Do scanners just miss messages no matter what?

[RedPenguin]

I live in the city that frequency I listen to is broadcast in.

I have my scanner on hold, PL tone, and Squelch of 1 on a BCT15 with a Diamond RH77CA.

I never normally seem to miss a message except once in a while.

I will hear the dispatcher say received but never heard anyone else talk before that. Yet, there are times, I will hear an officer say something, that they dispatcher claims they didn't hear or are not picking up.

So, is radio communication just flaky once in a while?

 

[rdale]

No, they probably have a better receiver / antenna combo.

 

[RedPenguin]

Yea

No, they probably have a better receiver / antenna combo.

Well, I can defiantly assume the antenna part, because I'm in a hole somewhat, while they are up in the mountains with huge antennas. Also, I can believe their receiver is better.

 

[RKG]

There could be a hundred possible explanations; here are two:

A) Sometimes, on a Motorola system using MDC, an officer will "acknowledge" by simply keying his radio. This causes his ID to come up on the console screen.

B) Sometimes a dispatcher misses something because he was not paying attention, was talking to someone on the telephone, was answering a walkin at the desk, or something else, and covers himself by saying something like you've reported. There is a feature of many (if not most) consoles that is designed to deal with this problem; it is called IRR and is a button or icon that, when pressed, repeats a temporary recording of the last transmission received, but a lot of times the dispatcher doesn't use it. I can't explain why not.

If you've ever spent time in a 9-1-1 dispatch center, you'll see that it is sometimes quite hectic.

 

[jon_k]

I will hear the dispatcher say received but never heard anyone else talk before that. Yet, there are times, I will hear an officer say something, that they dispatcher claims they didn't hear or are not picking up.

Do you have power saver turned on?

When no activity happens for X time the receiver goes into a mode where it sleeps and wakes up every 300ms (or similar) to check for a signal. If signal exists, it receives. If not, sleep 300ms more.

This results in battery conservation. If you have this turned on thats your problem. I'm betting this is what your issue could be.

I know the BCT15 is more of a desktop scanner, but it still may have the feature in firmware for mobile operation.

 

[MississippiPI]

I hear AMR dispatch great here in the Jackson, MS. area--it's rare that I will hear the units unless I'm sitting right there by them.

Be safe

 

[RedPenguin]

Do you have power saver turned on?

When no activity happens for X time the receiver goes into a mode where it sleeps and wakes up every 300ms (or similar) to check for a signal. If signal exists, it receives. If not, sleep 300ms more.

This results in battery conservation. If you have this turned on thats your problem. I'm betting this is what your issue could be.

I know the BCT15 is more of a desktop scanner, but it still may have the feature in firmware for mobile operation.

Nope can't seem to find this feature in settings at all. Only thing I can find is ACG but don't think that would do it.

 

[Pimpala03]

Maybe someone talked to them on a simplex (talk around) type channel and bypassed the repeater.

 

[zz0468]

So, is radio communication just flaky once in a while?

I would hesitate to use the term 'flaky', but the reality is, it IS less than perfect. Radio propagation is statistical in nature. In other words, you specify in percentage what the desired coverage is. 95% coverage 95% of the time is a commonly used specification. That means 95% of an area would be covered, and it could be expected to work 95% of the time.

Even microwave links, which you would expect to be there working all the time, are specified in terms of availability. 99.9999% availability would translate to about 30 seconds of path outage per year.

 

[n2mdk]

I'm not sure how fast the PL decode on the BCT15 is but if it's not really needed turn it off. It can at times make you miss the beginning of a transmission.

 

[RedPenguin]

Hmmm

I'm not sure how fast the PL decode on the BCT15 is but if it's not really needed turn it off. It can at times make you miss the beginning of a transmission.

I think I will try that because no other surrounding counties use the channels that I'm monitoring, so I don't need PL/DPL at all.

 

[RKG]

Maybe someone talked to them on a simplex (talk around) type channel and bypassed the repeater.

Most of the time (using a voted system), the dispatch console cannot hear "direct".

 

[chrismol1]

happens to me on a EMS dispatch, i guess the mobile EMS's guys radios are really weak, sometimes I hear them staticy and other times not at all and I only hear the dispatcher,
I almost guarentee its the antenna that you need to be high up and outdoors

 

[gmclam]

Missing stuff

I find that scanners do often miss a signal, even for no good reason. I'll run 2 or more scanners on the same channel, and sometimes scanner "A" misses the signal and sometimes scanner "B" misses the signal. This happens even when both scanners are connected thru a splitter to the SAME outside antenna. And I'll use different models of scanners too, but I don't have a BCT15 to test.

The misses seem to occur mostly on trunked channels, but it can happen on conventional as well. The more complex you've got things set up, the more likely a miss will be. For example, a receiver just sitting there looking at a conventional frequency 24/7 (not scanning) and w/o tone decoding is unlikely to miss something. Program in a specific CT/DC value and expect there to be more misses. If the channel is on a TRS, expect even more misses.

 

[LlamaZorz]

Would it be possible that, they are communicating on two different frequencies. If so you may only be hearing one side of the story.

 

[loumaag]

There is another possibilility I didn't see specifically mentioned here but have experienced quite a number of times monitoring in the Houston area. A lot of times either the dispatcher or the officer will send a message over the MDT, it is then acknowledged over the air. A lot of times it is evident from the traffic; like when the air has been absolutely quite for a while and then all of a sudden the dispatcher will say something like "20G64, that's clear", or you may hear a unit out of the blue say "20G62 en-route".