This circuit does not make a good preamp--it overloads too
easily. As the info in the Files states, it's for making a test
IMD preamp that can be duplicated with a characterized OIP3.
Recent posts have been about trying to measure IMD of preamps.
Steve
On 10/9/2024 12:10 PM, W0LEV via
groups.io wrote:
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Steve,
I've built a number of preamps similar to this.? I use them
for low VHF to ELF and lower HF frequencies.? I've measured it
to be relatively flat through 30 MHz.? I've typically used the
2N5109.?? It works well and others should build it as its
relatively simple and easy to build.? I have used 43 material
for the output transformer.
Dave
- W?LEV
On Wed, Oct 9, 2024 at 6:04?PM
Steve Ratzlaff via <ratzlaffsteve=
[email protected]>
wrote:
I've
uploaded to the Files a relatively simple one transistor 50
ohm
preamp with +30 dBm OIP3 that can be built using common
transistors and
used to check your own IMD test set. I tried seven different
transistors, three different types, different brands. Use a
power supply
you can set to 12.0 volts, as IMD is sensitive to supply
voltage, to
obtain the same results that I got.
/g/loopantennas/files/50%20ohm%20Preamp%20with%20+30%20dBm%20OIP3
73,
Steve AA7U
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