The IDA 24-66 remote control console with 20-88 multi-line controller (called the "remote" in these instructions) is not a radio per se but remotely controls a two-way radio, just like a remote control for a TV or VCR allows you to remotely control those devices. The remote is connected to the remote two-way radio (called the "base/repeater" in these instructions) via site telecom cables and is located in the GBT Control room in the Jansky lab. The base/repeaters are located at the site water tank.
The combination of remote & base/repeater allows the telescope operator to talks to employees on site equipped with either portable or mobile two-way radios.
The remote allows you to control most all the functions of the base/repeater, including transmitting, receiving, and channel selection. The remote also provides access to the GBT Public Address system, allowing the operator to make announcements over the PA system, but to also monitor alert & warning tones automatically sent over the PA system.
The remote is on whenever it is plugged in a wall outlet. There is no need to turn the unit off when it is unattended. Make sure the remote is plugged in a wall outlet and the Frequency & Clock Display shows text. Also note that one of the Line Select buttons has a red LED illuminated.
To set the Main Speaker volume, first make sure the handset is resting in the cradle of the remote (i.e., "on-hook"). Set the volume by turning the Main Volume control. Use voice traffic to set the volume to a comfortable listening level.
The Volume control also sets the handset volume when the handset is lifted from the remote (i.e., "off-hook"), and it can be adjusted for the desired level. However, the speaker volume will be changed if the Volume control was changed, and the speaker volume will need to be reset when the handset is put back on-hook.
Press the Line Select button to select the desired operating channel. Refer to the following list for the correct channel:
|
Ch # |
Use/Function |
|
1 |
(Future Admin/works) |
|
2 |
Future (GBT Ops) |
|
3 |
Future (85-3/Interferometer Ops) |
|
4 |
GET Public Address Sys. |
Channels 5 – 8 are not in use
Listen before transmitting for on going radio traffic. Do not transmit if anyone else is using the channel. The TX lamp will light if another operator is transmitting on the base station.
Pick up the handset and place it next to your ear & mouth, just like a telephone handset. If the channel is clear, press the PTT (push to talk) button on the handset. The transmit (TX) lamp will light steadily to indicate that you are "on the air".
Speak directly into the handset in a normal voice, keeping about 1 inch away from the handset. DO NOT SHOUT!!! It will not make your transmission any clearer.
Use the FCC assigned call sign KNAP30l when transmitting. Say the call sign over the air after each transmission or series of transmissions, by speaking each letter and number separately.
The base station will terminate your transmission if you hold the PTT button down for more than 3 minutes. You will receive no warning if the time-out time is about to shut down the transmitter. When PTT is released, the base station will be ready to transmit again. If your conversations get long winded, expect the system to cut you off! ! !
The 20-88 Multi-Line Controller gives the capability of simultaneously monitoring several radio channels. The eight Line Select buttons allow you to pick one channel to control & monitor via the 24-66 remote, while all other lines send their signal to the Monitor Speaker on the 20-88.
Selecting a desired operating channel for operating is detailed above. A steadily illuminated red LED next to a Line Select button indicates that that line (channel) has been selected for control by the 24-66 remote.
To set the Monitor Speaker volume, adjust the Monitor Volume control. Use voice traffic on one of the monitored channels to set the volume to a comfortable listening level.
Sometimes it's desirable to mute a channel when it has lots of traffic that doesn't apply to your operation. To mute a channel, press the desired Line Select button once. The green LED for that line will flash and the audio for that channel will be muted approximately 20 dB for approximately 60 seconds.
To unmute a muted channel, press the desired Line Select button once. This will unmute the channel, but will also select the channel and send it to the 24-66 remote. You will then have to reselect the desired operating channel by pressing the desired Line Select button twice. Or you can just wait for the muted line to return to its unmuted condition 60 seconds after it was muted.
Phone patch facilities are available on the base repeater to allow a telephone caller to talk to a radio user on site, under operator control. Presently, only Channel 1 base repeater has phone patch capability.
(This assumes you are already in contact with the portable/mobile user):
Press the AUX button. You should hear dial tone on the speaker or in the handset.
Dial the desired number on the Touch-tone Keypad. These buttons are stiff so make sure you press until you feel them click. You should hear dialing tones while dialing.
When the called party answers, talk to them as you would any mobile unit, i.e., push to talk, release to listen, and inform them of the call from the mobile radio user. The mobile radio user also talks to the telephone party the same as any other mobile or base radio (push to talk, release to listen).
Monitor the conversation and when it's over press the AUX button to hang up.
AUX - turns phone patch on & off
CLOCK - sets the time of day on the remote's clock. Press and hold the Clock key until the desired time displays. As you depress & hold the Clock button, the time will change at a faster rate. For best results, release the Clock button before the desire time and toggle the clock by a single press until the correct time displays.
MUTE - mutes the Main (Select) Speaker volume for approximately 60 seconds.
ALERT - transmits a 1000 Hz alert tone over the selected operating channel. Tone remains on as long as the button is pressed.
INTCM - allows conversations between parallel remotes on the same operating channel. These conversations are not sent out over the air. To use this function, press the INTCM button once. The red LED will light, indicating you are in the intercom mode. Pick up the handset and transmit normally. Parallel remotes will hear you, but your message will not be transmitted. When finished, press the INTCM button again, making sure the red LED turns off.
MON - Not used on the radio channels, but sends out an alert tone when the GBT PA System is selected. The tone will stop when the PTT button is pressed, when the MON button is pressed again or automatically after 5 –10 seconds.
F -SEL -not presently used on this system.
Unmarked Buttons -not presently used on this system.
Prepared by: Eric Knapp, GBT Operator
Last Modified: 30 JAN 02