BCD436HP P25 Auto mode not working

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mharris

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When using P25 Auto mode It appears that the scanner is not making adjustments in the auto mode. I noticed in auto the voltages don't change at all.

Is there a fix for this? The Franklin County MARCS site is really bad in Auto, meaning I must create a FL and use the P25 manual setting of 11 just to get acceptable performance, and even then the error rate is 30-50.

With my HP-1 the error rate is zero (using new FW 2.06). With my 996 the error rate is also zero.

Thanks!
 

UPMan

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mharris: Could you report your findings in the HP-1 system performance reporting spreadsheet. We will eventually roll out improvements to other models based on this testing.
 

redburgundy

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When using P25 Auto mode It appears that the scanner is not making adjustments in the auto mode. I noticed in auto the voltages don't change at all.

Is there a fix for this? The Franklin County MARCS site is really bad in Auto, meaning I must create a FL and use the P25 manual setting of 11 just to get acceptable performance, and even then the error rate is 30-50.

With my HP-1 the error rate is zero (using new FW 2.06). With my 996 the error rate is also zero.

Thanks!
Well known bug. The P25 Threshold "Auto" mode on the 436 doesn't work.

For example, see http://forums.radioreference.com/ma...re-bcdx36hp-users-maryland-3.html#post2149018
 

Boatanchor

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Auto mode doesn't work!

For better or worse, I do not own a HP-1, however, in all of my P25 monitoring of conventional and trunking networks, fixing the P25 mode to '8' gives the best results (lowest error rate) on my x96xt's.

The obvious caveat here is that these comments are only relevant if the HP-1 shares the same P25 demodulation scheme / system as the x96xt's.

I have never liked the 'Auto' mode. Having two identical scanners sitting side by side and monitoring both stable and fluctuating (signal strength) P25 signals, the scanner set to 'Auto' can be seen to hunt up and down randomly, or settle on a high level like 11, with high error rate, while the scanner, connected to the same antenna via a splitter, with the P25 mode set to '8' has zero error rate. This is a very consistent finding at my location with both mobile and handheld versions. Fixing the level to '8' also provides the most reliable (very) weak signal P25 decode too.

It reached the point several years ago, where I simply set the mode to '8' and the P25 'Level' to '200' and just left it there. IMHO, the Auto mode cannot deal with slowly fluctuating signals, let alone fast multi-path fading that occurs when the scanner is mounted in a vehicle or portable environment.

Unless you have two identical radios/scanners, connected to the same antenna, monitoring the same signal at the same time while trying different P25 modes on one radio, you will never know how much these settings alter the error rate/decode quality and therefore which settings are right for you. You will probably just end up going around in circles, because you do not have a simultaneous baseline/reference 'error rate' to compare your changes against.

Of course YMMV :)
 
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redburgundy

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For better or worse, I do not own a HP-1, however, in all of my P25 monitoring of conventional and trunking networks, fixing the P25 mode to '8' gives the best results (lowest error rate) on my x96xt's.

The obvious caveat here is that these comments are only relevant if the HP-1 shares the same P25 demodulation scheme / system as the x96xt's.
This thread was originally about a 436hp issue.
UPMan took it somewhat off-topic to HP-1 (although maybe not if HP-1 shares the same P25 decoding circuitry as the 436hp).

The 436hp comes with the P25 Threshold fixed to 8, even though it says "auto."
The auto mode does not dynamically change the threshold value to optimize P25 decoding, it just stays fixed at 8.
I get better performance by setting it to 11. Others have seen improvement when they set theirs to 5.

Based on your finding that a P25 threshold of 8 is optimal for a x96xt, it seems unlikely that the 436hp shares the same P25 decoding circuitry as the x96xt.
 

Boatanchor

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I apologize if I went off topic with the 996/HP-1 reference.

Maybe the x36HP has a slightly different decoding system/scheme/protocol.

Still, it is interesting that even Uniden seem to have now acknowledged that the 'Auto' mode doesn't work by fixing the default mode to '8'.

This whole issue must be a real PITA for them.
 

mharris

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Any updates on this? I would really like for the Auto mode to work so I don't have to enable a FL with a custom P25 parameter just for one site on one system.

Thanks!
 

pratzert

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I'd like to know exactly how to change this setting in the 436 ?
 

pratzert

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Thanks DDan.

I just recently read that the adjustment works only on Conventional system and not trunked systems.

Trunked systems are what I'm trying to tweak.
 

W6KRU

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Here is the simplified procedure for finding the best P25 setting:

Set the P25 Threshold Mode to Manual in Site Options for the Site.
Press Scroll control then Func then Scroll control.
Press Func and rotate the Scroll Control to set the decode threshold to a setting that most closely matches the optimum decode threshold This will be indicated by a minimal Err count.
 

pratzert

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Thank you all for the help !

I'm going to do some experimenting to tweak my local P25 Simulcast reception. (Baltimore County, MD)

Regards.
 

W6KRU

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Can I use the Sentinel software to do this ?

Thanks.
Yes, these settings are on the options tab for the site. It will take a lot of trial and error though since you can't monitor the error display as you make changes. The seemingly easy way is actually much harder.
 

AC2OY

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On my 536 I was advised to set my P25 to manual and threshold to 7, hands down the scanner sounds and appears to be decodeing much better. The NJICS systems don't sound as muddy I'm very happy!!
 

mharris

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Paul any updates on this? I would really like for the Auto mode to work so I don't have to enable a FL with a custom P25 parameter just for one site on one system. Not to mention, even with custom threshold of 11, my lowest error rate is in the 30's. My older Uniden scanners do not have this problem on this system and decode at close to zero.

I need the same fix for my 536.

I have been very loyal to Uniden and even purchased the HP-2 a few weeks ago knowing my x36 models are in need of updates.

I would really like to see this working correctly!
 
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