Whistler Wendy: Safe TRX2 speaker connections

[savage308]

i have a gree -psr 500, i plug mine into my ridgid work mate radio using the mp3 plug in, i use the scanner on minimum volume and crank the radio like a amplifier, been doing in now for 5 years outside daily

 

[Anderegg]

So, for testing, I bought a refurb WS1098, and attempted to attach it in place of my old PRO197, same power, antenna, and 3.5mm stereo line connection to the PC. NO AUDIO...get a slight little blip or pop when channels start to RX, but thats it. Tried headphone, which does work, but extremely low audio, not loud enough for the levels of my needs. Headphones attached to the speaker jack work very nicely. Since Whistlers position is that it is not possible to attach the speaker output to a PC, can someone with a Whistler scanner who has it attached to a PC specify what I am doing wrong?

Paul

 

[Ubbe]

Loudspeaker output is a mono connector and headphone is stereo. The groundloop isolators are stereo devices with two transformers in each and use stereo connectors.

Have you tried monitoring the other left/right channel with your PC?

Those of need of several isolators could use stereo to mono cables or adapters and use both transformer in one isolator.

/Ubbe

 

[Anderegg]

So I finally got it working...turns out I REQUIRE a ground loop isolator placed between the scanner and my passive mixer. I was running the isolator between the mixer and my PC, to keep DC feeding back from my PC to the 4 scanners attached to the mixer. Works fine with PRO197's, but not the 1098. So audio is clean and happy, and just as loud as the PRO197's using speaker output.

I only had one ground loop isolator, so it was a matter of just trial and error on where it went before it started working. Without the isolator between 1098 and the mixer, there is no audio output, just pops when the audio starts and stops.

Paul

 

[cmdrwill]

The Whistler scanner earphone jack is designed to provide audio to earphones which are 32 ohms or higher impedance. The audio IS limited so the scanner will not blow your ears out...

Some ' ground loop isolators ' may have too low of an input impedance to work correctly with Whistler scanners' earphone jacks.

And most inputs on PC's are way too sensitive, and you need an attenuator between the mixer and PC input.

 

[Ubbe]

Most isolators are something like 1k impedance but there are some associated with car HiFi that have 8 ohm input and 1k output with level adjusters that are used to connect to a power booster when the car stereo doesn't have a line level out signal. Turn that isolator the other way around and you get a very low signal suitable for a mic input on a PC.

/Ubbe

 

[Gene]

I used two of these years ago. Just tape the two together with electrical tape, suction cup to suction cup. One acts like a small speaker and the other one an an audio pickup device. Don't be concerned with impedence. Plug one into radio and the other to whatever device you want. Works like a charm.

Telephone Microphone Suction Cup Pickup | DefenseDevices.com

 

[slicerwizard]

Yup, seems like we can no longer connect scanners to anything else that is itself powered, or else the other devices DC current can flow back into the scanner and damage the audio circuit.

But look at the upside...the parts removed to cause this makes our scanners 10 cents cheaper to buy...yay!

Paul

Yeah, scanner manufacturers should stop using efficient push/pull amplifiers just so streamers can avoid the huuuge hassle of installing DC blockers...

 

[Anderegg]

So no issues to report connecting the WS1098 speaker jack now to my PC and mixer using a ground loop isolator directly attached to the speaker output of the scanner, along with all 3.5mm stereo line cables. If anyone has or ends up running across a blown speaker output on a Whistler, or hears about one, please link it here, so others can evaluate any risk that might actually exist, other than Wendy saying yuh jus cant dew it two it!

Paul

 

[BrianG61UK]

Yeah, scanner manufacturers should stop using efficient push/pull amplifiers just so streamers can avoid the huuuge hassle of installing DC blockers...

There is nothing more or less efficient about not having one side of the amplifier output connected to ground.

It's a trick to drive more power into a certain impedance speaker without needed a higher supply voltage. That's all. And I don't see any reason it would be needed in these scanners since they don't go very loud and don't need to.

 

[MichaelBhere]

So, for testing, I bought a refurb WS1098, and attempted to attach it in place of my old PRO197, same power, antenna, and 3.5mm stereo line connection to the PC. NO AUDIO...get a slight little blip or pop when channels start to RX, but thats it. Tried headphone, which does work, but extremely low audio, not loud enough for the levels of my needs. Headphones attached to the speaker jack work very nicely. Since Whistlers position is that it is not possible to attach the speaker output to a PC, can someone with a Whistler scanner who has it attached to a PC specify what I am doing wrong?

Paul

Did you adjust the volume after plugging in the stereo jack to the headphone port. On my TRX-1 the headphone audio level setting is independent from the internal audio level setting. When I first plugged int he headphone there was no audio at all until I hit the volume then all was good.

 

[Anderegg]

I think the default volume level is 10 in EZScan for the headphones, but it should be noted I had scanner audio and volume control, just had a buzz when disconnecting the USB, which went away as it was plugged back in. My 436HP, when I tried to run a remote audio feed, would buzz/hum horribly only when the UBS was connected to the same PC as the headphone jack!

The WS1098 at volume level of 15, matches my PRO197 scanners speaker jack output level perfectly.

Paul