Scanner Q&A

I am having problems with distant reception such as ANF frequencies, White tactical channels.

In the early morning hours, I could hear ANF channels loud and clear, but as the day progressed, became static, ultimately can only get every 4th word (if that).

Is this my location that is impacting this? Assume is similiar to CB radio, the sun impacting the ionosphere?

Others seem to be able to get enough during the day from these frequencies.

My antenna is supposed to be omni-directional... Should I try turning it?

Your thoughts?

At upper VHF the sun and sunspots have little direct effect.

What can happen, is if you are within a favorable inversion layer, you can get better than expected reception. That likely was NOT happening this morning, since you have to have relatively still, stable air for this to occur.

As humidities drop, static increases, and this raises the noise floor of the radio spectrum, making your radio seem less sensitive. This is very common phenomenon during wind-driven fires.

Additionally, they may have switched primary repeaters, selecting those more favorable to the terriain - or those that are still being powered - and you can't hear the one that they are now using. They also drop-in low-powered repeaters during fires that may be superior to the ones that are there 24/7.

Hope this helps.

Thank you TPGuy

Just frustrated can't help more

Are you able to hear more where you are located (since your in TP)?

Trying to figure out if there is something more I can do.

I am of the impression that our RS primary transcriber is hearing a LOT more on the Big HOrn incident than I am and is further east than I am but also a bit south.

Assume location also contributes? or do I just not have "the ear"?

Bruce - I have multiple scanners going - so what I miss on one, I might catch on another. Oddly enough, my base that is hooked up to an car antenna that is mounted on the roof is picking up ANF 172.3750 more clearly than the hand held that is hooked up to the Scantenna.... I finally shut down the online scanners because they were not focused on the Big Horn fire and I was hearing nearly everything on my own scanners anyway.

Location can be a factor as well as local interference issues. Some types of interference you just cannot hear. FM ignores most man-made wideband interference which is typically AM in nature.

Also "driving" a scanner with 100' of lossy coax cable - even with a good antenna, can sometimes be worse than a shorter antenna with a shorter coax run, as Vicki seems to have found out.

A beam antenna can help, as it focuses more energy in one direction AND ignores energy and undesired signals off the sides and back end.

Another thing that I forgot to mention - there are "links" to the main VHF repeaters for the USFS in the 414 and 415 MHz parts of the band.

You can find some of the frequencies on the internet, and some are temporary during fires, so you'll have to use your "search" mode on the scanner to find them.

Depending how they are used, you may only hear the "mobile" part of the conversation, or both sides. This may help some that have difficulty hearing some of the USFS ANF channels locally.

My head is spinning in every direction after reading this thread. LOL!!!!

Resurrecting this thread.....

The problem went away all by itself when I first started it... here we go again....

CHP Copper-1 (main CHP dispatch) BDF Dispatch and 170.000 (ANF-1) ....

In the mornings are fine..

Around 9 a.m. I get a lot of static between transmissions. When they talk on these frequencies they come in loud and clear. But after an xmit ends, about 3 mins of static then static ends and scanner continues roaming.

All of these frequencies are attenuated.

I have set CHP (as a test) to WFM, the followup static problem goes away, but I can barely hear them. This is not acceptable because if I turn up the volume to hear them then the whole neighborhood hears all the other frequencies.

I can not squelch the static down.

This is only happening on a few frequencies, and is only after 9 a.am.

Frustrated to the point of just shutting it off after the static starts.

My handheld can't even pickup these frequencies

Do I need to buy an attenuator?

Any help is greatly appreciated.

You may have a source of interference that is always there, and some squelch systems are designed to "open" on a strong signal, but lower their threshold once the squelch is open, so that fading mobiles can still be heard.... so this may explain part of the problem.

If it's a local source of interference, prime culprits can range from anything from "touch-lamps", ultrasonic bug zappers, light dimmers, wireless phones, CATV systems, or things with a processor in it - even computers and monitors. Many of these things that aren't intended to radiate sometimes will be temperature sensitive, so as the temperature in their environment changes, the problem becomes worse or better.

The problem above is more of an issue with the lower frequencies - which explains the problem with CHP in the 39 MHz range.

Here's where the fun begins. It can be in your house or at a neighbor's home. So try relocating the scanner or turning off appliances when the problem occurs. Some appliances are never truly "off", so you may have to unplug these.

You didn't mention the model of the scanner you have. If it has CTCSS/PL decoding, you can turn on this feature for CHP. Their tone is 118.8 Hz as I recall - that should eliminate the squelch staying open, but if you have a problem hearing their multiple 110W class transmitters - they simulcast from Strawberry, Keller and Onyx Peaks then you have an interference problem, or you could have a broken scanner... but I would suspect interference as being the prime culprit.

Note that most "manmade" interference is AM in nature, and some of it is wideband, so your scanner won't demodulate it. It will cover up signals, or open your squelch. If your scanner has a signal strength indicator, this may show a strong signal while you are hearing what sounds like "open squelch" or nothing at all, and that's certainly indicative of wideband interference.

BTW 170.0 MHz is not ANF-1, it's used as an air-ground coordination channel.

Happy hunting.