Typical sensitivity stated
in† millivolts RMS
5 Hz - 1 MHz
DIGITAL FREQUENCY DISPLAY
Eight Extra Bright, high
efficiency, red, .3 inch LED digits. Superb angle visibility, usable† in bright light, no back light required for
darkness or low light conditions. Automatic decimal placement at MHz position.
Lead zeros blank above decimal point.
ATH ONE-SHOT FEATURE†
&† RESET CONTROL
This single reading,
capture, lock and display function is not available on the ATH-10,† optional on the ATH-15, standard on the ATH-30 and ATH-50. This feature can be switched on or off and works in
conjunction with the ATH or Auto Trigger & Hold function. This enables
reading of a very short duration signal (80 ms or longer) or can be set to
trigger and hold a reading unattended, etc. A RESET Push Button is installed on
all models with the ONE-SHOT feature. After the ONE-SHOT triggers, RESET can
rearm and clear the display to zero.
The cabinet is black
anodized aluminum, using 4 machine screws.
H x 3.5" W x 1" D, <14
9 oz., with internal batteries.
EXTERNAL POWER REQUIREMENTS
Auto-Polarity external power input: Use 9-12
VDC 300mA AC adapter. When powering an ATH series Frequency Counter from an
automobile or other auxiliary power source, input to Counter should be 8.5 to
10.5 VDC. #APA-9 Vehicle Power Adapter accessory
has been designed for for powering a STARTEK ATH series Counter from an
automobile. Higher voltages can damage batteries, lower voltages may cause
counter to operate incorrectly or not at all.
Internal Ni-Cad batteries operate unit 3 to 6 Hours, 18-24 Hours required for
full charge.† Do not charge batteries (or
operate on AC adapter/charger) for more than 30 hours continuously.
Charging for days at a time will shorten battery life.
4.† SWITCH CONTROLS & INDICATORS
AC-CHG:† †††† Use
this position to turn unit OFF when
operating from internal batteries.
††††††††††††††††††††††† When powered by the AC
adapter or other external
††††††††††††††††††††††† 9-12 VDC power source,
via the power jack on side of unit,
counter will be on and usable and internal
††††††††††††††††††††††† Ni-Cad batteries will be
BAT:††††††††††††† Use this position to power unit ON from internal batteries.
COUNT switch has three positions labeled FAST, MED and SLOW that determine the
COUNT TIME (which may also be referred to as the† SAMPLE TIME or GATE TIME) for measurement of the input signal.
The green LED COUNT indicator is illuminated while the instrument is actually
slower COUNT time WILL SHOW more resolution or more digits will be displayed.
Frequently the higher resolution is not required and the quick reading obtained
using the FAST count selection is convenient and sufficient. If higher
resolution is preferred, use the FAST or MED count speed first, to establish a
steady, readable signal, then switch to SLOW for maximum resolution.
The response time and
resolution for the various COUNT times and ranges for each model are listed in
the SPECIFICATIONS section.
to select the appropriate RANGE for frequency being counted. The switch is
labeled in MHz.
Ranges overlap and sometimes one range will work better than
the other for a specific application.
††††††††††† MODEL††††††††††††††††††††† LOW RANGE†††††††††††††††††† HIGH RANGE
††††††††††† ATH-10††††††††††††††††††††† 1-400
MHz†††††††††††††††††††††††† 25-1200 MHz
††††††††††† ATH-15††††††††††††††††††††† 1-500
MHz†††††††††††††††††††††††† 25-1500 MHz
††††††††††† ATH-30†††††††††††††††††††††† 1-800 MHz†††††††††††††††††††††††† 1-2800 MHz
††††††††††† ATH-50††††††††††††††††††††† 5
Hz-50 MHz†††††††††††††††††††† 10-2800 MHz
low range (5 Hz to 50 MHz) on the ATH-50 has a 1 megohm, HIGH IMPEDANCE, input.
When counting a signal
with a probe, it will place minimal loading on the circuit under test.
other models and ranges have a 50 ohm, low impedance, RF input.
hold switch will stop the counter from counting and keep the current frequency
The red HOLD LED will be lit when the HOLD switch is ON.
the unit is initially turned on with
the HOLD switch in the ON position,
the digital frequency display will be blanked and the COUNT & HOLD LEDs
will be on. Although it is not necessary, this can be done to turn unit OFF
when charging batteries, if desired. Switching HOLD to OFF will immediately
activate the counter.
ATH switch enables the AUTO TRIGGER & HOLD function, which can be set to automatically
trigger, display and† hold a reading
when the signal stops - hands free!
the ATH (and HOLD switch off), the
unit will continuously cycle the selected COUNT rate (selected by COUNT
switch), updating the display after each count, just as most frequency counters
the ATH switch
ON, the unit will stay in the HOLD
status (red LED on) until or unless the input signal level is strong enough to
trigger the automatic count circuitry. When the ATH triggers, the red HOLD LED will go off and the
green COUNT LED will light. When the input signal drops below the trigger level
(or input signal stops), the unit will automatically switch to the HOLD status
and maintain the last complete
reading on the digital frequency display.
Automatic Clean Drop-out: When input signal stops amid the count time, the
partial count is ignored and the last complete
reading is held and displayed.††
the models with a Bar Graph (ATH-15/30/50),
the ATH will trigger with an input signal or noise level
strong enough to light one or more segments on the Bar Graph. When using the
unit with an antenna, the input level can usually be reduced, if necessary, by
altering the antenna (change antenna, reduce length of telescoping antenna,
ATH trigger level is factory adjusted for what should
be the best overall operation, however, the trigger level is user adjustable on
models ATH-10/15/30 via a small
access hole in the upper left area of the front panel. It is normally NOT necessary for a user to alter this adjustment.
If the adjustment is changed, the user is cautioned to alter by small
increments. On models ATH-15/30, this
adjustment will also affect Bar Graph sensitivity.
the ATH-15/30, the trigger level and
Bar Graph sensitivity are reduced (requiring a stronger signal) when the
adjustment is turned counter-clockwise.
the ATH-10, the trigger sensitivity
is reduced (requiring a stronger signal) when the adjustment is turned clockwise.
RESET switch is a push button, located on the top, right side of the
instrument. The RESET switch will clear the display to zeros and restart the
COUNT or GATE period that may be in progress. The RESET switch will function
any time the unit is powered ON.
control is on models that have the ONE-SHOT ATHfeature.
standard feature on ATH-30/50,
optional on ATH-15, not on ATH-10.
ONE-SHOT ATH switch is located on the top of the unit and is
labeled with the international symbols,
for OFF,†††† "1" for ON.
utilized, this function will display and hold the FIRST readable signal to trigger the counter, until manually reset;
only ONE COUNT period or GATE TIME
is used to prevent a subsequent signal from altering the display data.
"ONE-SHOT ATH" or "ONE READING, Auto Trigger &
Hold" function works in conjunction with the ATH.
The ATH switch
must be ON and the HOLD switch must be OFF, to use the
to the ONE-SHOT ATH switch are two LED indicators, SEL for ONE-SHOT function SELECTED and RDY for ONE-SHOT function READY.
When the ATH switch is ON and the ONE-SHOT ATH switch is ON, the yellow SEL LED will be ON.
the ONE-SHOT function is selected, use the RESET push button to clear the
digital display to zeros and light the RDY
LED. At this point the first signal to trigger the ATH circuitry for a full count time will turn OFF
the RDY indicator, the counter will display the frequency and automatically
switch to HOLD status. One push of the RESET push button† will clear the display and rearm or make the
ONE-SHOT ATH function READY again.†
a signal triggers a unit, in the "ONE-SHOT READY" status, for less
than the selected COUNT TIME, it returns to HOLD with ONE-SHOT READY and the
display will not be updated. This function of the AUTOMATIC CLEAN DROP-OUT
circuitry prevents the display of erroneous data from a partial reading.
Low Battery indicator is standard on the ATH-15/30/50,
not used on ATH-10.
yellow "LOW BATTERY" LED indicator will light (blink) with the COUNT
indicator, when the internal Ni-Cads need to be recharged.
are a few minutes of operation remaining after the initial warning. The counter
can be used, with no damage to the circuitry, until the batteries will no
longer power it.
indicator may be labeled "BAT CHG" on the ATH-15.
5.† BAR GRAPH & DIGITAL DISPLAY
SIGNAL STRENGTH BAR GRAPH
signal strength Bar Graph is standard on the ATH-15/30/50 (not used on the ATH-10).
The Bar Graph has a two inch display with 10 red LED segments that illuminate
from left to right indicating the relative strength of the input signal.
Bar Graph is quite useful for many applications from peaking the output of a
circuit to locating RF sources to showing the presence and relative strength of
a signal you may be trying to count, however, it is a relative indication and
can vary with frequency.
Bar Graph functions independently from the digital counter and will react to
the strongest input signal. When using an antenna with the counter, a signal
may sometimes light from one to all Bar Graph segments before a stable, usable
reading is displayed. This usually depends upon the number and strength of RF
signals within the band pass or input frequency range of the counter, at the
given location. The use of a Band Pass Filter can reduce the input frequency
range and minimize this effect.
counting a signal directly from a circuit with a probe or cable, you will
almost always be able to count a stable signal with as little as one or no Bar
Graph segments lit. This is due to the undesired RF being eliminated by the
shielded cable, reducing the overall noise level and allowing a weaker signal
to be counted.
Bar Graph will function normally with the HOLD function ON or OFF.
DIGITAL FREQUENCY DISPLAY
frequency of a readable input signal is displayed by an eight digit, red,
.3" character height, high efficiency LED display. The extra bright LED
digits take no more power than standard brightness displays but can be used in
very bright light, very low light, have excellent angle visibility and are
readable by most people to more than 15 feet away.
decimal point is automatically placed to display MHz. The display will
automatically blank leading zeros above the decimal point. The display can be
blanked and counter turned off by switching the HOLD ON before powering unit
ON. This is not required but can be done when charging batteries, if desired.
counters can operate 3 to 6 hours from full charged, internal Ni-Cad batteries.
The batteries consist of two packs each made up of two AA Ni-Cads that are
soldered on the PC board for a compact installation and a long term trouble
full charge a battery pack, power externally from an AC
adapter or other 12 VDC source, place the PWR SWITCH in the AC-CHG position
for 24 hours.
powering counter and charging the batteries from an external power source,
other than the supplied AC adapter, be certain the voltage, under load, does
not exceed 12 volts DC. If powering unit from an automotive electrical system, the
voltage must be reduced as voltages of 14VDC or more are typical in vehicles.
counter can be on and usable, while
being charged, or can be switched off
by placing the HOLD switch ON prior to applying the external power.
(The digital LED
display will turn off)
operating the counter from the internal batteries, use the PWR SWITCH for
OFF / ON:
Battery power ON††† &†††
AC-CHG = Battery power OFF
maximize battery life and capacity, do not keep the batteries charging for more
than one day at a time and occasionally discharge.
DISCHARGE BATTERIES (This can cause a cell to reverse polarity and ruin
the battery pack), operate unit until display is noticeably dim.
yellow LED, LOW BATTERY indicator labeled "LOW BAT" or "BAT
CHG" will flash with the COUNT indicator when the circuit voltage is low
and the Ni-Cad batteries need charged.
Unit may be operated with the low battery
warning but sensitivity will start degrading.
used on ATH-10).
BASE & FREQUENCY CALIBRATION
standard time base is a 15.625 MHz crystal oscillator with temperature
Typical accuracy to calibration of 1 PPM at room temperature.
rate <0.5 PPM per year typ.
standard time base is adjusted by a trimmer capacitor, accessible through a
small front panel hole labeled "CAL".
HIGH STABILITY TIME BASE† (OPTION #HST-15)
#HST-15 provides an upgraded, ultra High Stability, 15.625 MHz TCXO* time base
(sealed module). This option must be factory installed and may be ordered when
the unit is initially purchased or a unit, with a standard time base, may be
returned to the factory for upgrade.
premium time base will increase the accuracy of the counter and maintain the
accuracy over a much wider temperature range. Typical accuracy to calibration
<0.2 PPM from 18-40 C.
rate <0.5 PPM per year. (<0.2 PPM per year typ)
high stability time base is adjusted through a small hole in the cabinet back.
= Temperature Compensated Xtal Oscillator)
For an accurate frequency measurement, you must have a stable, repeatable
reading. The instrument accuracy to calibration is the "overall time base
accuracy +/-†1 count.
determine the "overall time base accuracy", the temperature stability
rating (at temperature equilibrium) and aging factor for time base, must be
"+/-†1 count" refers to the least significant digit displayed. This is called a† quantization error and is inherent in
digital measurements. Clearly at higher resolution (more digits displayed), the
quantization error is less significant.
Measurement accuracy is
+/-† a percentage of the frequency and stated in
"PPM" or Parts Per Million.
† 1PPM @ 150 MHz = 150 Hz,†††† 0.2PPM @ 150 MHz = 30 Hz.
1PPM @ 850 MHz = 850 Hz,††† 0.2PPM @ 850 MHz = 170 Hz.
STARTEK counters are calibrated just prior to shipment
from the factory.
To calibrate the counter, measure a precise
frequency signal. Use the MED then the SLOW count time for maximum resolution
and adjust the time base calibration control for the correct frequency display.
The highest possible calibration frequency should be used for maximum accuracy.
user is cautioned about making the calibration adjustment without proper
equipment. Consult the factory Customer Service Department if in question.
calibration service is available. Contact factory for details.
assistance is available by telephone from the factory. Please review the
applicable sections of this manual before calling, as every effort has been
made to include information in this manual to answer the majority of questions
If you wish to call, the customer service number
Technical assistance is not available on the toll
free order line.
CAUTION!!† DO NOT EXCEED MAXIMUM SIGNAL INPUT LEVEL!!
safe input signal level is +15 dBm or 1.26V RMS. This limit applies to all ATH series models with only one exception, the LOW
RANGE on the ATH-50, which uses a
diode protected input that can safely handle up to +10 dBw or about 22V RMS.
Never key a transmitter coupled
directly into the counter input.
a 5 Watt transmitter antenna at least 6 feet away from the frequency counter
antenna, higher power further, etc.
FACTORY SERVICE TO REPAIR DAMAGED INPUT AMPLIFIER
CIRCUITS, CAUSED BY EXCESSIVE INPUT POWER,
IS NOT COVERED BY WARRANTY!!
PLEASE BE CAREFUL!!
careful not to allow a static discharge from a TV screen or low humidity
environment to reach the antenna as it can damage the input circuit
protection circuitry is seldom used in products of this type as it
significantly degrades the high sensitivity performance.†
using the counter with an antenna for signal pick-up, random counts may appear.
This is normal, due to the high gain amplifier circuitry, weak signals and
noise are amplified in the absence of a stronger, readable signal. If the
frequency display changes each time the display is updated, the reading is not valid and is usually caused by
mixed signals or signals that are too weak to accurately count.
the counter is operated with no antenna, the display should read zeros. If a
unit is operated by battery, immediately after full charging the batteries, a
small random count may sometimes occur for the first few minutes of operation
as the battery voltage can be extra high for a short period. Any readable signal will override a random
readable signal must be at least 10 dB stronger than the next strongest signal
or noise level. If two strong signals have near equal signal strength, neither
can be accurately counted. This is analogous to multiple signals of near equal
strength on a receiver channel.
DISTANCE FROM TRANSMITTER, ANTENNA RECEPTION
distance from a transmitter at which a frequency counter can read the frequency
depends on many factors, such as type and location of transmitting antenna,
transmitter output power, type of antennas, obstacles, other strong RF signals
nearby, the sensitivity of the counter, the particular frequency and more.
frequency counter will simultaneously receive RF signals over a huge frequency
spectrum of hundreds of MHz or literally millions of radio communication
channels. A counter can not have the sensitivity of a radio receiver tuned to a
single channel. This is why you must have a strong signal and be much closer to
the transmitting antenna.
to the many variables, readability distances from a transmitter can vary
greatly, however, some typical situations are as follows:
DEVICE†††††††† TYPICAL DISTANCE
Cordless phone - 49 MHz†††††††††††† †††††††††††††††††††††††††††††††††††† 1
Cellular phone - 840 MHz†††††††††† ††††††††††††††††††††††††††††††††† 10
VHF 1W HT - 150 MHz††† ††††††††††††††††††††††††††††††††††††††††††† 10 - 100
UHF 1W HT - 450 MHz††††††††††††† ††††††††††††††††††††††††††††††††† 10
CB 5W - 27 MHz††††††††††††††††††††††† ††††††††††††††††††††††††††††††††††† 5
Significant improvements in reception distances can
be made using Band Pass Filters and antennas made for specific frequency bands.
The telescoping antenna is the most useful general
purpose antenna. When using a telescoping antenna, it will maximize the counter
sensitivity if you collapse it to a minimum length for UHF, 450 and 850 MHz
frequencies and above, fully extend it for HF and VHF, 150 MHz and below
Using an antenna cut and tuned for a specific
frequency band, such as an 800 MHz rubber duck, has two advantages. First it
will maximize the input sensitivity of the counter or receiving device in the
desired frequency band and reduce the sensitivity at other frequencies, which
can also help reception in the desired band. Finding the best antenna to use in
a particular situation is usually best done by trial and error experimentation.
HAM & CB FIXED STATION USE
When monitoring a fixed station transmitter at HF
frequencies, the† radio shack signal,
near the transmitter, may be relatively weak due to distance from the antenna
and the increased efficiency of the transmitter shielding at the longer
wavelength, lower frequencies.
If you have difficulty reading the signal with a
small antenna on the counter, there are other methods that may be tried.
A piece of hook-up wire can be run, from the input
connector on the counter, to and along the transmitter output cable.† Try 5 to 10 feet along the cable and a turn
or two around the cable.
MAKE NO DIRECT CONNECTION to CO-AX
If an outside antenna is† available or can be placed, that may work.
A SIGNAL TAP can be purchased or constructed. This
consists of a "T" connector or box in the transmission line, with a
pick-up loop or pin of some sort, feeding a small signal to the counter. This
can be done with negligible insertion loss in the transmission line.
A Band Pass Filter accessory, such as the LP-60,
which passes only frequencies below 60 MHz, can improve the ability to read HF
signals as well.
A CW, FM or AM signal can be read but an SSB
(single sideband - suppressed carrier) signal can not, unless there is a steady,
modulated output. The SSB transmitter can momentarily be switched to the tune
or CW position to obtain the frequency reading.
Most garage door openers, auto remote locking
devices and alike typically use a pulsed output to save power and extend the
battery life. You will not be able to read the frequency from many of these
devices without going into the circuit and disabling the timing circuitry to
allow a continuous output.
USE WITH ANTENNA ANALYZERS
The counters should work well with antenna
analyzers such as the MFJ-207 and other similar models. The frequency counter
output from most of these units is unregulated and can vary with the state of
the battery. Although the output should not damage a counter,† sometimes an erroneous reading of about
double the proper frequency may be observed. This is due to signal overload of
the counter input. If this problem is encountered, a series resister of about
150 to 300 Ohms, placed in the input cable, should cure the problem.
A custom interface cable with a built in resistor,
a BNC male connector on one end and an RCA phono plug on the other, is
available from STARTEK as part number M207-IC. This cable should work with any
counter and the MFJ antenna analyzers. See OPTIONAL ACCESSORIES section of this
manual for more information.
The resolution or number of digits displayed will
vary with the RANGE and COUNT switch selections. Sometimes the user may want
additional digits displayed, however, the accuracy of the time base and total
accuracy of the instrument must be able to support the resolution or the least
significant digits become meaningless, virtually a random number generator.
For example, if you have 1PPM instrument accuracy,
that would be 150 Hz at 150 MHz. If you then had 1 Hz resolution
(9 digits -- 150.000 000 MHz), it may appear impressive but the last two digits
would be meaningless; the 3rd digit
would be 2 counts!!†
The ATH series frequency counters have balanced resolution to
support a legitimate display, based on instrument accuracy.†
to AC VOLTS RMS† CONVERSION CHART
Please contact the factory by phone, prior to
returning a unit for service, to receive a RETURN
AUTHORIZATION NUMBER that must appear on the address label. Unauthorized
returns may not be accepted. Frequently, problems can be solved by phone, as
FACTORY CUSTOMER SERVICE PHONE
Technical help is
not available on the "Order Line"
Please be very specific when explaining your
frequency counter problem. Always specify the approximate frequency you are
trying to count, type of signal being counted, etc., such as: "1 watt FM
handy talkie at 147 MHz, 3 feet away from ATH-15
frequency counter, on low range with a telescoping antenna", etc. The more
specific information you give initially, the faster and better we will be able
to help without having to ask for each detail.
If it is necessary to return a unit for repair,
include a good description of your problem on a note and include a daytime
and/or evening phone number if possible.
For warranty repairs, include return shipping
charges, a copy of purchase receipt or information about when and where
For non-warranty repairs, we can usually give you
an estimate on the phone and make payment arrangements, such as credit card,
COD, prepayment, etc.
ADDRESS SERVICE RETURNS TO:††††††
†††††††††††††††††† 398 NE 38th
Lauderdale, FL 33334
INCLUDE RETURN AUTHORIZATION NUMBER
We recommend insurance for all items shipped to the
factory. Carefully† package to prevent
damage. Carriers will not pay for damage if an item is not well packaged.
STARTEK INTERNATIONAL INC.
warrants the ATH series frequency counters, to the
original purchaser, against defects in material and workmanship for a period of
5 years for parts† and one year for
repair labor, from date of purchase.
the first year, the current minimum labor charge will be made for all repairs.
All parts required will be provided at no additional charge, for five years
from date of purchase, provided repairs are made at the factory.
parts and labor costs to repair or replace a defective unit are covered for the
warranty does not cover instruments that have been modified, subjected to
unauthorized repairs, misuse or abuse.
warranty does not cover damage caused by excessive power levels applied to
warranty is limited to the value of the instrument and does not cover any
incidental or consequential damage or expense.
warranty does not cover transportation costs; all repairs are FOB our factory.
STARTEK instruments are not warranted as to suitability
for any specific application.
STARTEK INTERNATIONAL INC. PROVIDES NO OTHER WARRANTIES
THAT EXTEND BEYOND
THE ABOVE DESCRIBED††
A††††††††††† CC-90†††††††† Black vinyl zipper case††††††††
B††††††††††† TA-90††††††††† Telescoping BNC antenna
C††††††††††† TA-90-L†††††† Telescoping elbow BNC antenna
D††††††††††† RD-150†††††† 150 MHz Rubber Duck BNC antenna
E††††††††††† RD-2750†††† 27-50 MHz Rubber Duck BNC antenna
F†††††††††††† RD-800†††††† 800-850 MHz Rubber Duck BNC antenna
G††††††††††† M207-IC††††† Interface-resistance cable for MFJ-207
similar antenna analyzers.
H††††††††††† P-110††††††††† 200 MHz probe, 1X or 10X switchable
or frequency counter usage.
J†††††††††††† LP-22††††††††† Lo-pass audio frequency probe. Will
attenuate RF noise from audio frequencies.
K††††††††††† DC-10†††††††† Direct, 50 Ohm probe
Can increase readability distance from a
<1 dB pass band insertion loss.
†††††††††††††† LP-60††††††††† DC-60 MHz usage
†††††††††††††† BP-150††††††† 115-800 MHz Usage
†††††††††††††† HP-400††††††† 400-1500 MHz usage
†††††††††††††† HP-800††††††† 800-2000 MHz usage††††††††††
any reason it is necessary to ship anything to the factory, please call and
authorization numbers are valid for 30 days.
WITHOUT AN AUTHORIZATION NUMBER MAY BE REFUSED AND RETURNED TO SENDER.
PLEASE BE CERTAIN TO CLEARLY MARK YOUR RETURN
AUTHORIZATION NUMBER ON OR NEAR THE ADDRESS LABEL.
shipments should use the address below. Pack items carefully and avoid damage
& problems. We recommend the sender fully insure shipment.
INTERNATIONAL INC.†† 398 NE 38th
Street†† † Ft. Lauderdale, FL 33334