Advanced Taper's Guide | | -----Equipment------ |
Test Modes
Error Rate Counters
Dropouts
Channel Loss
1/2 Size Heads
Tapes

### What are error rate counters for ?

They are designed to give the technician and user a relative gauge of the condition of the machine or of a tape. In order to check the performance of the DAT machine, you must have a reference tape. It may be purchased from the DAT manufacturer or you can make a test tape yourself. To do this make a tape on your machine when brand new or after a complete mechanical and electrical alignment by an expert technician with years of DAT experience. Label this tape as a reference and don't play it except to check your machine. You should also note on the tape the error rates you see upon playback of the tape. This "base error rate" is your guide. You can compare this to any readings you get later to determine the overall condition of the transport. When the error rates climb to over 100, the heads need to be cleaned. If cleaning does not help, you should schedule a trip to the repair shop ! The same error rate readings can be used to tell the condition of a tape as well. When playing the tape you should see error rates comparable to your reference tape (within 50 of your reference). The Panasonic Pro Machines offer the best error rate counters. They display the actual Block Error Rate. The Tascam units, for example, have "error rate counters" that are not very useful (the DAP-1 excepted). You will note that Tascam does not mention or support these "features". These machines require an external error rate counter or an oscilloscope to detect errors accurately. Error rates under 300 are completely corrected. There is NO DIFFERENCE between the data transmitted to the D/A convertor or the digital output for a tape that plays back with error rates of 0000 or 0300. Above 300 error interpolation begins and the machine reconstructs data that may or may not be correct. We have seen Panasonic DAT machines play back tapes with error rates as high as 5000 without dropouts, but with a noticeable loss of fine ambient detail. Quite remarkable, now that's error interpolation !