RF Signal Levels
RF
Signal levels within the Exciter and RF Tray can be measured using an RF
Voltmeter, an RF Probe, a Power Meter or a Spectrum Analyzer. These
instruments provide a reading in either RMS Volts, Milliwatts or dbm.
Below is a conversion table of RF Signal Levels within the Exciter and RF Tray
when using any of the above instruments.
A
sufficiently accurate and the least expensive way to make these measurements is
with an RF probe plugged into an ordinary DVM. A good accurate probe is a
Fluke 85RF, part number 532457. The probe comes complete with the BNC
adaptor, part number 574756. All measurements are made terminated into 50
ohms. The RF probe should be plugged directly into a BNC Tee with one port
terminated in a 50 ohm load. A short cable (one foot maximum) can be
attached to the other port of the Tee and taken to the unit under test.
|
Conversion
Table |
|
Use an RF Voltmeter or Probe
to measure
Volts RMS |
Use a Power Meter to measure
mW |
Use a Spectrum Analyzer to
measure
dbm
reference 0 dbm = 1 mW into
50 ohms |
| 0.15 |
0.45 |
-3.5 |
| 0.16 |
0.51 |
-2.9 |
| 0.2 |
0.8 |
-1.0 |
|
0.3 |
1.8 |
+2.5 |
|
0.4 |
3.2 |
+5.0 |
| 0.45 |
4.0 |
+6.0 |
| 0.7 |
9.8 |
+10.0 |
| 0.95 |
18 |
+12.5 |
| 1.8 |
65 |
+18.0 |
| 2.2 |
97 |
+19.8 |
| 2.4 |
115 |
+20.6 |
|
Exciter RF
Signal Levels |
|
Module |
Connector |
Output
Level - In Volts RMS |
|
Reference
Generator |
J3 |
0.45 |
|
Reference
Generator |
J4 |
0.45 |
|
Reference
Generator |
J5 |
0.45 |
|
Aural
FMO |
J1 |
0.4 |
|
Visual
IF |
J3 |
0.7 |
|
Visual
VCO |
J2 |
0.2 |
|
Fv+IF
Generator |
J2 |
0.95 |
|
Fv+IF
Generator |
J5 |
2.4 |
|
Fv+IF
Generator |
J6 |
2.2 |
|
Video
Modulator |
J9 |
0.3
With
black and sync video and tip of sync from video tray is -0.7 volts below
ground |
|
RF Tray Signal Levels |
| Module |
Connector |
Output Level - in Volts RMS |
| Attenuator A |
J2 |
0.4
With
ALC Board in manual and R29 adjusted for 11 volts at TP8 (Violet).
This
level drives the Diff. Gain. Corr. Any level lower than 0.4 will limit
the Diff. Gain. Corr. from being adjusted for best system performance. |
| Attenuator A |
J3 |
0.15
With
ALC Board in manual and R29 adjusted for 11 volts at TP8 (Violet).
This
level drives the Incidental Phase Corrector. Any level lower than 0.15
will limit the Inc. Phase Corr. from being adjusted for best system
performance. |
| Differential Gain
Corr. |
J2 |
0.16 |
| Incidental Phase Corr. |
J4 |
1.8 |
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