Epson USN 52R, USN 52L manual Damping

Operation		Function check
Check	Result	Remark
9. Damping
For settings see 2. Also:	The echo drops in each case to approx.	The difference is approx.
DAMPING: 1 K ohms.	40% (with 150 ohms),	-6 dB
Set an echo to 80% screen HT, then	30% (with 75 ohms),	-8 dB
DAMPING to 150, 75 and 50 ohms.	20% (with 50 ohms).	-12 dB
10. Resolution test
For settings see 2. Also:	There should be no rise in the sweep between
RANGE: 5 mm	the trailing flank of the delay echo and the
RECTIF.: NEG HALF	rising flank of the 1st backwall echo.
Connect CLF4.
Shift the 1st Echo of the delay path to
the left edge of the display using DELAY,
Couple the CLF4 to 1 mm steel.
Adjust the 1st echo from the backwall
echo sequence to 80% screen HT.
11. Pulser/Receiver cross-talk
For settings see 2.	Read off dB REF value:	Echo must exceed gate, otherwise
PULSER: SINGLE	dB-REF value should be ≥ 60 dB.	db REF cannot be activated.
GATE LOGIC: POSITIVE
a-THRESH: 10%
a-START: 30 mm
a-WIDTH: 50 mm
N30 in Pulser socket
GAIN so that 1st echo is just over 20%
screen HTH.
Press dB REF, PULSER: DUAL
Increase GAIN until the echo or noise is
over 20% screen HT.

5-68 Issue 05, 02/00 Krautkramer USN 52R/USN 52L