Manual for T1600-series desktop remote?

[wa8pyr]

Anybody got a manual for a T1600-series desktop remote? I’ve got one at a museum I’m trying to get into proper working order but definitely don’t want to go guessing…

Specifically, I want to connect a GM300 to it for receive only.

Tom WA8PYR

 

[ffexpCP]

Tone or DC?

 

[kf8yk]

2 wire line goes to terminals 25 & 26, 4 wire line uses 17/18 (rx) and 25/26 (tx).

 

[wa8pyr]

Tone or DC?

Currently neither. It’s hooked up to an ancient EFJ radio (audio only) via pin 4 (labeled, I think, Quik Call) and pin 21 (Audio A). Said EFJ radio is going bad and I need to replace it, preferably with genuine Motorola parts.

My preference would be tone or DC remote; I have one or two remote adapters (I think DC but I’m not sure); if I have to go audio from the speaker pins I will, but that opens up a whole new can of worms about possibly grounding the GM300 speaker line.

It’s also currently got a very obnoxious ground loop hum that I’d really like to eliminate.

Tom

 

[kf8yk]

Assuming a short distance, you could take unbalanced rx audio from a mobile radio accessory connector into terminal 5 (signal tones) and terminal 1 (ground) on the T1600, no remote adapter needed. This will feed the audio into the remotes 5 W audio amp with volume controlled on the remote.

If you plan to use a remote adapter at the radio to drive a balanced line then the choice of DC or Tone is irrelevant for a receive only application.

 

[wa8pyr]

Assuming a short distance, you could take unbalanced rx audio from a mobile radio accessory connector into terminal 5 (signal tones) and terminal 1 (ground) on the T1600, no remote adapter needed. This will feed the audio into the remotes 5 W audio amp with volume controlled on the remote.

That’s how it’s currently done although different pins on the T1600. For a GM300 would you use the speaker output, or flat audio output? If the speaker output, would an isolation transformer be needed? Since I don’t know exactly what’s inside the T1600 remote box, I don‘t want to blow up the radio.

A pinout and explanation of what each pin is for on the T16xx would be super helpful if anyone has one….

If you plan to use a remote adapter at the radio to drive a balanced line then the choice of DC or Tone is irrelevant for a receive only application.

I‘d like to go that route; depends on how “authentic” I want to get. If I wanted to get really authentic, the radio and remote adapter would be in a bungalow outside the building; this is for RX-only demonstration purposes and I‘m not sure I have that much gumption anymore.

 

[kf8yk]

The attached schematic should help.

The use of pins 4 & 21 is odd as pin 4 is the input to the compression amplifier & pin 21 is the output, possibly someone cut some jumpers & did something custom? Pins 1 & 5 would be the standard way to feed low level audio right into the audio amp; bypassing compression, notch filters, etc.

The pin 11 rx audio on the GM300 acc. connector should be ideal, it's unbalanced, ground referenced and at a fixed level so the volume control on the radio and on the remote would work independently. If you go with a remote adapter at the radio you'll still want to feed the remote adapter with pin 11 rx audio.

 

[wa8pyr]

The attached schematic should help.

The use of pins 4 & 21 is odd as pin 4 is the input to the compression amplifier & pin 21 is the output, possibly someone cut some jumpers & did something custom? Pins 1 & 5 would be the standard way to feed low level audio right into the audio amp; bypassing compression, notch filters, etc.

The pin 11 rx audio on the GM300 acc. connector should be ideal, it's unbalanced, ground referenced and at a fixed level so the volume control on the radio and on the remote would work independently. If you go with a remote adapter at the radio you'll still want to feed the remote adapter with pin 11 rx audio.

Perfect, exactly what I needed, thanks!

 

[wa8pyr]

Perfect, exactly what I needed, thanks!

Update….

1 and 5 didn’t do the trick as the audio from the radio is too low. However, I put the audio into 25/26 (line audio) and it’s working like a champ.