User's Manual

120 20170-200 Paragon

Technical Manual47

Select Gen2 (Modulating tone fixed to 1KHz). All other Gen must be off.

Set deviation to ±3.0KHz for full channel or ±1.5KHz for half channel radios.

Use a X1 scope probe connected to IFR SINAD input and monitor the Discriminator O/P

on the backplane at SK1 pin 6 (RX-audio1). Alternately, it is also possible to monitor at

the receiver TP314 (T855) or at the receiver IC350 pin 7 (T835)

Lower the RF level to get a 12dB SINAD reading. Level must be better than

-110dBm

(in-

cluding cable loss).

Offset the IFR TX frequency 2kHz (full channel) or 1kHz (half channel) above the main radio

RX frequency, record the SINAD reading. It should remain within 1dB from the on frequency

SINAD reading. For T855, use above values, for T835 use 1.5kHz (full channel) or 0.8kHz

(half channel).

Offset the IFR TX frequency 2KHz (full channel) or 1kHz (half channel) below the main radio

RX frequency, record the SINAD reading. It should remain within 1dB from the on-frequency

SINAD reading. For T855, use above values, for T835 use 1.5kHz (full channel) or 0.8kHz

(half channel).

Note: If one of the above requirements is not met, try to re-tune the front-end. It

still failed, contact your Dataradio technical support.

6.4.2.5 RSSI Adjustment (UHF: T855)

Note: This check is only recommended for Paragon/R model running DBA protocol 3.06.009

series or later.

Apply an on-channel signal from the RF generator at a level of -110dBm with deviation of

±3kHz (full channel) or ±1.5kHz (half channel) at 1kHz tone.

Adjust RV320 (RSSI level) to give 2.0V RSSI output at SK330 pin 2 or on backplane SK1 pin

5 when measured with a voltmeter (See Figure 30).

Vary the RF level in 10dB steps and check that the RSSI output voltage (SK1 pin5) changes at

a rate of a 10dB/V (±0.20VDC) over the range of –120 dBm to -80dBm (see Figure 28). If the

requirement cannot be reached, contact your Dataradio technical support.

Figure 28 - T855 and T885, RSSI Curve: volt to dBm

Volt