Monday, February 3, 2014

Small Signal RF Amp - Rev 03 - Cont'd

Update added at end of post.

I connected a reasonably calibrated 100uVolt RMS 50 ohm RF source to the input of my Small Signal RF Amp (see previous post). The output of the amp with a 50 ohm load was 20mVolts P, for a Gain of about 43db. Similar gain was seen at frequencies from 1 to 26 MegHz, with more on the lower frequencies, and less gain on higher frequencies. Currently, I do not have proper equipment to do a complete characterization of the amp.

Test Setup Show 20mVolts  RMS
With 50 ohm Load On the Left
100uVolt  RMS Source from Sig Gen on the Right
I am a happy camper !

I think this amp will be used in several of my future projects, stay tuned!

The amp was originally designed for 12 volt supply, but I think a local zener diode regulation at 9 volts (or battery) will be useful for use within an actual project. Regulation will help avoid supply side noise from effecting the performance. The above test was done with a 9 volt battery.


UPDATE: Feb 04, 2014

I checked with the LTSpice Simulation, it suggests with 100uV RMS at 10MHz as input, I should only see 5mVolts P at the output. I am measuring about 4 times that as reported above, I wonder why?

More investigation needed.


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