Re: Marconi 2022C - Stopped working below 62.5 MHz
I did some further measurement and I found out that there is actually a signal, but at a different frequency, always about 10 MHz higher than the selected frequency (I don´t know why I haven´t seen it the first time). Level seems to be correct, the frequency is slowly drifting away, it´s most likely not derived from the OCXO.
When I add a 1nF (without removing the OM345), the frequency changes a few kHz, but nowhere near it should be.
As a replacement transistor, would a BFS17 work (NPN 1 GHz wideband transistor)? It´s available for just a few cents at my local source for electronic parts. How do I choose the other parts?
|