LDG TW-1 User manual

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LDG TW-1
Talking Wattmeter
LDG Electronics
1445 Parran Road, PO Box 48
St. Leonard MD 20685-2903 USA
Phone: [phone] Fax: 410-
586-8475 [email protected]
www.ldgelectronics.com

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LDG TW-1 Talking Wattmeter
Table of Contents
Introduction 2
Jumpstart, or “Real hams don’t read manuals!” 3
Specifications 3
Getting to know your TW-1 4
Installation 6
Setup 6
Language 6
Speech mode 6
Volume 7
Speech Operation 8
Tone Operation 8
Application Notes 9
Care and Maintenance 10
Technical Support 10
Warranty and Service 10
Feedback 10
Introduction
Congratulations on selecting the LDG TW-1 talking wattmeter. The TW-1 is a breakthrough
product, providing accurate and precise RF power and SWR readings aurally, by synthesized
voice over a self-contained speaker. It is ideal for situations when you need to watch something
else while making an adjustment, or for visually impaired hams.
LDG pioneered the automatic, wide-range switched-L tuner in 1995. From its laboratories in St.
Leonard, Maryland LDG continues to define the state of the art in this field with innovative
automatic tuners and related products for every amateur need.

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Jumpstart, or “Real hams don’t read manuals!”
Ok, but at least read this one section before you transmit:
1. Attach the RF input jack (right connector when viewed from back) to your transmitter or
transceiver with a 50 ohm coaxial jumper cable.
2. Attach your antenna to the RF output (left connector when viewed from back).
3. Connect a 12 volt power supply capable of delivering 200 ma to the 2.5 x 5.5 mm coaxial
power jack (center positive).
4. While transmitting RF, press and release the left-hand button. The unit will speak the forward
power level. Adjust the volume to the desired level.
5. While transmitting RF, press and release the center button. The unit will speak the reverse
power level.
6. While transmitting RF, press and release the right-hand button. The unit will speak the SWR.
7. The unit will turn itself off after use.
Specifications
• 0 - 2,000 watts, auto-ranging
• +/- 5% accuracy (measured on 14 MHz), 10% on 6 meters
• 1 watt or 1% power resolution
• Adjustable volume
• Verbose or terse speech
• Tone mode for continuous feedback
• Speaks in English, Spanish or German
• Size: 5 x 4.5 x 3 inches
• Requires 12 volts at 200 ma, 2.5 x 5.5 mm jack, center positive

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Getting to know your TW-1
Your TW-1 is a quality, precision instrument that will give you many years of outstanding
service; take a few minutes to get to know it. On the front panel, there is a volume knob and three
pushbuttons:
• Volume: adjusts the volume of the synthesized voice
• Forward: measures forward power in watts (FWD Button)
• Reverse: measures reverse power in watts (REV Button)
• SWR: measures the standing wave ratio (SWR Button)
Readout resolution is 1 watt or 1% of the reading, whichever is larger. For example, if the reading
is 75 watts, 1% would be 0.75 watts, so the achieved resolution would be 1 watt. The readout
would go from "Seventy Five Watts" to "Seventy Six Watts" as you increase power. At a reading
of 245 watts, 1% would be 2 watts (rounded off), so the resolution would be 2 watts; the reading
would go from "Two Hundred Forty Five Watts" to "Two Hundred Forty Seven Watts".
There is no range switch; the TW-1 auto-ranges from 0 to 2,000 watts. There is no On/Off switch;
the TW-1 automatically turns itself on during use and off after use. The idle current is less than
100 uA.

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On the rear panel, there are two SO-239 RF connectors. The right-hand connector is the RF input
(labeled Radio) for connection to your radio, and the left-hand connector is the output to your
tuner or antenna (labeled Antenna).
The 2.5 x 5.5 mm jack coaxial DC power connector is on the right.

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Installation
The TW-1 is intended for indoor use only; it is not water resistant. If you use it outdoors (Field
Day, for example) you must protect it from rain.
Position your TW-1 in a convenient spot on your operating desk, as close to your transceiver or
transmitter as practical. Connect the input jack to your transceiver with a 50 ohm coaxial jumper
(not provided) of suitable power handling capacity. Connect the output to your tuner or antenna.
Your TW-1 requires 12 volts DC at 200 ma. Connect a suitable power supply to the 2.5 x 5.5 mm
coaxial DC input jack using the provided 2.5 x 5.5 mm jack coaxial power connector (center
positive).
Caution: High RF voltages may be present on internal components when transmitting. Never
operate your TW-1 with the cover removed.
Setup
Setup options are selected by pressing and holding buttons or combinations of buttons while you
apply DC power. The simplest way to apply power for setup is to unplug the DC power plug, wait
10 seconds, then re-insert the DC power plug from the back of the TW-1, but you could also turn
the DC power supply off then on again. Setup options are retained indefinitely, even if DC power
is removed.
Language
Your TW-1 will speak in English, Spanish or German; the default is English. To set the language,
press and hold a button while connecting DC power:
FWD Button: English
REV Button: Spanish
SWR Button: German
To reset to a different language, simply remove DC power, press and hold the appropriate button
and reconnect DC power.
Speech mode
Your TW-1 will speak in one of two different modes: Verbose and Terse. In Verbose mode, the
TW-1 speaks in full sentences, as in "The forward power is ninety seven watts". In Terse mode,
only the numerical value is spoken, as in "ninety seven". The default is Verbose mode.
After you become accustomed to your TW-1, you will likely want the shorter readouts, without
all the extra chit-chat. To select "Terse" mode, press the REV and SWR buttons together while
you apply DC power. Thereafter, on pressing a button when RF is present, only the numerical
value will be spoken.

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To return to "Verbose" mode, press the FWD and REV buttons together while you apply DC
power.
Volume
Simply adjust the volume control to the desired audio level as you use your TW-1.
Verbose Mode Terse Mode

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Speech Operation
Spoken readouts are available on demand; the readout is spoken on button release. There is no
need to set the power range; your TW-1 auto-ranges from 0 - 2,000 watts. With RF present, press
and release a button to produce the following spoken readouts:
FWD Button: forward RF power
(Verbose mode example: "The forward power is ninety seven watts")
(Terse mode example: "ninety seven")
REV Button: reverse RF power
(Verbose mode example: "The reverse power is three watts")
(Terse mode example: "three")
SWR Button: SWR
(Verbose mode example: "The SWR is two point one")
(Terse mode example: "two point one")
Your TW-1 works best with a constant RF carrier. Using a voice mode (SSB for instance) would
require you to talk and listen at the same time.
Tone Operation
When adjusting a manual tuner or vacuum tube transmitter or amplifier, it is often desirable to
have a continuous readout of power or SWR. Your TW-1 provides this by playing a tone whose
pitch goes up and down with the power or SWR.
To place your TW-1 in Tone mode, simply press and hold any of the three buttons for more than
three seconds before applying RF. The TW-1 will beep to indicate it has changed to Tone mode;
release the button when you hear the beep. When you apply RF, the TW-1 will emit a continuous
tone who's pitch is proportional to the power; the higher the power, the higher the pitch. You can
select either Forward (FWD Button) or Reverse (REV Button) power for tone readout.
You can also select SWR for tone readout, as above (SWR Button). The pitch of the tone is
proportional to the SWR; the higher the SWR, the higher the tone. If the SWR is above about 3:1,
the tone will pulse to indicate that the SWR is excessive.
After 30 seconds with no RF present, the TW-1 automatically reverts to Speech mode (verbose or
terse, whichever you have set). You can also manually reset it to Speech mode by pressing and
releasing any of the buttons. The TW-1 will beep to indicate that it has returned to Speech mode.

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Application Notes
The TW-1 is primarily intended for visually impaired hams, and those of us more "experienced"
hams who must resort to bifocals, making small meters hard to see at any distance.
The TW-1 is also very useful for special situations when you need to "watch" more than one
meter, as when you are tuning the output stage of a vacuum tube transmitter or amplifier. With
your TW-1 in Tone mode, you can easily watch the plate current meter on the transmitter or
amplifier while listening to the power output on your TW-1 in Tone mode.
The TW-1 is perfectly suited to mobile use. Simply install it in a convenient location near your
operating position, and provide 12 volts DC through a fused line (fuse not included; LDG
recommends a 2 amp fast-blow fuse). SWR Tone mode is especially useful when tuning a
"screwdriver" antenna while watching the road. LDG strongly recommends pulling over to a stop
before adjusting your antenna, but we realize that not everyone does this; you know who you are.
Press and
Release
(RF Present)
Press and
Hold 3 sec
Press and Hold
On Power-Up
FWD Button Forward
Power
Forward Power
Tone Mode English
REV Button Reverse
Power
Reverse Power
Tone Mode Spanish
SWR Button SWR SWR
Tone Mode German
REV + SWR _ _ Terse Mode
FWD + REV _ _ Verbose Mode
Button Summary

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Care and Maintenance
Your TW-1 tuner is essentially maintenance-free; just be sure to observe the power and voltage
limits discussed in this manual. The outer case may be cleaned as needed with a soft cloth slightly
dampened in a mild household cleaning solution. As with any modern electronic device, your
TW-1 can be damaged by temperature extremes, water, impact or static discharge. LDG strongly
recommends that you use a good quality, properly installed lightning arrestor in the antenna lead.
You should never have to remove the cover, but if you do, be sure that no wires are within 2" of
the SWR sensor or the SO-239 connectors when you reassemble the unit.
Technical Support
We are happy to help you with your TW-1. Telephone technical support is available at 410-586-
2177 weekdays from 9am to 5pm Eastern Time. Inquiries by Fax at 410-586-8475 are welcome,
and prompt e-mail support is available at [email protected].
Warranty and Service
Your TW-1 is warranted against defects in parts or workmanship for two years from purchase.
The warranty does not cover damage due to abuse or exceeding specifications. This warranty
applies to the original purchaser only; it is not transferable. A copy of the receipt showing the
purchaser’s name and the date of purchase must accompany units returned for warranty service.
All returns must be shipped to us pre-paid; we will not accept units with postage due. A return
form is provided on our web site for your convenience.
If you need to return your TW-1 to us for service, package it carefully, keeping in mind that we
will re-use your packaging to return the unit to you. A self-addressed return-shipping label, while
not required, will help insure speedy and accurate delivery of your repaired unit. Include a full
description of the problem, along with your name, address and a phone number or e-mail address
where we can reach you with any questions. Repairs average about 3 to 6 weeks.
We will be glad to service your TW-1 after the warranty period has ended. We will notify you of
repair charges by phone or e-mail, and bill you after repairs are completed.
Feedback
If you have an idea to improve our software or hardware, please send us a description. If we
incorporate your idea in the TW-1, we'll send you a free upgrade as a “thank you”.
We encourage everyone who uses the TW-1 to contact us (card, letter or e-mail preferred) telling
us how well it works for you. We are also always looking for photographs of our products in use;
we frequently place such pictures on our Web site (www.ldgelectronics.com).