AirTalk.org Aviation discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Finding TE "membrane" style compensators?          AirTalk.org Forum Index -> Sailplanes View previous topic :: View next topic   Author Message Paul Adriance Guest Posted: Wed Jun 22, 2005 5:01 pm    Post subject: Finding TE "membrane" style compensators? I have a Winter combination Airspeed/Vario/Speed-To-Fly instrument that was designed to use a TE compensator between the capacity line & the pitot line. My assumption is this was a standard type of device prior to the common use of TE probes. Talking to some experienced members of my club confirmed this and they described it as an inline filter that had a membrane that would compensate for changes in pitot pressure to the capacity flask. Unfortunately, one of the previous owners of my glider misplaced or lost the compensator and now that I'm redoing the plumbing, I want to have it installed correctly per the manufacturer's suggestion. Does anyone have these or make these anymore? A google search didn't turn up much, and I don't see anything like this on Wings&Wheels or the other common soaring product sites. Any help would be appreciated, Thanks! Paul Adriance Back to top aarnaes Guest Posted: Wed Jun 22, 2005 5:41 pm    Post subject: Re: Finding TE "membrane" style compensators? I've got such a compensator you can have for the price of shipping. It is made by PZL, I think, (it has a label with "Rainco" on it) and worked fine when removed from my ship 3 years ago. --- Jens Back to top Bob Korves Guest Posted: Thu Jun 23, 2005 12:05 am    Post subject: Re: Finding TE "membrane" style compensators? "Paul Adriance" <padriance (AT) mindspring (DOT) com> wrote in news:YPgue.7516$hK3.5043 (AT) newsread3 (DOT) news.pas.earthlink.net: Quote: I have a Winter combination Airspeed/Vario/Speed-To-Fly instrument that was designed to use a TE compensator between the capacity line & the pitot line. My assumption is this was a standard type of device prior to the common use of TE probes. Talking to some experienced members of my club confirmed this and they described it as an inline filter that had a membrane that would compensate for changes in pitot pressure to the capacity flask. Unfortunately, one of the previous owners of my glider misplaced or lost the compensator and now that I'm redoing the plumbing, I want to have it installed correctly per the manufacturer's suggestion. Does anyone have these or make these anymore? A google search didn't turn up much, and I don't see anything like this on Wings&Wheels or the other common soaring product sites. Any help would be appreciated, Thanks! Paul Adriance Paul, It sounds like you have a Winter Sohlfahrtgeber. I once had one in a Pik- 20d. It is possible to hook it up with very good results without the diaphragm compensator. IIRC, it will have 3 tubing connections on the back. There is only one static connection for both halves (ASI and vario) of the instrument. Hook up the total energy probe to the port marked "static" (this is actually marked in German, something like "stat. druck"). Hook the port marked "pitot" to the gliders' variometer static system. Hook the capacity up to the port marked something like ".6 liter". It sounds strange, but it works. If you hook it up like it says on the case then the ASI will read too high -- you will have pitot at +1 and TE at -1 for a difference of 2. The ASI needs a. value of 1. So, instead you use static at 0 on the pitot side and TE at -1 on the static side, giving a difference of 1. This also gives you a back up ASI that does not rely on pitot. It also gives you a check of your TE system. If both ASI's agree at all speeds then your TE is correct (neglecting port position errors and instrument calibration issues). There is a knob on the front to set the Macready by rotating the ASI in the case. Then merely match the needles for (theoretically) correct speed to fly. Note that these instruments are mfg'd to match a certain polar. The one I used in my Pik was originally for a H-401 Kestrel, which worked pretty well. If you have one made for a Glasflugel 604 and you are installing it in a K-7, then you are going to have big problems. Mine had a label stating the glider it was calibrated for. The Sohlfahrtgeber was much more usable than the old Cambridge Mark IV with electronic speed to fly in the same glider, especially at high speeds. In fact, it was the easiest and most reliable speed to fly I have used. Many speed to fly units go wild at high speeds and become useless. I would recommend not using the diaphragm compensator with this vario. As another poster pointed out, the diaphragms get stiff (and/or perforated) with age. Sorry for the long post! -Bob Korves 5H Duo Discus 5K Lak-17A Back to top Paul Adriance Guest Posted: Thu Jun 23, 2005 6:56 am    Post subject: Re: Finding TE "membrane" style compensators? Wow, you all provided excellent information, thank you! I think I will follow Bob's advice as my goal is a nicely working instrument and not historical accuracy. The aircraft in question is 201B Libelle and I believe the instrument was factory installed or at least purchased with the Libelle polar in mind. The last thing I need is a diaphram blowout that would affect both airspeed indicators. The funny thing is that it appears it was plumbed to Bob's recommendations prior to refitting the panel. I assumed that someone made a mistake hooking things up after translating the labels on the back. Happy Soaring! Paul "Bob Korves" <bkorves@winfirstDECIMALcom> wrote Quote: "Paul Adriance" <padriance (AT) mindspring (DOT) com> wrote in news:YPgue.7516$hK3.5043 (AT) newsread3 (DOT) news.pas.earthlink.net: I have a Winter combination Airspeed/Vario/Speed-To-Fly instrument that was designed to use a TE compensator between the capacity line & the pitot line. My assumption is this was a standard type of device prior to the common use of TE probes. Talking to some experienced members of my club confirmed this and they described it as an inline filter that had a membrane that would compensate for changes in pitot pressure to the capacity flask. Unfortunately, one of the previous owners of my glider misplaced or lost the compensator and now that I'm redoing the plumbing, I want to have it installed correctly per the manufacturer's suggestion. Does anyone have these or make these anymore? A google search didn't turn up much, and I don't see anything like this on Wings&Wheels or the other common soaring product sites. Any help would be appreciated, Thanks! Paul Adriance Paul, It sounds like you have a Winter Sohlfahrtgeber. I once had one in a Pik- 20d. It is possible to hook it up with very good results without the diaphragm compensator. IIRC, it will have 3 tubing connections on the back. There is only one static connection for both halves (ASI and vario) of the instrument. Hook up the total energy probe to the port marked "static" (this is actually marked in German, something like "stat. druck"). Hook the port marked "pitot" to the gliders' variometer static system. Hook the capacity up to the port marked something like ".6 liter". It sounds strange, but it works. If you hook it up like it says on the case then the ASI will read too high -- you will have pitot at +1 and TE at -1 for a difference of 2. The ASI needs a. value of 1. So, instead you use static at 0 on the pitot side and TE at -1 on the static side, giving a difference of 1. This also gives you a back up ASI that does not rely on pitot. It also gives you a check of your TE system. If both ASI's agree at all speeds then your TE is correct (neglecting port position errors and instrument calibration issues). There is a knob on the front to set the Macready by rotating the ASI in the case. Then merely match the needles for (theoretically) correct speed to fly. Note that these instruments are mfg'd to match a certain polar. The one I used in my Pik was originally for a H-401 Kestrel, which worked pretty well. If you have one made for a Glasflugel 604 and you are installing it in a K-7, then you are going to have big problems. Mine had a label stating the glider it was calibrated for. The Sohlfahrtgeber was much more usable than the old Cambridge Mark IV with electronic speed to fly in the same glider, especially at high speeds. In fact, it was the easiest and most reliable speed to fly I have used. Many speed to fly units go wild at high speeds and become useless. I would recommend not using the diaphragm compensator with this vario. As another poster pointed out, the diaphragms get stiff (and/or perforated) with age. Sorry for the long post! -Bob Korves 5H Duo Discus 5K Lak-17A Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AirTalk.org Forum Index -> Sailplanes All times are GMT Page 1 of 1   Jump to: Select a forum Aviation----------------alt.aviationAviation safety EnhancementPlanes, gliders and flying in AustraliaAviation et pilotage (Français)rec.aviationAviation (Aerobatics)Hot air, gas balloons and airshipsHang-gliding, paragliding, foot-launched flightAircraft Design & BuildingInstrument Flight RulesAviation (Classifieds)Military AircraftNaval AviationAviation (Miscellaneous Topics)Owning AirplanesAviators (General Discussions)Aviation related productsAircraft RestorationHelicopters and rotary wing aircraftsFlight SimulationSailplanesAviation (Students)Light aircraftFlying related activities in the UK Airports----------------alt.airportsEdinburgh Airport Glasgow Airport Humberside Airport Luton Airport Aberdeen Airport Glasgow Prestwick Airport  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.