homepatrol crakle on certain channels

[Ncfirewire]

i was wondering if any of you would know why i am receiving a loud crackle only on a couple of channels but mainly on 424.350.
my signal bar is full but there is a loud crackle noise that almost drowns out the talking and turning off the attenuation doesn't make it better or worse i have it plugged directly into the wall and i am using a roof top antenna and there are no other agencies in the area that use that frequency any ideas?

 

[kruser]

What are you monitoring on 424.3500?

What happens if you disconnect the outdoor antenna and just use the little whip that came with the radio for a test only of course?

edit: nevermind on the frequency use. I see from your other posts that you are around New York and they allow public service use down around the 420 MHz area. That is something I never knew before!

 

[Ncfirewire]

if i use the regular antenna i wont pick the channel up at all

424.22500 WNMF545 RM 565 DPL BFD Ch1 Disp Fire Ch. 1 Dispatch FM Fire Dispatch
424.35000 WNMF545 RM 251 DPL BFD Ch. 2 FG Fire Ch. 2 Fireground FM Fire-Tac
423.90000 WNMF545 RM 114 DPL BFD Ch. 3 Fire Ch. 3 FM Fire-Tac

ch 1 and 3 are crystal clear its just ch2 that has the horrible crackle

 

[kruser]

if i use the regular antenna i wont pick the channel up at all

I was afraid that may be the case. I never could use the signal meter in most of the newer scanners that have the bar graph meter as they almost always show a full signal even on weak signals!
I think as long as a signal sounds to be full quieting to your ears, the scanner will show full strength even when it is not.

When you do try the units little whip antenna and open the squelch (if no tone is programmed), do you here any noise sources other than white noise?

It sounds like it is simple overload or intermod from another nearby transmitter. Maybe UHF paging signals if the crackling noise comes and goes when the 424.350 signal is on the air.
Is the crackling noise always there or does it come and go when a user is talking on that frequency?
If it comes and goes, you may be able to track down the offending frequency using another scanner set to scan across the UHF paging bands which I think are around 454 and 462 MHz but I could be way off on that one.
Monitor the 424.350 signal with the home patrol and when it becomes active. try and match the offending crackle with a paging signal using another scanner set to search mode for the common UHF paging band.
If you find a paging signal that comes on the air at the same time the crackling starts, you can use a PAR filter and notch out the UHF paging range.
It could even be a signal in the VHF band that is causing the problem but if you are going to try and search for the offending signal, I'd start my search in the UHF band.

 

[Ncfirewire]

with the whip antenna all i get is white noise the crakle happens the entire time they are talking

the problem is its hard to check because the only time they use this channel is when they have a working fire

 

[kruser]

with the whip antenna all i get is white noise the crakle happens the entire time they are talking

the problem is its hard to check because the only time they use this channel is when they have a working fire

OK, that should rule out a local source of the noise that is actually on the same frequency.

I understand the problem of finding the offending signal when the primary frequency is seldom used! That definately makes things hard.
Do you have access to another radio to see if the noise is still there?
Not sure what that would really prove though but I guess it would be interesting if it did go away.
Being a fireground channel, you would think it is not their equipment.
I'm still suspecting intermod or overload from another signal that is near your location.
If it is from paging signals, I'd think you would hear it come and go when fireground is active but some active paging signals can keep transmitting for 30 or more seconds so that may be too long to ever verify anything with the fireground comms being so short.
I'd also guess there are a ton of active signals in your area so it could be almost anything being as it seems to always be present when the fireground channel comes active. Maybe even from a local FM or TV broadcaster.

Any chance you could record a short sample of the crackling noise sometime and post it? I'd think you could set the fireground channel to record and then post that file from the HP1.
Maybe someone can tell what it is by the sound and offer some more help.

You may also try asking in the New York forum as maybe others that monitor that system in your area can help.

Good luck!

 

[Ncfirewire]

if they are at a working fire for 2 hrs it will make the noise the entire time i have a recording of it but i am not sure how to add sound files on this site

 

[kruser]

if they are at a working fire for 2 hrs it will make the noise the entire time i have a recording of it but i am not sure how to add sound files on this site

That is odd and a bummer at the same time. Talk about taking the fun out of monitoring that channel. Noise like that drives me batty!

For posting a sound clip, first find the sound clip in the SD card when you plug the HP-1 into to computer. I forget the folder structure of the HP-1 but you should be able to find the recorded audio files. Maybe Sentinal has a method of copying the sample to a folder on your computer?

Anyway, once you find the file with the correct sound sample, use some type of compression program like winzip and compress the file so it has a ZIP extension.

Then when you do a new post, look at the bottom of the new message window below where you are typing your message and you should see a bow called "Manage Attachments". Click that button and a new window should open that allows you to browse for and select the file you zipped. Just select that file and click the upload button and it should attach into your post.
Pay attention to the file size limitations as it will be rejected if too large.
I'm not sure the file size limitations are set in stone as I think I've uploaded a file that was slightly larger than what the attachment screen said is allowed.
Once the upload window shows the file was attached, you can close that window and go ahead and submit your message as normal or continue adding text into your message. It will show the message with the attachment if it worked after you hit submit.
You don't have a lot of posts here yet so they may place some restrictions on what you can do but I think it will work as you have been a member for several months now.

Or maybe someone else knows of a wiki link that explains how to upload files that would no doubt make a lot more sense than my dribble!

Oh yeah, I don't think you could upload the entire two hour recording! Maybe start and stop recording when the noise is present so the HP1 will create a single small file for the upload. Something like 15 seconds of audio would be plenty I think for others here to determine what it may be judging by how you say it stays on the entire time.

 

[Ncfirewire]

ok here is a short clip

 

[GTR8000]

Interesting. Do you hear that pulsing noise on the frequency when there is no activity? Tune the scanner to that frequency in search mode then open the squelch, do you still hear it? Or are you hearing it only when the repeater is keyed up?

I'm not too familiar with the HomePatrol, is there even a way to manually tune to a frequency with the DPL off, where you can open the squelch wide?

Basically, we need to figure out whether you're hearing interference on the frequency itself, or if you're hearing something coming from the repeater itself.

 

[Ncfirewire]

the pulsing noise is only when it is keyed up there is no pulse with the squelch wide open when no one is talking

 

[GTR8000]

So it's most likely not anything causing interference on that frequency nearby you, rather it's something going on with or near the repeater itself.

Next time they get a fire and the repeater is active, is it possible for you to go mobile and listen? Even if you walked down the block with the stock antenna on the unit, it would be interesting to so if there's any change to what it sounds like.

I know you said you can't pick anything up with the stock antenna, is that for all 3 repeaters or just the fireground repeater? I notice on their license, they have two locations listed. I'm curious if you're picking up a more distant repeater on fireground, as opposed to closer repeaters for Ch 1 and Ch 2.

 

[Ncfirewire]

buffalo is about 25 miles from me so it would have to be a road trip to see what happens with a portable

i get channel 1 and 3 perfectly that's whats strange so i don't think its a distance issue i have talked to a few people that live right in the city and they don't get the pulsing noise on 2


with the stock antenna i can only get channel 1

 

[kruser]

That is kinda weird as the system shows all the channels as being a repeater with decent power levels. I wonder why you can only hear the dispatch channel with the stock antenna. Maybe their tac and fireground antennas are not as high or maybe the repeaters are really not the same power as the dispatch channel.

I wish our fire was like yours.
Around here, unless the fire is very close, almost all fireground talk is simplex with no repeaters so no chance of hearing them from more than a mile or two away. At least not the portables. I can still here those in their vehicles as the mobile radios are pretty powerful.
There are some fire departments here that are on repeaters but the ones I'm interested in are mostly VHF simplex with no repeater.
This should change soon as they are installing a new countywide trunked system although I'm not sure if fire will move to the system.
St. Louis City has had a 800 MHz trunked system for years and then switched to a P25 system a few years back. City Fire is still on VHF but they have started testing on the P25 system a few months ago now. I've not really heard them make any full time use of it for fire though.
I would not be surprised if they stayed on VHF really.

 

[Ncfirewire]

my local fire dept the same as yours once they get on scene with their portables you cant hear anything on the ops channels that is why i changed the cable and antenna now i can hear the fire ops channels in a 15 mile circle

as far is buffalo goes i am not sure why channel 1 will work just about anywhere i am guessing the repeater does have more power but i would think i would either get ch 2 and 3 perfect or not at all not what im dealing with

 

[GTR8000]

Around here, unless the fire is very close, almost all fireground talk is simplex with no repeaters so no chance of hearing them from more than a mile or two away.

Which is exactly the way it should be...analog conventional simplex for fireground operations. KISS...the last thing you want is a repeater or trunked system failure, or inability of the portable to reach the repeater, to prevent a critical transmission from getting in or out of a fire building. I know it sucks for listening purposes, but I sincerely hope that no FD anywhere is silly enough to put fireground comms on a trunked or digital system, or even conventional repeaters for that matter.

Back to the OP's issue. Based on your distance from Buffalo, and the fact that people closer to the repeater don't have this pulsing issue...it's safe to say that there is something between you and the repeater that is causing this issue on that particular frequency. What exactly it is, that's hard to say.

 

[kruser]

my local fire dept the same as yours once they get on scene with their portables you cant hear anything on the ops channels that is why i changed the cable and antenna now i can hear the fire ops channels in a 15 mile circle

as far is buffalo goes i am not sure why channel 1 will work just about anywhere i am guessing the repeater does have more power but i would think i would either get ch 2 and 3 perfect or not at all not what im dealing with

One thing you may try if you have not already is unplugging things that are near your scanner. Computer stuff and most all modern electronics are really bad about spitting out garbage.
It would not be out of the question that some of your own equipment may be mixing with the 424.350 signal and causing the noise.
The reason you do not hear the noise when opening the squelch on the silent channel would be because it takes both sources to be active in order to produce the crud you are hearing.
Don't just turn things off like TV's as they are not really off, actually unplug things from the wall when the channel is active and see if the noise is being generated by some of your own equipment.

Just an idea but worth checking.

 

[kruser]

Which is exactly the way it should be...analog conventional simplex for fireground operations. KISS...the last thing you want is a repeater or trunked system failure, or inability of the portable to reach the repeater, to prevent a critical transmission from getting in or out of a fire building. I know it sucks for listening purposes, but I sincerely hope that no FD anywhere is silly enough to put fireground comms on a trunked or digital system, or even conventional repeaters for that matter.

I agree. While it does suck for monitoring, it is the fire fighters whose lives are at stake.
Our city is (or was) VHF direct and has been for a many years.
I'm in the county so I have a hard time hearing them until I found that they simulcast dispatch on a UHF frequency. I can hear that just fine at my location.
I never did really figure out why they simulcast on that UHF frequency but I think someone once told me that some of the station houses were in bad locations and the UHF channel assured them of hearing the dispatches.
When I've heard them doing radio checks or roll calls, I monitor the UHF channel and can hear the station houses or mobile units reply back as they keep what seems to be an open mic running on the UHF transmitter for the duration of the tests. I can actually hear the audio from the open mic being picked up from their VHF radio consoles as the units respond back. It is not perfect as you also hear the chatter of everyone in the radio room but at least I can hear something. Sometimes the open mic does drop out so I suspect it may be on some kind of auto timer. Anther words, I don't think a person is sitting there holding the PTT button in on the UHF radio! I think it is something tied in with the main VHF console that keys the UHF radio.
I do not monitor city fire that often so I'm not sure if this open mic condition is there during an actual dispatch.
If you ask me, the City of St. Louis fire department has a "noisy" radio system. It seems there is always a ton of background noise when they dispatch.
I'd never really thought about that before until someone posted the audio feed from an outdoor tent collapse during a storm that killed a person a few weeks ago.
One of the users here commented on that audio feed and said he sure hoped their audio was much better than the VHF feed recording when they made the switch to the P25 system. He said it was full of squeals and feedback. That comment made me listen to the feed recording that was posted in a thread in the Missouri forum.
The person that made that comment was from another state but he was right, the feed audio was horrible! It was not because of a bad feed either, it was from the background chatter mostly as far as I was concerned. It sounded like a bunch of background chatter going on in the dispatch room. It was only then that I realized the guy was right and I also started noticing that their signals were noisy but from human noise more than anything from what I could tell.
Should you wish to hear it, that thread with a link to the audio file is here if the audio link is still valid, I did not test it. http://forums.radioreference.com/missouri-radio-discussion-forum/239292-st-louis-tent-collapse-mass-casualty-incident-recording.html

If you listen to it, please post your comments. I do agree with the user, 902, with the negative comments that the audio was noisy and not very pleasant if that is what you hear as a firefighter while doing your job.
I have yet to hear them on the P25 800 MHz system other than a few tests so I cannot comment on how that sounds. Someone did update the system info here with the fire talkgroups but I've still not heard them use them for anything but testing. I should monitor them and see if they have actually switched or not.
And get this, I heard one of the reasons they had not switched was because they were waiting on some in building low power repeaters or maybe "leaky coax" systems to be installed in the basement areas of some of the downtown area buildings! Talk about things that could fail, I can't imagine they would depend on all of this for fire fighting. This sounded like a huge mess with many possible points of failure to me. Definitely far away from the KISS principal!

Would I like them to switch, sure as I could then hear them but in reality, no way as I feel it will put them at risk. Major risk in my eyes.
Now if they want to install mobile extenders that will only rebroadcast (no other purpose, their radios would still be analog direct) fireground comms for scanner hobbyist’s, I'm all for that! I'm sure that dream will never come true :twisted:

 

[Ncfirewire]

well today i got out my portable and opened the squelch and the pulsing was constant when they were ot even transmitting so what does that mean??

 

[kruser]

well today i got out my portable and opened the squelch and the pulsing was constant when they were ot even transmitting so what does that mean??

What were you using for an antenna?
If using the duck, walk around your home and see if it gets stronger when you get near any electonic equipment. Have you tried unplugging everything around your scanner? Maybe even unplug things around the entire home so you can rule out something in your home.
Of course it would be best if you find the source in your home as then you are in control and can repair/filter or remove the offending device.

See if you can figure out how to post a sample of the noise. That may helps tons.
If this only happens on the portable when it is connected to the outdoor antenna than my guess is some transmitter or noise making device near your home. It could be almost anything really but I'd try and unplug the stuff in your own home first and see if it goes away. That is the first step in troubleshooting something like this, eliminate sources of noise that are in your control. You could even kill the homes main breaker and if it stops, turn that back on and start killing the individual breakers until you hit the one that stops the noise. Then figure out what that circuit all powers and narrow it down to the device.
Do you by chance have an amplified antenna of any kind? One for TV or for your scanner?
If so, kill them and see what happens. You are not running a preamp on your scanner antenna feed are you? Those usually create many more problems that they help.

So, start with a process of elimination while using your portable. Kill the power in the home and hope the noise stops. If it does, you just need to narrow it down to what device is the cause.
If the noise continues, you may be SOL depending on the source. That is where a sound sample of what you hear may help. Things like intermod have a distinct sound and someone could tell you what it may be. If it is some type of intermod, then a filter may be needed. If it is a signal on the actual frequency then I doubt you could do anything about it short of maybe getting a yagi antenna aimed at the signal you want with the hopes that the offending signal is coming from another direction.

Try the power test first and see what happens.