ":H9" I look forward to testing it some Phase II systems when I find myself in range of them. I don't know what this is supposed to be; the trailing characters.
I am delighted with my purchase and again
T H A N K S! to the developer.
It is not advertised as such, but the heart of the p25rx:
: is advertised by TI as a single chip transceiver with an adjacent selectivity of 67 dB @ 6.25 kHz offset. Blocking Performance: 104 dB @ 10 Mhz
-Very low phase noise -115 dBc/Hz @ 10 kHz offset
My measurements may vary. (see the user manual).
Is that specific enough? ok... I know someone will eventually share. I just want to wait until that time if that is ok? I did my best to find a way to provide excellent performance and flexibility in an inexpensive design relative to the competition in the US. I know.. that is an impossible challenge. This design is all about software flexibility. I hope it is living up to expectations so far. There is at least NXDN to add next.
I didn't think it would, but your suggestion for manual rf gain may very well help someone. I thank you for that.
Please let us know if you figure out a solution.
Thank you,
btt
Please tell me this isn't a Honda system?
So far, the text display has only been known to work with Honda vehicles.Wow, ask me for information that most people understood that it would be ok to wait a while for... I answer... then turns out you are a an ******. Can I say that? It is true that I can't listen to P2/TDMA here, but from what I understand it is working ok in many places. Please go to another thread where you are wanted ok?
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oh.. I may have over-reacted again. I'm sorry air-scan. You probably didn't read this thread before posting. The P25RX does support P25 Phase II now. I'm used to working with (not so nice people). I apologize for the not-so-nice reaction. Please continue.
Excellent! First known case of a vehicle beside Honda that works with text BT AVRC! I will add this to the user manual.
Cheers , I have a moto xts5k pulling in signals my trx and 436 sds wont touch , so I'm looking for something like this ,
So , low uhf vhf support? , as in 140 mhz _ 186 300_512mhz approximately . Any plans ?
I don't think you read the entire thread beyond the first page or so; it now has very good P2 support. It has for some time now. I can attest to this. System I listen to is a large countywide P2 simulcast system. I was one of the "guinea pigs", as it were, and I am pretty "persnickity" when it comes to RF.
Don't jump to conclusions in a long thread discussing a very new device being developed with the developer actively seeking and acting on user experiences, complaints, and suggestions. Read through it all, or, at least look over the last several pages.
For the price, I would say this is a very good deal for anyone trying to monitor P25 P1 and P2 systems and who may be suffering from simulcast issues. It is not perfect, of course, it does not have the usual frequency coverage of most "normal" consumer scanners (bottoming out at 140MHz or so, somewhere around there, as I recall) and does not have a "display" outside of when connected to a computer. But, once programmed, it can be run independently of a computer (does not need to always be connected to a PC to run) and still output audio via a line out or Bluetooth. Pretty slick, really, especially given its size! I find myself thinking of many unique ways to make use of this device in special circumstances. Multiple units in an "array" could be especially useful in cases where simultaneous monitoring of either multiple systems and/or multiple talk groups subsets are needed; for example, a news media provider case.
Anyway - oh yes, they DO handle P2 P25 systems, so please dispel that concern of yours!
-Mike
air-scan,
How embarrassing.
Please accept my apologies for that completely unprofessional response last night. I have no excuse. I should have stayed far away from the computer. I see you were probably responding to the "firmware limitations" section of the user-manual. (it has been updated). Thanks for pointing that out.
For what it's worth, I briefly set it up with a 380MHz military base trunking system just as a test and it did "work" but my setup doesn't receive that system very well as it currently is. It was a very brief run with an early set of software and firmware. I need to test this again in a more aggressive manner with the latest firmware/software.
I don't have any VHF (138MHz to 174MHz) trunking systems close enough to me with my admittedly sub-optimal antenna system that I can receive for testing on that band, unfortunately. However, I know that another user in this thread does and was testing it and providing feedback to the developer. I do not know what the latest news is concerning that situation.
-Mike
This thread is pretty long and while not everyone reads at the same in-depth level I still think that when major changes come for this receiver, a new thread should be considered. It might help to consolidate certain topics and better serve specific issues.
It is working great overall I think. I actually have never used it in standalone mode but it is my intention to do so ASAP. I have a nice 5 volt brick that is roughly the same size as it is. And while there may be no display in that case, the end user has programmed it and has a pretty good idea of what they are listening to. There are a myriad of uses for this little gem. I can see it being used as an inexpensive and very effective feed providing device as well. What would be nifty along those lines would be a way to get the alpha tags for TG's into the feed as well. Future project for a third-party maybe as it is open source.
It is working great overall I think. I actually have never used it in standalone mode but it is my intention to do so ASAP. I have a nice 5 volt brick that is roughly the same size as it is. And while there may be no display in that case, the end user has programmed it and has a pretty good idea of what they are listening to. There are a myriad of uses for this little gem. I can see it being used as an inexpensive and very effective feed providing device as well. What would be nifty along those lines would be a way to get the alpha tags for TG's into the feed as well. Future project for a third-party maybe as it is open source.
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