Why can't I hear individual units but dispatch fine?

[medicfan3]

Hello, I was wondering if anybody could answer this curious question I have.

I listen to an EMS station, Cliffside Park EMS in New Jersey, I should also mention that I work as an EMT for this station as well. When I have my scanner on at home and recording, I can hear my dispatcher fine but I cannot hear myself when I'm on the ambulance, for some reason it's very quiet and often hardly audible. I don't hear any static or any interference that can cause issues for my scanner in receiving radio transmissions from the ambulance.

The ambulances do not transmit on a different frequency or channel from that of dispatch we're all on the same one, so I don't really understand why I can't hear myself well or even, say, at all at times. Would this be a reception issue or what else could it possibly be? I've included an audio sample to illustrate what I mean. Please let you're not able to access it. Just in case anybody's wondering, "CPA" stands for Cliffside Park Ambulance.

Thanks in advance.

 

[medicfan3]

Use this link for the audio sample: CPA.m4a

 

[wgbecks]

Would need to know about the radio system to answer your question.
What frequency does CPA operate on or what is the radio systems FCC callsign?

 

[GTR8000]

Is this on 154.445? If so, that's a simplex channel, not a repeater. Dispatch is using a high powered base station to talk, whereas units in the field are using a lower power mobile or portable radio, so unless you're nearby to the area those units are transmitting from, you're not likely to hear them.

 

[medicfan3]

The frequency that we use would be 501.7625. but I seem to hear the transmissions better when I have the modulation switch to just FM rather than NFM. Also, we use a repeater for radio communications. Thanks.

 

[medicfan3]

Would need to know about the radio system to answer your question.
What frequency does CPA operate on or what is the radio systems FCC callsign?

We operate on 501.7625Mghz and we use an analog conventional system.

I believe this page here should answer your other questions too: FCC Callsign WIM315 (CLIFFSIDE PARK, BOROUGH OF)

 

[mmckenna]

That's up in what is known as the T-band, and it was not touched by the narrowbanding mandate back in 2013.

Looking at the license, they are permitted to run 20K0F3E as well as 11K2F3E.
20K0F3E is the older wide band FM analog. Setting your radio to FM would probably give you better audio, as you noticed.

 

[wgbecks]

We operate on 501.7625Mghz and we use an analog conventional system.

I believe this page here should answer your other questions too: FCC Callsign WIM315 (CLIFFSIDE PARK, BOROUGH OF)

In your OP, you stated that the ambulance transmits on same frequency as the dispatch that has been identified as 501.7625 Mhz.
with a callsign of WIM315 (FB2 Mobile Relay). Are you saying the ambulance does not transmit on the repeaters input frequency
but is instead transmitting on the output?

Transmitting on the output does not make sense unless the mobile radio is in "Talk Around" mode whereby the answer provided
by @GTR8000 applies. Otherwise, there is no reason that the ambulance(s) should not be heard on the repeater output frequency.

Do you mean to say the volume of the ambulance is lower or different from the dispatch or that you usually can't hear the
ambulance transmissions at all?

 

[RMason]

For reference, this appears to be the info in the database

Cliffside Park​

UHF dispatch simulcasts to EBFMA - Line 1.

Frequency	Input	License	Type	Tone	Alpha Tag	Description	Mode	Tag
154.445		KED411	BM	118.8 PL	CSP FD Disp	Fire Dispatch	FMN	Fire Dispatch
501.7625	504.7625	WIM315	RM	445 DPL	CSP FD Disp	Fire Dispatch (UHF)	FMN	Fire Dispatch

 

[ff026]

Sounds like either one of 2 things.
1) From the sound of the clip you posted, the dispatcher is keeping the console keyed and you are hearing the mobile unit or portable unit thru the selected audio speaker on the console. The dispatcher has priority on the comparator hence why he can keep it keyed and still hear the field units.

Or

2) the deviation out of the comparator to the repeater is set improperly.

 

[kd2pm]

Sounds like either one of 2 things.
1) From the sound of the clip you posted, the dispatcher is keeping the console keyed and you are hearing the mobile unit or portable unit thru the selected audio speaker on the console. The dispatcher has priority on the comparator hence why he can keep it keyed and still hear the field units.

Or

2) the deviation out of the comparator to the repeater is set improperly.

Reminds me of the old days with FDNY.

 

[wgbecks]

My apologies, I just listened to the audio clip you posted. It's apparent the dispatch console(s) are directly interfaced via wireline
or IP gateway into the base/repeater and have normal audio levels but the repeat audio level is set (in the toilet) incorrectly.

I would make a complaint about the low repeat audio level to your dispatch supervisor or director and have them submit a trouble
report to the radio shop responsible for system maintenance for corrective action.

 

[mmckenna]

I would make a complaint about the low repeat audio level to your dispatch supervisor or director and have them submit a trouble
report to the radio shop responsible for system maintenance for corrective action.

I'd agree, however:

When I have my scanner on at home and recording, I can hear my dispatcher fine but I cannot hear myself when I'm on the ambulance, for some reason it's very quiet and often hardly audible.

How does it sound on your company issued radio?
You might get some less than ideal response if you word the complaint being about your scanner, if your company radio works fine.

Make sure your scanner is set up correctly.


But, I'd agree, it sounds like the audio levels are jacked up on the system, but it's hard to tell listing to a recording from holding a microphone up to a consumer scanner.

 

[medicfan3]

In your OP, you stated that the ambulance transmits on same frequency as the dispatch that has been identified as 501.7625 Mhz.
with a callsign of WIM315 (FB2 Mobile Relay). Are you saying the ambulance does not transmit on the repeaters input frequency
but is instead transmitting on the output?

Transmitting on the output does not make sense unless the mobile radio is in "Talk Around" mode whereby the answer provided
by @GTR8000 applies. Otherwise, there is no reason that the ambulance(s) should not be heard on the repeater output frequency.

Do you mean to say the volume of the ambulance is lower or different from the dispatch or that you usually can't hear the
ambulance transmissions at all?

What I meant to say is that we are on the same channel. We use a repeater system to communicate back and forth. Just confirmed that with a coworker. There is no use of a talkaround mode.

I'm trying to say that I can hear dispatch just fine on my scanner but when one of the ambulances gets on the air I can't hear them very well. They're either very low in volume or almost inaudible in many cases. Again dispatch comes in clean and loud with no issues, the ambulances come in very quiet.

When I'm here at work everything comes in great. Dispatch and the ambulances and other fire units come in loud and clear. It's just when I'm home on my scanner the ambulances and fire apparatus don't come in clear or loud. However, I do live about 20 miles away from where I work so I do imagine that having some sort of effect.

 

[medicfan3]

I'd agree, however:



How does it sound on your company issued radio?
You might get some less than ideal response if you word the complaint being about your scanner, if your company radio works fine.

Make sure your scanner is set up correctly.


But, I'd agree, it sounds like the audio levels are jacked up on the system, but it's hard to tell listing to a recording from holding a microphone up to a consumer scanner.

Everything comes in great on my company radio (APC 8000 radio) here at the station and around town. So there's no issues here with that, it's with my scanner at home. But I also live almost 20 miles away from where I work so I don't know if that has any sort of effect on anything. I hear dispatch loud and clear it's the individual units that key up the radio that come in very low in volume almost inaudible.

Not sure if it's anything on my end or anything I need to do with my scanner.

 

[ht396jm]

Everything comes in great on my company radio (APC 8000 radio) here at the station and around town. So there's no issues here with that, it's with my scanner at home. But I also live almost 20 miles away from where I work so I don't know if that has any sort of effect on anything. I hear dispatch loud and clear it's the individual units that key up the radio that come in very low in volume almost inaudible.

Not sure if it's anything on my end or anything I need to do with my scanner.

I don’t have an answer for you but I do agree there is a noticeably lower volume on the audio coming from the rigs and the portables, the desk key-ups are significantly louder. “411 to CPA!!”. For what’s it’s worth, I hear the voter closing out on the repeater so I’m hard guessing the audio level is just turned down a bit on the repeater.