Transmitter testing on a Motorola HT1250

[amateurguy]

Hi All,

I would like to do some basic transmitter testing including audio distortion testing on an HT1250. So I would like to know how to inject a 1kHz tone via the accessory connector on the HT1250 so I can monitor the recovered baseband signal on my service monitor.

So far, I did find the pinouts for the connector here on Batlabs. Pin 4 (Ext MIC) and pin 7 (GND). So I can connect my audio generator section of my service monitor to these two pins.

Now, pin 5 (Opt Sel 2) and pin 7 (GND) would be used to key the radio? Does grnding pin 5 (shorting pin 5 to pin 7) key the radio?

Thanks for any info!

--AG

[Al]

Transceiver bench testing on the HT750/1250/1550 involves the use of the global tuner software, a test cable configured to allow simultaneous connection of the UUT with both a RIB and test box, and some sort of test box which allows easy access to all the ports on the UUT, i.e. programming interface, baseband audio/data in, baseband/audio out, RSSI, and an external(to the UUT) PTT control.

Option select 2, when low(ground) tells the UUT that an external accessory is in use. So it needs to be held low, preferably before the UUT is powered up for testing(and continuously while you are testing). Option select 1 keys the transmitter when it's pulled low and the UUT is already powered up.