FLYING THE BORGELT B-10

INSTALLATION:

  1. Bolt the main instrument and the round meter into standard instrument holes in the panel.
  2. Mount the flask supplied in a convenient position. Install the flask as close to the B-10 as possible and connect the tube from the flask to the marked connection on the B-10.
  3. Using the T-pieces supplied, cut the pitot and static lines near the back of the ASI, insert the T-pieces and connect the pitot and static connections on the B-10 in parallel with the ASI. A petrol filter should be fitted between the T-piece and the B-10 pitot connection to prevent the entry of dust and dirt into the B-10.
  4. If connecting another vario and flask to the total energy probe, split the total energy line for the B-10 and the other instrument as close to the T.E. probe as possible. This minimises interaction between the two vario systems and optimises the B-10 performance.
  5. ELECTRICAL CONNECTIONS:
    DO NOT REVERSE POLARITY OF POWER SUPPLY AS INSTRUMENT WILL BE DAMAGED AND WARRANTY VOIDED.
    The electrical connections are marked on the rear of the instrument. A 250 mA fuse should be used in the positive supply line to the B-10 The mode switch can be mounted in any convenient position. In flapped gliders the flap handle is ideal, in standard class the trim lever or the left side of the cockpit or the control column. A micro-switch in the flap circuit actuated by flap movement can also be used. Switch closed puts the B-10 in climb mode, switch open, cruise mode.
  6. Before applying power, DOUBLE CHECK battery polarity and connections.
  7. Installation is now complete.
  8. If as a result of test flying you feel your B-10 is not performing properly, please contact me for advice.
  9. Extremely effective radio interference protection is built into the B-10 and no difficulties should be experienced. However it is good practice not to run the antenna coax and power leads in close proximity for any great length.
    A separate power lead to the battery is not required for the B-10.
  10. All aircraft instruments contain glues, paints and plastics. Their life may be extended by not subjecting them to extreme heat. It is good practice to use a canopy cover if the glider sits in the sun before or after flying and also to insulate under the black anti-reflection cover of most instrument panels. 6 to 10mm of styrofoam covered with aluminised mylar or aluminium foil works well. Make sure the foil doesn't short any electrical connections. If any difficulty or uncertainty is experienced in installation, I will be happy to advise.

B-10 ELECTRICAL ZERO INSTRUCTIONS

The sensor clrcuitry in the B-10 uses highly stable components and the zero stability of vario and speed sensors is carefully adjusted before delivery. However, components do change characteristics with age and it may be necessary to re-zero the B-10 at some time. This is not a daily or weekly task and should not be undertaken more frequently than every six months.

You may return your B-10 to the manufacturer for this or follow these instructions:

Four screwdriver adjustable trimpots are visible on the rear of the B-10.

REAR CONNECTIONS B-10
Rear Connections B-10

As shown the left hand two apply to the vario sensor (climb mode) and the right hand two to the speed sensor.

  1. For small i.e. less than 0.3Kt zero errors
    1. Instrument in CLIMB mode
    2. Zero round meter with vario zero trimpot
    3. CRUISE mode
    4. Zero round meter with speed zero trimpot.
    CLIMB mode MUST be zeroed BEFORE CRUISE mode. Block Pitot, Static and total energy ports while this check is carried out.
  2. Larger zero errors are corrected the same way, but the zero point may then vary slightly with temperature.

If this is the case carry out the procedure in the cool early morning and then at noon when the temperature has risen considerably do the following:

With all Pitot, Static and Total Energy ports blocked,

  1. CLIMB mode
  2. Note zero of round meter (e.g. ˝Kt up)
  3. Using the vario temp. coeff. trimpot adjust the reading to be an equal amount the other side of zero. In the example ˝Kt down.
  4. Re-zero with vario zero trimpot
  5. Repeat with instrument in cruise mode using the speed temp. coeff. trimpot and speed zero trimpot. Note carefully the locations of these trimpots.

If in any doubt about your ability to perform this maintenance contact the manufacturer and/or consider returning it to him for this procedure to the above address.

PRE-FLIGHT CHECKOUT OF B-10

  1. Turn power on and allow a minute or two for warm up.
  2. With mode switch to CLIMB both meters should read zero plus or minus 0.3Kt. If the aircraft has just been brought from a hangar into direct sunshine or has been sitting with canopy closed in direct sunlight, wait a while until temperature equilibrium is reached and/or block the total energy probe before carrying out this test as under conditions of rapid temperature change, a transient zero error may be induced. This error is of no importance while airborne. For small errors the vario may be zeroed with the mechanical zero knob on the front of the round instrument. In the event of a persistent zero error in excess of 0.3Kt refer to electrical zero trim instructions.
    Rotate THR (threshold) knob fully anticlockwise. A high pitched tone should be heard. This is the sink tone. It will decrease in pitch as the THR knob is rotated clockwise until at approximately the mid point of its rotation it becomes chopped and increases in pitch again. This is the climb sound. Normally the threshold is set so that on the ground the chopped tone is just about to cut in.
  3. With mode switch to CRUISE the round meter should again read zero plus or minus 0.3Kt and the vertical meter 2 to 4Kt down with the MacCready knob on zero (Depends on aircraft for which the B-10 has been calibrated). As the MacCready knob is turned to higher settings the needle on the vertical meter will move further down. Clicks will be heard. If a zero error of greater than about 0.3Kt persists refer to electrical zero trim instructions.
  4. The B-10 is now ready for flight.

FLYING WITH THE B-10 VARIOMETER SYSTEM

With the mode switch in CLIMB position the round meter is a gust filtered total energy vario and the vertical meter a 30 second averager. The scale of the averager is either 4Kt or 8Kt full scale selectable by the 4/8 switch. The averager shows the achieved climb rate over the last one to two circles and is a good guide as to when the thermal is weakening. It is also useful in making you work harder i.e. I got 3Kt average that circle, I will try for 3˝ or 4Kt in this one.

The round meter provides a clear scale and the gust filter provides a smooth but fast response enabling rapid interpretation of the vario with minimum fatigue. You are not mentally filtering out the rapid, short time period rubbish which tells you nothing.

The l0Kt scale handles both weak and strong thermals adequately and eliminates the possibility for error present when a scale changing switch is used.

The audio chopped tone for climb is pleasant to listen to and has a wide dynamic range. Half knot changes in climb can be heard. The audio goes over-range to about 14Kt so that extremely strong thermals may be centered even with the vario needle pegged. In CRUISE mode the round meter becomes a netto or airmass variometer showing you what the air you are flying through is doing. You can immediately see the effect of small course changes without the changing air being masked by sailplane sink rate changes. It is particularly useful when working blue thermal or cloud streets. The same gust filtering applies as in climb mode.

The vertical meter is a speed director with alternating tones indicating fly slower, and clicks to fly faster. There is an audio dead band which increases in width with airspeed.

The change from CLIMB to CRUISE and back again occurs instantaneously with the throwing of the mode switch, so don't feel inhibited about using the switch to get the instrument to give you the most useful information when you need it

You will find that you rapidly condition yourself to use the mode switch on entering and leaving thermals and you will appreciate the uncompromised vario and audio when in climb mode particularly when struggling at 600ft in plus or minus ˝Kt while drifting downwind at 20Kt and keeping an eye on your chosen paddock.

BORGELT INSTRUMENTS
P.O. BOX 379
GAWLER 5118
SOUTH AUSTRALIA
PH (085) 22 6533

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