[fmj]

I honestly can't remember if it showed up in the strobe or not, this was a few years ago. This procedure wouldn't be listed in the regular manual. It involves opening it up to adjust an internal potentiometer, and can't be reliably done without a frequency counter (I guess you could do it through trial and error, but it would take forever having to reassemble it and play a test disc after every adjustment,) so it is only in the service manual. You should be able to find a scan pretty easily though. Can't remember what frequency you need to hit, but it's low. If you don't have a proper frequency counter an Arduino will work just fine.