Just testing the IMD using 700 and 1900 Hz tones generated in Adobe Audition and playing through the radios USB sound card interface. TX EQ off, TXBW set to 50-3050. This is after I set (to factory specs) and balanced the bias of the VRF150 finals which yielded about a 2dB improvement. Keep in mind, this is IMD measured in dBc from the two tone carrier, ARRL along with many manufactures reference the IMD from a single tone PEP which gives you a 6dB better (lower) number. To convert my measurements to ARRL, add subtract 6db, so -30 dBc would = -36 dB ARRL.

Edit, I have since replaced the VRF150's with a new matched pair and now Im seeing a much better result. See this video for the update: [ Ссылка ]

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