ad: Schulman-1

??? Static on a wide frequency range ???

Discussion in 'General Technical Questions and Answers' started by MRKONG, Aug 8, 2017.

ad: L-HROutlet
ad: l-rl
ad: Left-2
ad: abrind-2
ad: Subscribe
ad: Left-3
ad: L-MFJ
  1. MRKONG

    MRKONG QRZ Member

    I'm pretty inexperienced with ham, I have never owned a fully functioning radio until last night (see previous thread), and I'm somewhat confused. My radio has been working great, and after a little bit of tuning with the orientation of my antenna I am receiving pretty much no static even on S4-5 signals, I never knew circularly polarized antennas has to be perfectly vertical to work right :oops:. I am experiencing one odd phenomena however, some frequencies are loud static 100% of the time. Now I know I can fix this by using my SQL/RF dial, but that isn't good enough for me; I want to know why I am receiving static S4-9 signals on some frequencies 24/7. For example, some of the frequencies are: 144.000 mhz (continuous s4-5) , 146.000 mhz (continuous s4-5), 147.300 ~ 152mhz (continuous s1-4 varries by frequency, 148.350 is s9++). I understand some of those frequencies are outside the legal range of the 144 band, but please focus on the question. Why is there a static S4-9 signal on these frequencies 24/7, expecially the 148.350 which is always S9++? Here is some additional info: FM, DNR on, DNF on, DBF on, YAESU FT-857D MARS MOD, Antenna is mounted 2 ft outside of a window on side of house, radio is powered by a battery.
     
  2. WR2E

    WR2E Ham Member QRZ Page

    What make/model antenna is that?

    When you say 'static', what exactly do you mean? Is it a constant 'hissssssss' like you might hear between stations on an FM broadcast receiver?

    I presume that you've got the mode set to FM ?
     
  3. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Having an antenna (any antenna) that close to the house is asking for receiving lots of interference/noise sources from inside the house.

    Not sure what "circularly polarized" antenna you have, but no matter what it is, you're likely receiving signal and noise sources from within your own home due to proximity and the fact that almost everything "electronic" that we own, from computers and modems/routers to TV sets (sometimes even if they're turned "off") to major appliances (again, even if they're turned "off") generate a lot of signals. Leakage from cable television is another possible source, especially if anyone has "hacked" into it or the system hasn't been serviced in a while.

    One way to determine if the sources of all these phantom signals is really "you," especially since your rig is battery powered, is to pull the MAIN breaker to OFF and let everything in the house go completely dead. For stuff that has batteries (like laptop computers and notebooks, many cable modems, etc.) you also have to remove their batteries to assure they're actually "off."

    Then, go back and tune around and see if some or all of the phantom signals disappear.

    Here at home if I use an antenna very close to the house I get all sorts of "RFI" (radio frequency interference) including phantom signals and noise; I have to install something like a 2m FM antenna 10-20 feet above the roof of the house in order to make them go away, and they are completely gone.
     
  4. MRKONG

    MRKONG QRZ Member

    It's very possible that they are signals from inside the house. Its not normal static like a hiss, it has a depth and strength that suggests they are real radio signals. The 148.350 signal is a S9++, so what ever is creating the signal is pulling some serious power. My guess is that it is the 1st gen LCD TV which draws a very high current, and I would assume it has some sort of oscillator inside.
     
  5. N8EKT

    N8EKT Ham Member QRZ Page

    without hearing it its hard to tell what it is

    Digital transmissions sound like "noise" to the untrained ear but I can tell the difference immediately

    ANYTHING electronic can and will produce birdies at various frequencies so it literally could be any one of dozens of sources

    If you could attach a sound file of the noise it would help
     
    KD2ACO likes this.
  6. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    With an FM receiver, ordinary "noise" normally doesn't come through at all unless it's riding on a signal.

    With any of my FM rigs "squelched" to threshold with no antenna connected, after connecting an antenna there could be S9++ "noise" and there's no sound from the rig -- only a rise in the S-meter reading. And that's normal for an FM receiver.

    However since what you describe has discreet frequencies and comes through like a carrier, they are likely real signals that either shouldn't be there at all or shouldn't be radiated in the 2m ham band. Household "appliances" of all sorts can easily be the culprit and the only way to find out is to turn off power to the whole house and leave your radio on, battery powered.

    If it's not coming from within your own home, it could be coming from a neighbor's, or more than one neighbor -- especially if you have neighbors very close by.

    Sometimes simply raising the antenna a lot so it's way above "where people live" helps enormously and it all goes away.
     

Share This Page

ad: elecraft