The hidden talkgroups method of scanning is proven safe if properly implemented.

What is the hidden talkgroups method, you ask?

It's something I came up with several years ago.

You can scan trunked talkgroups from a scan list slaved to a CONVENTIONAL personality.

Now, create your trunked talkgroups and assign them so that they all occur ONLY above channel 16 in the zone/channel assignment page.

Do NOT have a CHANNEL menu selection in your radio.

Only conventional channels get assigned to the first 16 positions in any zone.

With no channel menu programmed, you will thus NOT be able to access any channel above channel number 16 in any zone.

The trunked personalities are programmed only into channel (or sub) slots 17 and above.

The trunked personalities are referenced in scan lists that are referenced only from your conventional
personalities.

When you are then on your conventional personality, found on any given channel that can be accessed via the 16 position channel knob, and enable scan, then the trunked personalities that are chosen are scanned....from a conventional channel's scan list.

It's completely "safe" if implemented as described. NO radio will affiliate if it's only scanning the talkgroups and the radio's selected channel is conventional and not trunked.

And, for additional safety, set trunked personalities to low power and use the tuner to adjust low power
output to the absolute minimum setting. This is about -60 dBm on an XTX5000, or just one billionth of
a watt. Finally, set tx deviation to zero.

The transmitter range at this power level is measured in feet. With no deviation, the system can't even
figure out your ID even if you are in transmitter range, which would be within spitting distance of the tower,
practically. And it won't transmit anyway when only scanning trunked talkgroups from a conventional channel.

Enable hardware encryption and select secure TX only as well.

And set the time out timer to the minimum setting, which I think is one second.

You can't get any safer than that on an 800 MHz system.

On an other band system, VHF or UHF, simply enter an incorrect TX offset and then any transmissions
that manage to make it through all the other roadblocks I just described won't even be heard by the system anyway. This is as safe as it gets short of removing the transmit PA and driver from the radio.

Another thing about it is that if you don't have a channel menu in the radio, you can't even directly access any trunked personalities if they're kept above channel/sub 16. Turn scan off and nobody can find your trunked talkgroups in any zone on any channel they can access. (Also, don't have a VIEW menu enabled so nobody can look at your scan list.)

Safe scanning with a Moto radio is indeed possible. You just have to think about how many ways you can screw up the personality with regard to buggering the transmit capability.

The answer is, A LOT.

And, I've also successfully scanned digital trunked systems using ONLY conventional channels. This works OK if the system isn't very busy. If there's only one conversation going on in the entire system, scanning in conventional channels is just about as good as trunking scan. This works well for many .gov trunked systems because they're generally not very busy. It also eliminates any need to mess with that legally tricky issue regarding system key or equivalent access.


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https://batboard.batlabs.com/viewtopic.php?f=4&t=81662
basicsally the steps are first
Set your conv menu items as follows> zone mute tx inhibit, it doesn't really matter as long as you can get to your zones and enable tx inhibit. make sure to set squelch accordingly in the conv personality which will call your trunking scan list.

You don't really need anything in the trunking menu but I usually throw something there anyway, not sure why I did it but I have zone and channel in mine and I find it works just fine.


#1. make up your astro25 9600 trunking system, I know someone will jump in and correct me that it;'s biphase 4800,
put the CC's for only one site in to keep things simple. And don't turn on smartzone, you can play with this later but for now don't complicate matters.

The only fields you need to open in the trunk system are general, 700 800 astro25 control channels and digital, leave all others at the cps defaults.

I listen to single sites only and it works very well for me. I find that setting modulation to QPSK works fine in the digital selection.

#2 make up your trunking pers with the same system as in step 1 and assign this pers to scan list 1 and enable autoscan.
put as many talkgroups in as you want in this trunk pers. The Only fields you need to open in trunk personality are general, talkgroups and scan leave all others at the cps default.

Note: if later on you want to make up another trunk pers which for instance is a 3600 digital one then make sure you have the tx voice signal type field in the talkgroup selectiion set to digital. Even though the radio isn't going to tx it needs this field set accordingly for proper receive.

#3. make up a conventional pers, lets say pers 1, set the unmute time to zero and the receive to non astro, assign scan list 1 to this personality also and enable autoscan.
NOTE: Don't set any of the conventional channels which will call your astro trunk sytem to astro mode other wise you will hear nada, simply set all conv channels to non astro and it will work fine.

Another thing I forgot. I usually use the CPS default RX frequency fo my conv channels as I have never heard anything on 851.0625 but if you get interference then you will have to change the conv rx frequency to something with no activity.

I use the CPS default of unmute/ or mute rule and this works fine for me. Don't do anything else in the conv personalities.
The only fields in the conv personality you need to touch are RX option and scan, use the cps default for all others.

You'll have some errors in scan list #1 at this point until things are all tied together so ignore them for now.

#4 in the zone field for zone 1 assign the first 16 channels to conventional pers 1, assign channel 17 to trunking personality 1 and select whatever talkgroup you want to listen to, you can also add additional talkgroups for this same trunk pers after channel 17 if you want with the same trunking pers but different talkgroups.

#5 in scan list #1 turn on talkgroup scan but don't assign any priorities. Set the trunking system to r record #1 and then go to the channel field of scan list 1 and assign the first channel as zone 1 channel 17, assign any other talkgroups you want to listen to after the first channel in this scan list for instance zone 1 channel 18 for another talkgroup of the same trunk pers.

Also I do not have any conv channels in my talkgroup scan list, only P25 trunking.

Program the radio, remove the antenna and turn the radio on and in the menu select tx inhibit.

Attach the antenna and turn the radio on and when it comes up on any channel in zone 1 it will scan the system without user intervention and no affiliation.

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-Each tower site only has a limited amount of channels (some will refer to this as site loading). If you affiliate and drag in a non-native talkgroup to the tower, it can have a negative impact on all users of the tower system. It may cause a user to get a “busy” during a critical call. This is especially true on towers with a small number of voice channels, or towers that are very busy.

-If you affiliate, you take control of the radio ID you duplicated. So that user will begin to hear audio of the talkgroup YOU have selected, and if they make a call it can go out on the talkgroup YOU have selected. This can obviously be very dangerous to the user. In this case, the radio user will typically make a report with the sys admin about odd behavior. Around these parts, we usually DON’T brick the offending radio and re-program the legit radio. We then take the time to track down the offending radio.

-Some systems may automatically inhibit a duplicate radio ID

-As stated previously, if you are in public with a subscriber radio that has local talkgroup audio and looks like the same model the locals use, you will probably be asked questions about your radio.

-Possession of the system key may be a violation of local law. Having SKG may be some civil violation of Motorola rules.

How do you know if you made an error and are affiliating?

-If you are able select any system talkgroup from knob or CHAN you screwed up.

-If your TX light momentarily blinks red (trying to talk to system) you screwed up

-If you are able to see site data (RSSI, site number) or if you can site scan, you screwed up. The RSSI key should be inactive since you should be parked on a conventional channel.

-If you have the ability to do priority scan on the TRS talkgroups, you screwed up

My suggestion on multi system scan methods would be to always enable TX inhibit, and ALWAYS use radio ID 1. On our Motorola system 1 is not valid so if you do make a mistake, the affiliation would reject. I suspect this is the case with other P25 systems. Please be extremely careful if you choose to pursue this method with a hacked key.

On a site that is not busy, and has less than 11 channels, scanning the voice channels in a RX only personality, set to CQPSK and digital CSQ, would be the best method. This requires no system key and is completely safe.