7.5 RX Gain
7-18
7.5 RX Gain
Receiver gain is checked with a SSG connected to J1 (RX IN) connector on TX/RX
board. See Fig. 7.5.1.
Fig.7.5.1 RX signal flow
Table below shows the ratings. The receiving signal is attenuated by PRESEL board 2
to 3 dB. If the distortion meter is not available, use a vacuum tube voltmeter. S/N
(20 dB)
is about 20log
10
V
signal
/V
noise
. Adjust AF gain volume with AGC on so that noise
level from the speaker is 100 mVrms. Adjust SSG level to obtain the 1 V AF output
level to speaker. When the SSG level is +3 dBuV or less, the receiver gain is normal.
See Fig. 7.5.3 for the location of the adjuster.
Table 7.5.1 TX Gain Adjusters
Check Item Condition Rating Adjuster
J3E receiver total gain
(SSG level to obtain
4W speaker output)
4 MHz, J3E
AF and RF gain controls:
Maximum
AGC: ON
SSG output: F + 1 kHz
0 dBuV ± 3 dBuV None
J3E 20 dB SINAD
(SSG level for 20 dB
distortion), or
J3E 20 dB S/N (SSG
level for S/N ratio of 20
dB)
4 MHz, J3E
AF gain control: Midturn
RF gain control: Maximum
AGC: ON
SSG output: F + 1 kHz
+3 dBuV or less None
J3E AGC minimum
level
(same as S meter)
4 MHz, J3E
AF gain control: Adjusted
RF gain control: Maximum
AGC: ON (Fast)
SSG output: F + 1 kHz
+10 dBuV ± 2 dBuV R320 on
TX/RX
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