UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post

MotorBikeLes · 20th Mar 2018, 7:01 pm

I have just read your first two posts again. These 4 legged devices are NOT dual Fets, they are a normal 3 electrode device plus a shield.The BFW10 is a Mullard product (but could made by others as well) so you should find the specs online easily. Any decent equivalents book should show most of them.
You say your BFW0265 is marked 00734. This suggests to me it is a Union Carbide type UC734 or equivalent, not a date code, but almost certainly a selected value. When manufacturers mark their semis as BFW0265, and you can not find the info in a data book, you should conclude it is a BFWxx device, selected for properties, and marked 0265. Telequipment was a British company, and at that time Tek had little or no influence as far as I can guess. So they MAY have asked Phillips (Mullard) to supply them, with their "personal" markings. The same would apply to BFW0303, BFW1051, BFW1052
Other FETS you could select from might be TIS59Y, similar to these, as used in Dynamco Y-amps, WD212, and all the others I mentioned previously.
Les.

20th Mar 2018, 7:01 pm	#9
MotorBikeLes Nonode Join Date: Dec 2012 Location: Kirk Michael, Isle of Man Posts: 2,350	Re: Telequipment D54 ? I have just read your first two posts again. These 4 legged devices are NOT dual Fets, they are a normal 3 electrode device plus a shield.The BFW10 is a Mullard product (but could made by others as well) so you should find the specs online easily. Any decent equivalents book should show most of them. You say your BFW0265 is marked 00734. This suggests to me it is a Union Carbide type UC734 or equivalent, not a date code, but almost certainly a selected value. When manufacturers mark their semis as BFW0265, and you can not find the info in a data book, you should conclude it is a BFWxx device, selected for properties, and marked 0265. Telequipment was a British company, and at that time Tek had little or no influence as far as I can guess. So they MAY have asked Phillips (Mullard) to supply them, with their "personal" markings. The same would apply to BFW0303, BFW1051, BFW1052 Other FETS you could select from might be TIS59Y, similar to these, as used in Dynamco Y-amps, WD212, and all the others I mentioned previously. Les.