A Brief Guide to the Kenwood TK-350

Installation

1. Connect the DIN plug from the radio kit to the AUX connector on your Active 7 Sport or Pro 7 Sport or to the AUX5 connector on your SuperPro AVi.
2. Turn the volume control to about the 12-o'clock position.
3. Power on your AutoCom and enjoy.

General Concepts

Channels and Channel Groups

The part of the radio spectrum allocated to GMRS and FRS is divided up into channels. Each channel is allocated a frequency, the same as you would find on an FM broadcast receiver or your TV set. FM uses frequencies like 94.7 MHz and 106.7 MHz; GMRS uses frequencies like 462.55 MHz and 462.6375 MHz. TV has a standard set of channel numbers; FM does as well but it's unused by anyone but the FCC. No such standard exists for GMRS and FRS, and manufacturers of radios have come up with their own, many of which are different. The spreadsheet attached to RadioReference has a cross-reference for frequencies and the channel numbers used by a many manufacturers.

The TK-350(G) has the capacity to hold up to 160 channels in ten channel groups of 16 each. This works out well, because there are 15 GMRS and shared GMRS/FRS channels that the FCC will allow the radio to use. (There are seven additional FRS-only channels which can be used with "type-approved" radios. The TK-350 is not type-approved for FRS because it has a detachable antenna and is capable of more than 0.5 watts of power.)

Each channel group in the KenwoodTK350StandardLoad matches one of the popular channel layouts in RadioReference. While this is repetitive, it makes communicating with other radios easy without having to carry a copy of the reference table. Here is a brief summay of what radios each group works with:

Group	Prefix	Radios
1	HY	Most inexpensive GMRS/FRS radios
2	WB	Same as above, in wideband configuration. Rarely required.
3	FR	Most FRS-only radios. Channels 1-7 are shared with GMRS. Transmit on channels 8-14 is disabled, as the radio is not type accepted for FRS.
4	TK	Many Kenwood TK-3000 series radios with factory programming; Autocom AT-2
5	IC	Icom IC-F21GM
6	None	Same layout as group 1 above with a randomly-selected CTCSS tone (see below) on each channel. The first two digits of the displayed channel indicate the channel number. The second two indicate which PL tone is in use using the Motorola Talkabout PL scheme common on many hybrid radios. (For example, if the display on the TK-350 shows 1609, you would dial in channel 16, PL tone 9 on a hybrid.) The 16th channel is labeled ST-O for use by members of ST-Owners.com and uses channel 4, PL tone 25 and has transmit locked out if the channel is in use.

For example, if you're trying to communicate with the owner of an Icom IC-F21GM, you would select channel group 5 (where all of the channel names shown on the display begin with IC for Icom), and the channel numbers shown in the display will match up with those on the other radio.

Continuious Tone-Coded Squelch System

Many radios have a feature called the Continuious Tone-Coded Squelch System, also known by a number of trade names, such as Motorola Private Line (PL) and Kenwood Quiet Talk (QT). Many inexpensive radios refer to them as "privacy codes."

In short, CTCSS is a way to filter out some transmissions while letting others through. It works by encoding a subaudible tone on the signal along with the audio sent during a transmission. The tone works as a sort of password for the receiving ("decoding") radio, which opens up the squelch and allows the transmission to be heard on its speaker. On a radio programmed to decode a particular tone, you won't hear transmissions that have no tone or some other tone encoded. While this offers a form of privacy, it's privacy in the "do not disturb" sense rather than the "you can't hear what I'm saying" sense. A radio listening to the same channel with decoding turned off will hear everything, tone or no tone.

Channel group 6 in the KenwoodTK350StandardLoad has the same channel layout as group 1 (FRS/GMRS Hybrid), and each channel is set up to encode and decode a selected PL tone from the Motorola Talkabout tone list (see the CTCSS tab in the RadioReference spreadsheet). The left two digits in the display indicate the channel number and the right two indicate the PL tone number. These correspond to what you'd see on most inexpensive radios: 1624 on your radio would be channel 16, code 24. The ST-O is channel 4 with code 25.

Top Panel Controls

1 - Power/Volume Knob

Rotate this knob from the fully-counterclockwise position to turn the radio on and adjust the audio volume. On Autocom systems, the ideal level with these radios seems to be just shy of the halfway point.

2 - Channel Selector

Rotate this knob right or left to select a channel within the current channel group. (See Group Select (TA) Key, below). The radio will beep as you wrap around from the last channel in the group to the first one.

3 - Channel Name Indicator

This shows the name of the channel currently in use. If your radio is programmed with the KenwoodTK350StandardLoad, the first two characters will give a hint about what channel group is selected.

4 - Add/Delete Indicator

This indicator shows an A on the display when the current channel is included in the list of channel to be checked while in scan mode. (See Scan Key, below).

5 - Antenna Connector

Your radio will have an MX-to-BNC adapter screwed in here.

If you wish to use a "rubber duckie" antenna, any UHF antenna with an Motorola MX-type stud on the bottom will work. These are available from a number of sellers on eBay (search here). The longer, flexible ones are better for stuffing under the seat than the stubby, solid ones, and they tend to work better. Remove the adapter if you plan on using one of these antennas.

6 - Channel Group Indicator

This shows the number of the currently-selected channel group. (See KenwoodTK350StandardLoad for an explanation of what each channel group does.)

7 - Activity Indicator

This lamp shows what the radio is doing:

• Not Lit - The radio is idle.
• Green - The radio is receiving a signal on the currently-selected channel.
• Red - The radio is transmitting.

8 - Scan (SCN) Key

This key starts a search for signals on all of the channels in the currently-selected group which are in the "added" state. (See Delete/ADD Key below.) If there are less than two added channels, the radio will beep and refuse to start scanning.

While the radio is scanning:

• The SCN indicator on the display will light and the channel name will show SCAN.
• If the radio is stopped on a channel during or after receiving a transmission, pressing the D/A key will delete it from the scan list. (See Delete/Add Key, below.)
• If the radio is stopped on a channel after receiving a transmission, pressing the push-to-talk (PTT) button will transmit on that channel.
• If the radio is not stopped on a channel, pressing te PTT button will return the radio to the channel that was selected before scanning began and transmit there.

While scanning, pressing the SCAN key again will stop the scan and return the radio to the channel that was selected before the scan started.

9 - Delete/Add (D/A) Key

This key adds or deletes the currently-selected channel to or from the list of channels in the group to be searched while scanning. (See Scan Key, above.) If the channel is added, the Add/Delete indicator will show A, otherwise it will show nothing.

This key may be used to delete a noisy or unwanted channel when the radio is stopped during scanning.

10 - Group Select (TA) Key

This key has been programmed to behave differently than Kenwood's user manual describes.

This key cycles among the channel groups

11 - Low Power Key

This key toggles the power output of the radio between one watt (LO shown on the display) and four watts. This is normally used to extend battery life at the expense of range, and use of this feature when powered by a motorcycle should not be necessary.

Side Panel Controls

Along the left side of the radio are three keys:

Monitor Key

The small key closest to the top of the radio opens the squelch and allows whatever is coming over the air to be heard on the speaker.

Push-to-Talk (PTT) Key

The large key in the center makes the radio transmit whatever is entering the microphone. This function is handled remotely when connected to an intercom system such as an AutoCom or StarCom.

Lamp Key

The small key closest the bottom of the radio illuminates the display for approximately five seconds.

-- MarkFeit - 26 Sep 2007