396XT Scan Speed?

Curious.

I am currently monitoring (1) conventional VHF simplex Group, (20) channels...
(1) Air band group, 15 channels.
(1) Trunked conventional with 10 freqs..and (1) P25 group with 8 Freq's.

I ID search the conventional trunk and ID Scan the P-25

I've noticed what seems to be IMO VERY slow overall scanning.

I tested this by transmitting with my 2M hand held while the 396 scanned.

I would unkey the PTT on my handheld and wait for scan to resume, then key up again.

The round trip until the scanner picked up my transmission required nearly 5 secs!

If I understand the trunked systems, only the CC needs to have activity for the scanner to stop.

Further; if I disable ALL trunking and only scan conventional VHF freqs, the scanner is very fast..I would expect this.

I can (see) the SQK blink on/off as they are scanned..and it appears to either be too fast for me to see it or the SQK is not being sampled often enough.

Any clues to why this happening?

Thanks in advance.

What are the hold times on each your systems?

Mike

It takes about two seconds per trunked system, if the control channels are within range, to lock on to a system and determine if there is any activity on the system.

Then it goes to the next system.

2 secs each for your trunked systems is 4 of the 5 seconds.
The conventional frequencies only lock on if active carrier.

On the other hand, it would be a lot longer if any (trunked or conventional) had been active before coming around again.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

marksmith said:

It takes about two seconds per trunked system, if the control channels are within range, to lock on to a system and determine if there is any activity on the system.

Then it goes to the next system.

2 secs each for your trunked systems is 4 of the 5 seconds.
The conventional frequencies only lock on if active carrier.

On the other hand, it would be a lot longer if any (trunked or conventional) had been active before coming around again.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

Click to expand...

This seems to make sense.

My hold times are 2 secs for trunked; 0 for airband and VHF FM.

This "Lock on" you mention; it would appear then what you are saying is, even w/o activity on the CC, there is a dwell time seeking CC activity?

The "Hold" time is not relevant in this discussion as I am referring ONLY to when there is no activity on the CC;s.

Is the default 400ms actually stopping and looking for CC activity even if none is present?

Exactly correct about hold times not coming into play unless activity is received, and that the lock on I am referring to takes place whether there there is activity or not, as long as the control channel is within range. If out of range, it's the same scan time as an inactive conventional frequency.

The 400ms is a different thing. WHEN a DIGITAL signal us received, this is the delay the radio takes to determine essentially whether it is digital or not instead of making a lot of noise and assuming analog.

I find that setting the digital channels or talkgroups to an audio type of DIGITAL and then changing this delay to zero works better and can help eliminate missed transmissions, or the beginning of a transmission. If you use auto for the audio type, where the scanner figures it out, then I would keep a delay in there to avoid noise blasts.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

marksmith said:

Exactly correct about hold times not coming into play unless activity is received, and that the lock on I am referring to takes place whether there there is activity or not, as long as the control channel is within range. If out of range, it's the same scan time as an inactive conventional frequency.

The 400ms is a different thing. WHEN a DIGITAL signal us received, this is the delay the radio takes to determine essentially whether it is digital or not instead of making a lot of noise and assuming analog.

I find that setting the digital channels or talkgroups to an audio type of DIGITAL and then changing this delay to zero works better and can help eliminate missed transmissions, or the beginning of a transmission. If you use auto for the audio type, where the scanner figures it out, then I would keep a delay in there to avoid noise blasts.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652

Click to expand...

Thanks..I pretty much came to that conclusion.

I understand the 400ms default and see that is surely slowing everything down. 400ms if my math is correct is approaching .5 secs. I have (2) trunked systems, so that adds nearly a full second to cover both, assuming traffic is present on one and then the next.

marksmith said:

Exactly correct about hold times not coming into play unless activity is received

Click to expand...

The HOLD TIMES come into play any time a system is scanned - activity or not - trunked or conventional.

Set the hold times on everything to 0 for maximum scan speed. But, it will take about 2 seconds per trunk system minimum to scan those. That's so it can get all the data and not miss any activity.

The CHANNEL DELAY is what only comes into play on activity.

The 400 mS is the P25 wait time, and only affects mixed-mode systems. That is how long the scanner will wait to see if the transmission is in digital mode.

Last, there is no such thing as "trunked conventional". Maybe you meant trunked analog?

That's correct. Substitute DELAY for HOLD in my above comments. Delay takes place after a transmission. Hold takes place during the scanning process when there is no activity, holding on that system scanning before moving on to the next one.

Mark
WS1095/536/436/996P2/HP1e/HP2e/996XT/325P2/396XT/PRO668/PSR800/PRO652