- In response to some builder observations and questions: 1. One source of 8 pin microphone plugs (to mate with the supplied 8 pin jacks): MCM Electronics,Message 1 of 1 , Sep 11, 2010View Source
In response to some builder observations and questions:
1. One source of 8 pin microphone plugs (to mate with the supplied 8 pin jacks): MCM Electronics, http://www.mcmelectronics.com/product/27-718 ($3.29/ea)
2. When you wire your 8 pin mic jacks, be careful not to confuse the pin numbers on the jacks. The key on the jack is between pins 1 and 7, with pin 8 the center pin of the jack. If you’re at all unsure of the pin numbers, your transceiver manual will have a diagram. It is easy to confuse the pin numbers, because the numbers on the back of the jack are midway between two pins and it’s not obvious which pins they refer to. If you count clockwise from the key (as you face the rear of the jack) you won’t have any trouble.
3. Icom Microphone Jacks: On my IC-7700, and presumably other Icom radios, pin 8 of the microphone jack (the center pin) is an auxiliary AF output (ganged to the volume control). In my station, I wire pin 8 to the Spkr-R pad on the transceiver pod, and the speaker output jack on the rear of the transceiver to the Spkr–L pad on the pod. That way, I can easily feed both my L and R channel speakers, even though the IC-7700 doesn’t have dual receivers. If you do this, there is one caveat: the IC-7700 doesn’t disconnect the AF output from the pin 8 of the mic connector when headphones are plugged into the headphone, but it does disconnect the speaker output.
4. Many builders check out their completed StationPro controller by using an ohmmeter to verify continuity between the pads on the tranceiver pods and the jacks on the conroller. This is a good idea, except it won’t work for the amplifier relay jack. The reason is that the StationPro uses a solid state keying circuit for the amplifier relay, so there is no continuity between the amplifier relay jack and the relay pad on your transceiver pod.
5. If you measure the resistance to ground on the Mic+ pad on the front panel printed circuit board, don’t be surprised if Mic 2 shows infinite resistance, but Mic 1 shows roughly 20K (with the StationPro turned off). The 20K comes from a resistive voltage divider that inserts the tuneup pulser audio into the microphone circuit, and is normal.