i am going to guess a ground loop. 73...bruce
Sent from my iPhone On Jan 31, 2021, at 7:33 PM, Mark Brantana via BVARC <[email protected]> wrote: I am reaching out for ideas on a radio issue. I have installed an IC-745 Icom with an MFJ-2010 offset fed dipole. The power supply is a 20A MegaWatt switching power supply, which is located right next to the radio. The antenna is under some high power-lines with the long leg 90 degrees to the power-lines. I used my nanoVNA to study the band SWR response, and everything looks reasonable, though some small adjustments may need to be made. Nothing is grounded as yet. Here’s my problem. I am only attempting to receive at this time and I get consistent QRM white noise across all bands to the point where I can barely pick out some voices, etc. I am confident that the antenna is properly connected due to my antenna study. I don’t believe the power lines are an issue, since the problem would likely be more isolated show up as birdies at certain frequencies. The radio settings seem to all be correct according to the manual. Lack of grounding, but again the white noise is generally consistant across the spectrum. Still, this could be the problem. I have turned off my computer, so there no QRM from its power supply. It does not help to have the switching power supply right next to the radio, but other users give good reports on this model and no QRM issues are mentioned. I tried the radio at different times of the day on 20-m voice band, with the same noisy result. It could be the net result of a large number of small device transformers, but I doubt it. I turned off the wifi, and still no change. Hmm… I am a little stumped. Any thoughts or ideas? Personal experiences? Mark N5PRD ________________________________________________ Brazos Valley Amateur Radio Club BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
________________________________________________ Brazos Valley Amateur Radio Club BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
