Cobra 25 wx st SoundTracker

Sound Tracker, like Realistic's A.C.E., is a compander (COMpress and exPAND) circuit. It has its own little add-on board just like the weather receiver or an echo board.
It is an adaptation of technology that's been used by telephones for years. It selectively compresses the "voice grade audio", or around 300 to 2700 Hertz, and sorta packs more of it into the signal before it gets transmitted. At the receive end, a similar circuit "unpacks" the compressed audio, and allows more of the voice signal to be heard compared to the background noise. Even though the voices are less "broadcast" sounding, they do have more of the part of the voice that carries the actual word information. Less hi-fi, but more understandable words.

The net effect is clear audio that's much louder than the noise, effectively increasing the signal-to-noise ratio. FM commercial two-way radios made in the past few years also typically incorporate this feature with the same goal.

The problem comes when not all radios in a conversation are using companding. If you turn yours on and listen to traffic on the radio, you'll probably notice that the background static drops, but the voices sound kinda blasty or raspy. The expander part of the circuit expands *everything* it hears, including hissy letters like "S" and gravelly bits from the bass.

And if you have yours on and talk to folks who don't have it, you'll sound oddly muffled.

It seems as if Cobra and Radio Shack figured they were onto a way to set a new standard that everyone would want to have and would buy more of their radios to have it. Apparently not everyone took the bait.

I've got a few Cobras with it and a couple of Rat Shacks that have A.C.E. (I think it's "automatic compression & expansion") and they sound great, if I'm only talking amongst them, or with people who also have the feature enabled. Invariably, though, someone in a conversation won't have it on their radio, and the conversation will be difficult to manage. Lots of volume and mic gain diddling during a chat.

Otherwise your radio is nice, and is the equivalent of the '25s and '29s (except for the obvious lack of the useless SWR metering that the 29 has). The version of your radio that I have is a little older, and didn't have the RX Gain pot, which I miss.

By the way, if you don't want to get awakened by a weather alert, even when the radio is off, either disconnect the blue wire from the weather board, or leave the WX channel selector to Off.

The Aries is a decent dynamic mic, probably made by the same folks who make most of the other mics, possibly Merry. I actually like their coffin style, same as the ones on older Cobra mobiles.

Hope that helps,
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