Comet CAA-500 MARK II Instruction Manual

P.1
Important Cautions
This is a delicate measuring instrument; please take care not to drop it or subject it to physical shock.
The impedance bridge of this instrument is immediately inside the antenna connection point. Be absolutely
certain not to apply power from an external transmitter, as this will damage the CAA-500 MarkII.
Stronglocal RFfields(in a multi-station environment, for example) may cause unstable SWRreadings.
When not using Ni-MH batteries, always turn OFFthe Charge switch on the battery case. Failure to do so may
The external DCsupply voltage must be between 8Vto 16V, and the current supplied must be at least 250mA. Never apply DC voltages greater than 16V, nor AC voltage of any kind. Our warranty does not cover damage caused by the use of an improper power source.
When using AA batteries, the LCDdisplay will become unstable when the batteriesare weak. Change Batteries assoon asthe display starts blinking, and change all batteriesto improve the battery shelf life.
Remove the batterieswhennot in use for extended periodsof time to avoid damage caused by leakage.
Before using
To avoid ESD damage, it is important to dischar ge any static electricity that may have accumulated on the antenna system by touching grounding the antenna’s coax cable connector before screwing it onto the SWR analyzer.
Instruction Manual
Thank you for your purchase of this instrument. It was built under tight quality control standards and procedures; however, there is always the possibility of damage during shipping. Should this occur, please notify the dealer from whom you purchased it immediately so they can initiate the damage claim process with the shipping company. Please read this manual completely before beginning operation, so asto understand its features and capabilities fully.
Features
Built-in broadband high-stability transmitter for easy measurement of resonant frequency, SWR, and impedance.
Color LCD & cross-needle meter display provide SWRand Impedance information simultaneously.
Separate ham band segments can be swept to display the SWR characteristics in the graph automatically. Moreover, it is possible to plot the SWR characteristics manually with user-defined center frequency and sweep bandwidth.
Size AA alkaline (manganese) or Ni-MH rechargeable batteries(six required) may be used. Typical battery life is 9 hours of continuousoperation when usingAA cells.
External 8-16V DC power may be used to power the meter; this allows trickle charging of Ni-MH cells.
The programmable Auto Power Off function preserves battery capacity in case you forget to turn the meter off.
A hand strap post is provided, for ease of use and to minimize the chance of dropping the CA-500 MarkII.
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
P.2
Panel/Case Parts and Descriptions
Display Meter ThisCrossMeter displaysboth SWRand Impedance simultaneously.
Multi-function Display The color LCD (Liquid Crystal Display) shows frequency, amateur band, and SWR data
(impedance (Z)/resistance (R)/reactance (X)), and also can provide a swept-frequency SWRgraph.
BAND Knob This knob is used to select the frequency band within the range 1.8 to 500 MHz. Clockwise rotation of
this knob selects a higher frequency band. It is also used for setting of the APO (Automatic Power Off) function.
FREQ.Knob This knob is used to set the frequency within the selected amateur band. Clockwise rotation increases
the frequency, while counter-clockwise rotation lowersthe frequency.
SWEEP/CENTERButton In the “Normal” mode, pressing this button starts an SWRsweep of the band.
When in the SWRGraph mode, pressing this button sets the current display frequency to be the center frequency of the graph. In this mode, rotate the (3)BAND knob to adjust the Sweep width; press the (6) A.P.OFF/WIDTH button to confirm. Now rotate the (4) FREQ knob to create and display the SWRplot.
A.P.-OFF/BANDWIDTH Button In the “Normal” mode, press and hold in this button for three seconds to allow setting of the Auto Power Off feature’s time interval.・In the “Manual” plot mode, pressing this button allows you to set the bandwidth of the SWRSweep.・While in the “Manual” plot mode, pressing this button allowsyou to change the color of the SWRGraph.
GRAPH ON/OFFButton Press this button to switch between the “Normal” mode and the SWRGraph modes.
POWERButton This is the main Power On/Off button for this device. Press once to turn the unit on, and again to
turn it off.
RF Connectors These are the coaxial jacks used for connection to the coaxial cable. The left connector is an “M” (“UHF”) type (used for 1.8-300 MHz), while the right jack is Type N, used for 300-500 MHz. Switching is automatic, based on the Band setting.
Hand Strap Mounting Bracket You may connect a commercially-available hand strap here. As the diameter of the
mountinghole is greater than 1 mm, a sturdy strap (highly recommended) may be attached.
External DCPower Terminal External DC(8-16V) may be connected here. The center pin is positive (+).
Battery Case This is the housing for six AA cells. Please install them accordingto the inscription inside the case.
Charge Switch (Inside Battery Case) This is the switch for enabling/disabling trickle charging of Ni-MH cells, if used.
(※) Trickle charging is useful to help maintain a full charge on your battery by compensating for the slight self-discharge that can occur even without a load being placed on the batteries
Before You Start
This instrument has been calibrated with the unit being held horizontally, with the meter facing up. The discussion below is an operating example; the parameters you set may affect the actual results.
When using Alkaline or similar batteries, be sure to set this switch to the OFF position. In the event of battery leakage, serious damage to this unit may occur if the switch is set to ON during use.
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
P.3
OPERATION
It is helpful to review operation before commencing operation. Steps (1) and (3) may be omitted once you have
verified that the unit is operating properly.
Connect a 50-Ohm dummy load (not supplied) to the “M” (“UHF”) jack.
Pressthe POWER switch to turn the unit on in the Normal mode.
Normal Mode Display Screen
Battery Level Meter (※2,3)
Frequency Battery Status
Band Scale
The amateur bands 1.8-430 MHzare shown with a blue band (※1). Red underscore showscurrent band. “U” appears to left of Battery icon when on UHF.
SWR Scale and Bar
The SWRis displayed graphically and numerically here. The SWRis shown to two decimal places.
OHMSScale and Bar
The resistive component of the impedance is shown both on the bar graph and numerically. Impedance (R, X) is
also displayed numerically. Above 190 MHz, R/X do not appear.
1 Note that not all the annotated amateur radio bandsare available in all countries.
2. If using Nickel-Metal Hydride batteries, the battery status meter may never show “Full.” You should recharge the batteriesonce the Yellow indication appears. If using alkaline cells, replace when the Yellow indicator appears.
When connected to a 50-Ohm dummy load, the SWR indication should be 1.1 or less. If so, the meter is
performing correctly.
Perform measurements accordingto the discussion below.
SWRMeasurement
Connect the coaxial cable to the meter; use the shortest possible cable between the antenna and meter, as any cable between the antenna and meter can transform the measured impedance, and feedline loss can also cause the displayed SWRto be better than it actually is. See FAQ later.
Set the BAND and FREQ knobsto the band and frequency to be tested on the antenna.
You may now read the SWR and resistive value of impedance (OHMS) on the display. If there is a subtle difference between the mechanical and the LCD, the precision of the mechanical meter has priority.
About the Reactance Display
The display of impedance on the LCD includes both resistive (R) and reactance (X) indications. Note that the X display is absolute value, so the polarity (+ or -) cannot be viewed. Because of diminished accuracy, the numerical Rand Xdisplays do not appear above 190 MHz (but the impedance bar graph remainsoperational).
Measurement of Antenna Resonant Frequency
Connect the antenna to the appropriate antenna connector on the meter, using the shortest possible cable. If you use a long cable, the measurement will also include the effects of feedline loss, and impedance differences between the antenna system and coaxial cable will not show the actual antennaimpedance.
While watching the frequency display, rotate the FREQ knob while observing SWR. If you rotate the FREQ knob to the point where the frequency no longer changes, change the Band to set a new range.
The frequency at which the minimum SWRis observed is the resonant frequency for the system.
Always be sure that you connect your coaxial connector to the proper connector. If you are connected to the opposite connector, measurements will be impossible and if the wrong connector is used, damage to the jack may occur.
Full charge CcCharge Nearly full Battery low
Battery level Critically low
You created this PDF from an application that is not licensed to print to novaPDF printer (http://www.novapdf.com)
Loading...
+ 5 hidden pages