Mastodawn

Made some progress on the low-cost noise figure & gain measurement setup, and have it running pretty well at 440 MHz. Have pages of notes and pictures to put together a how-to post or web page. Still need to check calibration at other frequencies, but currently measuring my 10 dB attenuator very accurately for both NF and gain. More fun ahead! #HamRadio #TestEquipment #NoiseFigure

Gary @N8DMT Dec 8

Finished a first draft for my qsl.net web page documenting a low-cost DIY RF Noise Source suitable for making noise figure measurements under automatic program control (with SATSAGEN software). Still have a few more updates to the web page, but completed calibration of the ENR measurements for the new source. More fun ahead!
#HamRadio #TestEquipment #NoiseFigure
https://qsl.net/n8dmt/test-page/diy-test-equipment/low-cost-diy-noise-source/index.html

Gary @N8DMT Aug 9, 2025

Finished the third blog posting on the new noise-based amplifier gain and noise figure measurement setup. TLDR: it works!
3/3

Details at: https://qsl.net/n8dmt/rf-noise-source-part-3/index.html

#HamRadio #NoiseFigure #SATSAGEN

Show thread

Gary @N8DMT Jul 27, 2025

First RF Amplifier measured with new gain and noise figure system. Measuring ZHL-1042 with 25 dB input attenuator on NS output (ENR adjusted), DUT amplifier, 5 dB pad on output to cable to 5 dB pad on SDR RX input. Expecting to see ~28 dB gain (measure 23 dB gain with 5 dB pad in-line) and ~ 5 dB NF. Looks good for a quick test…
#HamRadio #TestEquipment #NoiseSource #NoiseFigure

Show thread

Gary @N8DMT Jul 26, 2025

Completed the proto Arduino Noise Source PC interface allowing SATSAGEN to automatically turn on and off the noise source under that program’s control enabling super easy measurements. Next will look in the lab stock for any more NOS plastic RS enclosures (pretty sure there is at least one larger box out there). Will add the LED’s to final package to make the PC control function visible when in use. Plan to measure a few amplifiers soon.
#HamRadio #TestEquipment #NoiseSource #NoiseFigure