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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

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Old 20th Dec 2014, 11:28 am   #1
dragonser
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Default BCY72 equivalent for Labgear pattern generator

Hi,
I have recently got hold of an old Labgear Colour Pattern generator.
Upon opening it up it seems that some of the bcy72 transistors have been physically damaged !
Would anyone happen to know what might be more modern replacement ?
I have attached a not very good photo.
the crystals are 4449.244 and 4417.994
I guess this is going to be a longer restoration project that I had realised ?

regards Peter B
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Old 20th Dec 2014, 11:39 am   #2
Nuvistor
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Default Re: BCY72 equivalent for Labgear pattern generator

New ones priced between £1 and £2 each are advertised as available, it appears to be a general,purpose PNP transistor but if the originals are available it would be easier just to replace like for like.
A search on the web will find a seller in the UK.
Frank
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Old 20th Dec 2014, 11:53 am   #3
G6Tanuki
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Default Re: BCY72 equivalent for Labgear pattern generator

They're general purpose low-power PNP Silicon jobbies - 2N2907A is pretty much a direct replacement. £1.01 a time from Farnell.
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Old 20th Dec 2014, 11:54 am   #4
ukcol
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Default Re: BCY72 equivalent for Labgear pattern generator

This transistor is listed in my vrt book as a 450MHz type which is presumably to allow for the high speed switching in your generator.

The same book lists BCX78, BCY78, 2N2906 and 2N2907 as equivalents.

There are also higher voltage versions of the BCY72, namely BCY71 and BCY70.
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Old 21st Dec 2014, 8:32 pm   #5
dragonser
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Default Re: BCY72 equivalent for Labgear pattern generator

Hi, just to say thank you for all the help, and also thank you to the person who offered me some of the correct transistors.
how the original transistors got damaged I can't work out !
regards Peter B
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