-
You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
Dc Grounded antenna question
- Thread starter nfsus
- Start date
It helps with noise. For a test use a 100k Ohm 5W across the feed point and see what happens. You could also put ferrite around the coax as well to provide a path to ground/shield. A capacitor in series with an inductor can help as well. Also, be sure this noise is not from your home and getting into the electrical wiring which your radio is plugged into. Lots of things to experiment with but be sure its not from your home like a noisy LED light or something like that.
DC ground, is a path for static charge buildup to dissipate. DC ground, will not solve RFI, which I suspect is your problem.
Start unplugging suspicious Electronics in your house one at a time to see if the noise stops. Or flip the breakers on the house one at a time. Or take a portable AM radio around through the house and outside the house it should pick up any stray RF. The closer you get to the source the louder the AM radio will squawk.
Doesn't the astro plane have a horizontal component to it? Maybe the astro plane isn't as good as you think?
As far as I know, the Sirio Tornado is DC grounded. It utilizes a shunt coil match, which is electrically DC grounded.
I would power the receiver from a battery and turn off the main breaker, if it is suspected to be a source, within the house. It would be more important, to first identify the type of noise, before trying to locate the source. It may not be in the house at all.
I had a look at the base assembly. There is a pin (rivet?) that goes through the insulator. Perhaps this is the connection? I am going by online visuals, so I can't be certain. The obvious telltale, would be to ohm it out.
I also looked at the specs on the Sirio store, that also state DC grounded. If the antenna is a .625 wavelength, it must have a matching network, which in this case, appears to be a shunt coil, but maybe it is some magic snake oil. It wouldn't be the first time I encountered that stuff in CB marketing.
Last edited:
I agree with previous posters in that you need to identify the type of noise. Is it just general static or is there some sort of "note" to it, as in a discernible tone under neath it? If it sounds a bit like a 50/60 or 100/120 cycle hum in the static, then some of your issue is likely from the house wiring and no related to the antenna, possibly a ground loop somewhere. An earlier posted suggested flipping off the main breaker and run the radio on a battery for a bit to see how much noise is still there. I would agree with that as a tool to help eliminate sources. Major suspects are any electronics or appliances that use switching power supply regulators. If the breaker trick DOES reveal its something in the house, then what an earlier poster suggested is correct - unplug things one at a time to isolate the noise source. Don't just turn it off as many items will still be using power even in an off state. Hopefully with a little time and effort you can determine the noise source and post your findings to this thread for more specific advice.