Foldback Mk3 instr

863 MHz UHF Foldback (Mk 3) - STEREO TRANSMITTER AND POWER BOOSTER

DESCRIPTION

Stereo Transmitter

This high quality Stereo Transmitter works on the licence exempt frequency of 863 MHz, for use with the Black Box Video Director's Foldback Receiver. The Transmitter has many innovative features all built into a slim line, robust, diecast case.

The Transmitter is crystal controlled and set to 863.75 MHz.

The unit is powered by a standard Hirose 4 pin power connector and runs on a nominal 12 volt supply.

Audio into the unit is via a standard Hirose 6 pin connector at nominal line level.

Modulation level is automatic and the unit switches itself on and off automatically to save power.

An optional 75 times Power Booster is available if increased range is required (not licensable in the UK).

Power Booster

The optional Power Booster is a very small unit, only about 2 inches square. It is simply powered from the bottom Hirose 4 pin socket on the main Transmitter unit.

It is also helpful to note that the Mk 3 version is NOT compatible with either the Mk 4 or the Mk 1 versions, but it IS compatible with Mk 2 units.

INSTRUCTIONS FOR USE

Operation

	Connect the supplied aerial to the BNC socket on the top of the Transmitter.
	Connect the audio inputs at line level to the 6 pin Hirose socket on the side of the Transmitter (a suitable 6 pin Hirose to Hirose lead is available from us if required).
	Connect nominal 12 volt supply to the UPPER 4 pin Hirose socket on the side of the Transmitter (pins 1 + 4, again a suitable lead is available from us if required).
	The Transmitter will operate satisfactorily from voltages between 10 and 15 volts. Current consumption is 70mA.
	The green power LED will be bright at 12 volts and dim at 11 volts and out at 10 volts. Below 10 volts the unit may still appear to work but dropouts and glitches will occasionally occur.
	Switch on the Transmitter with the toggle switch on the top of the unit (the one on the end). The green 'power OK' LED should light brightly.
	Apply some audio from the mixer and the orange 'power-up' LED should light.
	Check the signal is being received from the Black Box Video Foldback Receiver.
	The centre toggle switch allows the Transmitter to be fed with either left/right stereo in the centre position, or just left channel, or just right channel in the off-centre positions.

Modulation Level

The Transmitter incorporates a sophisticated automatic level setting system. As such the input range is from -14dB to +10dB, so long as the signal is within this range the unit will set the modulation level to a suitable level.

Note the system is designed to transmit A & B stereo. It is NOT designed as a separate two channel device with different signals on each channel. Whilst the crosstalk between channels is satisfactory for stereo, it is not adequate for bi-lingual or programme and time code.

Power Saving

The Transmitter uses a power saving system. If no input signal has been received for five minutes the unit powers down and the orange LED goes out. The green power LED will still be lit (this consumes negligible power). The unit switches on instantly any modulation is detected. To switch the unit off permanently use the toggle switch.

The lower 4 pin Hirose socket is for powering the optional Power Booster module. This lower socket is switched from the toggle switch, so the power module is also switched off when the toggle switch is used. The automatic power saving feature also extends to the power module. Current consumption of the power module automatically drops to one fifth its normal level in standby mode. However it is best to switch off completely for longer downtime periods to save power.

Aerials

The supplied aerial was carefully selected to give best performance with the unit. Use of different types of aerial will almost certainly compromise performance.

Extending the aerial via extra coax cable by about 2 metres to gain extra height will improve the performance. If extra range or reliability is required, use the Black Box Video 75 times Power Booster. This has a gain of 15dB and gives and output power of approximately 750mW. (You should note, however, that the Power Booster is not currently licensable in the UK).

Optional Power Booster

Remove the aerial from the main Transmitter and fit the aerial onto the Power Booster alongside the power indicator LED.

A BNC lead connects the Booster RF input (alongside the 4 pin Hirose power socket on the bottom of the unit) to the aerial socket on the main Transmitter unit.

The Power Booster will work from 9 to 18 volts with no change in performance. It uses a switch mode power supply so current consumption decreases as the voltage increases.

DO NOT short out the aerial outputs of either the main Transmitter unit or the Power Booster as irreparable damage will be caused. Equally, the BNC lead to the Power Booster must be perfect or irreparable damage could be caused.

863 MHz UHF Foldback (Mk 3) - STEREO FOLDBACK RECEIVER

DESCRIPTION

This high quality UHF Stereo FM Foldback Receiver works on the licence exempt frequency of 863 MHz.

It is a small lightweight unit designed to be used by Directors, PAs and anyone who needs to hear the sound mix on set. It receives stereo signals from the Black Box Video UHF Stereo Transmitter.

The unit has a top mounted volume control and on/off switch, a stereo minijack socket for headphones, a red battery level indicator LED and an orange charging LED.

A 2.1mm coaxial charger socket is located on the side of the unit to enable the internal rechargeable battery pack to be charged.

An automatic tuning system is fitted which tunes the Receiver each time it is switched on.

It is also helpful to note that the Mk 3 version is NOT compatible with either the Mk 4 or the Mk 1 versions, but it IS compatible with Mk 2 units.

INSTRUCTIONS FOR USE

Operation

Fit the supplied aerial to the BNC connector on the top of the unit. Switch on by pushing the volume control knob inwards and the red power light should be brightly lit.

The unit will automatically tune to the first transmission it find in the range 863 MHz to 864 MHz and remain locked to that frequency even if the Transmitter drifts slightly. In the unlikely event this is not the required transmission, press the small recessed black button on the side of the unit and it will select the next available transmission.

Aerials

The supplied aerial was carefully selected to give best performance with the Receiver unit. Use of different types of aerial will almost certainly compromise performance.

Battery Life

Battery life should be approximately 100 hours continuous use. The red power LED will start to dim when the units needs charging. The unit stops working when the LED goes out.

Only use the Black Box Video Chargers designed for these units.

When the Charger is plugged into the 2.1mm socket on the side of the Receiver unit the orange LED should light.

Troubleshooting

Because the frequency is in the upper part of the UHF band the maximum range is only obtained when the aerials are in light of sight of each other. A maximum range of about 100 metres should be achieved without the Power Booster with optimum line of sight positioning of the aerials.

The signal will travel through obstacles but will suffer considerable attenuation. A brick wall will cut out about 90% of the signal so range would then be about 10 metres.

The optional Power Booster increases the output power from 10mW to about 750mW, which is around 75 times. This may seem a lot, but two brick walls will bring you back to the position of no Power Booster! The Power Booster is best used to improve reliability of signal when the line of sight cannot be guaranteed.

Tuning

The units automatically tune themselves each time they are switched on. The tuning then auto tracks continuously all the time.

In the unlikely event that the Receiver tunes to an unwanted frequency the unit can be tuned to the next Transmitter channel automatically by pressing the small recessed black button the the side of the unit.

863 MHz UHF Foldback (Mk 3) - 4-BAY RECEIVER CHARGER

DESCRIPTION

This 4-Bay Charger is designed to charge up to four Mk 3 UHF 863 MHz Stereo Foldback Receivers simultaneously in about 12 hours.

It is also helpful to note that the Mk 3 version is NOT compatible with either the Mk 4 or the Mk 1 versions, but it IS compatible with Mk 2 units.

INSTRUCTIONS FOR USE

Check the mains voltage selector (next to the mains IEC input socket) is in the correct position, either 240 or 120 volts. Connect the mains via the IEC cable. The red mains indicator LED should light.

Plug a charging lead into the charge socket on the side of the Receiver unit and also the other end into an outlet socket on the Charger. The yellow LED next to the output socket should light indicating the unit is being charged. The orange LED on the Receiver should also light.

Charge time is about 12 hours, but the units can be left charging without damage for up to 24 hours (but remove them after this time).

Up to four Receiver units can be simultaneously charged. The yellow LED merely indicates that the batteries are being charged - they do not go out when the charge time is complete, as is the case with the Receiver's orange LED.

Please note that the Receiver units will be delivered fully charged.