JAGUAR PRO ONLY
J-INDEX (JIX) is an index value for measuring true MW reception conditions, kind of a "Nasdaq index for MW". Other common indices (such as A / K / solar flux and more) just describe sun-related geomagnetic characteristics but do not give a real MW reception index value. JIX is scaled from 1 to 100. By default, JIX is collected from the "overseas frequencies" based on the user's location. JAGUAR keeps track of signal levels on the first 100 MW frequencies (the overlapping NA/EU values are excluded) and creates the averaged value which is named as the J-INDEX.
JIX offers an excellent tool for finding interesting spots when checking the recorded files. In addition, JIX can be used for comparing antennas and even QTHs (however, the effect of using an external signal amplifier must be still taken into account when comparing signal levels in two different QTHs).
The current JIX values are being automatically calculated when the hardware is plugged in, and the value is shown on PLAYBAR. JAGUAR calculates and collects two separate JIX values: one for MW10 frequencies and second for MW9 frequencies. If the user changes the MW frequency stepping, the JIX shown changes accordingly.
The JIX values will be saved to the YAS LOG file at one-minute intervals. In the ARCHIVE mode, the JIX values are read from YAS LOG and shown as red curves ("JIX CURVE") on some displays. The exact JIX values on those displays are shown based on the mouse position in a red "JIX ball". These displays include the 12-hour and 24-hour YAS LOG displays and the extended views of the spectrum.
Additionally, JAGUAR collects JIXHISTORY.LOG with hourly values for the overseas JIX. This log is used on the CONDX display (more details in CONDX help) to compare classical solar index values (A / K / Kyoto / etc) with real trans-Atlantic reception results (JIX CURVE). Also JIXMAX.LOG is maintained for a quick lookup of daily maximum values. Note that CONDX display can show the JIX CURVE only on the original recording PC (JIXHISTORY.LOG is saved in the Jaguar installation folder so if you move the external HDD to another PC for playback, the JIX CURVE can't be shown on the CONDX display then).
In theory, the overseas JIX index could be used to automatically start recording when a user-defined threshold is exceeded. We have actually successfully tested that option. Then, all hot OUT-OF-TOH openings can be automatically recorded on MW or auto-recording can start when a user-defined frequency/frequency set opens well enough. However, today’s mega trend in MW DXing is to record everything overnight and use various analysis tools to pick up the results. JIX-based recording is simply not good enough: there may be situations when trans-Atlantic reception is poor, and automatic recording is not triggered. However, the few stations audible can be true rarities.
JIX is always collected automatically in the background.
When reviewing the JIX CURVE, you should look for the curve peaks (the sharper, the better !) - and even a small bump on the curve can indicate a good spot for DX. In addition, you should look for times when the JIX value is rising/falling rapidly. Experience has shown that those times often offer the most interesting reception periods (dominants may have not risen yet or may have already faded out - and the dial can be free for suprises). On a DXpedition we often monitor for these rapid changes as a trigger to be especially alerted.