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Author Topic: Basic choke to use  (Read 374 times)

W9IQ

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Re: Basic choke to use
« Reply #15 on: December 14, 2021, 06:46:53 AM »

If you are looking for a way to track down the noise, consider a Tiny SA (spectrum analyzer) for under $70 on Amazon. It is battery operated and comes with a small antenna so you can walk around and see the relative signal levels on the screen. While I own bench type spectrum analyzers, the pocket version has been helpful to use in tracking down noise and interference for other hams.

- Glenn W9IQ

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- Glenn W9IQ

God runs electromagnetics on Monday, Wednesday and Friday by the wave theory and the devil runs it on Tuesday, Thursday and Saturday by the Quantum theory.

W1VT

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Re: Basic choke to use
« Reply #16 on: December 14, 2021, 06:50:28 AM »

When I got started there were a ton of loud shortwave stations that could be heard that are now gone.
The BBC doesn't have a single transmitter providing North American Service.  The VOA's Bethany relay site is now a shopping mall.
https://en.wikipedia.org/wiki/Voice_of_America_Bethany_Relay_Station

Most of the day to day activity these days is on the digital mode FT8.  Tune to 14.074 and 21.074 USB.
SSB and CW are more likely to be found on weekends.  Especially on scheduled contest weekends.
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G4AON

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Re: Basic choke to use
« Reply #17 on: December 14, 2021, 08:39:21 AM »

And honestly, I'm not so sure much of what I'm hearing on 20 through 10 is the bandnoise.
<SNIP>
Most days, right now, 40 sounds pretty good but the minute I go to 20 the noise is generally unbearable. Even on a battery.
“Band noise” is going to be local electrical/electronic “fog”. If you take a radio and antenna out into the country, you will find the noise drops to zero.

You need a step by step approach. As earlier replies, do you pick up the noise around your locality? A shortwave domestic transistor portable radio can help, maybe you can even pick up noise on a medium wave pocket radio for a discreet walk around. Also there is a DF flag antenna project in March 2021 QST that looks handy.

73 Dave
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KH6AQ

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Re: Basic choke to use
« Reply #18 on: December 25, 2021, 12:33:04 PM »

And honestly, I'm not so sure much of what I'm hearing on 20 through 10 is the bandnoise. It's been a very long time since I've had anything setup (won't mention how long) but was first licensed in 1970. I'm trying to remember what things sounded like back then with my Knight R100 rcvr but seems to me it was much, much quieter. I think also the bands were peaking at that time -- I worked much DX on 10 meter AM back then when I got home from school.

Most days, right now, 40 sounds pretty good but the minute I go to 20 the noise is generally unbearable. Even on a battery.

Did you shut off all AC power to your house? That is how the battery powered radio RFI is conducted. If the noise goes away when AC is shut off the RFI source is in your house. If not, it is outside.

Bob Sherwood says residential ambient RF noise has increased 3dB per decade for several decades. Ambient RFI today is much higher than it was in 1970.
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