Tektronix 2715 5 MHz Resolution Bandwidth Adjustment

Adjustment Procedures
5-20 2715 Spectrum Analyzer Service Manual
l. When normalizations arecomplete, select the following settings on the
Spectrum Analyzer:
FREQUENCY 100 MHz
REF LEVEL --20 dBm
SPAN/DIV 100 kHz
m. Connect a 100,000,000.0 Hz signal to the RF INPUT. Set the controls
for a full screen display.
n. Initiate referencefrequency normalizations by pressing
UTIL55112W.
o. After normalizations arecompleted, press any menu button to return to
the spectral display.
Use this procedure to adjust the 110 MHz Bandpass Filter on the RF Mother
board.
1. Recall factory default power up settings by pressing UTlL1 1.
2. Select the following settings on the Spectrum Analyzer:
FREQUENCY 100 MHz
REFERENCE LEVEL --30 dB m
SPAN/DIV 2 MHz
VERT SCALE 10 dB/div
3. Connect a 100 MHz/-- 30 dBm signal to theR F INPUT.Center the display by
pressing CTR-MEAS TRKG.
4. Enable bandwidth mode by pressing APPL 9 0, entering -- 6 dB, and pressing
BKSP 0.
5. Change the resolution bandwidth to 5 MHz. (The bandwidthreadout will
continuously update as the adjustments are made.)
6. Starting with the capacitor towardsthe top of the instrument, adjust the five
capacitors for highest amplitude, best filtershape of the 5 MHz pass band
(4 to 6 MHz), and centering. See Figure5 --4 on Page 5--16 for thelocations
of the five capacitors on the RF Mother board (FILTERADJUSTMENTS).
If necessary,adjust C280 and C392 (See Figure 5--6 on Page5 --21) on the
Log board for amplitude and filtershape.
7. Decrease the referencelevel by one step and check that the filter shape is not
severely distorted.
5 MHz Resolution
Bandwidth Adjustment