SWR DJ9PK User manual

S
W
R
Meter
–
PEP Wattmeter
T
e
l:
07032
-
985866
Page
:
1
of
8
SWR METER
STANDING WAVE MEASURING DEVICE
PEP WATTMETER
NEXTION TOUCH SCREEN DISPLAY
This device was desig ed as a SWR a d power meter for Radio Amateurs.
I additio to SWR, it measures forward a d backwards
power, therefore ca also be used as a wattmeter.
With a large measuri g ra ge from 1 to 1000
watts, it is suitable for use from QRP to QRO.
DJ9PK
http://dj9pk.de
Feb. 2021 V

S
W
R
Meter
–
PEP Wattmeter
T
e
l:
07032
-
985866
Page
:
2
of
8
Summary:
 This standing wave measuring device —SWR Power Meter— was designed for a
frequency range from 1.8 to 3 MHz. It can be used up to 5 MHz with a
somewhat reduced accuracy.
 The transmitter and antenna connect via the PL-sockets on the meter’s back.
 6 to 16 volts @ 12 mA are required for operation. These can be from a plug-in
power supply or from the transceiver's 12V supply.
 The graphic display has two display options on two different pages: Page 1 uses
an analog format with a relatively small numerical display for the exact measured
values. Page 2 has a bar graph and a significantly larger numerical display for the
values measured. You can switch between the two pages by tapping on the
display.
 For accuracy, to always achieve a good resolution, the Power readings on both,
the analog and bar graph are auto-ranging.
Note:
An automatic zero adjustment is made every time the device is switched on.
If there is RF power present when the device is powered-on, zero is also displayed.
To obtain correct values, the carrier must be momentarily removed.
Only when the carrier is removed, then applied again, will the display values be correct.
Preferably tur the device o WITHOUT RF power!
Note 2:
If the displayed values of an RF carrier signal wobble in the "fast" setting (more than
only the last digit), this is not caused by the SWR meter: This is hum in the RF source.
This has been observed several times, especially with larger power amplifiers.
In these cases, only fast/PEP display can help.
Features:
The display is touch sensitive (touch screen). All settings will be
done by “tapping” the screen.
The following two pictures show which functions can be set by tapping the corresponding
buttons.
The display is the “Resistive” kind: This means that it reacts to a point pressure and not
just to contact.
It is best to use a plastic pen (ballpoint pen without metal tip) or your fi ger ail.
The fingertip is sometimes a little too big.

S
W
R
Meter
–
PEP Wattmeter
T
e
l:
07032
-
985866
Page
:
3
of
8
Butto s o Page 1:
Buttons on Page 2:

S
W
R
Meter
–
PEP Wattmeter
T
e
l:
07032
-
985866
Page
:
4
of
8
Technical
Details
:
The microprocessor corrects the Non-Linearity of the Rectifier Diodes in the SWR sensor.
This ensures a high level of accuracy is achieved (typically 3%) over the range from 1 to
1 watts.
The resolution for low power is 1 mW. This is reduced at higher outputs due to the
number of digits available on the display.
A "fast" display and a slower Peak Value display (PEP) are provided.
The latter shows the maximum value that occurs within an observation period of 1
second.
A sample rate of 2 kHz is used (2 , measurements per second). This
ensures that even short peaks are recorded and makes it suitable for Peak Performance
readings on SSB and CW modes.
Date and time:
The date and time feature is only included if requested.
It requires a different display, which unfortunately is
a bit more expensive.
Since it is displayed on a separate page, it makes the
Meter suitable as a station clock when not used for SWR.
The clock continues to run when the Meter is switched off thanks to its back-up battery.
The date and time can be manually set on another page. The accuracy is 1-2 seconds per
week.
The clock is set on a separate page that can be accessed by tapping on “adj. clock”
There, all numbers can be changed with the "+" and "-" buttons.
A good technique is to set the time approx. 1 to 2 seconds ahead of the actual time,
then while watching a reference clock, press the "set clock" button when this time is
reached. This allows you to set the device to the exact time.
The clock has an automatic feature:
The button on the bottom right of the page allows switching between "fix" and "auto"
modes. In "fix" mode, the time display always remains on. In "auto" mode, the device
switches automatically to the last selected screen as soon as RF power is applied.
Cleaning:
Do ot use Tempo tissues or other paper towels to clean the screen surface; they cause
scratches. It is best to use alcohol and a microfiber cloth.
Microfiber cloths are available free of charge from opticians as a cleaning cloth for
glasses.

S
W
R
Meter
–
PEP Wattmeter
T
e
l:
07032
-
985866
Page
:
5
of
8
Technical
Details
:
Power supply 6 – 15 V DC
Power consumption 12 mA
Displayed values
Forward RF power
Reflected RF power
SWR (Standing Wave Ratio)
Radiated Power (forward power
minus reflected power)
Measuring range (power) 1 – 1 Watts
Resolution 3 Digits (1 mW with low power)
Accuracy +/– 3% (1 – 1 Watts at 1.8 – 3 MHz)
Insertion loss (3 MHz) . 2 dB
Insertion SWR 1. 1
Dimensions 113 x 76 x 49 mm (4.4 x 3 x 1.9 in.)
Display size 3.2” Diagonal (4 x 24 pixels)
Calibrating and changing the background:
The Meter is calibrated with high-precision
measuring devices before shipping and
recalibration is not necessary.
However, users can calibrate it to their own
standards if desired, as described below:
An exact 5 Ohm “dummy load” must be
connected and precisely 9 watts of power
applied to the unit.
Screen with black background
You can get to the calibration page by clicking on the gear wheel, top center, on page 1.
The calibration page is shown in the picture above.
There you click on the “calibrate” button and follow the instructions in the scrolling text.
It is also possible to do a Factory Reset to restore the settings to what they were upon
delivery.
Access the calibration page as described above and then click the “reset cal.” button.
The “background” button is new. It allows switching the background from the previous
speckled gray to black.
The black background provides a higher contrast. The background setting then applies
to all pages.

Circuit Diagram (Display):
SWR Meter – PEP Wattmeter Tel: [phone] Page: 6 of 8

Circuit Diagram (SWR Se sor):
SWR Meter – PEP Wattmeter Tel: [phone] Page: 7 of 8

Layout a d Placeme t Diagram
SWR Meter – PEP Wattmeter Tel: [phone] Page: 8 of 8