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-   -   BC107 Vce disparities (https://www.vintage-radio.net/forum/showthread.php?t=156712)

GW4FRX 21st May 2019 6:51 pm

BC107 Vce disparities
 
Thanks to the generosity of a very kind gentleman on here I've just received a very useful packet of BC107s.

There seems to be a very wide spread of Vce values quoted in the data sheets for these, anywhere between 25 and 50V. Rather oddly the figure for the supposedly complementary BC177 is given in all sources as 45V.

Anyone have a definitive Vce figure for these devices?

G8HQP Dave 21st May 2019 9:13 pm

Re: BC107 Vce disparities
 
Wasn't higher than normal voltage handling the whole point of the BC107? BC109 was high gain and low noise; BC108 was everything else, but often put into current gain bins.

paulsherwin 21st May 2019 9:20 pm

Re: BC107 Vce disparities
 
https://en.wikipedia.org/wiki/BC108_family

GW4FRX 21st May 2019 10:02 pm

Re: BC107 Vce disparities
 
Quote:

Originally Posted by G8HQP Dave (Post 1147162)
Wasn't higher than normal voltage handling the whole point of the BC107? BC109 was high gain and low noise; BC108 was everything else, but often put into current gain bins.

That was the impression I had, but several data sheets list the BC107 with a Vce of 25V. I'd always assumed it was 45V as with the BC177.

The Wiki entry seems to be a good summary.

Maarten 23rd May 2019 11:25 am

Re: BC107 Vce disparities
 
The BC107 is supposed to be identical to the BC547 except for dissipation. Philips used the exact same die in them once they were both in production. The identical dies should be in at least BC107, BC147, BC237, BC407, BC547, BC847 the only difference being in the case.

Of course, if some manufacturer gives different data on a particular type, that's only appliccable to devices of that particular manufacturer (if it's not an error). Sometimes different manufacturers have different specs, even though that should have been avoided. One possible cause of such differences is the manufacturer in question stamping a roughly equivalent transistor from their existing range. In the early days, differences could have been caused by limitations of the production process or simply by not having the correct data on the competitors device.

paulsherwin 23rd May 2019 11:35 am

Re: BC107 Vce disparities
 
When the quoted Vce is dramatically different then it's normally an error. The whole point of the BC107 et al is to have a higher voltage variant of the BC108.

I suspect the BC546-9s are actually all the same part now, able to meet the voltage specs of the BC546 and the noise specs of the BC549. They are just marked differently for marketing reasons.

Refugee 23rd May 2019 12:03 pm

Re: BC107 Vce disparities
 
They most likely just aimed for the higher spec and printed the numbers on to fulfill the orders as they came in.

GW4FRX 23rd May 2019 5:20 pm

Re: BC107 Vce disparities
 
Quote:

Originally Posted by Maarten (Post 1147558)
The BC107 is supposed to be identical to the BC547 except for dissipation. Philips used the exact same die in them once they were both in production. The identical dies should be in at least BC107, BC147, BC237, BC407, BC547, BC847 the only difference being in the case.

Of course, if some manufacturer gives different data on a particular type, that's only appliccable to devices of that particular manufacturer (if it's not an error). Sometimes different manufacturers have different specs, even though that should have been avoided. One possible cause of such differences is the manufacturer in question stamping a roughly equivalent transistor from their existing range. In the early days, differences could have been caused by limitations of the production process or simply by not having the correct data on the competitors device.

Fascinating stuff -- many thanks to all for the enlightenment. It's amazing what you learn on this forum.

Maarten 24th May 2019 11:49 am

Re: BC107 Vce disparities
 
I forgot one identical equivalent, might be BC182. Also what paulsherwin says is very likely, parts being binned on characteristics.


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