Signal

[03msc]

The site is constantly transmitting on the control channel.

Please explain it, though.

 

[boy7777777777]

I used to monitor AWIN using and outside antenna. For some reason the signal would come and go similar to Walters issues. I finally figured out it was my coax running from the antenna to the scanner. Replaced it and I stopped having issues. Also, I totally agree with you 03msc, even if there is no radio affiliating with that tower it will still produce a constant signal. There will just be no voice to decode.

 

[03msc]

Also, I totally agree with you 03msc, even if there is no radio affiliating with that tower it will still produce a constant signal.

Exactly!

 

[K5DVT]

I live up in Huntsville. (20 ish miles from combs) up on a decent hill that's not quite line of site to the Combs tower. I pick up that tower on a Discone fairly well year round. Very rarely do I have trouble decoding.

 

[Walter0954]

I bought a discone from Whistler and thought I could pick up towers north of me.but can’t get nothing.was told by Whistler the model I got wasn’t made to receive the 700 and 800 frequencies.back to combs tower I lost the tower yesterday my scanners skips over the site I get the swain tower north of Huntsville from time to time.I have a small hilltop north of my house that hinders me getting anything north.what antenna do you use.

 

[03msc]

Just verifying you have the latest info from the database correct? Complete signal drop out seems like not all of the control channels are programmed (main and alternate(s)). Locally they don’t really change very often but some people report control channels changing periodically. I’m just grasping at straws here since we aren’t there with scanner and programming in hand…

 

[wtp]

if no one is in the forest to make a radio sound, does the tower still heat it ?

 

[03msc]

if no one is in the forest to make a radio sound, does the tower still heat it ?

Yes, because the control channel is always active. From what I understand based on what he’s said, he’s losing that signal.

 

[03msc]

@doctordialtone You have made light of replies here but have yet to explain why you don’t agree that the system operates as it does. Please explain. Are you talking about something else?

 

[wtp]

could the tower be switching to an alternate control frequency and it is not in his radio ??

 

[03msc]

could the tower be switching to an alternate control frequency and it is not in his radio ??

That’s what I’m wondering. Sounds plausible.

 

[Walter0954]

This is what I have programmed in the scanner for the combs tower.
851.4875ac
852.2875ac
858.4625ac
859.1375CC
859.4625ac

 

[tvengr]

You have the correct frequencies programmed for the Combs tower.

 

[03msc]

Yeah, those are correct so this gets more and more interesting. Since you said you have light of sight from mountain top to tower, it doesn't seem like it would be foliage (though that's definitely a plausible explanation if you weren't line of sight).

If you take the scanner outside does it receive then?

 

[03msc]

Meant *line of sight, obviously.

Are you close to a cell tower? I've heard people report those desensing a scanner and causing it to not receive as well as it otherwise would. I know that doesn't really explain the difference between cold weather/warm weather but just wondering.

 

[Walter0954]

35°51'44.3"N 93°49'53.6"W I believe this is the location that of the tower I’m just NW of this location 1.5 miles.when I do receive a signal it’s a strong signal it’s never weak.no cell towers around cell coverage sux at my location.

 

[03msc]

The Combs site is scheduled for some maintenance today, it appears. Just FYI.

 

[Alliance01TX]

One other possible cause that folks in the Microwave Radio world ( analog days especially ) experienced was "Fresnel Zone" issues and also typical temp inversion issues, especially during Spring & Fall....Fog, light rain / mist and tree leaves can (at times) significantly attenuate receive signals from my experience. That's were Space & Frequency diversity helped mitigate the issues somewhat. These may or may not be a contributing factor, but we have seen it happen....

Why not take a ride to a close-in Transmitter(s) and confirm you have good receive at that (or multiple) location(s)?

LINK: https://en.wikipedia.org/wiki/Fresnel_zone

That would validate your scanner is correctly programmed / decoding and takes that out of the "what if" questions....Better Coax (LMR) better antenna or YAGI's higher if possible might help too, in some cases - not all. Some use a proper AMP but that too is not always the right solution either...An RF Filter for the 800 MHz band is another option (not cheap) and that helps if you are getting strong RFI and migh be overloading the receiver - not likely, but an option.

Just a few ideas to ponder, but a simple "road trip" would be the first thing I would do to as a logical/simple trouble-shooting method....

Just my opinion and hope you get it solved as here in the DFW area we have issues with P25 Simulcast and heavy RFI (now some G5 interference too) that can drive you mad trying to get the best solution's that work for your specific location and station.

I go up that direction once in a while and if think about it will bring my SDS200 and see what I get...

Hope you get it worked out.

Bill