MicroP25RX
- Thread starter btt
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It is ready to go! I'm impatiently waiting for USPS to open the doors.
I can't tell you how annoyed I was with our mail carrier yesterday. At about 8:20 PM, they marked the package as mailbox not accessible. The carrier then finally delivered the mail after 9 PM! but no package. Got a notification after 9:30 that the package was delivered, but was very sceptical that was accurate. However, it was in the mailbox this morning. WTF?
N4GEX
Member
Can anyone comment on the relative sensitivity of the MicroP25RX compared to a plain old RTL-SDRV3 stick on 700/800 MHz? I live on the deep fringes of a simulcast system that I struggle to receive using an RTL-SDR and DSDPlus. This is connected to an attic mounted 7 element resonant Yagi antenna pointed directly at the site. Most of the time I get fair-to-good decode, but other times the error rate is just too high to be usable. I've been reluctant to try any other receivers because anything less sensitive than the RTL-SDR would just be an expensive mistake.
I can do some head to head comparisons, but likely won't be able to until tomorrow sometime.
There's a good chance that a decent filter and preamp combo would meet your needs for a bit less money. Especially if you would rather continue using software to decode/log. If you're just listening, this might work a bit better.
I have been thinking about this the past few days. Could you send me the link for the frequency mappings again? I'm not going to use the approach I was working on before. I'm going to try and implement this from the P25 decode and not from the synthesized audio. I won't have a way to test it here unless they start transmitting fire dispatches over P25 again. I haven't received any for a long time.
N4GEX
Member
Thanks! I'm just interested in simple listening- period. I don't like having to leave a computer running just to monitor this one system. I have other scanners to monitor other things, and I'd like something simple to handle this one simulcast system so long as it can make sense of the puny signal.
There are other factors beside sensitivity involved, so really hard to say how they would compare. The MicroP25RX does have a good analog IF filter and a higher resolution ADC (12-bit). As AuggieActually suggested, you can gain some sensitivity (low noise-figure, high gain) by installing a good preamp close to the attic mounted antenna (on the antenna side of your coax feed) to compensate for the feed-line loss.
I checked on your tracking. It was in the Spokane sorting facility on the 15th (same day it was shipped). I'm sure it is somewhere in your vicinity now. Expected to be delivered today.At least you got yours. Mine still shows to be in Spokane.
Second useability request. Button status indicators.
There seems to be enough room on the screen to tighten everything up enough to put small hotbar, or status text near the top buttons to show what they currently do. Maybe I'm still getting used to the interface, but I always forget I'm in a certain mode when I want to skip a TG or go into the config menu. I know there's a mode indicator at the bottom, but it might be clearer up top?
There seems to be enough room on the screen to tighten everything up enough to put small hotbar, or status text near the top buttons to show what they currently do. Maybe I'm still getting used to the interface, but I always forget I'm in a certain mode when I want to skip a TG or go into the config menu. I know there's a mode indicator at the bottom, but it might be clearer up top?
Aaaand a couple questions, @btt . This thing has my tinkering side going.
Is the big back circuit board used for anything besides interfacing with the wio? eg rf shielding, filtering? I see the resistors on the back, but it looks like they are just for the wio.
Have you had an experience with the thermal performance on this? Overheating and/or frequency drift? How much ventilation it needs?
Ignore all this if it's a bother.
Is the big back circuit board used for anything besides interfacing with the wio? eg rf shielding, filtering? I see the resistors on the back, but it looks like they are just for the wio.
Have you had an experience with the thermal performance on this? Overheating and/or frequency drift? How much ventilation it needs?
Ignore all this if it's a bother.
No, this version of the larger PCB is only used for interfacing to the Wio. I probably should have brought out easy connections to the Wio I/O for those that want to do other things with it. It should still be pretty easy to solder something to the header pins if you have an idea to try. The larger pcb is intended to form part of the RF shielding. The reference TCXO on this is very stable. I did have overheating issues with the first attempt when making the pcb as small as possible. This version has a larger analog circuit board and different voltage regulator. It does get warm, but I've been running here 24/7 with ambient room temp for months with no issues. I haven't done further temperature testing. Please keep the ideas and suggestions coming.
I made it to the post office. Looks like your receiver is estimated to arrive on Monday.
Looks like mine will be here Monday as well, I'm looking forward to comparing it to SDRTrunk. That's my current solution as the SDS series doesn't hear very well at my location due to rf from a nearby cell tower.
SDRTRUNK is a nice program and it works ok, just not portable when paired with my desktop. After reading the various threads I'm hopeful this may be a viable solution.
SDRTRUNK is a nice program and it works ok, just not portable when paired with my desktop. After reading the various threads I'm hopeful this may be a viable solution.
At least you got yours. Mine still shows to be in Spokane.
As usual with the USPS with me it’s a no show. Oh well, there’s always next week.
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