27-11-2017, 05:12 PM
Hi Miguel.
Hope you are well and the recent terrible storms have not caused any great problems for you.
I have found that using Silicon transistors in a set designed for Germanium doesn't always works successfully. IF stages can work but as you have found biassing needs to be altered, also you will need to re-align the cores and trimmers as different construction of the transistors alter the internal capacitance.
This is one reason that the mixer or RF stage can be out. Best idea is to try a full re-alignment after fitting the Silicon replacements and see if it improves matters.
I tend to stick with germanium types if at all possible, often using the Russian GT332 transistors.
Hope you are well and the recent terrible storms have not caused any great problems for you.
I have found that using Silicon transistors in a set designed for Germanium doesn't always works successfully. IF stages can work but as you have found biassing needs to be altered, also you will need to re-align the cores and trimmers as different construction of the transistors alter the internal capacitance.
This is one reason that the mixer or RF stage can be out. Best idea is to try a full re-alignment after fitting the Silicon replacements and see if it improves matters.
I tend to stick with germanium types if at all possible, often using the Russian GT332 transistors.
