No, the FDNY did not use digital on 9/11. At that time we were still using VHF fireground radios (Saber and MX series portables) and VHF dispatch channels. UHF came along in 2003 I believe and we tried digital on our fireground channels for a short time with terrible results and quickly went back to analog
The digital debacle began on 14 Mar 01. B/C John Joyce has his account, as well as photocopies of trouble reports from March, 2001 in the book Radio Silence F.D.N.Y. (ISBN: 0-9759021-3-X). Warning, Joyce gets into politics and goes tangential on procurement policy and mixes up 9/11 radio systems. By the time 9/11 came about, FDNY had gone from UHF digital back to what they had on VHF. A known quantity.
There can be a lot of s-house quarterbacking, but at the end of the day, the safe statement here is that nobody should ever assume that one kind of radio is just like another kind, even if they look the same. Common use of the FDNY included the use of pretty much 1 fireground channel (153.83) which relied heavily on the capture effect of FM. A closer transmitter would take out a more distant one. You would hear heterodyne with some of the traffic if the signals were roughly the same signal strength. They also used a technique called "feedback assisted rescue" (FAR) technique where they keyed their mic and members cranked up their volumes. As they got closer, there would be howling feedback. It worked good for them.
Digital radios cannot tolerate simultaneous transmissions. In fact, two digital transmissions are mutually destructive and you won't hear anything. The Queens mayday incident on 19 Mar 01 at Myrtle Ave, Richmond Hill may possibly be attributable to several simultaneous uses within the same area. The mayday transmission was NOT received on HIS fireground, but ANOTHER fireground using the same frequency 10 blocks away.
Joyce included a memo from B/C Jay Fischler to Chief of Operations Daniel Nigro dated 19 Mar 01 (same day as the above incident), which stated that echo sounds affected clear transmissions. These echos are the digital signal processing and vocoding/ demodulation of data. FAR cannot work in that environment. This means all of the training and user anticipation that this technique would work in a linear fashion was negated.
It's not unique to FDNY, though. While FDNY was simplex digital, thankfully the FF was rescued. Not so fortunate on another incident. On 16 Apr 07, Prince William County, VA experienced a communications-related LODD using digital trunked radio for fireground. Notice the digital radio "gollywobbles" (pixelated audio) at certain points, as well as echo.
http://blog.tcomeng.com/wp-content/...am_county-loddreportvideosection2-jan2008.wmv (WARNING! Graphic!)
http://blog.tcomeng.com/wp-content/uploads/2008/01/prince_william_county_fire_loddreport-jan2008.pdf
APX guy, you make a bold statement. Tell me why the APX6000 is better than an analog radio and why an AMBE vocoder is better than the human mind for dealing with environmental noise. I have an open mind, but when there are statements like that, they need the support of evidence.