Helpful Tips

This Months Tips
  1. Fixing a jumpy needle
    A jumpy needle is a symptom of a problem not the actual problem. Because of the Sage Variometers very sensitive nature, the instrument responds to the slightest input. Several things can cause a Jumpy needle so you need to checkout a few things to find the problem first check the system for leaks do this carefully with the Sage removed from the system. Know where all your tubes go and be sure you have everything going to the correct place. Check the t.e. system with the t.e. probe in place and the small holes on the end taped over this will ensure that the seal on the end of the probe is doing itís job. Check the capacity line this should have no leak whatsoever. Check to see if you have a capacity type gust filter this will look like a small bottle with a line in and a line out, the plastic variety of these have been known to flex as they get bumped around and cause very erratic readings if you have one of these in place you might try it without this to see if it is your problem, if all these things are ok check to see if you have a restrictor in the t.e. line this is supplied with new variometers and should dampen the t.e. signal and reduce the jumpiness. You should chose a restrictor that reduces the jumpiness to just where you can stand it, the more restriction you put in the line the less sensitive your variometer will be to small inputs (small weak lift). Unfortunately it is impossible to test the system on the ground so I would recommend keeping notes on how the system is working from flight to flight so you can make improvements and keep track of your changes this may take several flights but the result will be well worth the effort to have a variometer system that works to your liking.

  2. Recommended Service interval
    I have been asked what the recommended service interval is for Sage Variometers, the truth of the mater is that there is no time period when the variometer must be returned for service. If I had to give a number I would say that every 20 years it would be a good idea to have it checked and re-calibrated. I expect the Variometers I am producing today to long outlive me.

  3. Returning for service
    It is important when returning for service that the instrument be properly protected to prevent further damage and documented to help speed the repair process.
    1. The instrument should have at least one inch of padding on all sides two inches is recommended it can be placed directly into foam peanuts if it is packed tightly to prevent settling DO NOT PLACE IN A PLASTIC BAG.
    2. Include a return address, name, phone number, email and the problem with the instrument. This is important to help speed the repair. (pdf form to print & fill out)
    3. The average price for most service is around $400 plus shipping and handling.
    4. Ship or Mail to SAGE Variometers, 2668 Husted Road, Williams, CA 95987 USA
    5. Please be sure to indicate "Civil Aircraft Parts returned for Repair" on any shipping documents to avoid unnecessary customs fees.

  4. Switching from static to TE on motorgliders

    Many motor glider pilots switch their varios from TE input to static input for powered flight to get the signal going to the vario out of the propwash. I am often asked if the large change in pressure during switching will affect the Sage Variometer. The testing I have done switching from TE to static at speeds from 40 knots to 100 knots shows that the Sage Variometers can take this switching with no adverse affects, there will be a large jump of the needle but the instrument remains undamaged and I do not see any reason why this would hurt the instrument in the long run as long as the maximum reading does not exceed approximately 1.5 times the maximum range of the instrument

  5. Recalibrating the netto of a total energy box

    You can change the netto of a schuemann total energy box by replacing the capillary tube, this is the very small tube in the only tube on the outside of the box that makes a loop coming out of the box and going back in. If you are moving to a lower sink rate glider you will need to replace this tiny tube with a longer one or more correctly one with more restriction. The capillary in the box is most likely a .015 ID. Teflon tube there is no set length you may need to start with 18 inches and carefully cut off an inch at a time to reach the correct length the cutting should be done with a new razor blade being careful not to collapse the end of the tube.


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