ELECRAFT XV50 User manual

Elecraft XV Series Transverters
Models XV50, XV144, XV222
Rev B, November 7, 2003

Table of Contents
Introduction..........................................................................................................................................................................................1
Specifications.......................................................................................................................................................................................3
Preparing for Assembly .......................................................................................................................................................................4
Parts Inventory...................................................................................................................................................................................10
Front Panel Board Assembly.............................................................................................................................................................24
RF Board Assembly – Part I ..............................................................................................................................................................29
RF Board Assembly – Part II .............................................................................................................................................................42
RF Board Assembly – Part III ............................................................................................................................................................51
Final Assembly ..................................................................................................................................................................................54
Alignment and Test............................................................................................................................................................................58
Installation..........................................................................................................................................................................................64
Using Your Transverter......................................................................................................................................................................76
Options and Modifications..................................................................................................................................................................78
Circuit Description..............................................................................................................................................................................82
Schematic and Parts Layout Diagrams……………………………………………….……………………………...……………..Appendix A
Troubleshooting...................................……………………………………………….……………………....……...………….....Appendix B

——1
Introduction
The Elecraft XV Series high-performance transverters may be used with
any transceiver or transmitter/receiver pair that covers 28 MHz. Separate
transverters are offered for the following bands:
•Model XV50: 50 to 52 MHz.
•Model XV144: 144 to 146 MHz.
•Model XV222: 222 to 224 MHz
I.F. connections to the transceiver can be either single-port (single RF
cable) or dual port (separate receive and transmit cables).
The transverters include an adjustable input level control that will provide
full output from I.F. power levels from as low as 0.01 watts up to 8 watts
continuous. Full protection against accidental high-power transmit of up
to 100 watts into the I.F. port is also included.
The receiver features a very low noise figure with a PHEMT RF stage for
weak-signal work. Relays are used for transmit/receive switching to avoid
receive performance degradation by diode switches in the signal path.
The transmitter is conservatively rated at 20 watts output PEP SSB, CW
or data modes. The RF output is displayed on the front panel with a 10-
segment LED bargraph. The LED display may be switched between dot or
bar modes and has two brightness levels when used with an Elecraft K2
transceiver.
The transverters are housed in attractive, low-profile enclosures that may
be stacked for multi-band operation. An illuminated band label identifies
the transverter in use. Several transverters may be connected to the
transceiver in most cases. Internal relays select only the transverter for the
band in use, avoiding the need to switch I.F. cables.
Using an Elecraft K2 as the I.F. Transceiver
While the transverters will work with nearly any HF transceiver, using
them with our Elecraft K2 (or K2/100) offers additional benefits. The
high-performance K2 provides:
•Low noise, single-conversion, wide dynamic range receiver
•Four adjustable I.F. crystal filter bandwidths per mode
•Automatic transverter band switching with individual menu-
selected output power levels for up to three transverters.
•Direct display of the transverter operating frequency to 10 Hz,
including per-band adjustable offsets of +/- 9.99 kHz
•Four RIT ranges from +/- 0.6 to +/- 4.8 kHz
We recommend that K2’s with serial numbers 3445 and below be
equipped with Elecraft-approved modifications that reduce spurious
responses and enhance frequency stability. See page 68 for details.
Figure 1. Three Transverters May Be Controlled by an Elecraft K2.

——2
Transverter Kits
The XV Transverters are intermediate-to-advanced kits, yet you'll be
surprised at how uncomplicated they are to build. All of the radio
frequency (RF) circuits are on one printed circuit board (PCB). A second
smaller PCB holds the microcontroller and front-panel LEDs. High-
quality, double-sided PCBs are used, with plated-through holes for
optimal RF performance. Point-to-point wiring is minimal. All
components to be installed have wire leads; the few surface-mount devices
required are pre-installed on the circuit board.
This kit uses just one torodial inductor, which is easy to wind. However, if
you prefer not to wind this inductor yourself, you can order one pre-
wound with the leads tinned and ready to install from an Elecraft-qualified
source. Ordering information is on our web site at www.elecraft.com.
Customer Service and Support
Whether you build the kit or buy a factory-built transverter, you’ll find a
wealth of information on our web site at www.elecraft.com. Among the
materials there you’ll find the latest application notes, photographs, any
updates to this manual, and information on new products. We also have a
popular e-mail forum, for which you can sign up from the web site. It's a
great way to interact with other Elecraft owners, exchange ideas and find
answers to many questions.
You can also get assistance by telephone or by sending an e-mail to
[email protected]. E-mail is preferable because it gives us a written
record of your question. Telephone assistance is available from 9 A.M. to
5 P.M. Pacific time, Monday through Friday (except US Holidays) at 831-
662-8345.
Repair Service
Contact Elecraft before returning your equipment to obtain the current
information on repair fees.
To ship the unit, first seal it in a plastic bag to protect the finish. Use a
sturdy packing carton with at least 3-in (8 cm) of foam or shredded paper
on all sides. Seal the package with reinforced tape. (Neither Elecraft or the
carrier will accept liability for damage due to improper packaging.) Ship
the equipment to:
Elecraft
P.O. Box 69
Aptos, CA 95001-0069
Elecraft 1-Year Limited Warranty
If building a kit, complete the assembly, carefully following all instructions in
the manual, before requesting warranty service.
What is covered: During the first year after the date of first consumer
purchase, Elecraft will replace defective parts free of charge (post-paid). We
will also correct any malfunction caused by defective parts and materials. You
must send the unit at your expense to Elecraft. We will pay return shipping.
What is not covered: This warranty does not cover correction of assembly
errors or misalignment; repair of damage caused by misuse, negligence or
builder modifications; or any performance malfunctions involving non-Elecraft
accessory equipment. The use of acid-core solder or any corrosive or
conductive flux or solvent will void this warranty in its entirety.Also
not covered is any reimbursement for loss of use, inconvenience, customer
assembly or alignment time, or cost of unauthorized service.
Limitation of incidental or consequential damages: This warranty does not
extend to non-Elecraft equipment or components used in conjunction with our
products. Any such repair or replacement is the responsibility of the customer.
Elecraft will not be liable for any special, indirect, incidental or consequential
damages, including but not limited to any loss of businesses or profits.

——3
Specifications
Numeric values are typical; your results will be somewhat different. Also,
specifications may be affected by the options or accessories chosen. See
www.elecraft.com for details about options and accessories currently
available. Specifications are subject to change without notice.
General
Size
Cabinet: 1.3” H x 7.8” W x 8.3” D
(3.3 x 19.8 x 21 cm)
Overall: 1.5 H x 7.8 W x 9.5 D incl. feet and connectors.
(3.8 x 19.8 x 21 cm)
Weight: 2.5 lbs (1.1 kg)
Supply Voltage: 13.8 VDC
Current Drain:
Receive: 250 mA (typical)
Transmit1: 4 A (typical)
Frequency Ranges:
XV50: 50 – 52 MHz
XV144: 144 – 146 MHz
XV222: 222 – 224 MHz
T/R Switching Time: 3 ms (typical)
T/R Key Input: Ground for transmit: must pull 5 volt
logic level to within 0.5 volts of ground
at < 1 ma.
I.F. Overload Protection: Survives 100 watts RF input at the I.F.
Port without damage with transverter
un-keyed (in receive mode).
1Current varies with supply voltage, load impedance and power output. We
recommend a minimum 5 A supply.
Amplifier Key Output: Ground on transmit: 200 VDC at 1 A
maximum.
Connectors:
K2 Interface: DB9
Keying Line Input: RCA
Keying Line Output: RCA
I.F. In/Out: BNC
Aux (Rx-Only Ant): BNC
Antenna: SO-239 (UHF) on XVR 50
Type N on XVR 144 & XVR 222
Transmitter
Power Output: 20 watts into 50 ohms
Minimum Supply
Voltage Recommended: 12 VDC
Operating Modes: CW, SSB, AM, FM, PSK
I.F. Input Frequency Range: 28 – 30 MHz
I.F. Input Power Range: 0.01 mW (-20 dBm) to
8 watts (+ 39 dBm)
Harmonic Content: < - 60 dBc at 20 watts output.
Receiver
Noise Figure: < 1 dB
Conversion Gain: 25 dB (typical)
Image Rejection: > 60 dB
3rd-Order Intercept: +20 dBm (typical)

——4
Preparing for Assembly
Overview of the Kit
The Elecraft XV transverters use modular construction, both physically
and electrically. This concept extends to the chassis (Figure 2). Any
chassis element can be removed to provide access for troubleshooting.
Figure 2. XV Transverter Modular Cabinet Parts.
There are two printed circuit boards (PCBs) in the transverter: the front
panel board, which sits vertically behind the front panel, and the large RF
board.
The boards are interconnected using board-to-board connectors which
eliminates the need for a wiring harness. Gold-plated contacts are used on
these connectors for reliability.
Tools Required
You will need the following tools to build this kit:
•Fine-tip temperature-controlled soldering station with 700 or
800°F tip (370-430°C). Do not use a high-wattage iron or gun
with small components since this can damage pads, traces, or the
parts themselves.
•IC-grade, small-diameter (.031”) solder (Kester #44 or
equivalent).
•Desoldering tools and supplies are invaluable if you make any
modifications or need to do any repairs. Narrow solder wick or a
good vacuum desoldering tool such as the Soldapullt® model
DS017LS are recommended. See Soldering, Desoldering and
Plated-Through Holes, on page 9 for more information.
iDO NOT use acid-core solder, water-soluble flux solder,
additional flux or solvents of any kind. Use of any of these will void
your warranty.
•Screwdrivers: a small, #2 Phillips and a small flat-blade for slotted
screws.
•Needle-nose pliers.
•Small-point diagonal cutters, preferably flush-cutting.
•Digital Multimeter (DMM) for voltage checks and confirming
resistor values. A DMM with capacitance measurement capability
is desirable, but not required.
•Noise generator (Elecraft N-Gen or equivalent2) or signal
generator with output in the RF frequency range of the transverter.
•RF power meter capable of measuring RF power levels up to 25
watts at the RF frequency used by the transverter.
•50-ohm dummy load capable of handling 25 watts, minimum.
Refer to www.elecraft.com for tool sources and solder recommendations.
2Check www.elecraft.com for availability.
BACK PANEL
LEFT
SIDE PANEL TOP
COVER
FRONT
PANEL
BOTTOM
COVER
(RIGHT SIDE
PANEL NOT
SHOWN)
.

——5
Preventing Electro-Static Discharge Damage
Your XV transverter uses integrated circuits and transistors that can be
damaged by electrostatic-static discharge (ESD). Problems caused by ESD
often can be difficult to troubleshoot because components may be
degraded but still operating at first rather than fail completely.
To avoid such problems, simply touch an unpainted, grounded metal
surface before handling any such components and occasionally as you
build, especially after moving about.
For maximum protection, we recommend you take the following anti-
static precautions (listed in order of importance):
1. Leave ESD-sensitive parts in their anti-static packaging until you
install them. The packaging may be a special container or
conductive foam (Figure 3). Parts which are especially ESD-
sensitive are identified in the parts list.
2. Ground yourself briefly before touching any sensitive parts or
wear a conductive wrist strap with a series 1 megohm resistor.
DO NOT ground yourself directly as this poses a serious
shock hazard.
3. Make sure your soldering iron has a grounded tip.
4. Use an anti-static mat on your work bench.
Figure 3. A common anti-static packaging is conductive foam which
keeps all of the terminals of a device at the same potential.
Unpacking and Inventory
We strongly recommend that you do an inventory of the parts before
beginning to assemble the kit. Even if you don’t count all the parts, an
inventory is helpful to familiarize yourself with them. A complete parts
list is included in the next section.
Identifying Parts
The parts list contains illustrations of the parts to help you identify them.
Identifying marks on the individual parts are shown in the text in
parenthesis. For example, “Transistor Q4 (PN2222)…” indicates a
transistor, Q4, which may be located in the parts list that has the
characters shown in parenthesis printed on it. Sometimes these letters are
not obvious. They may be printed in light gray on a black body, for
example. Also, there may be other marks on the device in addition to the
letters listed.
Identifying Resistors
Resistors are identified by their power capacity and their resistance value.
The power rating in watts determines the physical size of a resistor. The
most common resistors are 1/4 watt. Higher wattage resistors are
proportionately larger. The resistance value and wattage of each resistor is
shown in the Parts Lists and in the individual steps of the assembly
procedures. The silk screened outlines on the circuit boards indicate the
relative physical size of the resistors as well.
Most resistors use a color code. The color bands are listed in the text along
with the values of each resistor. For example, “R4, 100k (brn-blk-yel)…”
indicates a 100k ohm resistor and the colors to look for are brown, black
and yellow, starting with the band nearest the end of the resistor.
Some resistors use numbers instead of color bands. For example, an 820
ohm resistor might be stamped with the digits 821 instead of having gray,
red and brown color bands. Some larger resistors have their value in ohms
stamped on the body using numbers. For, example the 820 ohm resistor
would be stamped with 820 instead of 821 as described above. Normally,
when the value is shown in ohms it will be followed with the word
“ohms” or the Greek letter omega: Ω

——6
Reading Resistor Color Codes
It is very helpful if you learn to read the color codes. A color-code chart
showing how to read the four-color bands on resistors with a 5% or 10%
tolerance is shown in Figure 4. 1% resistors are similar except that they
use a fifth band to provide a way of showing another significant digit. For
example, a 1,500 ohm (1.5 k-ohm) 5% resistor has the color bands brown,
green and red signifying one, five and two zeros. A 1,500 ohm (1.5 k-
ohm) 1% tolerance resistor has the color bands brown, green, black and
brown signifying one, five, zero, and one zero.
The optional band shown in Figure 4 indicates other performance
specifications for the resistor. When used, it is separated from the other
color bands by a wider space.
iIf in doubt of a resistor’s value, use a DMM. It may be difficult to see
the colors on some resistors, particularly 1% tolerance resistors with a dark blue
body. Do NOT be concerned with minor deviations of your DMM reading from
the expected value. Typical errors in most DMMs and the tolerances of the
resistors normally produce readings that are slightly different from the value
indicated by the color bands.
Identifying Molded Inductors
Small molded inductors have color bands that use the same numeric
values as resistors but they start near the center of the inductor and work
toward the end. These colors are listed in the text after the value of the
inductor, for example: 27µH (red-vio-blk). The red stripe would be near
the center of the inductor and the black strip would be closer to the end.
On very small chokes, the first color will be only slightly farther from one
end than the last color. There may be a variety of other stripes on
inductors as well, indicating their tolerance, conformance to certain
specifications and other data.
FIRST DIGIT TOLERANCE:
OPTIONAL
SECOND DIGIT
MULTIPLIER
Black
Brown
Red
Orange
Yellow
Green
Blue
Violet
Gray
White
Silver
Gold
0
1
2
3
4
5
6
7
8
9
-
-
X 1
X 10
X 100
X 10K
X 10K
X 100K
X 1M
-
-
-
X 0.01
X 0.1
COLOR DIGIT MULTIPLIER
GOLD = 5%
SILVER = 10%
Figure 4. Resistor Color Code.

——7
Identifying Capacitors
Capacitors are identified by their value and the spacing of their leads.
Small-value fixed capacitors usually are marked with one, two or three
digits and no decimal point. The significant digits are shown in
parenthesis in the text. For example: “C2, .01 (103)”.
If one or two digits are used, that is always the value in picofarads (pF). If
there are three digits, the third digit is the multiplier. For example, a
capacitor marked “151” would be 150 pF (15 multiplied by 101).
Similarly, “330” is 33 pF and “102” is 1000 pF (or .001 µF). You may
think of the multiplier value as the number of zeros you need to add on to
the end of the value.
Note: In rare cases, a capacitor manufacturer may use “0” as a
decimal placeholder. For example, “820” might mean 820 pF rather than
82 pF. Such exceptions are usually covered in the parts lists. If possible,
measure the values of all capacitor below .001 µF. Most DMMs include
capacitance measurement capability.
Fixed capacitors with values of 1000 pF or higher generally use a decimal
point in the value, such as .001 or .002. This is the value in microfarads
(µF). Capacitors also may have a suffix after the value, such as “.001J”.
The lead spacing is noted in the Parts Lists for most capacitors. If two
different types of capacitors have the same value, the lead spacing will
indicate which one to use. When the lead spacing is important, both the
value and the lead spacing is shown in the assembly procedure. For
example, “LS 0.1” means that the Lead Spacing is 0.1 in.
Hard-to-Identify Capacitor Values
2.2 pF: These are “disc ceramic” capacitors with round, pillow-shaped
bodies about 1/8” (3 mm) in diameter and a black mark on the top. The
capacitor should be labeled “2.2” but the marking sometimes requires a
magnifying glass to see clearly.
150 pF: These capacitors are marked “151” on one side, but the other side
may be marked #21ASD. The “#21” may look like “821”.

——8
Assembly Process
There are seven steps in the transverter assembly process:
1. Front Panel board assembly.
2. RF Board Assembly, Part I, parts common to all models.
3. RF Board Assembly, Part II, band-specific parts.
4. RF Board Assembly, Part III, installing the RF Power
Module.
5. Final Assembly.
6. Interconnect cabling.
7. Test and alignment.
Follow the assembly process in the order given. Each part builds on what
has been completed before it. For example, the Front Panel assembly
procedure contains details about installing certain parts that are not
repeated when similar parts are installed later.
Forming Component Leads
Sometimes the space provided for a component on the PC board is larger
than the distance between the leads on the part itself. In such cases, you’ll
need to carefully bend the leads out and then down to fit the given space.
Always use long-nose pliers to accomplish this task, and bend the leads –
don’t tug on them. This is especially important with capacitor leads, which
are fragile.
Step-By-Step Procedures
Perform the assembly steps in each procedure in the order given, and
do not skip any steps. Otherwise you may find that you’ve installed
one component that hinders the installation of another. When groups
of components are installed, they are listed in a logical order as you work
around the circuit board to reduce the time needed to find where each part
goes.
Each step in the assembly procedures has a check box.
Some steps have more than one task. For example, you may be installing a
number of components listed. When a step has a number of tasks, each
task is indented with space for a check mark:
Check off each task as you complete it.