On Thursday, January 23, 2020 at 6:00:12 AM UTC-5, wrote:
Hello Guys. I am restoring another 1-26 and have a spare older 302 I would like to use. Have any of you used that vario without the external TE probe, setting it to the internal compensation mode? The manual for it does’nt recommend it but I would like to save the bother and drag associated with installing an external probe.

I use a 302 with external TE in my other machine and it works great but have never experimented with the internal compensation setting. Any shared experience comments sure welcomed.

There was a Johnson report, "DEVELOPMENT OF A TOTAL ENERGY SYSTEM FOR THE PW-5 SAILPLANE By Richard H. Johnson, Published in Soaring Magazine, April 1998" which describes a simple fuselage-mounted short TE probe that worked well. It includes instructions for building your own probe. It should be in the SOARING archive.