SIGNET WINDPOINT

MK 24

The Signet MK 24 Windpoint is a very reliable wind direction indicator., both for racing and cruising boats. It is the product of several years of develop ment by marine instrument specialists and is designe ''''~Rd and built for effective and efficient service. It is designed for use with the MK 23 "0 Adjust" Close Hauled Indicator.

UNPACKING INSTRUCTIONS

Because the Windpoint is a precision electronic instrument, care should be taken in unpacking it. You will find the following items:

INSTALLATION

Meter Unit Installation

After selection of the meter location, proceed as follows
Note that windpoint operation can affect a closely mounted compass.

1.     Cut a 4-5/8 inch diameter hole in the bulkhead.

2.     Remove the clamp ring. Install the three screws.

3.     Install the indicator with a non-hardening bedding compound or sealant around the rear of the bezel.

4.     Install the clamp ring on the case from the rear as shown in rig. 1. With the meter indicator flange against the bulkhead,, position the clamp close to the rear of the bulkhead. Tighten the clamp securely. Turn the three bracket screws clockwise against the bulkhead until the indicator flange is seated on the bulkhead. Do not overtighten; this will cause the clamp to slip.

5.     Connect the power (Requires 12 VDC @ 0.1 AMP) and other cables except the cable to the masthead as shown in Fig. 2, 3. or 4. The Figure used depends on complexity of your system. If you are using a Windpoint Repeater as shown in Fig. 3 or a Close Hauled Repeater as shown in Fig. 4., the required Repeater Cable should be included with the repeater. Extension cables can be obtained through your local dealer.

     As an initial check., plug the masthead unit directly into the indicator and check for proper operation as the masthead sensor is rotated.


6.     It is recommended that the lights be connected to a 12 volt source through a switch or dimmer. Uses 2 each 161R Bulb., total current drain 0.4 AMPS at 12 VDC.

Masthead Unit Installation

1.     Select a location on the top of the mast that will permit the staff to point aft as shown in Fig. 7. Masthead can be mounted pointing forward, however it is then not visable from the helm and is more subject to sail damage,

2.     Locate the holes to be drilled using the mounting base as a template.

3.     Drill two 0.20 inch diameter holes with a #7 drill and thread with a 1/4-20 tap.

4.     Install the mounting base (Fig. 7) using the two 1/4-20 bolts.

5.     Remove the 10-32 lock nut and bolt (Fig. 7) that goes through the mounting base and staff. Pivot the staff in the base to the set of holes that brings the vane nearest to level. Replace the 10-32 bolt and lock nut, and tighten.

6.     Turn the upper unit dust shield shown in Fig. 5 until the M24 notch matches the white line on the staff.

7.     Holding the dust shield in places mount the vane pointing forward. Tighten the two set screws with an Allen-head wrench.

8.     Run the cable from the masthead unit to the indicator or repeater cable. Make sure the cable end with the pair of wires with the 4 pin male connector is at the indicator. This lead connects to the Windspeed meter when used.

9.     Connect the-cable connector to the masthead unit. Tape or tie the cable to the staff or mast below the connector to prevent strain on the connector.

10.     Connect the other end of the cable to the indicator.

11.     For ease in removing the mast, a function box, Signet MK20.91,, can be installed in the cable at the base of the mast.

CARE AND MAINTENANCE

We have intentionally constructed the Signet Windpoint for trouble-free operation. It is very important not to dismantle your Windpoint meter unit. If a question should arise, your inquiry will be answered promptly by technicians at Signet or your local dealer.

CALIBRATION AND ADJUSTMENT

1.    Turn on power to the instrument.

2.    Turn the upper unit dust shield until the MK 24 notch matches the white line on the staff. Note that the other notches represent 300 increments.

3.    Turn the adjustment screw on the back of the indicator until the needle points to zero degrees (Fig. 2). If you have a Windpoint Repeater, also adjust the repeater until the needle points to zero degrees.

4.    Your Signet Windpoint is now ready to use.

5.    Unplug the mast cable at the indicator and record the reading on the Windpoint and MK 23 Close Hauled as a fixture reference of correct operation. Readings should be between 100 port and 400 starboard from the internal masthead simulator,

TROUBLE SHOOTING

Indicator Check

The indicator has a built-in masthead signal which, with the masthead unplugged, forces a reading on both the Windpoint and MK 23 Close Hauled of between 100 port and 400 starboard. It is recommended that these readings be checked and recorded after initial installation and alignment as a future reference on indicator correct operation.

The indicator may be checked with or without a mast head unit. Rotate the masthead through the various positions and note the response of the indicator. Indicator positions should be the same as the vane positions. Incorrect readings can indicate an open lead/s or bad amplifier sections in the indicator. If an amplifier or lead is bad, refer to the windpoint schematic and trace the problem, using the vane as a convenient source of 0 to 6.8 volts to the amplifier sections. The voltage on the coil leads should be the same as the input voltage with Pin 5 to #8 on coil, Pin 6 to #9 on coil, and Pin 7 to #10 on coil.

Masthead and Cable

If you cut the cable from the Windpoint Indicator to the mast unit to remove the mast and/or are having instrument readout problems, it is important you make a resistance check of the cable and masthead assembly after reconnecting the wires. Unplug the cable from the Windpoint Indicator or Repeater cable, if you have one. The indicator readings should be as recorded previously. With an ohmmeter, check across the cable connector pins for the following readings.

1.    Pin 1 to Pin 2 - 1250 ohms.

2.    Pin 1 to Pin 5 with the vane pointing 30 port -less than 50 ohms (with MK 20 slot aligned with line on staff).

3.    Pin 2 to Pin 5 with the vane 150 starboard - less than 50 ohms.

Note that readings in 2 & 3 above are a function of vane position and assume a correctly aligned vane and dust cover. Misalignment will move the minimum resistance points.

4.    Pin 5 to Pin 6 - 1111 ohms.

5. Pin 5 to Pin 7 - 1111 ohms.

6.    Pin 6 to Pin 7 - 1111 ohms.

If you have a Signet Windspeed:

    Pin 3 to Pin 4 - 4000 ohms.

The resistance readings may vary as much as 15% and your Windpoint will still operate properly. If you can determine a problem does exist, the masthead unit can be checked at its connector using the same set of resistance values shorn above,

Resistance measurements will vary some, depending on accuracy of the meter used and the masthead assembly. If one section of the masthead potentiometer is open the resistance values will increase., showing, for example:

        from 1 to 2     2500 ohms
        from 7 to 5     1660 ohms
        from 6 to 5     1660 ohms
        from 6 to 7     3300 ohms

which indicates that the potentiometer section between 6 and 7 is open.

An open wire to the masthead unit will show up as a high resistance, greater than 15,000 ohms on measurements using that wire.

Page 8 is a schematic of the indicator and masthead unit. The windpoint indicator is a DC servo where the wind vane position determines the masthead potentiometer slider position. The three taps on the potentiometer provide three voltages with a direct relation to vane position. These three voltages are current amplified in the indicator (there is no voltage amplification) and used to drive the indicator 3 coil meter assembly.

Masthead - Indicator Voltage Checks

With both the masthead unit and indicator plugged in and with 12 volts to the indicator, you can check the signals to and from the masthead unit at a mast base junction box.

Use Pin 2 (orn) as the (-) reference and a 10 to 15 volt voltmeter, the voltage readings should be

         to Pin 1 (Blk) 6.8 volts + - 10% independent of vane

         to Pin 5 (Red) 6,8 volts, vane at 30 port forward to 0 volts at 150 port

         to Pin 6 (White) 6.8 volts at 90 starboard, 0 volts at 900 port

         to Pin 7 (Green) 6.8 volts at 150 port, 0 volts at 30 starboard

Incorrect voltages can indicate a problem in either the indicator or masthead unit. Disconnect the masthead unit and recheck the voltages

         to Pin 1 (Blk) 6.8 volts

         to Pins 5, 6, or 7 about 3 1/2 volts

         0 or 7 volts indicates a possible amplifier failure.

Oil Leakage from Masthead

Storage or shipment of the masthead on its side or upside down may allow oil seepage from the damping assembly. The oil seepage will not bother the operation if it is cleaned off the outside and does not collect between the staff and dust shield. The damping assembly prevents fluttering in very light winds.