SDS100/SDS200: Bug fix? Headphone audio out of phase?

[tvengr]

I seriously doubt that the scanner has a FM multiplex decoder and true left/right channel stereo is available. If you can find anything about that, please let me know.

 

[cmdrwill]

OK who has a road map?

 

[jonwienke]

So, how are they delivering stereo when in the broadcast FM mode?

It doesn't. THe output is always mono.

 

[RFI-EMI-GUY]

It doesn't. THe output is always mono.

yes from the manual, a manual so sadly lacking this is all it has to say about the earphone jack.

"Earphone Warning
You can use an optional 32Ω stereo headset or earphone with your scanner. Use of an incorrect
earphone or headset might be potentially hazardous to your hearing. The output of the phone jack
is monaural, but you will hear it in both headphones of a stereo headset"

If tip and ring are sourced from different amplifiers, it is possible they are out of phase.

How to tell?

If a speaker across tip and ring produces audio they are out of phase a standard stereo headset will have L and R out of phase with each other when referenced to sleeve.

If no audio, they are in phase and audio is referenced to sleeve. A stereo headset will produce sound in phase in both ears.

 

[W5ATX]

I am using a pair of the Inland Pro 2000 speakers, I have never explored max volume settings on these speakers out of fear of blowing them up, and because a mid-range '5' volume setting is way more than enough to hear the SDS100 over anything else on my desk. The only speakers louder (and w/out distortion) are my studio monitor Mackies which I use for MP3 music from my Dell. The Inland Pro 2000 speakers should cost at least $100 a pair, not $20! I think the quality is that good.

i bought these speakers to prove a point, they are the worst speakers i've ever heard, they are currently $13 on amazon and if you want to know what they sound like, talk into an empty milk jug. these speakers are JUNK! i'll make a video of how crappy they are and compare them to a set of $9 logitechs i got on sale at office depot that will BLOW them away.

 

[KE5MC]

...snip...

How to tell?

If a speaker across tip and ring produces audio they are out of phase a standard stereo headset will have L and R out of phase with each other when referenced to sleeve.

If no audio, they are in phase and audio is referenced to sleeve. A stereo headset will produce sound in phase in both ears.

Along the lines quoted I sacrificed a shielded TRS 1/8 inch stereo cable. I pigtailed one end into left signal, right signal and common and confirmed connect between tip, ring and shield. Plugging the modified cable into my SDS100 earphone jack and selecting a WX channel.

Then using an inexpensive 2" speaker I placed it across one at a time the three combination of T-R-S. Admittedly the volume of the sound was less than the speaker in the radio, but speaker was not mounted in an enclosure, but open. While of lower volume the sound was as clear as the radio's speaker and the same perceived volume across all three combination of connections of T-R-S.

I also checked that the phone jack shield/common, antenna base and USB cable connected to charge port both shield and power common are all connected together.

Conclusion:
Tip and Ring audio are out of phase on the phone jack. Using a mono plug will short the Ring to the Shield and negatively effect that audio driver output if a separate device or half of a dual chip. If using phone jack to drive a single powered speaker pick Tip or Ring and leave unused signal floating. If using stereo power speaker use the units stereo plug into the phone jack.

At the beginning of this thread I was skeptical of audio out of phase reporting. Using a different testing method I can confirm that I now believe the initial reports were true. Never to late to learn something new.