Fabled listing Here is that promised listing from J.Keneally of Exeter. The utility checks the health of your tape drive not for azimuth but for defects in the mechanics. It works by recording a fixed-frequency test tape, then replaying it to measure fluctuations in frequency every 0.1 of a second. These are plotted on a graph as speed variations over + 5% of the average. Several things can be deduced from the graph. If there is a general trend downwards with time, it indicates a tight wind-off spool. Occasional sharp peaks would point to 'snatching' of the spool. A regular variation indicates a fault related to rotation of a part of the. mechanism - the frequency of this will give a clue to which part. At the end of the test you will get a read-out of the maximum and mi nimum variation. For a good drive these should be within ±1%. Anything over ±3% suggests a problem. The most common of these is the pinchwheel. The program gives you two more graphs to help in diagnosing this. The first shows a filtered version of the original graph, making it easier to see any regular changes. If you can line up the pinchwheel grid with regular peaks (use Shift and the cursor keys for faster motion) it indicates slippage each time the pinchwheel rotates. This can be taken further by pressing E to take you onto a frequency spectrum plot of the section around the grid. AA#16 |