How exactly does the scanner scan? (Do we hear everything?)

[EivlEvo]

Alright folks. Here's the deal. I flew through RDU's airspace yesterday 10/15/2006 I picked up RDU approach on flight following at approximately 1815zulu. However, I've downloaded the appropriate clips (1800-1830, and 1830-1900 GMT (zulu)) and cannot hear myself come through. All radio calls are identifiable and the two controllers working both of the frequencies I was on are present and accounted for. I also checked the particular frequencies listed and I utilized two of them.

So my question is, I know that scanners scan. So if someone speaks up on one frequency, it will stop and listen to that freq until the person stops talking and then continue to scan. Is this the reason that my radio calls don't come through? The reason Im confused is that I figured since their is only one controller on the frquency and I definitely talked to him should I not be able to at least hear his transmission? If per se he heard me on freq A and someone else was talking on freq B?

Any help on this?

~DAVE

[RayZor]

I too have had problems with the RDU archive; the five times I've tried finding audio of myself, I was not successful. 

To answer your question:  I think you were on the right track.  The RDU feed covers four frequencies; 132.35, 125.3, 124.8, and 128.3.  The feeder I believe prioritizes the feeds, so that if there are simultaneous transmissions, the one with higher priority is heard.  I am assuming that whenever you were speaking, there was someone on a different, higher priority frequency speaking over you.  The bulk of traffic out of RDU is to the north.  Thus the northern frequency probably takes priority.  It is also possible that some of the freqs. for the RDU feed are wrong; only the first two freqs. listed on this site are actually used as approach, so it's possible the feeder made a mistake with listing, but I don't know. 

[EivlEvo]

Rayzor, thats exactly what i was thinking. The only thing that detracts me from that thesis is that I talked directly to both of the controllers heard on the feed. I assume they had one working north (the female) and one working the south (male). I passed to the west side of the airspace from south to north and was with them for awhile talking to each controller a couple times.

Anyways... this being the case, is this based on the way the feeder has the site setup? Or will every scanner/feed operate this way?

The thing that sucks is that I was flying from KLBT to KCBE and dealt with Potomac approach which I believe has the frequency covered on the Charlottesville feed. But I was hoping to use the time that I was handed off from RDU to Washington Center to narrow down the time I would've been through their airspace. Oh well... you win some and you lose some.

But if anyone has info on if its just the way the feeder is setup lemme know.

~DAVE