Equipment/BBC AF signal generator: Difference between revisions

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{{EquipmentInfobox
|name=BBC sig-gen <!-- Name of the item. -->
|image=BBC_AF_signal_generator_front.jpg <!-- Image of the item. Leave with placeholder image if none exists. -->
|model=Unknown <!-- Model -->
|category=Equipment <!-- Main category. Please leave alone to keep item in this category -->
|subcat=Test equipment <!-- Sub-category if one exists. Please check main listing to see other categories contained within the main one -->
|status=Unknown <!-- Set to one of; Good working order, Faulty, Out of order, Under construction, Out of consumables, Scrapped, or Unknown -->
|consumables=Unknown <!-- Any items used up in normal operation, such as; ink, paper, saw-blades, cutting disks, oil, etc.. -->
|accessories=Unknown <!-- Any items associated with the equipment but not consumable, such as; drill bits, safety gloves, goggles, etc.. -->
|reqtraining=<!-- Is training required to use this equipment? Yes or no. -->
|trainlink=Unknown <!-- If training is required, provide a link to training signup or contact page. Otherwise leave blank. -->
|acnode=Unknown <!-- Is the equipment ACnode locked? -->
|owner=Russ <!-- Provide a link to owners members page if other than LHS -->
|origin=On-loan<!-- If via pledge, please link to the completed pledge page on the wiki -->
|location=Ground Floor Electronics Lab<!-- Floor, room/zone and location within that area -->
|maintainers=<!-- If someone is nominated as managing the upkeep of this item, please list them here. No links please; it currently breaks the template. -->
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}}
BBC AF signal generator
BBC AF signal generator


[[File:BBC_AF_signal_generator_front.jpg|thumb|siggen, Click for bigger picture]]
This belongs to Russ. You can use it but Russ will be grumpy if it gets damaged.
 
 
== History ==
 
 
This unit was made sometime around 1989 and looks like it was built from modules from the RS catalogue. Russ purchased it from an auction of old BBC equipment.


This belongs to Russ. You can use it but Russ will be grumpy if it gets damaged.


Quickstart  
== Quickstart ==
To produce an audio tone:  
To produce an audio tone:  
Connect a small loudspeaker to the binding posts at rear
Connect a small loudspeaker to the binding posts at rear
Line 21: Line 45:
[[Beware]]''' This unit has a built in amplifier. The loudspeaker terminals on the back can produce up to 40 volts peak to peak and a lot more current than a typical 600ohm signal generator output. You can blow up things like computer audio inputs!
[[Beware]]''' This unit has a built in amplifier. The loudspeaker terminals on the back can produce up to 40 volts peak to peak and a lot more current than a typical 600ohm signal generator output. You can blow up things like computer audio inputs!


Controls


Front panel


Frequency Control
 
 
 
== Controls ==
 
'''Front Panel'''
 
'''Frequency'''
This is a three turn potentiometer, the markings on the dial bear little relationship to the output frequency but the control is smooth and noise free.
This is a three turn potentiometer, the markings on the dial bear little relationship to the output frequency but the control is smooth and noise free.


Frequency Range
'''Frequency Range'''
Four ranges, 0.1Hz-100Hz, 1Hz-1kHz, 10Hz-10kHz and 100Hz-100kHz.
Four ranges, 0.1Hz-100Hz, 1Hz-1kHz, 10Hz-10kHz and 100Hz-100kHz.


Output Level
'''Output Level'''
Adjusts level at PO jack at rear and drive to amplifier.
Adjusts level at PO jack at rear and drive to amplifier.


Output On/Off
'''Output On/Off'''


Sweep Rate
'''Sweep Rate'''
Four sweep speeds, 0.1,0.2, 0.5 and 1 octave/sec.
Four sweep speeds, 0.1,0.2, 0.5 and 1 octave/sec.


Sweep On/Off
'''Sweep On/Off'''
Starts a single sweep from the current setting of the Frequency Control down the scale to the low frequency of the selected range. To initiate another sweep return the switch to Off and then On again.
Starts a single sweep from the current setting of the Frequency Control down the scale to the low frequency of the selected range. To initiate another sweep return the switch to Off and then On again.


Modulation Frequency %
'''Modulation Frequency %'''
Four values, 1, 2, 5 and 10%
Four values, 1, 2, 5 and 10%


Peak Deviation %
'''Peak Deviation %'''
Four values, 1,2,5 and 10%
Four values, 1,2,5 and 10%


Modulation On/Off
'''Modulation On/Off'''


Rear Panel


Mains Inlet (IEC)
'''Rear panel'''


Mains fuse (5amp
'''Gain'''
Sets the gain of the amplifier module.


Mains On/Off


== Supply ==


'''Mains Inlet''' (IEC)


'''Mains Fuse''' (5amp


'''Mains On/Off'''


'''Amplifier fuses'''
One 20mm 2amp T for each of the + 45v and -45v rails of the amplifier supply




== Inputs/Outputs ==


'''Oscillator Output'''
PO Jack socket  Sleeve = Chassis    Ring = ?  Tip = ?


'''Amplifier Input  '''
PO Jack socket  Sleeve = Chassis    Ring = ?  Tip = ?


'''Loudspeaker Output'''
Two binding posts carry the output from the ILP amplifier module. Output power not known but should be good for 20 watts into 8/16 ohms.


== Operating Notes ==


The frequency control feels very loose, this is normal and does not mean that anything is broken....


(More notes to follow when the precise Modus Operandi has been established)




The 100-100K range seems most usefull, other ranges seem to be mostly below what little loudspeakers can produce.






The low level audio output requires a quarter inch jack plug (it might need a PO316 plug, as used on studio patch bays, rather than a standard 1/4" jack). There isn't one handy with the unit.


It contains an ILP amplifier module. It my experience the overload protection on those would not protect it from all possible loads. It may be easier to blow up than a typical 600ohm signal generator output.
[[File:BBC_AF_signal_generator_rear.jpg|thumb|siggen rear panel]]
 
The 100-100K range seems most usefull, other ranges seem to be mostly below what little loudspeakers can produce.


The frequency dial is a bit wobbly and dosn't stop distinctly at the ends of it's travel. The variable resistor inside may not be in top mechanical condition.


History
== Log. ==


This unit was made sometime around 1989 and looks like it was built from modules from the RS catalogue. Russ purchased it from an auction of old BBC equipment.
Please add any observations or repairs here...


[[File:BBC_AF_signal_generator_rear.jpg|thumb|siggen rear panel]]
Log.


June 2011. Someone reported it not working, supposedly one of the fuses on the back was blown and blew again when replaced.
June 2011. Someone reported it not working, supposedly one of the fuses on the back was blown and blew again when replaced.
The two fuses on the right hand of the rear panel supply +45volts and -45volts to the amplifier module. The +ve fuse was ok and is a 2amp T fuse. A 250mA fastblow fuse had been fitted in the other holder. Seems fine with a 2amp T fuse.
The two fuses on the right hand of the rear panel supply +45volts and -45volts to the amplifier module. The +ve fuse was ok and is a 2amp T fuse. A 250mA fastblow fuse had been fitted in the other holder. Seems fine with a 2amp T fuse.
May 2012 There are now two leads tied to the back each with a PO jack plug and free ends. Use these to connect to the osc o/p or amp i/p. 
Shield = sleeve
Red = ring
White = tip
[[Category:Equipment/Electronics]]
[[Category:Equipment]]

Latest revision as of 18:22, 8 December 2019

BBC sig-gen
BBC AF signal generator front.jpg
Model Unknown
Sub-category Test equipment
Status Unknown
Consumables Unknown
Accessories Unknown
Training link Unknown
ACnode Unknown
Owner Russ
Origin On-loan
Location Ground Floor Electronics Lab

BBC AF signal generator

This belongs to Russ. You can use it but Russ will be grumpy if it gets damaged.


History

This unit was made sometime around 1989 and looks like it was built from modules from the RS catalogue. Russ purchased it from an auction of old BBC equipment.


Quickstart

To produce an audio tone: Connect a small loudspeaker to the binding posts at rear Select 100-100K range Frequency dial at 6 gives roughly middle C (720Hz). Gain knob on rear at 2 Front output knob up 20 degrees Sweep off Modulation off. Rear on/off switch on Front on/off switch on Tone should be heard in the loudspeaker.

Beware This unit has a built in amplifier. The loudspeaker terminals on the back can produce up to 40 volts peak to peak and a lot more current than a typical 600ohm signal generator output. You can blow up things like computer audio inputs!




Controls

Front Panel

Frequency This is a three turn potentiometer, the markings on the dial bear little relationship to the output frequency but the control is smooth and noise free.

Frequency Range Four ranges, 0.1Hz-100Hz, 1Hz-1kHz, 10Hz-10kHz and 100Hz-100kHz.

Output Level Adjusts level at PO jack at rear and drive to amplifier.

Output On/Off

Sweep Rate Four sweep speeds, 0.1,0.2, 0.5 and 1 octave/sec.

Sweep On/Off Starts a single sweep from the current setting of the Frequency Control down the scale to the low frequency of the selected range. To initiate another sweep return the switch to Off and then On again.

Modulation Frequency % Four values, 1, 2, 5 and 10%

Peak Deviation % Four values, 1,2,5 and 10%

Modulation On/Off


Rear panel

Gain Sets the gain of the amplifier module.


Supply

Mains Inlet (IEC)

Mains Fuse (5amp

Mains On/Off

Amplifier fuses One 20mm 2amp T for each of the + 45v and -45v rails of the amplifier supply


Inputs/Outputs

Oscillator Output PO Jack socket Sleeve = Chassis Ring = ? Tip = ?

Amplifier Input PO Jack socket Sleeve = Chassis Ring = ? Tip = ?

Loudspeaker Output Two binding posts carry the output from the ILP amplifier module. Output power not known but should be good for 20 watts into 8/16 ohms.

Operating Notes

The frequency control feels very loose, this is normal and does not mean that anything is broken....

(More notes to follow when the precise Modus Operandi has been established)


The 100-100K range seems most usefull, other ranges seem to be mostly below what little loudspeakers can produce.



siggen rear panel


Log.

Please add any observations or repairs here...


June 2011. Someone reported it not working, supposedly one of the fuses on the back was blown and blew again when replaced. The two fuses on the right hand of the rear panel supply +45volts and -45volts to the amplifier module. The +ve fuse was ok and is a 2amp T fuse. A 250mA fastblow fuse had been fitted in the other holder. Seems fine with a 2amp T fuse.

May 2012 There are now two leads tied to the back each with a PO jack plug and free ends. Use these to connect to the osc o/p or amp i/p. Shield = sleeve Red = ring White = tip

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