Hello,
A question for Ian Robertson, if I may.

Can I substitute a SE1001 transistor out for a BC549. There are 3 in the front end of my Astor P14n with the mixer one intermittently low on gain.

It's a daily user and would like it reliable again.

Thanks in advance.

Dave

Absolutely!

A BC548 or BC547 will also work.

I've also used BC557s successfully to replace PNP germanium transistors in radios. I recall replacing OC169s / OC170s in a British radio, all 3 were dead. The result was a stable and very lively performer. Didn't even need to re-align it!

Thank you Sir.
There is actually 4x so I might just change them all out and see what happens. I will experiment with the replacements of germaniums one day. I have a couple of donor radios to play with.
Regards
Dave.

I don't recall those Oz-made Fairchild blob-tops being particularly unreliable. Not like the Anodeon transistors, anyway.

I currently have an HMV gram chassis on the bench that's full of Fairchild blob-tops and they are all good.
Same cannot be said for the IRC and Morganite resistors that surround them!
Although having said that, this particular chassis didn't have this problem either. Just a main electro that had started to vent and a broken dial cord.

There are very few "troublesome/unreliable transistors".

Those that are, are well documented.

So, my advise is if not documented as troublesome and test OK, leave them in situ.

Generally all transistors are very reliable.
JJ

Thanks Ian,
It was the RF amp transistor that was faulty, With it out of the radio it sometimes test as a diode (open circuit C-E) and sometimes test ok but with a low current gain of between 5 and 10. In circuit, the heat of a soldering iron would bring it back to life when the radio was dead. The new BC549 has sorted it out.