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Discussion Starter · #1 ·
I've been experiencing some strange signal drops on UHF 21 and would like some help identifying potential causes. Antenna is a ClearStream 2V pointed in between the two antenna farms in my area about 75 degrees apart. No pre-amp, using Philips LTE/5G filter.

I use the Signals GH iOS app hooked up to a HDHomeRun tuner, which charts signal quality over time. Since I have two tuners, one chart is orange (channel 10 - can be ignored) and white for Channel 21.

First type of signal drop - signal quality has quick drops and recoveries of 20-30% or more for a few minutes, then signal quality issue disappears.
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Second type of drop - signal gradually drops and recovers over time (20-30+ minutes). While not captured, I have seen it go from 98% signal quality, all the way down to the 50s, then back up to 98%
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Discussion Starter · #3 ·
Sorry about that. RabbitEars.Info

Any tips on identifying the source of the RF interference? I thought low VHF (and to a lesser extent high VHF) was most susceptible to interference, what's common to cause issues for UHF? There's two nearby low power FM stations on 96.5 and 88.7, but I do have a channel master FM trap in place that pretty much nukes those signals.

Tower is 17.1 miles away, direct line of sight. I am having a hard time understanding what power they are transmitting at. On RabbitEars, I see a special temporary authority for 0.25 kW and a license for 1000 kW. And also a construction permit for 100 kW. Not sure why they would want a STA for 0.25 kW when their license is for 1000 kW.
 

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Discussion Starter · #6 ·
For locating interfering signals on UHF, I would suggest a cheap SDR dongle and have a listen on RF21. If you hear interfering signals, build or buy a small directional antenna and try to track them down.

I've purchased two of the cheap blue R820T2/RTL2832U ebay dongles and they work fine, but rtl-sdr.com sells a modded dongle that is good-to-go right out of the box, with an SMA connector...
I already have a cheapie RTL-SDR dongle, hooked up to my TV antenna, usually for running spectrum scans.

Do you mean just hook it up without an antenna and listen/look for interfering signals on RF21? Then if I find something, add a directional antenna? Which software do you recommend?
 
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