MicroP25RX

[btt]

Disregard the previous fw. Please try this one instead. goldmyne99 and I have been testing. It may help with LTE issue while trying to receive the distant P25.

 

[ScannerDude244]

Both radios are connect to a multicoupler via 700mhz yagi with 40ft LMR 400.

Here's the plot of op25 signal strength using a cheap rtlv3. I forgot with gain setting i'm using but it's very low.

 

[btt]

Obviously, you shouldn't have any issues receiving that signal. Hard to say what the power level is from that plot, but it is obviously plenty of SNR.

 

[FreqNout]

The rssi comparing between different devices is really not valid. Too many unknowns on the rssi calc between devices plus the LTE near by raises the rssi on many devices giving false data.

Better to focus on the test FW Todd is working on to see if he can tweak performance.

my 2 cents...

edit: If you have a spec an plot of the 770 band with the LTE system that would be helpful.

 

[btt]

I have to step away for a bit, but I think the firmware change will probably fix the issue. If not, we'll get it fixed.

 

[ScannerDude244]

I have to step away for a bit, but I think the firmware change will probably fix the issue. If not, we'll get it fixed.

No worries Todd! when I get home I'll try that FW we are teething the micro out

 

[KMG54]

Living in the sticks has it's advantage.

 

[maus92]

25miles, but yagi pulls them with no problem

-60 dBm 25 miles from a site is exceptional - almost unheard of. Subsites on a 7/800 system are designed to serve an area 8 -12 miles radius, and less if you want in-building coverage. That yagi 30' up is doing a great job - and the LMR 400 doesn't hurt either. S/N is also exceptional.

 

[KMG54]

My picture is from Paris mountain 20 miles from here and is a simulcast site, I have Ceaser's head, Hogback and Simpsonville on the same freq.

 

[FreqNout]

A calibrated Spec An would provide the real data. I travel to and from Cell sites everyday. I can tell you, my sds will always show -60 or better near a cell tower regardless of the monitored P25 site. There are other threads on RR that also discuss this sds rssi topic.

Let Todd tweak his known calibrated hardware. We are lucky to have him here.

 

[btt]

Let Todd tweak his known calibrated hardware. We are lucky to have him here.

Thank you sir. I appreciate that, but I think it is me who is lucky to have all of you here.

 

[goldmyne99]

MicroP25RX

Disregard the previous fw. Please try this one instead. goldmyne99 and I have been testing. It may help with LTE issue while trying to receive the distant P25.

forums.radioreference.com

Here are a few screen shots of my MicroP25RX running the test FW posted above. I am not able to create good video.

This 770 simulcast system is 12 miles from me. I am using the little whip antenna Todd shipped with the unit.

Two pics of the CC. The TSBK/Sec, EVM, and IQ plots all look good with the distant weak signal.

I will be drive testing this test FW today. I hope others will test this FW to help Todd.


Here are two sample pics of voice decodes. EVM, ERATE, and the audio are also very good.

 

[AuggieActually]

I'm looking forward to these comparisons. Also, I really like your idea of having the current button-mappings shown on top of the display. I will be making this happen.

Apologies for the delays, real life keeps demanding attention. Here's a quick sample of the same transmission, RTL-SDR using DSDplus on the left channel, and the MicroP25 on the right. This is a very strong local system, so not a weak signal comparison yet. No filtering, pre-amp, or any other tweaks, just gain adjustments. (Way, way down in the case of the rtl).

This really doesn't give an useful results, btw. I'm working on the more marginal cases, but, being marginal, getting consistent results is tricky. Hopefully can report more in a day or two. This is turning into a much more comprehensive study than I bargained for.

 

[ScannerDude244]

Ok I got in late last night loaded the new FW it's a lot better! here is a short video of it. I will run more test this afternoon and try to import my dsd+ groups files and see how well that works.
Good work Todd!

 

[btt]

Ok I got in late last night loaded the new FW it's a lot better! here is a short video of it. I will run more test this afternoon and try to import my dsd+ groups files and see how well that works.
Good work Todd!

Traffic channels are looking good now! Still room for improvement on the CC.

I'm working on a gain control interface + signals display. It will also help identify LSM / FM visually. I need to switch over to hardware mode for a while, but will get back to fw soon. Here are a couple of images for FM vs LSM screen shots. Gain control not added yet.
View attachment 131489

 

[dcr_inc]

No longer "impatiently waiting".. Its here and its working 100%.. Better P25PII audio than the P25RXII.. Great job Todd !!..
Now for the two Tone decode.. LOL

 

[btt]

No longer "impatiently waiting".. Its here and its working 100%.. Better P25PII audio than the P25RXII.. Great job Todd !!..
Now for the two Tone decode.. LOL

Excellent news! Thank you. I've already been looking into the two-tone decode for P25 implementation. It looks like P2 will be relatively easy. P1 may take more work.

 

[dcr_inc]

So far I'm very impressed.. It scans much better than the P25RXII.. Zip code search and learn was a breeze !!.. Great feature !!.. Now to learn the key clicks to do what I want to do..

 

[ScannerDude244]

Looks good! I can't import my groups from DSD+ keeps locking up

 

[btt]

Looks good! I can't import my groups from DSD+ keeps locking up

Please email me your file when you have time. I will get it figured out.