Attached is the response from Cecilia Henderson at Brittain Industries.
I understand the servo valve is difficult to come by, other pilots on the look-out have begun to refer to it as “the unicorn”. We are hopeful that this situation changes soon.
Okay, here is the thing. The Brittain turn coordinator, model TC100EVT, does in fact utilize the same valve technology as the servo control valve. Therefore, it can be used to install B-11 Accu-Trak and/or B-12 Accu-Flite in lieu of the servo control valve. This is NOT an STC’d installation of the product and to be installed legally in this manner would require an FAA Field Approval. This has been done in recent years on a few Mooney’s in different parts of the country (i.e. different FSDO’s).
Now as for the TC100EVT gyros. There are three generations of gyros primarily different cosmetically only. The P/N 2911 being offered at Hangarswap is a second generation TC100EVT. This means it has a pendulum inclinometer and no electric flag. The latest generation TC100EVT has a fluid ball inclinometer and an electric off flag. Otherwise, fit, form and function are the same. The unit you linked us to has a good valve for interconnect to the B-11/B-12 systems and the only unknown we can think of is a question of the rotor. It is possible the unit contains what my technicians call a “split rotor”. If this is true we would not be able to repair the unit. This is unknown until we open the case. So if we assume it DOES NOT have a split rotor, sight unseen and untested we estimate the cost to repair the unit to manufacturers specifications and convert it back to 14v around $750.00 (incidentally there is a small modification we make to the unit when we know it will be used as the servo valve for the B11/B12, we then nomenclature the gyro with an “NP” to indicate this modification has been made). So $750.00 plus the $250.00 core cost to Hangarswap puts you at $1000.00 for a second generation TC100EVT turn coordinator.
If you are serious about this course of installation we have on our shelf a third generation TC100EVT (fluid ball, electric off flag) in yellow tagged condition, already modified for use with the B11/B12, we would sell to you outright (no core) for $1540.00. If accepting delivery of an Accu-Trak and/or Accu-Flite system in addition to this gyro purchase we would give you a discounted price of $1232.00 on the gyro. This option makes the cost of the B-11 Accu-Trak $788.92 (new controller, new installation hardware and tubing, installation manuals, flight manuals and STC). The cost of the B-12 Accu-Flite system is $2583.02 (overhauled DG, Switch and Cable Assy., new DG Adaptor, new installation hardware and tubing, installation manuals, flight manuals and STC). We also have some example 337’s to share with your installer if needed in assistance of the field approval. The add-on pricing is good regardless of which TC100EVT you elect to purchase and all components are on the shelf except an overhauled DG which we can find or you can locate yourself, just let me know (knocks $900.00 off the price of the Accu-Flite making it $1683.02).