Yes, I too read 1.1V
pp as just under +5dBm - I can try a lower input signal of say 500mV
pp == -3dBm which given the 12dB gain and P
1dB of 10dBm might be less problematic. Yes I guess it's possible it could be oscillating or saturated, but the output from the following gain block
1 looks OK at about +23dBm. I'll have to try probing the ouput of the first stage directly. Here's a close up of the first gain stage:
Nothing sophisticated for the signal injection a nasty old maplin BNC to a pair of grabbers with the centre core to the blocking cap, and the outer to ground.
1. I cannot identify the MMIC used in the 2nd stage as it's just a gold coloured four legged MMIC with no marking AFAICT. - Here's its portrait:
Cheers
Dave