ROM Elektronik HFA-3 User manual

ROM-Elektronik GmbH
elektronik
µ
RF-Analyzer HFA-3
Manual

Seite 2
ROM-Elektronik GmbH
Many thanks for deciding on the purchase of this device.
You are now able to determine the high-frequency situation quickly and
simply, and carry out a simple selection of the frequency ranges (as it were,
a simplified RF spectral analysis).
Reference: In case of the mobile communications frequency ranges
GSM900, GSM1800 and 3G (UMTS) of our HFA-3, ONLY the so-called Down-
link is measured; therefore the frequencies of the base stations! A mobile
communications telephone can be measured in the operating mode
"All-pass", since the frequency range (GSM900, GSM1800 or 3G (UMTS)) is
generally known in this case.
The operation of the HFA-3 is simple. We have given this the highest priority
value!
Through our long-standing experience in RF measuring device construc-
tion, with support from the University of the German Armed Forces, Munich,
our "large" HF Measuring Unit PDM-3 and its "little brother" HFR-2, as well as
our multifrequency filter MFF-1, have undergone some decisive improve-
ments. Only by means of this (expensive) development effort, could we
also realize many of these improvements for the HFA-3.
The HFA-3 is a broadband receiver for the verification and evaluation of
high-frequency signals (mobile telephones C-Net, GSM900, GSM1800,
cordless telephones (DECT, CT1+ ...), radio and television transmitters,
microwave cookers ...).
The built-in peak value recording allows the measurement of pulsed RF si-
gnals according to building-biology requirements.
The sensitivity and gauging accuracy has been further increased in com-
parison with the HFR-2. On the LC display of the conveniently handled de-
vice, the electrical field strength can be read off directly in mV/m or the
radiant flux density in µW/m
2
.
The indicated values agree in a range ±3 dB in case of approx. 1 GHz (1000
MHz, GSM900 area) and direction of the antenna in the plane of polariza-
tion.
Over the switchable internal loudspeaker, the modulation of the radio fre-
quency signals can be made audible (e.g. pulsed RF radiation).
The direction and the polarization of the RF radiation can be determined
simply by the attachable, logarithmic-periodic broadband antenna inclu-
ded in the scope of delivery, (logper antenna).

Seite 50
ROM-Elektronik GmbH
T
ips and notes on frequently asked questions
Avoid the operation of a mobile telephone (cell phone) in direct proximity
to the HFA-3! Never allow the antennae of the HFA-3 and mobile telepho-
ne to come in contact during operation!
DANGER OF DESTRUCTION
!
In case of the peak value recording, it takes a certain time until the mea-
sured value has adapted; in particular downwards. The reason for this is
that the measured values are stored and a certain time passes (approx. 30
sec) until this storage is emptied. Also, the display becomes very unstable
if pulsed signals are registered.
The measurements of the long-term recording are always stored on the
hard disk TO AVOID DATA LOSS!
~H0000.TMP: Header file
~A0000.TMP: Measurement file
In the case of a program crash, a valid file HFA-3 can be generated from
these files, where the following occur
• The program is newly started,
• The recording is set adjusted
•
in the menu: Recording\Save is selected with specification of a
name. This file can be again normally loaded with Recording\Open
and displayed as color graphics!
Technische Daten
Frequency range: ca. 100 MHz bis 2500 MHz
(Approx. 10 MHz to 3000 MHz with decreased precision)
Measuring range: 6 mV/m to 2000 mV/m (= ca. 0,1- 10000
µ W/m
2
= 10 pW/cm
2
- 1 µ W/cm
2
)
Max. sensitivity: Better than 0,01
µ W/m
2
(= 1 pW/cm
2
)
Filter frequency ranges:
All-pass network, broadband (100 MHz to approx. 3 GHz)
GSM 900 (935 MHz to 960 MHz)
GSM 1800 (1805 MHz to 1880 MHz)
Cordless telephones according to DECT standard (1880 MHz to 1890 MHz)
3G (UMTS) (2110 MHz to 2170 MHz)
WLAN, Bluetooth, microwave oven (2400 MHz to 2500 MHz)
Display: LC-Display, 2 lines
Ambient temperature: 0 to 40˚C
Dimensions: 85mm x 117mm x 55mm
Functions: Adjustable volume
Weight: Approx. 300 g
Power supply: 9V block battery
Current consumption: max. 20 mA
Scope of delivery: HFA-3, Logper-Antenna 900MHz - 2600 MHz, Battery
Also optionally available with serial computer interface and recorder outlet
Seite 3
ROM-Elektronik GmbH
Preliminary notes - Notes on safety
You have acquired an electronic measuring device. Handle your HFA-3 ca-
refully! Due to the high level of sensitivity, the electronics of the measuring
device are sensitive to shocks and jolting. Please do not let it fall!
The antenna of the device conducts electric current very well. Do not bring
the antenna too near plug sockets, current-carrying cables or rigs! The
HFA-3 could be destroyed with contact of the antenna with current! Also
the electric shocking of the user cannot be entirely excluded!
The HFA-3 does not belong in children's hands! Although the device is quite
rugged, nevertheless the antenna can suffer damage in case of inappro-
priate use.
Never bring to the HFA-3 in contact with water! Do not use in the rain. The
sensitive electronics can be damaged.
Avoid high temperatures! The device should not be placed on heating units
or left in the car in summer under full sunlight!
Please note that the device uses a relatively large amount of current and
thus the battery can be used up fast. The HFA-3 signals a used battery in the
display with the message "Change battery". Rechargeable batteries can
also be employed.
The HFA-3 is maintenance-free. A re-calibration is not necessary! Clean the
device only on its exterior with a moist cloth. Do not use any cleaning
agents!

Seite 4
ROM-Elektronik GmbH
Operational startup
If not already carried out, insert a 9 V battery (or rechargeable battery)
into the battery compartment on the reverse side.
Screw the supplied logper antenna onto the HFA-3 where appropriate,
tighten with a tool.
Installation of the antenna with tuning assistance
Seite 49
ROM-Elektronik GmbH
Liability and guarantee
Every liability which arises from application of the device is excluded. The
guarantee period is 24 months from delivery date. Within this time, all de-
ficiencies, which are not attributed to inappropriate treatment, are repaired
immediately and clear of all charges. In case of repair being necessary,
please send the device to us with the proof of purchase.
Assistance and support
Should you require assistance in the application of the device, then you can
reach us under Fax No.: 08282-7305 or Tel.: [phone] with operational que-
stions concerning the device.

Seite 48
ROM-Elektronik GmbH
Setting adjustment of the correct baud rate
If, contrary to expectation, only unreadable "hieroglyphs" should appear
on the PC, this can be attributed to a slightly deviating baud rate of PC
and HFA-3.
In this case, the HFA-3 can be re-calibrated. For this, the left-hand and
right-hand pushbuttons are to be pressed SIMULTANEOUSLY with switching
on. A signal appears on the display as follows:
after a pause followed by
Where the number in the second line decreases continuously.The following
should be observed on the screen terminal.
If the text "Wait until it can be read ... then press x" can be read off without
error, then please activate the key "X" on the PC keyboard. The correct
baud rate is now set adjusted and stored permanently.
This procedure can be repeated as often as necessary.
Screen for baud rate calibration
OscCal: 7E
EEPROM: 126
Kalibrier-
wert: 63H
Seite 5
ROM-Elektronik GmbH
Switch on the HFA-3 with the slide switch located on the side.
The following message should appear shortly on the display:
then e.g.
With this, your HFA-3 is in operation.
Built-in loudspeaker
A volume control is located on the front panel of the HFA-3. The volume of
the built-in loudspeaker can be adjusted here and/or optionally using plug-
ged-in headphones.
The loudspeaker reproduces the modulation signals which are received
Operator elements of the HFA-3
Volume for built-in
loudspeaker and
optional
headphone
Switch
On
Off
Antenna connector
Headphone
plug Batterycase at
the backside
Pushbuttons
ROM-Elektr.
HFA-3 V2.0
65.4 mV/m
¥¥¥¥¥¥¢

Seite 6
ROM-Elektronik GmbH
over the antenna. Do not be surprised when you hear the signals for the first
time. Here you get an impression that signals are in the "ether" that you do
not notice because none of your senses is able to register these.
A signal which is simple to identify is that of a DECT cordless telephone. The
base station constantly sends a 100 Hz tone whether telephoning or not! As
soon as the power plug is pulled on the base station, the hum tone disap-
pears.
Mobile telephones (cells), which communicate according to the GSM
standard, send a 217 Hz signal. However, this is sent only during telephon-
ing. The corresponding base stations, on the other hand, can be identified
through a high whistling tone with approx. 1733 Hz (8x217 Hz =1733 Hz).
Radar systems send signals from 600 Hz to 1200 Hz.
There are innumerable other, in-part "exotic" signals, which cannot all be
counted here. With time, you will gain your own experience.
Functions
The HFA-3 has a built-in filter bank in order to carry out the measurement for
individual frequency ranges only. The filters are set adjusted to fixed fre-
quencies. In the measurable frequency range, the 3 bands of the mobile
communications are offered (GSM900, GSM1800, 3G (UMTS)), cordless te-
lephones (DECT) and the services employed for computer networking,
such as WLAN and Bluetooth.
The pushbuttons located on the front side are employed to alternate bet-
Frequency designation Frequenzbereich
All-pass network (no filter) 10 MHz to approx. 2500 MHz
GSM900 935 MHz to 960 MHz
GSM1800 1805 MHz to 1880 MHz
DECT (Digital Enhanced Cordless Telephone) 1880 MHz to 1890 MHz
3G (UMTS) 2110 MHz to 2170 MHz
WLAN, Bluetooth, Mikrowellenherde 2400 MHz to 2500 MHz
Designation and frequency range of the frequency filter of the HFA-3
Situation of the frequency filters on the HFA-3
Seite 47
ROM-Elektronik GmbH
After a click on OK, the first data can be sent to the PC.
If everything has proceeded successfully, data should now appear conti-
nuously on the screen in similar form as represented above. If a filter is selec-
ted, this is output behind the measured value.
Select 2400 baud, 8 databits, 1 stopbit, no parity
Data output of the HFA-3

Seite 46
ROM-Elektronik GmbH
The interface must be set adjusted to 2400 baud 8N1!
Attach a new connection
Select a free serial interface
Seite 7
ROM-Elektronik GmbH
ween the different functions of the HFA-3.
Frequency filters
The individual frequency ranges are selected with the right-hand pushbut-
ton (RT). Simply activate the pushbutton until the required symbol for the fre-
quency range is indicated in the display.
Table of the function on activating the pushbuttons
left
pushbutton
right
pushbutton Function
push Peak value storage (PeakHold) On/Off switching
push RF filter stored cyclically at every actuation
push and hold then push Branching off in main menu
push in main menu Selection between display or menu data logger
push in main menu Branch between mV/m and µW/m2
push in display menu Selection between mV/m and µW/m2
push in display menu Return to the normal operation indication
push in data logger
menu Set or delete dataLog and/or cyclical flag
push in data logger
menu Return to the normal operation indication
Symbol In the display Meaning
DD
DD
Filter for GSM900 (935 MHz to 960 MHz) active
EE
EE
Filter for GSM1800 (1805 MHz to 1880 MHz) active
dd
dd
Filter for DECT (1880 MHz to 1890 MHz) active
UU
UU
Filter for 3G (UMTS, 2110 MHz to 2170 MHz) active
WW
WW
Filter for WLAN (2400 MHz to 2500 MHz) active
Table 1:
Meaning of the symbols in the display
left pushbutton right pushbutton
65.4 mV/m D
¥¥¥¥¥¥¢
A „D“ signals
Filter für GSM900
active

Seite 8
ROM-Elektronik GmbH
Selection of the measurement unit
The HFA-3 is able to indicate the measured value either in units of electrical
field strength (mV/m) or in radiant flux density (µW/m
2
). The unit is changed
as follows:
Keep the left-hand pushbutton (LT) pressed and then press the right-hand
pushbutton (RT) until the following display appears.
Typical frequency response of the HFA-3
65.4 mV/m
¥¥¥¥¥¥¢
”Anzeige
DatenLogger
Seite 45
ROM-Elektronik GmbH
• The program is restarted,
• The recording is set adjusted
•in the menu: Recording\Save is selected with specification of a name.
This file can be normally loaded again with Recording\Open and dis-
played as color graphics!
In order to save the data on a PC (long-term recording), the HFA-3 is to be
connected with a free serial interface using the cable supplied (if option has
been ordered). If your PC does not have any serial interface, the connec-
tion can also be realized with a USB serial converter.
Serial RS232 data output (PC connection, alternative
method)
Below is described the procedure in example form for a Windows PC. A si-
milar procedure is possibly necessary for other computers. Where appro-
priate, inquire with your computer dealer or specialist.
Start the software "Hyper Terminal" on the PC (can be found in /Pro-
gram/Communication/Hyperterminal). After the start, the configuration is to
be carried out.
Display of recording, open recording

Seite 44
ROM-Elektronik GmbH
All specifications from the recording display are stored in an ASCII file (mo-
de, maximum values, recording beginning, recording duration, location
and comment).
The measurement curve is saved with time, measured value, filter and co-
lor code.
Thus it is possible to load an already implemented recording into the HFA3
1.0 again at a later time for viewing.
This comes about by clicking the icon Open (or in the menu) and by selec-
tion of a file name in the opening dialog window. The file is searched for
first in the Directory\Recording as a default.
The measurements are always saved on the hard disk IN ORDER TO AVOID
DATA LOSS!
~H0000.TMP: Header file
~A0000.TMP: Measurement file
In the case of a program crash, a valid file HFA-3 can be generated from
these files where
Display of recording, Save recording
Seite 9
ROM-Elektronik GmbH
With the left-hand pushbutton (LT), the selection is reached:
In the same way, you can skip back and forth between the units with the
left-hand pushbutton (LT). The arrow to the left near the unit identifies the sel-
ection. The selection is confirmed with the right-hand pushbutton (RT) and
the display changes into the display mode:
Configuration of the data logger
The HFA-3 is able to transmit measured values to a data logger connected
to the serial interface (e.g.: Uni MMC Data Logger I or our data logger that
is just being developed). The configuration of the device for operation with
a data logger is as follows:
In normal operation indication, hold the left-hand pushbutton (LT) pressed
and press the right-hand pushbutton (RT), then the following display ap-
pears.
Then selecting the data logger entry with the left-hand pushbutton (LT).
Through pressing the right-hand pushbutton (RT), change into the data log-
ger menu.
mV/m
” µW/mˇ
65.4 µW/mˇ
¥¥¥¥¥¥¢
65.4 mV/m
¥¥¥¥¥¥¢
”Anzeige
DatenLogger
” DatenLogger
Anzeige
zyklisch
”
DatenLog.

Seite 10
ROM-Elektronik GmbH
With every press on the left-hand pushbutton (LT), the arrow changes bet-
ween both options and the data logger (Data Log.) and the filter rotation
(cyclical) is activated or deactivated.Whether the data logger and/or the
filter rotation is activated can be identified on the "<" character at the end
of the word.
When "Data Log." is activated, all measured values with 4800 baud are
transferred to a connected data logger over the serial interface.
If "cyclical" is activated, the filters are additionally cyclically changed ac-
cording to 5 measured values in each case.
The selected adjustments remain until the switch-off of the device and are
deactivated automatically on restart.
With a press on the right-hand pushbutton (RT), you return to normal ope-
ration indication.
PeakHold
The HFR-4 has a peak-hold funcion. This funcion enables to „freeze“ the
measured value on the display. Therefore, it is necessary to push the left
button (LT) until the symbol for peak-hold appears.
With activated peak-hold, the value reading changes wehenever the
measured value is greater then stored value. The bargraph shows allways
the actual value (follows the actual reading)
Modulation
Radio frequency signals are difficult to measure, not only because of their
very different frequencies. A complicating factor is that there are also
many different modulation methods. The latest research results indicate
that the modulation method (e.g. pulse modulation) has a strong influ-
ence on the biological relevancy of a radio frequency signal.
Exactly as biological systems, the radiation detector also does not react si-
milarly to all modulation methods. The modulation of the RF signals can be
detected over the built-in loudspeaker.
zyklisch<
” DatenLog.<
218 µW/mˇ^
¥¥¥£££
Symbol for
PeakHold
Seite 43
ROM-Elektronik GmbH
With a click on the Save command button (or in the menu) a recording can
be saved.
A dialog window is opened in this case, in which the file name for the recor-
ding and a memory location (path) for this file are entered. Standard me-
mory location is the Directory\Recording which is attached during the
installation.
Display indication: Power flux density S, Mode: automatic