kamil2475

Newbie
Joined
Sep 3, 2020
Messages
3
Hi guys,
Im new this forum and in radioscanning at all. I just bought Uniden SDS100 with DMR unblocked and I have problem. I use this device in Europe where we do not have these databases to programm (like in US or Canada) and I scann these frequencies one by one and its not working as fast as I thought (maybe its different with database) but its not a case. I have problem with CloseCall function which I think do not work properly. I tried with analog walkie-talkie Boafeng UV-5R (6 watt) and it was shocking for me - in the same room Uniden do have problem with seeing this duobander (130 and 440 mHZ) - it hapens but not always and it is more common in 440 band. I do not know what is the problem - I tried with different settings - squelch , filters (but i dont know what is the difference between these filters Global, Normal Invert). I used two different antennas - the short standart and 72 cm Magnum Stik ( car antenna) - like I said - it was shocking for me - distance 400 m (eye contact with no area obstacles) - no chance to catch strong signal - it works when you know frequencies. Maybe programming by computer giving more possibilities ? But I have windows 7 and now have problems with USB connection (Sentinel) (reconstructing full database failed - Database could not be read - cant find file hpdb.cfg)
 
Last edited:

OldRabbit

Member
Joined
Jul 15, 2020
Messages
62
First - the database is useless outside the US and Canada - forget about that.

In my country, the government has a web site listing all assigned frequencies - I can download lists of who has license for which frequencies - including addressa & LAT/LONG for the transmitter and owner. Check if your country have the same. I have downloaded this database and use it for manual reference when programming my channels.

Close call works fine on mine (but then I obviously do not know what I miss :). If I key a Baofeng or other transmitter, my SDS100E reacts within about a second, sounding an alert and showing the requency.

I get CC alerts several hundred meters from mast mounted 25W repeaters sending beacons - but my Baofeng UV-5R failed to trigger CC even about 60 meters from my house. Audible voice range with several low obstacles/trees in between is more than a mile - so CC is very picky.

I have set Close Call mode to DND - and enabled all bands except Airband

Filters .. good question - some users suggest Wide Invert will filter some noise from nearby transmitters.

Computer programmng will not change CC range.
 

Ubbe

Member
Joined
Sep 8, 2006
Messages
5,514
Location
Stockholm, Sweden
The filters do not have a general setting that works for all users. It is very location and frequency dependent and have to be tried out which one that will make a difference. It's impossible to advice a certain filter setting without a frequency spectrum survey at the specific location. If you on the move it will change what filter settings are needed and Uniden then has the Auto mode to let the scanner try and decide what's best for a frequency but it will take time and slow down the scanning rate.

CloseCall needs more or less a clean signal without any other other signals interfering to be able to function. It should work when tested with a radio nearby but it could overload and stop working, so choose a low power setting on the radio and perhaps even remove the antenna.

/Ubbe
 

OldRabbit

Member
Joined
Jul 15, 2020
Messages
62
I think I read somewhere - that it need a specific amount of dB between the noise floor and the signal - so filters could likely improve the sensitivity if there are strong transmiters on nearby frequencies. The issue however is, that explanation of what the filters do is nowhere to be found.
 

Ubbe

Member
Joined
Sep 8, 2006
Messages
5,514
Location
Stockholm, Sweden
The filters action are explained several times in the RR forum and are an IF shift operation that you can read about how it works in shortwave receivers. But those are not used for CloseCall, they are only in the first IF of the receiver and CloseCall in Unidens all other scanner are a seperate chip that are a complete frequency counter and only use the front-end band pass filters, which seems to measure to be a bit of a low performer compared to other scanners, but might be due to having a different front end design, or could be the reason if SDS scanners don't have as good working CloseCall as other scanners.

/Ubbe
 

pb_lonny

Member
Joined
Jul 2, 2012
Messages
1,614
Location
Tasmania
Welcome to the forum, which country are you from? We might be able to help with some information.
 

kamil2475

Newbie
Joined
Sep 3, 2020
Messages
3
Thank you all for response,
First - the database is useless outside the US and Canada - forget about that.
These one dedicated to US and Canada are useless but I thought maybe there are some made for Europe Market but I cannot find - I am now trying to cumulate my own database in my location :D I am from Poland (Central East Europe) and we also have the Government agency for electronic communication and there are some acts which regulate this but we we do not have sth like these US frequency allocation map :) but there are some amateurs databases.....
and yes CC is very picky but distance 1 mile would be very fine - 1600 m for me
The filters action are explained several times in the RR forum and are an IF shift operation that you can read about how it works in shortwave receivers. But those are not used for CloseCall, they are only in the first IF of the receiver and CloseCall in Unidens all other scanner are a seperate chip that are a complete frequency counter and only use the front-end band pass filters, which seems to measure to be a bit of a low performer compared to other scanners, but might be due to having a different front end design, or could be the reason if SDS scanners don't have as good working CloseCall as other scanners.
 

kamil2475

Newbie
Joined
Sep 3, 2020
Messages
3
The filters action are explained several times in the RR forum and are an IF shift operation that you can read about how it works in shortwave receivers.
Sorry, I do not know what is If shift operation... can you please explain this shorcut IF ?
 
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