BCD436HP 'Analyze' Question

[connah]

Morning all. I'm relatively new to the forums and I've done my best to search for the answer before posting this. If I've overlooked something, please forgive me and point me in the right direction. I have also checked Mark's Scanner manual, the factory manual, and Google to no avail.

On the BCD436HP, when one goes into 'Analyze' mode, there are 3 vertical bar graphs labeled "S", "Q", and "A". Can someone please tell me what each bar represents? I'm guessing the "S" is signal strength, and I don't know about the other two. Thanks so much!

Connah0047

 

[fxdscon]

Signal
Quality
Activity

 

[connah]

fxdscon: Thanks for the insight! A couple of questions though. What's the difference between signal strength and signal quality? Wouldn't they be inextricably linked? As the signal goes down, so does quality and vice versa, right? Also, if "A" is activity, why is it a bar graph that moves up and down at various points? Wouldn't this simply be a "ON" or "OFF" proposition, either there's activity or there's not? Thanks again!

 

[jonwienke]

Signal quality is dependent on the ratio between signal strength and the strength of any noise/interference on the same frequency.

 

[rwier]

I have tested multiple combinations of antennae, boosters, cables, etc., using the HP-1(E) Analysis Features (a more colorful rendition of the 436's graphs). Strength and Activity were the graphs that showed considerable variability. I would guess that more than 98% of the Quality readings were pegged at the top or nearly so. On extremely rare occasions the Quality graph would show near the bottom (zero?). Can't recall ever seeing the Quality indicating anything between 5% and 95%. As to the Activity graph, I imaging some sort of averaging takes place. Maybe an indication of how much activity over the last hour or two (or days). Something like that.

 

[marksmith]

Quality is the one you want to maximize with any antenna adjustments.

Signal strength is important, and often drives the quality level, but given the chance to drive one up, quality is the one. You can have great signal strength and have the radio not decode digital very well.

Theoretically if you max the quality you are getting the best decoding of the signal.

536/436/ws1095/996p2/996xt/325p2/396xt/psr800/396t/HP-1/HP-2 & others

 

[Jay911]

I've seen (as recently as today while driving around the countryside searching for new signals and talkgroups) sites with very low S (signal) but outstanding Q (quality).

On a digital transmission (which trunking control channels are), S and Q are not necessarily tied. You can have a very weak signal and still decode all (or most) of the data packets.

 

[jonwienke]

Exactly. A weak signal with little background noise can decode perfectly (or nearly so), while a strong signal with a lot of interference may not decode at all.