Practically speaking, there were two issues that the Winlink 2000 owners tried to address:
1) Have a workable sound card mode. SCAMP = Sound Card Amateur Messaging Protocol) 2) Have busy detection built in. There was no time as a beta tester that I did not have the busy signal detection. The two came hand in hand. The performance was excellent in detecting any kind of emission in the passband, including a computer carrier or any other constant carrier of this type. So you need to keep your own operating location clean as possible. It was also adjustable for the amount of signal it would not transmit over. The performance for ARQ data transfer was also excellent with good signals. It worked in a similar manner to what the HF DV operators require for adequate signal. This means that it needed a fall back mode as well and they did not plan for that, even though some of us pointed out that the RDFT protocol did not operate much below 10 dB S/N. The programmer was convinced that he could get it to work down to zero dB, but it just was not possible due to the limitations of the protocol. 73, Rick, KV9U Rud Merriam wrote: > SCAMP and busy detection are two entirely different pieces of software and > capability. > > SCAMP took the RDFT image transfer protocol and added pieces to it for file > transfer and ARQ. > > Busy detection was a totally separate activity in parallel with SCAMP. > > Just trying to keep the confusion and subsequent misinformation to a > minimum. > >
