View Single Post
Old 25th Dec 2017, 8:03 pm   #83
ParcGwyn
Hexode
 
ParcGwyn's Avatar
 
Join Date: Jun 2005
Location: Aberystwyth, Wales, UK.
Posts: 358
Default Re: Spectrum Analyser

It is good for above 500kHz when driving the 3RP1A, not that it's needed for a spectrum analyser. I didn't thermally tie the fets together and the circuit does drift a bit for the first few minutes of operation. I used BC178s for the output pair and just a pot as the input attenuator everything else as per the circuit. A very simple circuit and more than enough gain when using the G4PMK circuit.

Dave

GW7ONS
ParcGwyn is offline