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Taking a Radio Camping

(ewpratten.com)
139 points ewpratten | 2 comments | 27 Jul 24 02:26 UTC | HN request time: 0s | source
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curiousfab ◴[27 Jul 24 09:12 UTC] No.41085383[source]▶
The variation in local noise between different locations is huge. As an apartment dweller and radio amateur, this is something I am fighting every day and in a densely populated environment, the noise floor changes all the time, depending on which neighbor operates which electrical device at the time...

The amateur radio community is very aware of the problems and several initiatives have been launched to quantify the effects. One of them is the DARC's ENAMS, which is described in detail here:

https://web.tapr.org/meetings/DCC_2020/DK5HH/F_ENAMS-DCC-DK5...

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wkjagt ◴[27 Jul 24 12:08 UTC] No.41086039[source]▶
Have you tried a QRM Eliminator? I haven't tried one myself yet, but I hear good things about them. Also, some really simple things can be really noisy. Cheap LED bulbs for example can be super noisy. I had one above my desk that was terrible.
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1. ztetranz ◴[27 Jul 24 12:24 UTC] No.41086126[source]▶
I think that's a phasing device. You attach an auxiliary antenna specially to pick up the noise. The signal from that is phase shifted and mixed into the signal from the main antenna. The phase shift circuitry has knobs to vary the phase and amplitude. You adjust them so that the noise cancels out.

That can be effective but it's really only useful for cancelling out one noise source. I once used a similar device when there was something bad happening on a power pole down the street. It's no use if you have general noise from multiple directions.

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2. aaomidi ◴[27 Jul 24 15:03 UTC] No.41087036[source]▶
This would be an effective method against Iran’s scrambling of satellite TV