Wolftrap - 417.975

[W4BOZ]

I've had this freq in my scanner for a while and have never heard anything on it. It also shows up in my old Washington-Baltimore Scanner Almanac as the frequency for portables for Wolftrap.

I'm not too far from Wolftrap (Vienna) at the moment and for the past few days I've been hearing what sounds like 9600bps trunking stuff popping up on 417.975 but it's really weak. I've never really heard any Wolftrap operations on this freq because I'm probably too far away and they're on simplex. Anybody have any idea on what could be going on here?

edit: Here's a soundclip. Is this encryption?
http://media.putfile.com/417975

 

[dtscho]

Sounds like P25 audio, but not a control channel. It's probably just interference, but maybe Wolf Trap has switched to P25 on that channel.

I have 417.9750 as a repeater output for rangers at Wolf Trap. 411.7750 was the input. But this was from a few years ago. I would wait until there's an event there, and then park as close as possible and do some searching.

Also, Wolf Trap has four UHF business band simplex frequencies licensed. 461.4250 [ d712] was found to be in use by volunteers. The other three (464.8000, 466.4250, 469.8000) were not heard.

Dave

 

[freqhopping]

I get a lot of interference on a lot of bands in the Tysons Corner area. I think a lot of has to do with being close to the govt transmitter there. The 008-0101 380mhz TRS transmits from there and as best as I can tell so does the A73B 400mhz TRS too (solid signal even without an antenna).

 

[W4BOZ]

Yeah, I was thinking it was interference from some TRS as well.

However, the area I'm located in is an RF hole especially for UHF signals and I've never had any intermod/interference problems, even with my VX-5 ham rig that needs to have a dummy load for an antenna to not hear everything within the electromagnetic spectrum.

I dunno, I guess I'll have to go sit over by Wolftrap and see what's going on. The park is closer to me than Tysons.