Thank you. No plasmas.
Sent from my iPhone > On Feb 1, 2021, at 11:23 AM, Rick Hiller via BVARC <bvarc@bvarc.org> wrote: > > > Mark, > > Have a read of the September 2017 BVARC Newsletter -- The Radio Hotel column > is about receive noise, etc. Also look at the referenced QST column. > > Might help you in your quest. > > Rick -- W5RH > >> On Mon, Feb 1, 2021 at 8:47 AM Mark Brantana via BVARC <bvarc@bvarc.org> >> wrote: >> I will check all these things. >> >> Sent from my iPhone >> >>>> On Jan 31, 2021, at 10:16 PM, Doug SEYLER via BVARC <bvarc@bvarc.org> >>>> wrote: >>>> >>> >>> If you have. A battery powered sw receiver, check to see if it is present >>> there. If so, trip the main power to the house to see if it goes away. RFI >>> can be very broad banded. I’ve had power line noise that extends cripples a >>> lot of the spectrum. >>> >>> Doug W9LCQ >>> >>> Sent from my iPad >>> >>>>> On Jan 31, 2021, at 9:00 PM, Rick Hiller via BVARC <bvarc@bvarc.org> >>>>> wrote: >>>>> >>>> >>>> Although it is a Ham Band antenna for 40,20,10....you might try listening >>>> to General Coverage and tune to 10, 15 or 20 MHz for WWV......see if you >>>> can hear it.....from what you say, I doubt it, and if so, you have a radio >>>> set up issue, IMHO.....Rick >>>> >>>> Virus-free. www.avast.com >>>> >>>>> On Sun, Jan 31, 2021 at 8:45 PM Rick Hiller <rickhille...@gmail.com> >>>>> wrote: >>>>> Mark, A few questions, comments and tests: >>>>> Sounds like a radio problem to me...so....not in any particular order, >>>>> just what I thought of first to last.... >>>>> . >>>>> -- What S level is the noise? Does it change level with the RF Gain >>>>> control? >>>>> -- What if you disconnect your antenna coax? Does it go away? >>>>> -- What if you connect a dummy load? Same noise? >>>>> -- What does the Nano VNA show? Impedance wise (R and j) and SWR? What >>>>> is the SWR bandwidth of the antenna across 40 and 20? >>>>> -- Where is your RF Gain pot? Maxed? Try reducing the setting a bit. >>>>> -- Do you have your "pre-amp" on? If so, turn it off. NB off too. >>>>> -- What about CW mode....does the Narrow filter on make a difference? >>>>> -- Where are the IF/PBT shift sliders set? They should be in the center >>>>> for a base reference. >>>>> >>>>> -- Are the rear panel Receive Antenna In and Out jacks jumpered and is >>>>> the jumper OK continuity wise? >>>>> >>>>> -- Is the Ham/General select switch in Ham position? I am not sure if >>>>> the band pass filters are bypassed in General....just a guess. >>>>> >>>>> -- Take your coax off. Then using ONLY the center pin of the PL-259 >>>>> insert it into the radio SO-239 center ONLY. Is the noise similar? >>>>> Then screw on the PL-259 outside....does the noise change? Usually, >>>>> using only the center pin causes lots of receive noise and then when you >>>>> screw on the 259 outside the noise reduces as the antenna system is then >>>>> a closed system. >>>>> You can also do this with a 10 foot long piece of wire and just connect >>>>> the wire to the inside center terminal of the SO-239 on the radio. The >>>>> receive noise should increase when you touch the wire to the center >>>>> pin......is this noise the same as you are complaining about? >>>>> >>>>> Have you run power to the antenna? What is the SWR? Similar to the >>>>> Nano reading? Use the internal SWR meter and meter switch to select RF >>>>> PWR and SWR set etc. >>>>> >>>>> That's about it for a 745 brain dump for tonight. Something is amiss >>>>> in your set up, IMHO, no external wideband white noise source is jacking >>>>> with ya. Sounds like receiver noise is at max gain and no received >>>>> signals are being processed. >>>>> >>>>> GL and 73...rick -- W5RH >>>>> >>>>> >>>>> >>>>> >>>>> Virus-free. www.avast.com >>>>> >>>>>> On Sun, Jan 31, 2021 at 7:33 PM Mark Brantana via BVARC >>>>>> <bvarc@bvarc.org> 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 >>>>>> BVARC@bvarc.org >>>>>> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >>>>> >>>>> >>>>> -- >>>>> Rick Hiller >>>>> e-mail: rickhille...@gmail.com >>>>> Cell: 832-474-3713 >>>>> Physical: 9031 Troulon Drive >>>>> Houston, TX 77036 >>>>> >>>>> Virus-free. www.avast.com >>>> >>>> >>>> -- >>>> Rick Hiller >>>> e-mail: rickhille...@gmail.com >>>> Cell: 832-474-3713 >>>> Physical: 9031 Troulon Drive >>>> Houston, TX 77036 >>>> ________________________________________________ >>>> Brazos Valley Amateur Radio Club >>>> >>>> BVARC mailing list >>>> BVARC@bvarc.org >>>> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >>> ________________________________________________ >>> Brazos Valley Amateur Radio Club >>> >>> BVARC mailing list >>> BVARC@bvarc.org >>> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org >> ________________________________________________ >> Brazos Valley Amateur Radio Club >> >> BVARC mailing list >> BVARC@bvarc.org >> http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > -- > Rick Hiller > e-mail: rickhille...@gmail.com > Cell: 832-474-3713 > Physical: 9031 Troulon Drive > Houston, TX 77036 > ________________________________________________ > Brazos Valley Amateur Radio Club > > BVARC mailing list > BVARC@bvarc.org > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
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