Just a quick question, what are the Data Decode Thresholds, and what should their settings be to hear everything the best? I've got the GRE 800 and it looks like default settings are 75 low 95 high. Should this be left alone or are there ways to tweak for better reception? From time to time I get either the garbled message or the busy signal tone.
Data Decode Thresholds
- Thread starter TnRuralCarrier
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The busy signal is the audio that is substituted for the data buzz of an encrypted channel. You can use EZScan to change that setting. I don't think you can really get much improvement by changing those settings. I have tried to improve my 800's decoding on simulcast systems by changing them without much luck. I think their main purpose is to set the point where the scanner switches to another control channel.
I set my threshold hi to 99 so the scanner locks onto one of the strongest control channels available instead of a weaker second best control channel. I also found that control channels worth using are typically at 99% most of the time when being monitored using the analyze feature.
For the threshold lo, I found a setting of 90-92 works the best (on the DTRS Colorado system). Below a value of 90, the scanner begins to have troubles decoding the audio signal to the point of becoming inaudible and will not attempt to find a new control channel. Above a value of 92, the scanner may have difficulty staying locked onto a control channel in areas where all control channels are weak.
Shawn
For the threshold lo, I found a setting of 90-92 works the best (on the DTRS Colorado system). Below a value of 90, the scanner begins to have troubles decoding the audio signal to the point of becoming inaudible and will not attempt to find a new control channel. Above a value of 92, the scanner may have difficulty staying locked onto a control channel in areas where all control channels are weak.
Shawn
Just a note that these threshold settings have no bearing at all on the voice decode quality. They are solely related to the data decoding of the control channel.
When the scanner starts scanning, it will scan all frequencies in a system for a control channel that it can receive until it finds one with a decode percentage above the high threshold.
It will remain on that control channel until the decode percentage drops below the low threshold setting. At that time, it will begin to scan all of the frequencies again until it finds a control channel with a decode percentage above the high threshold.
Depending on where you are in relation to the system you are monitoring, you may need to adjust these settings accordingly. For example, if you're in one county and trying to monitor a site or zone in another county, you may need to lower the threshold numbers in order to ensure that your scanner will actually monitor the control channel, rather than constantly search for a stronger control channel to monitor.
When the scanner starts scanning, it will scan all frequencies in a system for a control channel that it can receive until it finds one with a decode percentage above the high threshold.
It will remain on that control channel until the decode percentage drops below the low threshold setting. At that time, it will begin to scan all of the frequencies again until it finds a control channel with a decode percentage above the high threshold.
Depending on where you are in relation to the system you are monitoring, you may need to adjust these settings accordingly. For example, if you're in one county and trying to monitor a site or zone in another county, you may need to lower the threshold numbers in order to ensure that your scanner will actually monitor the control channel, rather than constantly search for a stronger control channel to monitor.
smokestack
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What they are talking about is on the trunked systems tab. Its at the very bottom.
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True, however in many areas the data channel originates from the same tower and with the same signal strength as the corresponding voice channels. In these areas, a weak data channel corresponds directly to weak voice channels. So, by preventing a weak data channel a person also prevents weak voice decode quality.
smokestack
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What does the ATT button do exactly? I read about it and best i can tell it limits the recieve power? I am right near a tower and it was sounding strange most times. When i turned it on to where the G and A shows on the display it sounded better. Sorry for the derailment of the thread. Same topic but going the other way
I understand that point... but I've experienced a few occasions where I can receive the control channel with a very high decode rate, but voice quality is extremely poor still. In cases like this, there's nothing you can do about that.
Unfortunately, the PSR-800 doesn't have the nice Analyze feature that the PSR-500 has, so you can't see how well you're receiving control channel data without hooking it up to your computer and using Pro96Com (or maybe Unitrunker; never used it so I don't know if it displays that info).
Unfortunately, the PSR-800 doesn't have the nice Analyze feature that the PSR-500 has, so you can't see how well you're receiving control channel data without hooking it up to your computer and using Pro96Com (or maybe Unitrunker; never used it so I don't know if it displays that info).
Att
Attenuation weakens the signal by 20dB in the case of the PSR 500 or 600
See page113 of the manual.
Attenuation weakens the signal by 20dB in the case of the PSR 500 or 600
See page113 of the manual.
What does the ATT button do exactly? I read about it and best i can tell it limits the recieve power? I am right near a tower and it was sounding strange most times. When i turned it on to where the G and A shows on the display it sounded better. Sorry for the derailment of the thread. Same topic but going the other way
On multi-site systems, the 800 is designed to "roam", i.e. pick up the strongest control channel. I have found, when Im driving, that the voices sometimes sound like "Donald Duck" when I am approaching one tower and leaving another. Im hoping setting the decode thresholds to around 90 will make this go away. I'd rather hear nothing than this. My 106 (PSR-500 equivalent) has the ability to select Stationary or Roam on multi-site systems, my 106 never got the "donald duck" voices because I have it set to Stationary on Project SAFE-T here. Can't do that with the 800 unless GRE decides to give us an update to do that (hint, hint). Im too lazy to put each tower in its own scanlist, like some say to fix the problem.
Setting the "Low" threshold higher will cause it to start looking for a new site sooner. Setting the "High" threshold lower will cause it to lock onto a site with less of a signal. If you find that you're holding on to one site beyond its "useful signal", you may want to leave the high threshold at its original value, but set the low threshold higher (not necessarily 90, maybe 80 or 85). If you adjust both close to the same number, then it is possible that the scanner would start searching for a new site, only to return to the same site it just left.
Unitrunker displays decode rate among other things.
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