interfacing 100W vhf spectra to tone remote

[miken8eqd]

I have a couple of 100W spectra mobiles that i would like to see if it would be possible to interface to a tone remote.

I would like to use the center DB25 connector (behind the handle) .

I THOUGHT the pinout was:

PIN 1 = PTT

PIN 9 = Receive audio

PIN 10 = GND

PIN 11 = Mic low (tied to pin 10)

PIN 12 = mic hi.

Is this correct? If not, what would be the best way to conenct the radio to the tone remote. I have a CPI MR200 or Vega RC223

Thanks
Mike W8VPC

[Will]

The pin out looks good. You may have to add a couple of those one ohm 'jumper' resistors on the PTT line.

And you can jumper pins 20 and 22 A+ to SW A+ so you do not need the control head.

[jmfirefighter20]

I could be wrong, but AFAIK I think you have to have a consolette to do tone remote with a Spectra, Astro Spectra, XTL, or APX. They are not set up to do tone remote if you were to take a mobile, mount it in a building on a power supply, and hook it up.

I would venture to guess that you can remote key it using the PTT Pin 1 and ground Pin 10, and feed your audio in. But tone remote to change channels I believe would be a no go, again unless you had a consolette.

[PETNRDX]

The CPI MR200 he mentions is the radio end of a tone remote setup. A tone termination panel.
You use that at the "far" end to connect to pretty much any radio, and operate the radio remotely.
I think your pinouts sound correct too Miken8.
Is it not working? What are the symptoms?
Maybe the console tones arriving at the CPI (or Vega) are wrong function tones or levels.

[Jim202]

Have you tried to measure the audio levels coming into the tone remote adapter?

The easiest way to measure them is with TIMS unit. If you don't have that, then use a normal AC voltmeter set to AC. Then look up on the internet for a conversion to get what the level is. Do the measurement with the dispatch just pressing the PTT switch and no audio from the mic. The dispatch room needs to be quiet when you do this.

The level of the LLGT (low level guard tone) should be someplace between a negative 30 and a negative 37 db. Most tone remote adapters drop out if the level goes below a negative 40 db. If it's too high, you run into cross talk problems and can bring down the wrath of the telephone company for causing audio complaints from other users in the same cable, but on different pairs.

As was also said, the function tone could be the wrong frequency. Normally the function tone would be 1950 Hz. for an F1 TX selection.

If you listen to the control line going to the tone adapter, you should hear the high level 2175 Hz. wakeup tone, then the function tone and then the steady 2175 LLGT that keeps the transmitter keyed. The duration of the first two tones are not very long. The wakeup tone only has about a 120 milliseconds duration. The function tone only lasts for a 40 milliseconds duration.

Unless you have a storage scope to catch the tones, you can't easily measure them.

Jim

[miken8eqd]

Thanks for the replies,

Will,

I might solder A+ to SW A+ just to eliminate having to run DC to the control head. Control head is A9 , system 9000.

JMFIRE...

I would like to have Consolettes with 2CH tone remotes. but they would have to have 2 separate receivers. i have 8 channels that are configured for a 2 ch transmit and dual receive configuration. and thats the next challenge!


PETNRDX

The MR200 is configured for a GM300. So i had to make up a jumper with a RJ45 on one end and a DB25 on the other. I'm going to go back and verify the pins to make sure i have it soldered corectly. Tone remote ptt relay energizes on transmit so guard tone is correct. Is there a website that has a good connector diagram? I found one that shows J005 and J006. I'm thinking the connector behind the handle is J006. Pin 18 is digital ground, should i solder that to 10 and 11?

Jim 202,

I have a friend who has a TIMS and is willing to show me how it works and loan it to me. I want to set audio levels and deviation on each radio/ channel etc. the radios and tone remotes came from one county, console came from another county that used the same tone remotes and radios (they were told to throw the radios out before i grabbed the console)

thanks
mike

[Jim202]

Let me make another suggestion when you do start to play with the consoles. Generally I have found that the radio shops like to set the mic gains in the consoles rather high. This way the dispatchers can be 5 feet away from the mic and you can still hear what they are saying rather clearly. Problem is this also causes all the room background noise to be transmitted over the radio at the same time. If someone is talking 10 feet away, you will be able to hear what that person is saying.

So plan on having to crank the mic gain in the console down. I like to set them so that when your about 6 inches away from the mic, the audio is already starting to drop off. This way if your TV is going in the background, everyone on the other end of the radio won't be hearing the program at the same time your trying to talk.

Also when using the TIMS unit, make sure it is in the bridged mode and not in the terminate mode. This way when the unit is removed, your audio level won't jump up some 3 plus db. The console is terminated and the tone remote adapter is terminated. You don't want to terminate it again. If you end up putting more than one console or desk remote on the cable pair, only one of them wants to be terminated. Generally the one that is furthest away will be the one that has the termination in place. All the others will have the termination removed by the placement of the jumper in the console line card or the desk remote.

As was said before, the DB25 connector in the handle area of the Spectra normally doesn't have the pin for the PTT connected. So you will either have to add a wire, or find the jumper that needs to be put in place. There are several circuit boards that were used in the face of those trunk mount radios, so make sure you have the correct drawing layout to work from. They are also a pain to get at.

Jim

[Will]

Mike,

I jumper the A+ and SW A+ pins in the male DB25 connector.

Remember, Motorola numbers the RJ45 connector pins backwards........