alpha-8 and alpha-4, the receivers for electric powered models The alpha series are ultra-compact, lightweight radio control receivers designed specifically to satisfy the increasingly stringent demands of modellers concentrating on electric-powered models.
Depending on the special pulse procession in the alpha-8 receiver it also can be used it in RC-cars. The schulze name on a receiver means not only that it is manufactured to schulze quality standards in our own production facility, but also that its performance satisfies the schulze requirements we have laid down for electric flight applications. A successful fusion of high-end design with small dimensions, light weight and low cost. Features in detail: The asc (automatic signal strength control - automatic regulation of received signal amplification) ensures optimum close-range and long-range reception.
The receiver automatically reduces the gain of powerful received signals, thereby avoiding the risk of overloading the aerial input stage, which always has unwanted side-effects. Reliable operation when adjacent channels are in use is a fundamental requirement as far as we are concerned.
For this reason we employ narrow-band filters which provide safe operation using the standard 10 kHz channel spacing. When a receiver is operated close to its range limit it is particularly vulnerable to interference. These are the signs:
The servos start to jitter; under certain circumstances they may run against their mechanical stops and overload the receiver power supply;
if the model is electric-powered, the motor may burst into life and make the interference even worse - which of us has not experienced that at launch or on the landing approach when the receiver aerial is poorly positioned?
A crash is simply inevitable. At the development stage we also placed considerable importance on the digital post-processing (apd, apdr) applied to the received signal for this very reason. Our techniques allow the receiver to detect interference, suppress it, and replace the invalid signal by previously received valid values (similar to PCM techniques). The signals passed to the servos always lies within normal limits, and the servos are usually able to process them without problem. The servo jitter which occurs when the signal is weak is greatly reduced. Some conventional PPM receivers are so bad in this respect that we were obliged to program a suitable filter for our future heli speed controllers to avoid them responding with fluctuations in rotor head speed. If interference persists, the receiver switches off the servo signals completely. Under certain circumstances the servos may then be moved back towards neutral by aerodynamic pressure. Every time you switch on the system the receiver counts the channel signals in order to ensure that a receiver signal with the incorrect number of channels is not passed to the servos.
(The channel-check is permanent in the alpha-8 receivers. In the alpha-4 receivers it will only be done when returning from squelch mode)
If a PCM transmitter on the same RF channel is switched on, it will not cause the servos connected to an alpha receiver to jitter. That was a brief description of the advantages provided by apd technology.
apdr technology goes one stage further: it can generate (r = restoration) either the actual transmitted signal (suppressing a glitch caused, say, by an electric motor) or a signal close to the original signal. This it does by analysing the interference contained in the received signal. CAUTION: all this sophistication is no guarantee for problem-free flying.
If you fly close to the range limit, or even at close range if the aerial is poorly positioned, a problem may arise which the receiver automatically corrects, leaving you unaware that there ever was a problem. That is why we have also installed a reception quality indicator LED.
The receiver counts the invalid transmitter signals it picks up, and informs you of the number of errors by a pattern of flashing.
1* flash = 1 glitch (2 to the power of 0)
2* flashes = 2 ... 3 glitches (2 to the power of 1)
3* flashes = 4 ... 7 glitches (2 to the power of 2)
4* flashes = 8 ... 15 glitches (2 to the power of 3)
5* flashes = 16 ... 31 glitches (2 to the power of 4)
6* flashes = 32 ... 63 glitches (2 to the power of 5)
etc. We suggest that you experiment with various arrangements of your receiving system and power supplies in the model (receiver position, aerial position, receiver battery position, flight or drive battery position) and read off the glitch count after each test flight or test run. In this way you can establish the optimum installation of the components in your model by adopting the configuration which reduces the glitch count to a minimum. Incidental information: Splash water protection on the alpha-4xxW types
Ideal for seaplanes and boats. Auxiliary cables: If your receiver lacks a vacant socket for an airborne voltage indicator, you can use a Y-lead to produce the necessary socket. Technical features: Single conversion
Selection (narrow band) better 10 kHz
Digital-Squelch
Leightweight hard plastic case (3,6 g - alpha 8 and 2 g - alpha 4)
Long or short (minimum is 40 cm) aerial depending on preferred purpose
Voltage range: 4-5 cells = 4.8 - 6 V nominal voltage = 3.6 - 9 V min/max.
LED current: 1mA We recommend to use our crystals for best function.
The use of crystals other manufacturers is possible - but reduced range or interference from the neighbour channel can occur.
A range check is generally advisable in any case,
but is absolutely essential if you use non-Schulze crystals. Price and weight without crystal, but inclusive of case. Frequ
ency
band
[MHz] | Sensi-
tivity
[µV] | Current
Draw
[mA] | Size
[mm] | Weight
[g] | | 40 | 10 | 8.5 | 45x21x13 | 13 |
| 
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