396T won't stop on 450-470mhz in search mode

[freqhopping]

In custom search mode my scanner will not stop on active frequencies in this range. I have one range of 450-460 and another 460-470. I don't have this problem in my other search ranges. I know there are active freqs because my BC250D stops on them. If I leave the 396T on a known freq in that range it will receive it fine. Adjusting the squelch does not change anything. ATT, Data Skip and Control Channel Only are all turned off.

 

[n1das]

I've noticed the same thing with my 396T. I only noticed the behavior above 470MHz so far. No problem searching 450-470. It's the exact same behavior you described.

I suspect the radio's PLL isn't locking up fast enough on each step in frequency as the frequency steps along. The squelch circuit could be opening too slowly, causing the search function to overshoot an active frequency and just keep going. The squelch circuit also has too much hysteresis for my liking and the extra hysteresis will tend slow down its opening/closing. (Typical Uniden design.)

The strange thing is that scanning known active frequencies it skips during search works fine if you program those individual frequencies into a group in a system.

Too bad there isn't a scan/search speed control to help test my theory. Older scanners years ago often had a selectable scan rate (fast or slow). I found it to be the most useless feature on a scanner, except for testing a situation like this with a 396T.

I've witnessed the exact same behavior with searching some frequency ranges.

 

[brandon]

I too have this problem but with a BCD996T.

 

[bravo14]

I have a 396. I have a custom search on 460-480 had no problem searching on it stops on everything on the search. Did you set it up right? I have my squeclh set at 1 also I don't know if that will help.

 

[slicerwizard]

Check your Broadcast Screen settings, including custom bands.

 

[morfis]

Too bad there isn't a scan/search speed control to help test my theory. Older scanners years ago often had a selectable scan rate (fast or slow). I found it to be the most useless feature on a scanner, except for testing a situation like this with a 396T.

I too seem to miss freqs everywhere above 400MHz, not a specific chunk. Checks done with very small search bands and long logged time periods on all radios to minimise the affect of their differring scan speeds.

Straying from topic, the idea of a variable scan/settling time combined with varying the squelch is actually very useful if you are doing a spectrum search of a locale. First pass with very fast scan/fast settling/high squelch and you get all the really strong local signals. Slowly reduce the settling time the settling time/scan speed to get weaker signals to start building up a fuller picture. Squelch threshoild is too coarse in most scanners (especially Unidens) to rely on this alone.

 

[freqhopping]

Check your Broadcast Screen settings, including custom bands.

That was it, thanks.

 

[loumaag]

Check your Broadcast Screen settings, including custom bands.

That was it, thanks.

Interesting, I have just the opposite problem. I have a my Broadcast Screen Band 1 range setup as 470.0125 - 472.9750 in an effort to avoid (what I assume is) cable interference. Yet when I start the Public Safety search, it still stops on all stuff in there; my work around was to lock out the specific ones, but it just seems that the Broadcast Screen should handle this.

 

[Dewey]

Interesting, I have just the opposite problem. I have a my Broadcast Screen Band 1 range setup as 470.0125 - 472.9750 in an effort to avoid (what I assume is) cable interference. Yet when I start the Public Safety search, it still stops on all stuff in there; my work around was to lock out the specific ones, but it just seems that the Broadcast Screen should handle this.

Hi Lou,

I'm at work right now, and don't have my manual with me, but....

is it possible that the "custom bands and screens" only apply to the custom searches and close call? IOW, is it possible that since you are selecting a service search (pre-programmed), that the custom settings are not being considered? Just wondering out loud.

Take care, and Merry CHRISTmas,
Dewey

 

[loumaag]

...is it possible that the "custom bands and screens" only apply to the custom searches and close call?

Well that is the rub...the owner's manual is not very clear on the subject. On one hand, in regard to broadcast screen, it says (pg 108), "This setting determines whether the scanner automatically ignores transmissions found during Custom Search, Service Search, or Close Call operation that are..." But just below that is the following note: "Broadcast screen is not effective during some service searches."

Either it works or it doesn't work! There doesn't seem to be any further amplification of what service search(es) it is not effective on, nor is there any reason I can see for having this exception.