APX-7000 Slow Scan across frequencies - makes radio not usable. Is this correct?

[rggann]

Hello,

I operate a Fire Department in which we use both VHF and 800MHz Trunked systems. All engines have 2 radios and officers must carry 2.

We just received an APX-7000 radio - but I'm finding that if I'm scanning both VHF and trunked channels - the scan speed is so slow that I miss conversations - particularly on the VHF side.
If I modify the scan list to be scanning only 1 side - say VHF, then it operates normally. I suspect the same is on the 800 trunked side but I'm not sure.

In my operations environment, scanning on both bands is required - I don't have the luxury of operating only on VHF or 800.

Right now the APX is basically an expensive brick - I can be on scene (with 3 radios hanging on me now - 1 VHF, 1 800, the APX). I will hear a conversation start on the VHF radio - on a channel I'm scanning on the APX - and the APX may or may not ever respond. Often it is 6-12 seconds before the APX picks it up, if ever.
It does seem that if I to get a VHF transmission - the next 'few' will work - probably something to do with scan delay saying on that bank.

Many conversations are shorter than that - for instance, somebody calling me will just say "xxxx, yyyy on VFIRE 21" - where xxx is my designation and yyy is theirs. I'll never hear them.

My comm guy as talked to the county comm guy who does not think this problem exists - he says he has not heard about it and does not see it in the shop - yet I've seen it on every call.
His response is "okay - if you don't like it I'll give it to somebody else".
What I need is either
- you are imagining things
or
- here is what is wrong.
or
- this is a characteristic of the radio - so it really is an expensive brick.

I'd really love to get this to work. I really don't like carrying multiple radios if I don't have to.

Because this radio is managed by the county - I have no info on f/w version - etc. If somebody can tell me how to see it, I can provide that.


- Bob

 

[noaffiliatefan]

Bob -

First of all, welcome to the site (am I allowed to say that? LOL)!

This site gets less action on the weekend, so I suspect someone with a definitive answer will chime in over the next couple of days.

Interesting that you raise this point - my local FD also uses VHF (mainly "red" or 153.830) for fireground, and 800 MHz P25 trunked with APX 7000 radios. I have heard more than a few arguments over the air about missed transmissions and replies, plus also transmissions meant for red going to the 800 system and vice versa. One chief totally lost his cool and asked for an immediate "face to face" with a crew since "they weren't going to reply to his calls."

As far as I know, the APX7000 is dual-band but not simultaneous receive. If there's a transmission on the 800 system, it will be deaf to anything on VHF, and vice versa. I suspect there are scan delay timers that could be adjusted to make the situation better, but if a there's a long transmission on 800 and a VHF transmission starts after that and ends before the 800 ends, I'm guessing you'd never hear it.

Not sure how your comms guy couldn't figure that out.

Again, I'm not an APX user or programmer, so wait for a more definitive reply before going back to the comms guy.

 

[Notarola]

I dont have APX but Isuspect the default setting are the culprit. try making the following changes to the codeplug under scan configuration-scan wide.

voice rx/tx change 6 to 1
data rx/tx change 6 to 1
monitor hold time 6 to 2
system search time 255 to 1

with these changes try just placing a active trunked TG and a Vhf freq in a scan list. then while you know the trunked to be active key up the vhf with a different unit and hold it keyed and see how long it takes the APX to receive the VHF signal after the trunked stops talking. You can also reverse the test by keying up the trunked TG and unkeying the vhf to see how fast it detects the active TG.

 

[radioinstl]

No Public Safety agency should operate mission critical communications using Mixed mode scan (conv and trunked). You WILL miss transmissions. If you are operating in an environment that requires you to hear 2 different channels at the same time (working fire, active hazmat, rescue etc)you need 2 different radios. It does not matter the band. That is why many places have a command aid. If you are forcing non command personnel to operate in the "hot zone" with 2 radios you should reevaluate your comm plan. 99% of NIOSH Firefighter Fatality Reports list communications as a direct factor in the death. The last thing you need to do is add a 2nd radio to that.

All radios suck with mixed mode scan. As soon as you leave the traffic channel to listen to a conventional channel or to scan you will miss stuff.
Fix the problem (operating on 2 channels) not the symptom (mixed mode multiband scan does not work)

 

[CSAdmin]

The APX series radios are not true dual-band (at same time) receivers. This is a basic function of most ham radios, but Motorola left it out as they figure it can confuse the end users.

Your solutions:

- Reprogram as outlined in Notarola's post to minimize the effect;
- Set up a multicast patch from 800-->VHF or vise versa
- Use two separate radios.

There is no other way to do it. The problem is the fact the radio must monitor the trunked control channel for a minimum amount of time, to determine if there's voice traffic for your talkgroup(s) on the site you're affiliated to. It requires a minimum of a second -- or longer, if scanning a busy TRS. While monitoring the TRS, you aren't "rapidly" scanning the conventional frequencies on VHF.

 

[hambone]

No Public Safety agency should operate mission critical communications using Mixed mode scan (conv and trunked). You WILL miss transmissions.

Our policy board banned cross band scanning for the exact reasons radioinstl gave. The system manager then removed the option in all the code plugs.

 

[Firebuff66]

This has been happening since trunking came around, we used to have astro spectra's scanning a trunked channel and a conventional channel and we missed things all the time.

We currently have a PD doing the same as you, 800 trunking and VHF, with no way to have priority while scanning trunked and conventional together they some times miss things, we advised them from the start that this is how the radio will work and that's it.

Any good Motorola shop should have been able to tell you this before you started operating the radios in that way, and as stated by others, life safety operations should be on a simplex conventional channel.

I was involved in a Firefighter fatality investigation years ago and its not a pleasant thing to try and tell the department that just lost men in a fire that using the repeater system on the fire ground is part of what caused the tragedy.

But with NIOSH reports out the A** about the same thing, we still have departments that use talk groups or a city wide simulcast system in the fire buildings and wonder why they can't talk from the sub basement.

 

[moetorola]

This is just how the APX works for Multi Scan, there is no priority when in multi scan. It was not designed to operate the way you want it to.
Scan should never be used for any critical comms on scene IMO.

Commander/s should be the only one that has multiple radio's (mobile radio's in our case in the back of a suburban), all others should be on there designated assigned Channel/TG and scan turned off. And this is usually only in M/A situations, the commanders of each department have a designated staging area next to each other.

Please don't take what I say as bashing, it is hard to convey the seriousness of your situation thru a keyboard. Just want you guys to be safe.

 

[Mars]

Any good Motorola shop should have been able to tell you this before you started operating the radios in that way, and as stated by others, life safety operations should be on a simplex conventional channel.

I was involved in a Firefighter fatality investigation years ago and its not a pleasant thing to try and tell the department that just lost men in a fire that using the repeater system on the fire ground is part of what caused the tragedy.

In my city of around 750,000~, they use a shitty 800 MHz SmartZone 4.1 TRS with only three sites (south, central, north) for fireground operations. They far west/east areas of town have insufficient portable coverage and bonks are very common -- especially when wearing the radio against the body, using a speaker-mic and inside of a basement!

I remember a structure fire incident where the on-site district chief issued an urgent "GTFO" message to all firefighters as the homeowner reported a large amount of ammunition in the basement, where the fire was burning. It took several transmissions and verbal messages (personal contact) to get everyone out of the building.

The brainiacs here have only ONE simplex frequency in their radios, designated for fireground use. And it's never used. Ever.

If this wasn't bad enough, dispatch assigns multiple incidents, such as automatic alarms, motorvehicle collisions, small fires, high-angle/trench rescue, etc, all on the same primary response talkgroup. They have one additional fireground talkgroup, if it's required.

I've heard district chiefs/engine captains become extremely irate when they're unable to get on the air.

We have all kinds of stupid, in Winnipeg, Manitoba.

 

[motorola_otaku]

My $0.02 as a fire comms guy (IANAL, IMHO, YMMV, the views expressed herein do not represent the organization, and all of that...)

When we transitioned from conventional to trunking using APX subscribers we told everyone from the onset that cross-system and cross-mode (conventional/trunking) scanning would not be permitted, and made it a part of user training. We also did not permit user editing of scan lists (kind of hard to do on a Model 1.5 portable anyway) and only permitted scanning on the home system. One, we didn't want the radios constantly de-affiliating and reaffiliating when they hopped between systems or modes, and two, we didn't want each shift or user jacking with the scan lists just because they did or did not want to hear something. Scan on mutual aid/outside agency channels is completely disabled. Again, user training was key.

 

[box]

Our policy board banned cross band scanning for the exact reasons radioinstl gave. The system manager then removed the option in all the code plugs.

I'm sure by cross band you meant conventional and trunking, which just happen to fall in different bands in your situation. Just want to clarify that two band conventional scanning would be no different than single band.

 

[radioman2013]

That's just plain dumb, even if the radio is not receiving on either channel the radio when scanning between conventional and trunking has to go back to the control channel for trunking assignment and then switch to the group, and that takes time. Any dept whether it's Fire, PD, EMS or whatever is looking for trouble having a radio scanning on an active scene.
In my FD the Chief officer could be walking around with as many as 4 to 5 radios. Interior, Water, Ops, EMS, and maybe PD or Interop.
Why a crew lets say doing Interior overhaul has to listen to somebody else other than his crew or Chief is beyond me. Sounds like too much oversight and technology is getting in the way.

 

[dustymedic]

Around here, fire scenes use 2 trunking TGs on the same system and the ICs use 2 radios to monitor ops. You can't depend on a scan feature for emergency operations no matter what...

 

[Notarola]

Either way its a pain to have to carry and monitor 2 radios. The solution is for a coordinated single freq or TG to be used by everyone on scene. I know that there will be logistical issues but these are not impossible to overcome.