Stratomaster Knowledge Base - The five questions posted most recently:

Connecting your XCOM to your Enigma

Mon, 14 May 2007 18:55:53 GMT

Connecting your XCOM to your Enigma (5856 views)

XCOM Instructions:

You need to enable the serial interface on the XCOM radio if you are going to set Frequency from the Enigma, using the option XCOM/Enigma cable. You can do this executing the following steps:

1. Switch the unit off by holding the ON button for 3 secs
2. Hold down the DUAL and MODE buttons and press ON
3. The unit should start and show the software version (Note the version)
4. Press the F/CH knob until RHEAD is shown
5. Turn the F/CH knob clockwise and the display should show ON
6. Press the FLIP/FLOP (double arrow) button

Once this is done the serial interface will be enabled and you can set frequency to the XCOM from your Enigma.

Enigma Fuse / Circuit Breaker

Fri, 26 Jan 2007 00:51:45 GMT

Enigma Fuse / Circuit Breaker (6284 views)

The Enigma at full brightness at 12V uses just under 800mA.
SP-4 is 80mA with heater on.
SP-2 is 45mA.

A good choice for a fuse/circuit breaker would be 2.5A

Use a slow blow fuse. Circuit breakers are all slow blow.
Slow blow fuses are marked "S". You get medium and fast as well ("M" and "F").

Capacitance Fuel Level Probe that works with Stratomaster

Thu, 16 Nov 2006 18:15:22 GMT

Capacitance Fuel Level Probe that works with Stratomaster (6605 views)

All resistive fuel level probes work with all Stratomaster instruments.

If your installation requires a�capacitance-style probe that works with all
Stratomaster instruments:

Contact Centroid Products
Technical contact Joel
http://centroidproducts.com/

This sender puts out the required outputs for Stratomaster instruments:

Part number:
CGF-24A-12V-0/90-3" Bendable, sidewires, 5-hole, will cut

You can specify the length, or you can cut yourself

Radio Frequency Interference - General Wiring Guidelines

Tue, 14 Nov 2006 18:03:12 GMT

Radio Frequency Interference - General Wiring Guidelines (6371 views)

a) Keep the antenna cable away from any other wiring and ensure that the cable is not routed close to the display.
b) Do not mount the radio close to the display - some handheld models are poorly shielded as this is not normally a requirement for a hand held unit. If you place such a radio close to the display, the unavoidable EMI in front of the display may be received by the radios front end amplifier directly.
c) Ensure you radio and intercom wiring (power supply included) are not routed near the display.
d) Do not mount the�antenna close to the display unit.
e) It is often of great benefit to provide two sets of power supply systems. Power your radio and intercom separately with own power and ground wires back to the battery.
f) Be very careful with using any airframe parts as ground wiring. This is not a good idea as DC currents will cause galvanic corrosion, in addition to any and all AC components of your power supply (including RF) will now be coupled into the airframe making this a very nice antenna.
g) Keep the�instrument power supply wiring (12V and ground) plus the RDAC cable away from the radio and the antenna cable, by at least a few inches. The same applies for the ambient temperature probe.
h) Bundle up any excess RDAC cable at the RDAC close to the engine, not close to the display unit.
�
To find out if the power supply to the instrument it part of the problem, remove the wires (both + and ground) and supply the instrument�temporarily with a small 9V battery. Does this help? If yes, route a separate set of wires to the battery for the instrument.

Sharing Engine Senders

Mon, 13 Nov 2006 19:45:38 GMT

Sharing Engine Senders (6181 views)

NTC resistors, resistive fuel level gauges, resistive fuel and oil pressure senders all use ground as common return (that would be the engine block and your battery minus). In order to measure the resistance, you need to send an electrical current of known value through the resistor, which causes a voltage level to appear accross the sender you want to measure. This voltage is then measured and used to calculate the sender reading.

The trouble comes in if you have two gauges trying to send current through the resistor (and each gauge will use different current values to add to the confusion). The voltage will be higher (probably significantly) as the two currents add up. As a direct result, both gauges will read incorrectly.

EGT/CHT thermocouples are different since they actually create a small (very small) voltage dependent on temperature. You could connect a single EGT probe to two of our RDAC units without trouble, but add an old "analog" gauge and the gauge will load the probe to such an extent that your Stratomaster will see less voltage and thus under
read. The analog gauge loads the probe to extract the tiny amount of energy required to move the needle (the power for that has to come from somewhere).

RPM, fuel flow and similar switched DC or AC signals can most of the time be connected in parallel without too much trouble. For example, it is quite common to connect a rotax (aviasport) rev counter in parallel to our RDAC unit.