403.025

[devicelab]

This is the default Motorola frequency when using Astro CPS or TRBO CPS. I'm sure it's also the default frequency for APX CPS too.

I was advised to give this frequency a listen and after several days of monitoring I actually got [DMR] audio traffic. Sadly it wasn't from anything federal.

I still haven't pinned down the exact source of my traffic but it appears to be a construction crew that interacts with a particular building crane. Traffic is very terse and barely lasts more than a few seconds so it took a while to understand what I was listening to.

Given the excess in profanity, I figured it was either construction or our local naval base.

 

[mancow]

I've always wondered about those defaults like that, same as 136.

 

[wmm1200]

Very interesting. Coincidentally, I also logged this frequency back in 2015 and 16, turned out to be a construction contractor crane operations at a local naval shipyard. I wondered if it was an image, Analog traffic though, 136.5.

 

[devicelab]

The crane traffic here has been isolated to a particular construction zone in downtown Seattle. I haven't confirmed myself but I've been told the construction company is using different color codes for various users and/or areas of the work zone. It's fairly busy M-F in the morning hours.