CONNECTING A TONE REMOTE ADAPTOR TO AN A5 SPECTRA

[Radiogeek97]

GENTLEMEN
I have a a5 spectra (d44) and a command series tone remote (mod l1548a) that i want to hook into our centracomII I could make the physical interface cable but i am not sure which pins from the radio's accy connector go to which pins on the tone remote adaptor. The pin out of the adaptor is as follows:
PIN - FUNCTION
1 - Rx audio - (7)
2 - F1
3 - Rx audio + (11)
4 - F2
5 key pin
6 - PTT (3)
7 - mic hi (2)
8 - monitor (14)
9 - mic lo (7)
10 - osc ground
11 - duplex control
12,14,16 - ground (7)
13,15 - DC+ (13)

The pin location i got from here for the specta is :
1 TX Audio
2 Emerg
3 VIP out 2 (dash mount only, not used in remote mount)
4 SWB+
5 Ignition (dash mount only, not used in remote mount)
6 SPKR Hi
7 SPKR Lo
8 DIG GND
9 BUSY
10 BUS-
11 DET Audio
12 VIP out 1 (dash mount only, not used in remote mount)
13 DATA PTT
14 BUS +
15 MIC Hi

thanks in advance for any help it is much appreciated.

[wavetar]

Your pinouts for the remote adaptor have the Maxtrac pins in brackets, neat.

The cable should look like this:

Remote Adaptor_________________________Spectra

12,14,16 - ground_______________________8 DIG GND

3 - Rx audio +__________________________11 DET Audio

6 - PTT________________________________13 DATA PTT

7 - mic hi______________________________15 MIC Hi

The 'MIC LO' and 'Rx audio -' from the remote adaptor also connect to ground. That should do it.

Todd

[Radiogeek97]

Todd


you are the man!! thanks!

I wish I could take credit for the diagrams, they were provided to me by XMO.

Todd so if i understand you right i can connect the'MIC LO' and 'Rx audio - with #12,14&16 on the tone remote end and then those 5 commonly connected pins shoot over and connect to the spectras number 8 pin (dig gnd) ?


Thanks for taking the time to lend a hand
john

[Alan]

Message for Radiogeek97:

Just for your info (it will help make things clearer for others) it is not a tone remote control that you have but a tone remote "adapter".
If you refer to it as a command series tone remote others might not understand.
I actually saw your post earilier but overlooked as I thought it was an actual remote you wer tying to interface.
Like I say, just a note for you to help you get maximum response.

[Radiogeek97]

ALAN THANKS

I renamed the topic after reading your post.

[GEMOTO]

I was searching the board and found this topic. I have one question.

If I take the Speaker Hi audio from the Spectra and feed it through a non polarized 16V 10uF cap into the RX audio + on the tone remote adaptor will this effectively keep the speaker line from touching ground and damaging the audio amp ic in the Spectra?

I do not want to use the Det Audio due to the fact that it is unsquelched and flat.

[Will]

Yes, provide a load for the speaker output with a resistor..I use a 20 ohm 5 watt resistor.

Yes add a capacitor in the SPKR Hi going to the external interface. Depending on the input impeadance of the adaptor, .1uF to 1.0uF will work well. + side to the SPKR Hi on the Spectra.

[KE9GK]

Another question, because I am going to do the same thing with a spectra remote mount so the console operator can have a freq. agile radio...the tone adapter is a Gai-tronics ICP2000A

Would I / Could I :

- use pins 6/7 on the spectra Spk HI / Spk LOW and connect them to a 1:1 isolation transformer such as a Radio Shack PN 273-1374

- connect a 5 ohm 5 watt resistor on the AMP speaker plug at the head for the speaker load

Would the above connections work correctly to provide me with tone squelched robust non de-emp audio????

---Also---

If I used the above connections on a non-remote mounted radio, would I just put the (load) resistor between the spk hi and spk low pins ahead (on the input side) of the isolation transformer, or would the load be on the transformer output (tone adapter) side?

I think I have this all figured out correctly, just looking for a little support...or a "what the heck were you thinking" if I'm way off base.

Thanks All

[Will]

Would I / Could I :

- use pins 6/7 on the spectra Spk HI / Spk LOW and connect them to a 1:1 isolation transformer such as a Radio Shack PN 273-1374

- connect a 5 ohm 5 watt resistor on the AMP speaker plug at the head for the speaker load

Would the above connections work correctly to provide me with tone squelched robust non de-emp audio????

You need the CORRECT load on the speaker output. Spectra is designed for 8 ohms, and sometimes will have bad audio with anything lower than 8 ohms.

Best to use 10 to 20 ohms for the load. If local/adjacent to the remote adaptor no isolation transformet is needed. Put the 'load ' reistor on the speaker leads of the 15 pin ACCY plug cable. A .1 to 1.0 uF non polorized capacitor from SPKR HI lead to the remote adaptor audio input works well... DO NOT tie the speaker leads to anything else they ARE a floating output.

This will give you the correctly De-emp'ed audio for remote operation.

Note: 11 DET Audio on the 15 pin Accy connector is UN-squelched RAW discriminator audio. It is low level and direct from an op amp output.

[wavetar]

You need the CORRECT load on the speaker output. Spectra is designed for 8 ohms, and sometimes will have bad audio with anything lower than 8 ohms.

Then why is the Motorola supplied 13-watt Spectra external speaker 2 ohms?