PL tones???????

[Larry]

I'm trying to figure out how to program an Astro Saber so that it will be able to talk with my fire dept. HT 1000.

The fire dept. has one of its' UHF channels in simplex mode. The TX freq. is 486.4375 Mhz

By using my PL search on my bearcat scanner I've determined that the radio is transmitting using a PL tone of 225.7

I programmed my Astro Saber with TX and RX freq of 486.4375 and the TX and RX PL tone with 225.7

When I TX on the HT 1000 I receive on the Astro Saber however when I TX on the Saber the HT is not receiving... I'm not sure how else I can program the Saber

[Astro_Saber]

actually I would try csq first or better yet ask the radio programmer

[nmfire10]

Your sure that it is not a duplex? If you can hear it transmit but it can't hear you on the same frequ, maybe it does have an off-set?

[Astro25]

I am not sure what you really did wrong, but it sounds to me like maybe you didnt put the right output frequency in. You put the correct input frequency in to receive but you need the output frequency with a PL tone to transmit on the radio. I believe I am correct here because that is what I had to do with my astro saber when I programed it, but maybe someone else out there can make better sense than me. On many radios the output frequency will automaticaly go into the radio when you program the input frequency.

[Larry]

I programmed the output and input frequncies with the RSS. The ouput and input frequency is the same 486.4375...

Ch. 1 dulplex is Rx 483.4375 Tx 486.4375 (repeater input) 146.2 PL tone

Ch. 2 simplex is Rx 483.4375 Tx 483.4375 (direct mode) 146.2 PL tone

Ch. 3 simplex is Rx 486.4375 Tx 486.4375 (direct mode)

Using a frequency counter for the PL tone on Ch. 3, I'm getting a PL of 225.7

To keep Ch. 1 radios from talking on Ch. 3, Ch. 3 needs some kind of PL tone other than 146.2... and if CSQ mode is used, I cannot block Ch. 1 traffic from being Rx'd on Ch. 3

There isn't any repeater for Ch. 3... this frequency is strictly used for on-scene radio-to-radio communication for sensitive/private information.

[Astro25]

Well it sure does appear you did it correct, but maybe your PL tones are not correct and if you are 100% sure they are then I am just as stuck on the problem now as you are, so maybe some one else here can enlighten you more with some better info than I can.

[nmfire10]

That is an interesting setup. I never heard of a talk-around channel on the input frequency, even with a different PL. Doesn't that cause a problem if someone wants to talk on channel 1 while someone is talking on channel 3?

[Larry]

This is used in a small town fire dept radio system..... typically the only units that would be Tx'ing would be the only units on the air.....


Typical senerio.... E-1 is dispatched to a car fire... they're always on Ch.1

E-1 notifies fire alarm they are off at the scene, fire alarm acknowledges.

then the officer with a portable radio has some sensitive information and orders E-1 to Ch. 3... once on Ch. 3 the information is Tx'd....

Since Ch. 3 is in simplex a portable radio is not powerful enough to be heard at fire alarm so E-1 would switch back to Ch. 1 and request fire alarm go to Ch. 3 and relay the officers message to fire alarm...

Each time any radio goes to Ch.3, at the conclusion of the communication the radio is switched back to Ch. 1

Typically no one would be talking on Ch. 1 while anyone else is on Ch. 3 there's not that much radio traffic... since there's only 4 mobile units in the fire dept.

[Will]

Simplex operation on the input to a repeater is generally considered a no no. Usally there is a tactical frequency in the aera for that type of operation. The scanner nuts are still going to figure it out anyway.

[nmfire10]

I guess if you have a small enough department, it wouldn't be a big deal. It will hide it from some of the scanner nuts out there, at least those that do not insist on monitoring the inputs of every repeater too. In a busy dept though, it would never work, everyone would be stepping on eachother.

[RKG]

Simplex transmissions on a 486 channel are a violation of FCC regulations and the Department's license. Transmissions by a base station on 486 are a separate violation of FCC regulations and the Department's license. I agree with someone else who said that if you want a "side door" channel, there has to be a better way.

Indeed, most savvy buffs monitor the input to repeater systems as a matter of course, so, apart from the regulatory issues, using your input as a "side door" that civilians won't chance upon is probably the least effective way to go about it.

The ASTRO Saber program looks like MTSX, and there is an option that will automatically plug in an offset; I'd go back and look very carefully at your program.

[RadioSouth]

Very odd setup. Best to have the Astro read to verify the freq's. and PL tones.
If both radios are working properly you should have been able to use them in direct mode
(unless the HT1000 is inavertenly set up with QC on that channel).

[RADIOMAN2002]

Whoever says simplex on the input is illegal is nuts. The FCC doesn't regulate the receive frequency or PL tones, of radios. Since you are already on the licensed input of the pair, there you are, licensed operations. Most marine radios have simplex operations on the marine operator channels on the input also. Another note, N.Y.P.D. does it also.

[Jim202]

[quote="RKG"]Simplex transmissions on a 486 channel are a violation of FCC regulations and the Department's license. Transmissions by a base station on 486 are a separate violation of FCC regulations and the Department's license. I agree with someone else who said that if you want a "side door" channel, there has to be a better way.

If there is a rule by the FCC on this operation, please tell the rest of us the part and section for this rule. I try to stay current on the rules and am not aware of this. But, I could have missed a change or two in the last 35 years.

Jim

[RKG]

The FCC DOES regulate the types of transmissions that may be legally broadcast on a given frequency. Broadcast on an input frequency for direct reading by anything other than a repeater (or a two-frequency simplex base station) is prohibited by the rules. For obvious reasons.

Also forbidden are transmission not within the scope of one's license. The base station license does not include transmissions on the input frequency (if it did, it would not have been approved).

The maritime mobile service is not in Part 90, and is governed by different rules.

[jcobb]

So, does that mean that the FCC is now licensing RECEIVERS, too?

I think, while it may be foolish to do simplex on the repeater input, it is only because it can block transmissions intended to be repeated - not against the rules.

They are, indeed, licensed to transmit on that frequency, and if they "intercept" that transmission before it can be repeated, then so be it.

I think it is the wrong thing to do, but from a design/operations perspective.


Just my 2 Pesos.


Jack

[Jim202]

RKG,

Please tell the rest of us where to look up this non allowed use of the input frequency of a repeater. I am not trying to be a hard nose, but I would like to see just what FCC rule your refering to so I can go read it and update the gray matter.

There are a number of us oldtimers here that have grown up with repeater use and customer troubles. This issue, I would like to clear up, as I have public safety agencies asking to change their system operations. Just want to make sure I haven't missed any rule changes.

Jim

[Tom in D.C.]

I've never, ever, heard of a talkaround channel which is on the repeater's input frequency. Doing so would certainly screw up the normal operation of the repeater, even when the TA is in use at a half or one watt of power. Rules aside, it just does not make any sense to run a system this way. In addition, fireground channels always run on their own, separate, frequencies in 99.5% of the FD's in the USA.

1. If you have a decent scanner, try first to listen for both HT's on the channel you want to use for talkaround. If you hear them both then the receive settings on the radio that can't hear are messed up.

2. A long shot would be think of front end overload on one of the radios - - the one that can't hear - - especially if you're trying to do your testing with both radios in the same room.

Let us all know what happens.

Tom, W2NJS
...in D.C.

[tom IL]

I believe FDNY does something similar that they refer to as “mixer off.” My understanding is that when a Company has something sensitive like info on a possible arson or the name of a victim they call the alarm office and request “mixer off” the dispatcher then turns the audio mixer off, witch effectively turns off the repeater. They then transmit there info to the alarm office.

[larryepage]

1. Talkaround is on the repeater output frequency. This way, if the repeater fails, those tuned to the repeater channel can receive simplex instructions to move to talkaround. Communications transmitted on the input would not be received at all by users still listening to the repeater.

2. (And this is based on an actual problem I've had in my area)...Using the repeater input with the idea of privacy in mind is a bad idea, even if your licensing allows it. You may be happily talking privately on the input frequency with a different squelch code, but if someone farther from the repeater keys it with the correct code, your stronger signal is going to go out for the world to hear, and you won't even be aware that your privacy has been compromised.

3. There are certainly rules and operating guidelines in place governing which kinds of stations in systems can typically transmit on which frequencies. (And I've seen some errors in coordination and licensing which have resulted in some fairly weird situations.) But in the end, what is allowed boils down to what the specific line items on your license document authorize you to do with each class of station. There is a line item for the repeater, one or more for your mobiles, and probably one or more for your portable units. Certainly a separate transmit frequency grant is required for talkaround in any case, because talkaround involves a different transmit frequency for portables and mobiles. While simplex operation on a repeater input channel may or may not be illegal in a particular situation, it is always considered bad operating practice, as far as I am aware.

Regards,
Larry

[xawmx]

Providence, RI Fire Department also does this, at least in the near past, for sensitive information. A unit would state "Engine 14 to Fire Alarm, shut the repeater off" they would then transmit on the repeater input frequency 153.8300, yes I understand we are talking about UHF here, but this procedure of transmitting on the repeater input is quite common in the northeast.

[x1sspic]

My volly EMS unit in Northern NY also uses the repeater input as a simplex talk around frequency. However no one really uses it. Especially those of us that understand radios

[Tom in D.C.]

The question of "mixer off" or "shut the repeater off" simply means that the repeater's transmitter is shut down and the dispatcher is listening to the input channel without retransmitting it. It's obviously done for privacy and I don't understand what it has to with the question of using an input channel for talkaround. When the sensitive information has been transmitted, the dispatcher turns the repeater transmitter back on and says, in FDNY parlance, "Your message received" or "10-4," depending on how long he's been a dispatcher.

Tom, W2NJS
...in D.C.

[nmfire10]

What it is doing is making so LESS people hear your transmision. Obviously, anyone within range of the portable with a scanner monitoring the input can hear it. But that is VERY FEW people in most cases. As opposed to over the repeater which everyone and their brother can hear.

[Will]

The Los Angeles County Sherriff's does this, BUT has a BUSY beep on the repeater output and that keeps the sacnners locked on the repeater output. A side benifit, they origianaly did not want others arround to hear the radios at an incident. More departments sometimes need this feature.

[RADIOMAN2002]

I think the Batuser Larry is looking for an answer, and some are just clouding the issue. If you are one of the Batusers who state it is against FCC Rules, then list the title,section,paragraph,and subparagraph. Otherwise you are talking through your hat.(A nice way to say you are full of S--T. Personnaly I would like to see it in writing, since I have used this very practice for over 25 years. Those who are saying it is not common practice or that they wouldn't do it, thats fine,thats an opinion. Larry still has a problem, going back to the beginning, he cannot get an Astro and HT-1000 to talk to one another on simplex. My feeling is that he has the two portables too close together, or as another Batuser has suggested try Carrie Squelch first.

[Cowthief]

Hello.

Here, in Houston, the FCC says, that a mobile can transmit, " on both sides " but MUST monitor both sides, i.e. dual RX, a base, or repeater, can TX only on the output.
However, if you want to run simplex, one radio, to another radio, no dual RX, you must do this on the repeater output, this is due to the fact that the user needs to listen to, and for other repeaters, perhaps a distant COR 'carrier' unit is TXing.
The FCC has issued fines, usually what happens is a department uses portables, 2 watts or somwhere around this, no problem, then, someone gets a convertacom, 60 watt amp, 5 db gain antenna, at the edge of their service area, goes in this mode,,,,,.

888-225-5322 FCC info center
800-418-3676 FCC forms

Have fun, I do.

[Tom in D.C.]

Like many of you, I've been reading this thread for the whole time it's been on the Board, and I would suggest the following:
How about using some common sense and not getting bogged down in all the rules? Common sense usually conforms to whatever rules might be in effect. So, these points seen to make sense, at least to me:

1. Using your own repeater input frequency for simplex is a dumb idea.

2. Because when another unit tries to use the repeater in normal fashion you will both probably not be heard. FM capture effect is something which sometimes does not work and all you may hear is a buzz on the output channel, as well as on the radio of the other person who is listening for the simplex signal. The result is that neither party gets heard, and isn't THAT great in an emergency?

3. And doing the simplex comms without the PL or DPL won't help one bit, because the repeater user will open the receiver and you'll both still be going into the machine.

4. A "radio tech" who thinks up the idea of using the repeater input as a simplex channel does not, to put it kindly, have his head screwed on straight.

5. Perhaps there are or are not rules which cover the situation, but either way it seems to me that if you were to take time to think the matter through you'd want to find a non-repeater channel for fireground simplex use.

Tom, W2NJS\
...in D.C.

[nmfire10]

OK. I think we have beat this topic to death a few times over. Obviously, it isn't the best thing to do. But that is not what the poor guy wanted to know. THEY ALREADY DO IT AND IT IS TOO LATE TO CHANGE THAT. How about we help him figure out his problem at hand rather than how to restructure their entire system that as it seems, is working just fine for them.

[Randyman]

I would check both radios (Saber and the HT1000) with the counter and make sure they are transmitting the same PL tone. Also, does the HT1000 open squelch from other radios when on channel 3? (Eliminate all variables that you can!)

Does the Saber's PL on transmit open the repeater? This should eliminate deviation or other problems with the Saber if it does--

Randyman

[kc8svs]

Shelby Co, OH Sheriff's office has their talkaround on the input frequency (156.150) of their repeater, BUT, it's CSQ, and their input has a PL tone to access repeater. It's definately ODD. But what can I say?