Audio fluctuations on SDS200/BCD536HP but none on Whistler TRX-2/WS-1065 - P25

[rvacs]

Hello my Uniden Friends - hopefully someone has something that can help.

On my SDS-200 / BCD536HP and BCD996P2 - volume of the transmissions between users(transmitting) varies a bunch...some talking loud make you want to turn down the scanner volume / some talking light make you want to turn up the volume. Not fun when listening bedside at night.

BUT on my CHEAPER (Less Expensive) WS-1065 Whistler or even the TRX-2 - the volume level stays pretty constant among all the people transmitting.


Is there a setting I am missing on UNIDEN? Its amazing the difference.
It's my only real grief with the Unidens. Otherwise the BCD536 and SDS200 are stellar !!

 

[dave3825]

Its called volume offset and works with favorites thru Sentinel or on the scanner. Open your fav list in the editor and find what you want to adjust.

Volume Offset This setting controls whether the scanner attenuates the Channel by about 20dBs.
-3, -2, -1, 0, +1, +2, or +3



From easier to read sentinel

SDS Sentinel Software Manual

and easier to read 436.

Easier to Read BCD436/536HP Digital Scanner Manual

 

[trentbob]

Hold on the object that you want to adjust then press function and then 0 and that will toggle through the different negative and positive levels. Do this for each object you are having an issue with and then the next time you hook up to Sentinel make sure you transfer your data card to Sentinel first thing and it will be kept in your profile.

 

[rvacs]

@dave3825 I understand the Volume Offset is for a particular channel but what if on that channel you have some loud people and some soft people ?? That isn't going to help - my thoughts. If it was all loud on a channel yes that should help by taking it down but if you have loud and soft people on a channel not sure this will work. Have you had to adjust any of your's?

@trentbob - I understand what you are saying and will try but as talking with Dave above think there is loud and soft volumes on an object or trunk id.

 

[trentbob]

Now you're talking about AGC or the lack of... that's a horse of a different color.

 

[RoninJoliet]

The man is correct, on my 996P2 models the audio on some people is low but the same person on my RS 197 scanners is loud , it seems the modulation is better on RS/GRE/Whistler ....You can use the "menu" on Uniden for help which is a very helpful feature by touching F plus five

 

[MStep]

Now you're talking about AGC or the lack of... that's a horse of a different color.

Hi Trentbob and all-- one of the biggest issues I found with the SDS200 (and perhaps the 100 as well) is the poorly designed and implented AGC circuitry, which will have you reaching for the volume control on your unit every 5 - 10 seconds--- a real annoyance. In my opinion, one of the unit's worst design flaws. This has been prevelant since the introduction of the series and apparently there is no known firmware update to handle this deficiency.

 

[trentbob]

Do a search here on RR or on your favorite search engine which will take you to the threads that discuss this issue. I'm trying to remember but I think it's been pretty well hashed out.

Really not a viable solution, I do like the volume offset function zero shortcut as it allows you to have real-time results in picking the volume level.

 

[Ubbe]

Hi Trentbob and all-- one of the biggest issues I found with the SDS200 (and perhaps the 100 as well) is the poorly designed and implented AGC circuitry

The 436/536 has audio AGC but not as aggressive as Whistlers which sometimes are just too much and backfires. The SDS100/200 have no audio AGC at all. Uniden left that out.

If you set the target model in Sentinel to x36 you'll see that a systems Options tab have digital and analog AGC features that can be selected but if you change to a SDS100 or SDS200 target the AGC are gone from Options and I have also verified with a signal generator that no AGC action exists in a SDS100.

/Ubbe

 

[trentbob]

Yep, I have just been doing some reading about that in the archives, I stumbled on this post of Paul describing the last firmware update April 15th, 2019.

 

[trentbob]

 

[ratboy]

This is my main complaint these days with my SDS200's.

I've got a local med talk group that's on MARCS-IP with huge variations between units. I normally run the volume about 8 or 9, and that lets me understand most of what is said, but on this thing, about 1/3 the units are really low and all I can hear is a mumble, 1/3 are perfect, and the other ones are BLAST LEVEL. On my old PSR-500/Pro-106/Pro-651 radios, there is almost zero difference in audio level. I've got the programming pretty much perfect at this point and I guess the only thing maybe that will work is to find one of those old powered speakers that had audio AGC built in, or take one of the audio amps with it and stick it inside an old speaker (got lots of those) and run the volume on the SDS200 up and let it handle things. Maybe an experiment that could be a jackpot..

 

[Ubbe]

Maybe an experiment that could be a jackpot..

Read up on using a light bulb in series with an external speaker. When the bulb lights up, when there's audio, it will increase its resistance and lower the power to the speaker. The more it lights up the more resistance it will have and the more it will reduce the signal to the speaker. It probably takes some experiments to find a suitable bulb, if not already found by someone else.

/Ubbe

 

[kruser]

Read up on using a light bulb in series with an external speaker. When the bulb lights up, when there's audio, it will increase its resistance and lower the power to the speaker. The more it lights up the more resistance it will have and the more it will reduce the signal to the speaker. It probably takes some experiments to find a suitable bulb, if not already found by someone else.

/Ubbe

I've seen reference to this before.
One question I always had was do you place the lightbulb in series with the speakers + output lead or in parallel across the the speaker output + and - leads?

Series would increase or decrease the impedance across the output while wiring the lamp in parallel would do the same but by creating more of a short to lower impedance at the speaker output.

I've never tried building such a circuit as it always looked more like a snake oil solution!

Was this called the Sonic Cushion? I've found descriptions of that things wiring but the way it was worded, the circuit could have been hooked up in parallel or in series at the radios speaker output. That was the confusing part.

 

[Ubbe]

the circuit could have been hooked up in parallel or in series at the radios speaker output. That was the confusing part.

A good amplifier doesn't care if you load it more or less, it's still a constant voltage that the loudspeaker sees.

If the amplifier struggles to support power, it has a high impedance output, it would have the reverse effect on the audio if the light bulb where in parallel. The audio would expand making high audio levels even louder and low levels even lower. The light bulb has to be in series and the speaker audio will be reduced to half and needs the volume to be turned up. The light bulbs type and its wattage and voltage will set the level of action of the audio leveler.

/Ubbe