Electronics & Innovation 411LA User manual

The material contained in this document is the property of Electronics & Innovation Ltd., it is subject
to change without notice.
August 2012 Page 1 of 12 Revision C
411LA
Broadband Power Amplifier
HIGH RF VOLTAGES MAY BE PRESENT AT THE OUTPUT OF THIS UNIT. All
operating personnel should use extreme caution in handling these voltages and be
thoroughly familiar with this manual.
Do not attempt to operate this unit prior to reading this manual.

The material contained in this document is the property of Electronics & Innovation Ltd., it is subject
to change without notice.
August 2012 Page 2 of 12 Revision C
Warranty
Electronics & Innovation Ltd., (hereafter E&I) warrants for the period of three years from
the date of original delivery, each unit to be free of defects in materials and workmanship.
For the period of 36 months E&I will, at its option, repair or replace defective parts so as
to render the unit fully operational such that it performs according to the original
specifications; free of charge to the original purchaser.
Should warranty service be required, the unit must be returned to E&I, freight cost to be
borne by the owner. If, in our opinion, the unit has been damaged by use outside the
limits prescribed in this manual or by accident, then the warranty shall not be honored. In
such a case E&I will provide an estimate for repair, assuming repair is possible and
provide a quote at standard service rates.
Contents
Chapter 1
General Information……………………………………………………………3
Chapter 2
Operation………………………………………………………………………..4
Chapter 3
Technical Information………………………………………………………….7
Chapter 4
Maintenance……………………………………………………………………8
Chapter 5
Safety……………………………………………………………………………12
Chapter 1 Introduction
1.1 Introduction
The E&I Model 411LA is an all solid state amplifier which has a flat frequency response
from 150 kHz to 300 MHz. It provides up to 10W of linear power with low harmonic and
intermodulation distortion. Gain is 40 dB nominal, with variation of less than +/-2.5 dB
over the entire frequency range. Input and output impedances are 50 and the unit may

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to change without notice.
August 2012 Page 3 of 12 Revision C
be driven to full power output by most RF synthesizers, signal generators and swept
signal sources.
The E&I Model 411LA will provide its rated forward power output into any load
impedance, regardless of match. It will absorb the power reflected from a mismatched
load without causing failure or oscillation.
The Model 411LA is packaged for bench mounting and can be supplied with rack
mounting adapters. It has an integral power supply which operates from 100 –240 VAC
47 - 63 Hz main supply.
The Model 411LA will raise the power level of signal sources and generators without
requiring tuning or band-switching. The Class A linear circuitry will amplify signals of AM,
FM, SSB, TV and complex modulations, limited only by their peak input and bandwidth,
with minimum distortion.
1.2 Specifications
Physical and electrical specifications are listed in Figure 1.
1.3 Instrument Identification
Each amplifier is identified by a serial number tag on the back panel of the unit. Both the
model number and the serial number should be given in any correspondence with the
company.
Chapter 2 Operation
2.1 Introduction
The E&I 411LA RF amplifier is used to increase the RF output level of signal sources in
the 0.15 to 300 MHz range. No tuning or any other form of adjustment is required.
2.2 Mains Voltage Setting
The unit automatically adjusts to accommodate the available AC line voltage.
2.3 Mains Fuse Rating
The Mains Fuse Fl is located on the rear panel. The replacement part number is F981-ND
2.4 Rack Installation
In order to install the Model 411LA in a standard 19 inch relay rack, the mounting
brackets must be attached to the cover as follows:
a. Remove the four feet on the underside of the amplifier if the minimum
vertical usage of the relay rack is necessary.

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to change without notice.
August 2012 Page 4 of 12 Revision C
b. Remove the two M4-10 screws located on each side of the cover nearest
the front panel.
c. Attach the rack mounting brackets to the sides of the unit using the screws
removed in step (b).
2.5 Mains Lead Connection
The unit comes supplied with a 6 foot mains cord.
2.6 Cooling
When the 411LA is enclosed by an external cabinet, provisions must be made to ensure
an adequate flow of cooling air to the unit. Ambient temperature of the air must not
exceed 40° C.
2.7 Proceed as follows:
(i) Ensure that there is at least 3” / 7.5 cm clearance at the rear of unit for air flow.
(ii) Ensure RF input voltage is not excessive
a. The 1 V rms indicated maximum input voltage is 5 times the level of the
input signal required to achieve maximum output. Input voltages in excess
of 2 volts peak may permanently damage the instrument.
(iii) Connect the output via a 50 ohm coaxial lead and BNC plug to the load.
(iv) Connect the input signal via a 50 ohm coaxial lead and BNC plug to the input
connector.
Chapter 3 Technical Description
3.1 GENERAL DESCRIPTION
The E&I Model 411LA is a linear Class A amplifier capable of increasing the output of any
signal generator, frequency synthesizer, sweep generator or laboratory signal source
from 150 kHz to 300 MHz. The Model 411LA is completely protected against damage due
to load mismatch provided that the input RF level does not exceed 1 VRMS or 1.4V peak.
If the attached signal source is capable of generating substantially more than this input
voltage, please use caution in adjusting it. The Model 411LA will saturate well before the
maximum input voltage and there will be no increase in output power at that point. The
411LA is unconditionally stable. Any impedance can be connected to the input and output
of the amplifier, without causing oscillation. The 411LA will deliver its rated power to any
load impedance regardless of match. Load mismatch will cause RF power to reflect back
to the amplifier. The unit is designed to withstand 100% reflected power (a pure

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to change without notice.
August 2012 Page 5 of 12 Revision C
reactance open or short circuit load will cause 100% reflected power) continuously
without damage.
3.2 Control, Indicators and Connectors
The power switch is located on the front panel.
The BNC connectors are marked with the universal symbol for input and output.
3.3 Operating Procedure
Refer to the following procedure as a guide to operating the Model 411LA.
a. The input and output are connected via the front panel BNC connectors to the signal
source and load respectively.
b. The input signal should be increased gradually while observing the output voltage on
the output RF voltmeter.
3.4 Precautions
a. The input and output of the Model 411LA should not be connected together. This
will cause oscillation and may damage the input preamplifier.
b. When the input signal voltage of the signal source is unknown, insert an attenuator
between it and the Model 411LA input.
3.5 Performance Checks
To determine the amplifier's performance carry out the following procedure.
3.5.1 Initial Check
The following check can be made whenever the condition of the unit is in question.
(i) Connect power supply. Switch on power and observe that the switch illuminates.
(ii) Connect the output of the 411LA amplifier to 20 dB attenuator.
(iii) Connect a calorimetric power meter (HP434 or equivalent) to the output of the attenuator.
(iv) Connect a sweep generator (Wavetek 2001 or similar) capable of sweeping the frequency
range 1 to 300MHz to the input connector, ensure that the output power of the generator is
initially set to minimum.
(v) Adjust the output level of the sweep generator to -10dBm.
See Figure 2 for Front and Rear panel
drawings

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without notice.
August 2012 Page 6 of 12 Revision C
(vi) Adjust the input CW signal to any frequency between 1 and 300MHz for 10W output.
If you can not attain RF power, verify that:
(a) The mains fuse is correctly selected and not blown
(b) The switch is illuminated.
If the mains fuse is not blown but you are still unable to get any RF power, either return the unit to E&I
for repair or proceed to chapter 4.
3.2 Measurement of Gain
Equipment required:
(a) Two power meters; HP 434 or equivalent
(b) Sweep/Signal Generator
(c) 20 dB Coupler
(d) Attenuator, 20 dB
Connect the equipment as shown in Figure 2, then proceed as follows:
(a) Increase power from the signal generator to attain an output power measurement of
3 watts as indicated on the output power meter.
(b) Measure input power and calculate gain. Gain should be a nominal 40 dB
(c) Vary the frequency of the sweep generator across the band from 150 KHz to 300
MHz. Note that the variation of gain is within +/- 2.5 dB
3.3 Measurement of Harmonics
Equipment required:
(a) Sweep/Signal generator
(b) Attenuator, 20 dB
(c) Power Meter - HP434A
(d) Spectrum Analyzer
Connect the equipment as shown in Figure 3 then proceed as follows:
(d) Adjust the sweep/Signal generator at a CW center frequency of 300 MHz for an
indicated output of 10W on the power meter.

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without notice.
August 2012 Page 7 of 12 Revision C
(e) Using the spectrum analyzer, check that the level of harmonics are less than -25 dB
with respect to the carrier.
(f) Vary the frequency of the generator from 150 KHz to 300 MHz, the harmonics
should remain at -22dBc or below.
Chapter 4 Maintenance
4.1 Introduction
The E&I 411LA RF amplifier requires no periodic maintenance. The instrument is unconditionally
stable and is fail safe under all load conditions. Damages can only be externally caused by an input
signal in excess of the specified IV RMS maximum.
This chapter therefore, deals only with certain fundamental procedures for fault location and with the
subsequent re-alignment procedures.
Performance limits quoted are for guidance only and should not be taken for guaranteed performance
specifications unless they are also quoted in Figure 1.
4.2 Packing for Reshipment
In the event of the equipment being returned for servicing it should be packaged in the original
shipping carton and packing material. If this is not available wrap the instrument in heavy paper or
plastic and place in a rigid outer box of wood, fiberboard or very strong corrugated cardboard. Use
ample soft packing to prevent movement. Provide additional support for projecting parts to relieve
these of unnecessary shock. Close the carton securely and seal with durable tape. Mark the shipping
container FRAGILE to ensure careful handling.
4.3 Access and Layout
NB: Removal of the cover voids the warranty!
The E&I Model 411LA amplifier is housed in an aluminum chassis. A block diagram schematic is
illustrated in figure 4. The cover can be removed by releasing the 6 M3 screws on the side of the unit.
The rear panel supports the mains fuse holder, AC line cord and the cooling fan.
4.4 Power supply
The power supply is mounted vertically on the right hand side of the amplifier. It is a wholly self
contained unit controlled by the control board.
4.5 The Amplifier Module

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without notice.
August 2012 Page 8 of 12 Revision C
The power amplifier module is mounted on the RF heat sink. To remove this module, the RF heat
sink must be demounted from the chassis. The RF drive unit sits underneath the PA section
Chapter 5 Safety:
Do not attempt to operate this unit with the cover removed. High AC, RF and DC voltages are
present. The cover prevents against electrical shock due to AC line voltages, high DC and RF fields.
Further the cover provides part of the cooling system design. Components, specifically on the RF
boards are prone to over-heat and eventual failure if the unit is operated without the cover in place.
Ensure that the load is connected to the output prior to connecting the RF input to the unit. This will
prevent high voltages being present and exposed at the output connector.
Only use the AC cord provided or equivalent.
Ensure that the mains outlet is properly grounded.
Appendix:
Figures
Figure 1 411LA Specifications
Figure 2 Front and Rear View
Figure 3 Gain Test Set-Up
Figure 4 Harmonic Test Set-Up
Figure 5 Block Diagram

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subject to change without notice.
August 2012 9 Revision C
Figure 1:
411LA Specification:
Frequency Coverage:
150 kHz to 300 MHz
Gain:
40 dB
Gain Variation:
±2.5 dB
Maximum Class A Linear Output:
10W
Harmonic Distortion:
All harmonics more than 22 dB below
main signal at 10W output; lower at
reduced power output.
Drive Source Requirements
Any signal generator, function
generator, or oscillator capable of 1
mW of output into 50
Input/Output Impedance:
Input VSWR:
Output VSWR:
50
1.5:1 Maximum
2:1 Maximum
Power Requirements:
115VAC ±10%, 50-60Hz, 3.5A;
230VAC ±10%, 50-60Hz, 1.7A
Noise Figure:
10 dB Maximum
Typical 3rd Order Intercept Point:
+50dBm
Stability:
Continuous operation into any load or
source impedance.
Protection:
Unit will withstand a +13dBm input
signal (IV RMS) for all output load
conditions, including short and open
circuit loads.
Front Panel Controls:
AC Power On/Off
Front Panel Connections:
RF Input RF Output
Operating Temperature:
0° to 45° C
Cooling System
Forcedair
Size:
7.5" H x 9.5" W x 12.5" D
19.05 x 23.13 x 31.75 cm.
Weight:
25 lbs; 11.3kg.
Input Connector:
Type BNC
Output Connector:
Type BNC
Rack Mounting:
19 inch adaptors optional
Figure 2

The material contained in this document is the property of Electronics & Innovation Ltd., it is
subject to change without notice.
August 2012 10 Revision C

The material contained in this document is the property of Electronics & Innovation Ltd., it is
subject to change without notice.
August 2012 11 Revision C
Figure 5
Figure 4
Power
Meter
Sweep
Generator
RF
Output
150 KHz –300
MHz
20 dB
Attenuator
Spectrum
Analyzer
Power
Meter
Power
Meter
Sweep
Generator
RF
Output
150 KHz –300
MHz
20 dB
Attenuator

The material contained in this document is the property of Electronics & Innovation Ltd., it is
subject to change without notice.
August 2012 12 Revision C
Figure 5
411LA-SCH-01
1
411LA RF Amp
A
1
1
Tuesday, July 05, 2005
Title
Size
Document Number
Rev
Date:
Sheet
of
J2
BNC
1
2
PS1
PS_24V
110VAC_line
110VAC_neutral
earth_gnd
+24V
+24V_ret
AC In
1
2
3
50 ohm
100W
Front
panel RF
input
0dBm
A1
Fan
+24V
Ret
50 ohm
+34dBm
IPA1
VHF_driver
+2
4V
RF_in
RF_out
Gn
d
IPA1_2
10W_VHF_amp
+2
4V
RF_in
RF_out
Gn
d
J1
BNC
1
2