I have had my SDS200 for a week now and I'm for the most part I'm pleased. I'm hearing departments here in the Cleveland Ohio area on the MARCS-IP system that I couldn't pickup on my HP536. That's the reason I bit the bullet and purchased the 200. Also the display is awesome and fun to play with. My only issue so far is I get an a popping noise after every transmission. It only happens when I'm using earbuds. I'm using this radio in the bedroom and need to use the earbuds at night . I recall a similar issue with my 536 but I believe it got resolved with a firmware update. Is there something I can do in the settings to fix or hope for a firmware update to fix.
SDS200 Popping Noise
- Thread starter tonya
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doctordialtone
Member
Thanks. I'm ordering now but just to be clear I'm not having issues with the humming noise I've been ready about just the popping noise after transmissions.
I'll let you know if it works.
Thanks Again
I'll let you know if it works.
Thanks Again
You may be hearing the audio amp turning off after a transmission. Remember the old days of turning off stereo amps and you hear pops on the speakers.
Generally, ground loops cause a very noticeable hum rather than a popping noise. They result from two AC powered devices connected by audio cable where device 1 will be inadvertently grounded through the connecting audio cable to device 2. A ground loop would not be a problem when using earbuds as they're not connected to AC.
No one's talking ground loops here. Isolation transformers have other purposes besides fixing the hum caused by ground loops. It's been proven that isolation audio transformers can fix the popping sound caused by the DC spikes when the audio amp turns on and off. Look at the Uniden DMA portables Regardless if AC or battery powered.
Try changing the "AMP OFF TIMER" setting on the scanner to "Infinite. I don't know if this setting powers down the headset amplifier like it does the speaker amplifier but it is worth a shot.
Ubbe
Member
I don't know if it was Upman or a user analyzing the circuit solution that mentioned that the audio amplifier was a stereo IC with one channel to the speaker and one to the earphone. That would make a common mute/disable pin of the IC to be active on both outputs so disabling that amp off timer would probably be correct while using the earphone jack. The earphone audio level are probably so heavily attenuated to avoid ear damages that none of the background "hum" issues can be heard from it.
/Ubbe
/Ubbe
oldtimeradio
Member
I have the same problem. Seemed to happen after one of the firmware updates where they started turning off the audio amp after a radio transmission ended. What's annoying is the popping is there even in the mute mode. Mute the receiver turn the volume all the way down and rotate the BIG SILVER KNOW pop pop pop. It was bothering me while sleeping so I had to shut the scanning off.
I'm hoping it gets resolved in a firmware update.
NO, I have ZERO hum.
My Audio Off Timer is already set at Infinite
I'm hoping it gets resolved in a firmware update.
NO, I have ZERO hum.
My Audio Off Timer is already set at Infinite
doctordialtone
Member
Big Silver Know?
I saw the reference to "Audio Off Timer" and thought it might be a way to extent battery operation. Mine is already "Infinite", but greyed out. Played with a few other settings on that tab and nothing seemed to un-grey it, I don't spend much effort. Anyone know what might keep it greyed out on an SDS100?
oldtimeradio
Member
Sticky Fingers It's a KNOB...
Looks like a SDS200 option and greyed out on the SDS100. Go Figure...
Ubbe
Member
Most portable scanners already have that speaker amp turn off feature to save battery power but it's not user accessible.
/Ubbe
/Ubbe
I wonder if you can install an older firmware version like I did on my hp536 when I had the same popping issue?
Ubbe
Member
Just put a firmware file in the firmware folder of the SD card and turn the scanner off/on.
sds200 - Google Drive
/Ubbe
oldtimeradio
Member
Thanks Ubbe,
I went back to 1.08.05 ant the popping was still there.
I'm going to try the ground loop isolation transformer as soon as I get to the mailbox. In the middle of a hail storm at this minute.
Let you know.
OTR
OK, dumb question. I saw in the 1.02.01 Sub / 1.08.05 Main release topic that this was added in the settings section and I’m on the most recent firmware, I just double checked before posting. I can’t find this anywhere in Sentinal or in the menu on the scanner to try this out on my SDS 100.
In the other thread they said Settings > Set Audio Off Time but I have no Set Audio Off Time in my settings. Is this exclusive to the 200?
It likely is unique to the SDS-200. It, and the metal shield part, were added to help mitigate the data "hum" noise issue that is present on the speaker amplifier of some/many SDS-200 units. I have not seen this issue reported on the SDS-100.
I believe so.
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