HET Radio Operation

At this time, the most common handheld radio at the HET is the ICOM IC-M88. The PDF document ​here goes into detail on the buttons used for transmitting and receiving.

Channels

Use the buttons with the up and down arrows to change channels.

H1

H1 is the channel used by the HET repeater. A radio repeater is a combination of a radio receiver and a radio transmitter that receives a signal and retransmits it, so that two-way radio signals can cover longer distances. The actual repeater is located in Greg's office, and the repeater antenna is located on the side of the building next to the Kraben Hut. The H1 repeater provides strong coverage throughout the McDonald Observatory including upper and lower housing.

The H1 repeater is the primary channel for communications. It is also the channel used for emergency or safety communications.

H2 and H3

H2 and H3 are used to communicate directly from one handheld radio to another handheld radio. Both radios need to be on the same channel, H2 or H3.

The range of these channels are extremely limited, compared to H1. The use of H2 is H3 is generally only possible on the HET site. They are mostly used to reduce traffic on H1. If a long conversation is required, radio users are encouraged to switch to H2 or H3 if possible to free up H1 for higher priority communications.

rP

rP is the channel used by a repeater on Mt. Locke, normally called the McDonald Observatory repeater. This channel is rarely used by HET staff.

Tips for Transmitting

• When you push the transmit button, wait a second or two to before speaking. If you begin speaking immediate after pushing the transmit button, then the first second or two of what you say will be cut off.
• When first trying to talk to somebody, say something like "This is Stephen, calling Jim", or "This is Stephen, calling Jim - come back Jim".
• Hold the radio a couple of inches from your mouth when transmitting. Your transmit could sound muffled if you hold the radio too close too your mouth.
• Guide to Two-Way Radio Lingo

Squelch

The little button under the transmit button is the squelch button. If you tap it once, then you can control the squelch level using the up and down arrows on the front panel. Set your squelch level to 7.

If you press and hold the squelch button, you will hear static. This feature is called "squelch off". This is useful for checking your audio level.