Uniden sds200e gain help

[adsbgreenock]

Hi Guys,

I didn't know where to post this so mods delete or move if inappropriate and accept my apologies.

OK I have been trying to pick up some DMR stations some 10-15 miles away from me with a nearly newish uniden sds200e.

The uniden is missing these stations on the receive with the same antenna (Diamond X50n) my rsp duo is also hooked upto (not even a flicker of change in the noise or RSSI meter).

This is really starting to piss me off to be honest, as Uno shows at least a signal 8 on the METER and decodes the voice channel not a problem.

I have tried another two antennas, one a yagi and another colinear in my loft and the uniden skips on past the frequencies in search mode.
Even when i Hold and sit on the frequency. I get ZILCH.

The Duo is a different story and even the normal rtl-sdr blog v3 receives OK. Obviously with the gain adjusted a little.

Is there an rf gain hidden somewhere that I am overlooking? It is much required I think.

Even playing around with the Global filters I am unable to even receive the UHF stations the rsp duo is receiving. It is not just this frequency either there are around 10 most showing at least a signal 8 in UNO..

I mentioned this somewhere else and received a snarl from some of the more fanatical uniden lovers.

Are there any rf gain settings in this scanner that can be accessed and adjusted I may have overlooked?

I just ordered a gps unit after searching everywhere for one but in all honesty I'm ready for boxing this radio up and throwing it on fleabay.

Any help is appreciated as always and thank you in advance

Kind Regards

 

[R0am3r]

Does this radio have the DMR upgrade?

 

[adsbgreenock]

Does this radio have the DMR upgrade?

Yes, In the UK it comes as standard. I am hearing other DMR stations with stronger signals.
Also I paid for the dPMR which was the only upgrade outstanding.

Regards

 

[buddrousa]

Adjust the filters and do not ask which work best as each location and system work better for some and not better for others.

 

[adsbgreenock]

Adjust the filters and do not ask which work best as each location and system work better for some and not better for others.

Lol I actually just got one of the elusive there on the scanner screen just as i read your post and adjusted the filters. . What a pain in the ass. I give uniden 10/10 for complicating the hell out of these menus.

I'm guessing there is some sort of minimum cut off where this radio will pull from the mud digital signals? It sure feels like that.

Thanks for the advice.

 

[Ubbe]

Any help is appreciated as always and thank you in advance

What you should do are to enter that frequency by doing Channel+freq+Channel and then open the squelch and listen to the noise. You can probably not hear the DMR data. If you have a splitter and can monitor with another receiver at the same time, set that to audio mute and only watch when it receives a signal and at that time listen to the SDS200E.

Do Fn+7 to set IFX and listen. Go into the menu and to settings and global filter and set another filter type, but not the auto ones, then push menu button until you are back at your monitoring frequency and listen to any signal. Test each filter in both IFX and non IFX mode.

Compare the sensitivity of the SDS200E to the Duo in each frequency band. Maybe the SDS200E isn't performing as it should and needs to be repaired. Check that Srch/CloCall Opt have the filter set to Global in the menu and attenuator are Off. Also try both FM and NFM mode by Fn+Channel.

Are there any rf gain settings in this scanner that can be accessed and adjusted I may have overlooked?

Connect a cable to the rear micro USB port. Check in Windows device handler what port number it got. Use something like PuTTY or the serial command window in Proscan. In PuTTy set the connection type to serial and set the correct port number and the speed to 115200 and open the session.

If you push the . key on the keyboard, the dot key, it should respond with the type of SDR receiver chip in the scanner, R840, and what IF filter are used, 262.550MH or 380.750MHz and some other stuff.

If that works then you can change the gain. All settings will be re-initialised after a power cycle so you can't screw up.
There's very little increase in gain to set when I try the different settings. Remember that if one amplifier are left in the auto setting it will compensate when you change the manual gain of another setting. The ^ character in my keysetting only get sent after I push the spacebar. All other commands are instant and doesn't need any enter key to be used.

SDS100: - "Mystery of The USB1 Port" by Franklin W. Dixon | RadioReference.com Forums

4: Commands that CHANGE SDR Properties Proceed with extreme caution!!!

@ CHANGE RF Gain Mode between Auto and Manual RF_GainMode,AUTO
# CHANGE VGA Mode settings (default is Auto) VGA Mode Manual,2
^ CHANGE LNA Gain 1 settings (default is Auto; cycles through 016) LNAGain1,2
* CHANGE LNA Gain 2 settings (default is Auto; cycles through 016) LNAGain2,2
/ Toggle MixerGain settings (default is Auto) MixerGain,1

/Ubbe

 

[adsbgreenock]

Hello Ubbe,

This is what I was looking for but it's a pity the gain can't be set LNA/RF gain can't be set permanently by these commands. Maybe as a future update we will have write permission to this However it is good that Uniden has let us access this much to begin with.

I had a look at Steve Holoways Band scope for the sds series. That at least let me see what the filters were doing.

After all the humming and hawing the RSP still picks up pretty strong incoming signals that the Uniden doesnt even register.

I don't know why that is, despite having played around with gains for days. Same antenna, same Coaxial cable. Even tried different antennas.
It appears that unless its a medium to strong (S2-S4) signal it won't even show up on the RSSI

Idk I'm lost lol

 

[adsbgreenock]

Hello again ,

I have spent a week on this playing around with gains IFX and various antennae and coax , even different connectors (Messi and Paoloni NTYPE)

I have concluded that the Uniden will decode DMR and CAP+ showing with no bars on the signal icon in the top right of the screen . Which is good in one sense .

However, this really puzzles me as when the rsp duo is plugged in side by side along with the SDS on the same antenna :

The Uniden won't decode what shows a 7db DMR signal reading on the DUO /Uno S meter .

It seems the SDS is not hearing the signal , the noise level on the scanner fluctuates a little but that's all .

So for now it's looking like its a hit and miss with medium to low level signals with the SDS . I have tried all the different filters and it seems as though the radio just isn't interested in processing the weaker signals .

I have bought yet another antenna ( superyagi - slim jim tuned to 450mhz ) I'm also considering a preamp but I'm not sure how the frontend will play with amplification ?
The current antenna is a Diamond x50n at the end of a 15m run of LMR400 mounted 7m from the ground, I'm around 113m ASL and it is quite terrainy around me . But I have a clear path and line of sight (20-30 miles up river ) to where most of the DMR stations are located .

Can anyone else shed some light on this ? I don't know if there's a cut off point with regard to noise / RSSI that may be the problem .

Thanks again

 

[rocky28965]

I've got my SDS200E set up here atm monitoring a DMR Tier 3.
Its showing 2 bars, and the same when a signal comes through.
I don't think it's very accurate. On VHF/UHF it's not consistent with my other radios.

 

[Ubbe]

My SDS100 sometimes show dashes for RSSI when I receive a signal and when I test with a signal generator it can get stuck showing a very high signal level when it's hardly opening squelch. So there's some bugs in the signal strength handling.

/Ubbe