Mechanical Vibrations; Position Of The Receiver - Technogym Rotex XT Service Maintenance Manual

ROTEX XT: Service & Maintenance Manual - rev. 1.0
• presence of electromagnetic fields which interfere with reception or saturate the receiver;
• problems due to interaction between the receiver on one machine and the signal transmitted by a
user training on another machine that is too close and cannot be moved farther away.
Sensitivity is reduced by soldering a resistor in parallel with the coil. Normally, the receiver already
has a 15 KOhm resistor mounted in series with the coil, however it is advisable to check for its
presence.
The following table shows the nominal values of reception distance based on the value of the resistor
soldered on the coil:
Please note that these are only nominal values. The actual reduction in sensitivity must be verified
experimentally, taking great care not to excessively reduce the reception distance.
OBSERVE: if there is already a 15 KOhm resistor mounted in parallel with the coil,
note that adding another resistor in parallel will produce a total resistance value
equivalent to the parallel combination of the added resistor and the existing 15 KOhm
resistor.
11.1.4. M
ECHANICAL VIBRATIONS
Mechanical vibrations may cause slight shifting of the coil, giving rise to transient pulses. If these
transients occur only occasionally they can be easily filtered by SW. However, if the mechanical
vibrations are periodic, they can produce periodic pulses which may be interpreted as correct heart
rate values.
To eliminate or reduce the effects of vibration, house the receiver between the foam pads in such a
way that any vibrations are correctly damped.
OBSERVE: when securing the foam pads and the receiver with a strap, be careful not to
overtighten the strap as this may reduce the damping capacity of the foam pad.
11.1.5. P
OSITION OF THE RECEIVER
Carefully position the receiver according to the specifications below:
• the coil must be directed toward the user;
RESISTANCE DISTANCE
(Ohm)
15K
13K
11K
9K1
6K8
5K1
3K
2K
1K
(cm)
89
88
87
85
84
81
74
69
57
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