Thank you for your reply. You could have chosen a +10V internal rail - and a 10V regulator - but, no....
Yeah, you probably designed the amp with IM requirements - and high linearity, etc. Phooey! As my 12V 14+
A-Hr backup battery runs 12-13.2V, I guess I'll just have to 'try' it and see. It will be for emergency/loss
of power, much less common in my newer home, anyway. Probably time to get out my collection of parts destined
for my homebrew remote loops... if I could just find my soldering pencils... I did find my 200W iron...
moving isn't fun!
In my design (in the group files section) I chose a 12V supply rail as it was best suited for direct operation from 12V batteries, such as Gel Cells, which would take care of any concerns of power supply induced noise. The biasing of the two stages was selected to give a decent power consumption vs. performance. At HF frequencies the NF performance is secondary to IMD performance due to terrestrial and galactic background noise and the presence of numerous high-power broadcast stations.
The performance of my amplifier exceeds that of Pixel and Wellbrook, having a 2.42dB NF at 10MHz. To get better IMD performance than I attained would require a 2W or more power amplifier, which would at least double the power consumption. Using an older transistor such as the 2N3553 or a newer device such as the NE46134 in the output stage and boosting the biasing current to 100mA or so would do it.
Chris
When the going gets weird, the weird turn pro
- Hunter S. Thompson
