Last Modified: October 28, 2011
Contents: Basics; Caveats; Alinco; Icom; Kenwood; Yaesu; Odds & Ends;
Sometimes when we buy a used radio, it doesn't come with a manual. I think they should, but that's a whole new story! In any case, most late model manuals are free, and can be downloaded from the manufacturers' web site. Manuals for older models typically cost a few dollars for obvious reasons. Other times, all we really need is a microphone jack pinout, or perhaps a data port pinout. What follows certainly doesn't cover all of the jacks and ports, or even all of the brands and models. In fact, all of them shown here are considered mobile transceivers, and for good reason in this case!
All of the photos are JPGs, and clicking on them will make them larger. There are a few missing, but as I locate them, I'll add them. The notations given are based on data from the specific owners manuals. If you need more detailed information, then you will need to refer to the manual in question.
There are a few things you need to know if you make your own cables, and most of those are in the Modular Cables & Connectors article. However, there are a few things you just don't want to do, unless you like to pay for expensive repairs.
Most microphone hot leads have DC voltage applied to them (typically 8 volts) to power the microphone element and/or amplifier. While most are protected by a series resistor, not all are. If you replace the factory microphone with one not specifically designed for the transceiver in question, this DC voltage must be blocked with an appropriate capacitor.
Most microphone jacks also have a regulated 8 volt DC supply on one of the pins. Some, like the Alinco, are 5 volts. In most cases, shorting this pin to ground will not only cause the regulator to fail, in some cases a circuit trace will also fail. It is always a safe bet to check for shorts and/or correct wiring before any home brew cable is used.
Accessory, and tuner jacks always have supply voltage on one of the pins. While there are internal fuses to protect these ports from overload, all too often a circuit trace fails before the fuse blows. Further, most of these ports have power limits. In the case of Icom, that's one amp total (accessory and/or tuner), and 3.5 amps for the Yaesu. However, most of the time, the voltage drop at the rated maximum can be as much as 1 volt, generating about 12 watts of heat in the process. This is the exact reason why these ports should never be used to power remotely controlled HF antennas. For that power, or other ancillary device, read the Wiring article.
Alinco, Icom, and Kenwood have easily replaced internal fuses, albeit you might have to remove one of the covers. Yaesu's internal fuse, on the other hand, is surfaced mounted, and requires special tools to replace. Just one more reason not to use accessory ports to power ancillary equipment!
It is very tempting for some amateurs to try to use a microphone from one make of transceiver, on another make just because the jacks are the same (modular or round). With one exception (no I won't tell you what that exception is), doing so will result in an expensive fix. Read that as letting some smoke out!
Lastly, most microphone connections use a different ground connection than the PTT does, so play close attention to the nomenclature.
Alinco's new DX-SR8T is a worthy replacement for their older DX-70. While Alinco transceivers haven't been all that popular, they are in fact decent transceivers with a lot of good features, especially considering their low street price. As with all of the models shown here, there is more information on the DX-SR8T in the Miniaturized Radios article. Alinco is the only current HF mobile transceiver which uses an 8 pin, round microphone jack. That fact makes microphone cable replacement or repair much easier.
It has another unique feature; the built in speaker is in the head, not the main chassis! The only drawback speaker wise, is the fact the remote speaker jack is mounted on the front of the remote head. There is a separate headphone jack next to it, which could be a plus for some operators.
Unlike the tuner jack of the Icom, the Alinco has 5 pins, but otherwise uses the same protocol. All you need to do is make a short 5 pin to 4 pin jumper, remembering to connect the TKEY to pin 1, and leave pin 2 of unconnected.
Alinco Microphone Jack
Alinco Tuner Jack
Icom's IC-706 in its various configurations, is the world's most popular mobile transceiver, bar none. Its replacement, the IC-7000 is selling at even a greater rate, and may overtake the IC-706 within the next couple of years. There are some basic differences in their port arrangements which need to be mentioned.
First is their accessory jacks. For example, pin 7 has no connection on the 706, but is the VSEND line on the 7000. Pin 4 is the band data line in the 706, but isn't connected in the 7000 unless you make an internal modification (solder pad jumper). These differences shouldn't cause any undue problems with any ancillary hardware.
It is possible to use a 706 microphone on a 7000, but not the other way around. If this is your plan (I can't imagine why), refer to the 7000's service manual about changing the internal solder pad. By the way, doing so will not allow you to send live touch tones as one on-line site says you can. To do so takes a different microphone altogether.
Incidentally, the colors listed on the accessory jack layouts correspond to the pigtail colors on the factory-supplied accessory plug. Kenwood uses the exact 13 pin jack, and plugs for them (without the pigtails) are available from most amateur retailers for about $7.
One interesting point about the Icom data jack. The pinout is identical to the one in the FT-857D. They do have different current carry capabilities however, so using them to control a mobile amplifier depends on which radio, and which amplifier.
Icom 706 Accessory Jack
Icom 706 Microphone Jack
Icom 7000 Accessory Jack
Icom 7000 Microphone Jack
Icom Data Jack
Icom Tuner Jack
At 200 watts output, Kenwood's TS-480Hx is the most powerful HF mobile transceiver currently made. Like the older model B-2000, it is a remote-only transceiver. In other words, you can't connect the face plate directly to the radio like you can an Icom 7000 for example.
If it has a drawback, it is the fact the microphone connects to the main chassis (just like the Yaesu FT-857 does), and not to the remote head. While extension cables are available, they're not inexpensive. As a result, folks try to use CAT5 cable. Shielded or not, this invites all sorts of RFI problems. Trust me, it just isn't worth the effort to save a few dollars.
Kenwood's communications port is essentially the same as the TS-2000, and most software packages will work with either radio. You can download the data port information directly from Kenwood here.
Kenwood Communications Jack
Kenwood Remote Jack
Yaesu's FT-857D is getting a bit long in tooth, which leads some folks into thinking a new HF mobile transceiver is in the works. If that's so, it is a closely guarded secret even the Japanese marketplace doesn't know about. Nonetheless, it has a loyal following, and some unique features, although some are a bit quirky. For example, you can change the color of the display based on 7 different schemes. It's one of those things you either love or hate!
Another unique feature is the ALC jack, with one obvious use. Less obvious is what happens if you ground the TX REQ. The radio transmits a 10 watt carrier which can be used to manually tune a screwdriver antenna.
The CAT/Tuner port can be used for one or the other function, but not both at the same time. And, it has some limitations is an ATAS 120 antenna is used. A complete description of the operation is on page 71 of the owner's manual.
As noted above, the data port is identical to the Icom's. However, it does have a higher current sink capability, and the aforementioned limitations apply here too.
Yaesu ALC Plug
Yaesu CAT/Tuner Jack
Yaesu Data Jack
No matter what cable you're making up, and for whatever use, it is always best to consult the users manual. In some cases, you need a service manual as well. Fact is, I've always wondered why most amateurs don't buy service manuals for their gear. Perhaps they should remember the old adage about an ounce of prevention is worth a pound of cure, because it sure fits well when you're making your own cables.