
ARA-1 Operations Manual
6-4
INTEROPERABILITY NOW
Should I use NAT with the ARA-1?
The only time it is advisable to use NAT with the ARA-1 is when you wish to have multiple units
on a network, but have only one public IP address. An example of this would be a bank of ARA-
1s sharing a broadband type connection, such as DSL or cable modem, where only one IP address
is allocated by your ISP. Again, it may be necessary to use different local SIP ports for each unit
and to enable the use of STUN on each unit for proper operation.
Can I change the vocoder on the ARA-1?
Yes. This is the voice compression method used to convert the audio signal into a digital format.
There are times when the user may want or need higher voice quality or transparency to certain
kinds of signaling tones. The preferred vocoder may be selected from the
Web Configuration
page.
Can I pass modem tones over the voice port of the ARA-1?
While the ARA-1 is designed primarily for voice operation, it can pass many types of signaling
tones if the 64 kbps vocoder is selected. However, due to timing and/or bandwidth considerations,
proper operation of modem tones can not be assured. If you have an application that requires use
of modem tones, consult JPS.
I've connected my radio to the ARA-1, I have the levels turned all the way up, and can still
barely hear the audio. What's wrong?
The ARA-1 uses balanced audio on the input. If, instead of connecting to both balanced input
lines, you connect your audio to one audio input and ground, you will get the effect described
above. There is enough leakage in the transformer to get some audio through, but it will not work
properly. The solution is to ground one side of the ARA-1 balanced input.
I've connected my radio to the ARA-1 and it works, but the audio sounds very "tinny" and
doesn't have much bass.
Make sure you have not used the discriminator output, which is sometimes available on FM
receivers and transceivers. Discriminator audio is pre-emphasized, and there is no de-emphasis
circuitry in the ARA-1. You will need to use your regular audio output instead.
I've configured the settings on the ARA-1 incorrectly and would like to reset the unit to the
factory default settings.
Locate an access hole on the rear panel of the ARA-1 marked
DEFAULTS
. Inside is SW1, the
defaults switch. With the ARA-1 powered on, insert a small object into the hole and press and
hold the switch inside for 5 seconds. Upon releasing the switch, the ARA-1 will restart and the
unit will be set to factory defaults.
End of Section 6
.