Spectrum sweeper

[mejnetguru]

Question on Spectrum Sweeper (SS).

Anyone know more detail on how SS this works vice service search? The manual/"easier manual"s are pretty nonspecific.

Ex. I have a hotel right across the street from me (CONV UHF). The come in just fine, with decent signal, when I program them in a scan list or direct tune. However, when I am running scanner 2 in SS mode, it never stops on them even when I can hear them chattering away on scanner 1. It does stop on the weather channels even though they are many miles away and with weaker signal levels. For testing, I even removed all the other bands to minimize the sweep range, still nothing.

Aside from the local weather channel and two strong control channels, I have any SS mode stops even when I can see someone talking on a HT nearby.

Ideas?

 

[pb_lonny]

Is this like Close Call on Uniden's?

 

[mejnetguru]

Same basic principles, but with some implementation differences.

 

[Ubbe]

From RR Wiki:
Spectrum Sweeper - The RadioReference Wiki

Spectrum Sweeper functions by rapidly sweeping through the RF spectrum in 1 MHz segments. If RF signal energy is detected in a 1 MHz segment, Spectrum Sweeper will sweep through the 1 MHz segment in finer steps until the source of the RF signal energy is found.

/Ubbe

 

[BrianG61UK]

Oops deleted double post.

 

[BrianG61UK]

If SS is failing to stop on a strong signal check that:
a) The frequency isn't locked out ( search menu / lockouts )
b) Try again with special mode in SS disabled.
c) Try again with zeromatic in SS disabled.
d) Try again with attenuator in SS disabled.
To change the settings in SS press menu while the scanner is searching in SS mode.

 

[noelp]

Be sure the frequencies ar not blocked from scanning. You can turn off and on which freq ranges to search, thanks Brian for your info!

 

[nanZor]

Signal Stalker / Spectrum Sweeper is similar, but not quite, to Uniden's close call.

Basically, the Whistler/GRE/RS version is more sensitive than close-call. Ie, my use of close-call is really that - within a few feet of the transmitter. Think 1990's frequency counter boxes close, or a transmitter so powerful and close you can almost smell it. That limits my use of Uniden's close call to some extent.

Signal Stalker is MUCH more sensitive than close-call, but not as sensitive as listening to a channel programmed directly, or during a service search or limit search.

In other words, signal stalker has an in-between sensitivity level - it pretty much acts the way most people wanted close-call to work! That is, a bit longer than just 10 feet away or running 3kw of power.

Not surprised that you only triggered sweeper hits on wx and those two strong control channels, but not the low powered ht's across the street.

Despite being lower in signal level, the wx and control channels were easier to find since the signals are basically constantly on. The ht's however, being low power and intermittent were harder to detect. Had those hotel users been higher-powered mobile units, then you would have likely caught them. So while sweeper/stalker are more sensitive than close-call, it is NOT running at full sensitivity.

Everything is working correctly, so don't sweat it. Put it this way - it is possible that with the Uniden, you may have not had the wx and control channels even register at all!

Tip: if you want to "emulate" Uniden's less sensitive close call, enable attenuation before doing a sweep.

 

[rayvelcoro]

See "Brian"'s response. Now: you are simply not close enough to their transmitting portables. You need to plug in an earphone and lolly-gag in the hotel lobby for a while to get sweeper hits.

 

[Ubbe]

As you know the frequency, try doing a search with start at 1MHz below and end at 1MHz above their frequency.
Maybe they use a frequency that doesn't corespond to the bandplan you have selected and search and sweeper
never actually hit on their exact frequency and by doing a search you can check that.
But whistler seems to use different tables for search and sweep as foreign users report that bandplan for search have been modified to more suit their country but the sweeper is not.

When sweeper works you can easily see on the display that the sweep slows down conciderably when it detetects energy within it's 1MHz window.
If it then doesn't indicate a hit the frequency are probably not matching the bandplan, or are filtered by all the other things already mentioned, like the zeromatic.

/Ubbe