The problem I have with my 536HP is it often misses P25 transmissions altogether. It sounds pretty good, but misses a lot. <snip>
If it helps anyone, here's what I've learned about my BCD536HP monitoring the Portland P25 system:
As posted earlier, I had been having trouble with the radio clipping or missing transmissions altogether. Yesterday I put each of the system frequencies into the radio as conventional P25 channels, and then monitored each channel for at least five or six transmissions. I had my Unication G5 parked on the same conventional frequency at the same time as a control. During this testing I only observed the 536 clip or miss a tx three times out of about a hundred transmissions. Then I set the 536 to ID Scan the system, while simultaneously scanning the system with my Whistler WS1065. These two radios have similar scan lists and delay times, and shared the same 800mhz yagi+Comet GP-1 combo by way of a BNC T-connector and an SP-1300 Combiner/Splitter. Then I had my Unication G5 scanning a similar list as a control.
While scanning the system the Whistler passed the audio on nearly every tx, while the 536 clipped or missed a lot. I estimate the 536 missed about 10% of tx's. The whistler maybe 1%. But the Whistler audio was sometimes choppy and broken. The Uniden audio was usually quite good, very rarely choppy.
What I gleaned from this testing is the 536 actually does quite well on each frequency when monitored conventional,
but it misses a lot when scanning. For some reason it's not receiving or executing the control channel commands consistently.
After doing some googling on this issue, I tried a changing a few different things that had worked for others, and I did notice some improvement.
These changes seemed to have a cumulative positive effect, I can't say any one by itself made much difference:
Upgraded the firmware to latest version (1.11.20)
AGC I changed to OFF (system setting)
I locked out East Simulcast and Goat Mtn sites
For W. Simulcast I set the Digital Threshold Mode to Manual, and set Digital Threshold Level to 5
Attenuator is left OFF (site setting)
I deleted ALL the site frequencies except the control: 772.60625 (Sentinel downloads all RR site frequencies)
Squelch set at 2
Lastly, I set the System Hold time to 3 sec.
See post #15 in this thread regarding the System Hold Time:
http://forums.radioreference.com/florida-radio-discussion-forum/232146-new-p25-system-help.html
Also post #5 here showing it relates to the x36 models as well:
http://forums.radioreference.com/uniden-tavern/291925-some-intresting-notes-scanner.html
After these changes the 536 is still clipping or missing a tx occasionally, but it's more like 3-4% of tx's now. So it's back in the error range of its conventional P25 performance. Still not acceptable, but I can at least live with it.
I should mention the most important single thing anyone can do if they are having P25 trouble is to try a different antenna configuration first, or even parking your radio in a different spot might help if you're not using an external antenna. My 800 MHz yagi made a big difference for me. Also googling "simulcast distortion" will bring up a wealth of information on the topic.
Let us know if you try these settings and what changes, if any, you observe.
Hope that helps.
.