July 2002 product reviews

flected power and SWR simultaneously.
stances you’ll be concerned with average test gear you’ll ever own is your watt- power, leaving it up to you to “ask” for do an adequate job in this department.
the output of your transceiver and adjust a calibration knob. Other wattmeters dis- at 2, 14, 28, 50 and, for those meters with it accordingly. A wattmeter can alert you play only forward or reflected power— curacy tests were conducted at 5, 100 and power at a particular point. With the for- reading. That is, they can display power levels that are present at extremely brief wattmeter to calculate feed line loss—just SSB signal that can have a relatively low compare the power at the input of the feed average power, but include numerous bursts of higher peak power that exist for are not laboratory-grade meters. Al- ers include wattmeters, but these are tied meters: active and passive. The active brated ARRL Lab equipment, it isn’t fair stalled. In contrast, a stand-alone wattme- wattmeters sample peak power levels elec- to expect the same level of performance.
If you require extreme accuracy, you have nient when you’re trying to troubleshoot take a measurement at the feedpoint of an can tolerate reasonable accuracy; you guess, active wattmeters provide the most don’t need to split hairs at tiny fractions accurate peak-power readings. In most in- DIAMOND SX-200
stacked scales and a single meter movement lighted, but you have to supply an external12-V power source (Diamond includes the 200 you have to use the front-panel switches to jump between forward power, reflectedpower and SWR functions as necessary. The SX-200 is a passive peak-reading meter with a switch to select either average or peak- power modes. To measure SWR, you mustfirst calibrate the SX-200 in the calibrate control, then switch to the SWR mode. TheSX-200 specifies a frequency range of 1.8 desktop meter, the SX-200 measures 6 × 2 one of the heftier meters of the bunch.
quite good in our Lab tests, but the for-ward power accuracy could have beenbetter. From a user standpoint, we foundthe need to frequently change switch set-tings a little cumbersome. The meter isruggedly built, however, with a sleek, at-tractive appearance.
Manufacturer: Diamond Antenna, 435 tel 760-744-0900; www.rfparts.com/
diamond/. $99.95.
button selects average or peak power dis- × 35/16 × 33/4 inches) designed to be as gedly built as the Diamond SX-200. In plays. The frequency range of the“hands off” as possible. The SX-20C is intended for mobile use, but it works just housed in a 41/2 × 31/4 × 31/4-inch alumi- Manufacturer: Diamond Antenna, 435 num case. The display is illuminated and, other (the so-called “cross needle meter” 92069; tel 760-744-0900; www.rfparts.
com/diamond/. $89.95.
12-V dc “wall wart” supply to power the PALSTAR WM150
Frequency Range: 3.5-150 MHzPower Range(s): 30/300 WPEP Measurement: None Actual Forward Power (Average only)Frequency (MHz) From July 2002 QST ARRL
Palstar states that the meter is not specifi- Frequency Range: 1.8-150 MHzPower Range(s): 300/3000 W cally designed for accuracy above 50 MHz.
45356; 937-773-6255; www.palstarinc.
com/. $89.95.
the cross-needle meter design more than20 years ago, and it has been showing up 101L is a desktop meter with three switch selectable power levels: 15, 150 and 1500W. The frequency range is 1.8 to 150 was 1.7:1 (2.5:1 indicated onmeter), possibly affecting unit requires more than 5 Wfor proper operation.
requiring external power isused. “Passive” indicates a peak envelope power (PEP). The CN-101L isn’t well designed for peak powermeasurement, and the manual says asmuch (see the note in the data table).
pany, 60 9th Floor, TOC Building, 22-17-7 chome, Nishi-Gotanda Shinagawa-ku,Tokyo, Japan. Available from several US DAIWA CN-101L
dealers. Typical street price $94.75.
Power Range(s): 15/150/1500 WPEP Measurement: Passive† that also features Daiwa’s famous cross- pleasant experience in the shack as well.
The CN-410M is designed for operation (peak or average). The CN-410M comeswith a mobile mounting bracket. Accord- 3 W, but this aspect of its performancewas not tested.
CN-410M has been discontinued. How-ever, this meter is still quite popular at hamfest fleamarkets and on-line auctions.
*According to the CN-101L manual, “For monitoring PEP, a condensor is placed into detector circuit. This function can not hold peak envelope power.” but we noticed that its accuracy declined at †For PEP monitoring, “Active” indicates that a circuit requiring external power is used.
the high end of its range. Also, on 2 meters, “Passive” indicates a circuit that requires only RF.
‡Amplifiers for 6 meters or 2 meters were not available at the time of testing.
a significant figure at this frequency.
From July 2002 QST ARRL
Frequency Range: 1.8-54 MHzPower Range(s): 30/300 WPEP Measurement: None Actual Forward Power (Average/Peak)Frequency (MHz) DAIWA CN-410M
Actual Forward Power (Average only)Frequency (MHz) Note
*SWR on input was 2:1 at 100 W on 144 MHz, so test was not
dealers. Typical street price $98.75.
and at 5 × 31/2 × 5 inches it is the largest VECTRONICS PM-30
meter tested for this review. A Lexan face varied considerably according to thepower level and frequency. SWR accu-racy was fair.
Manufacturer: Vectronics, 300 Indus- trial Park Rd, Starkville, MS 39759;
800-363-2922; www.vectronics.com/.
Frequency Range: 1.8-60 MHzPower Range(s): 300/3000 W MFJ ENTERPRISES MFJ-860
wattmeter in this group. At about 41/2 × 31/2 × 21/2 inches, it is also among the smallest. It sports the convenient cross- readings. In fact, the only switch on the two power ranges: 30 and 300 W. TheMFJ-860 is average-reading only. The was surprisingly accurate. Its insertionloss was also acceptable and well within related to the small size of the meter dis-play itself. It can be difficult to read un- †For PEP monitoring, “Active” indicates that a circuit requiring external power is used.
“Passive” indicates a circuit that requires only RF.
‡Amplifiers for 6 meters or 2 meters were not available at the time of testing.
674-1800; www.mfjenterprises.com/.
From July 2002 QST ARRL

Source: http://ham.srsab.se/test/wattmeter.pdf


Lieven Saerens Lieven Saerens studeerde geschiedenis aan de KU Leuven, waar hij in 1999 promoveerde tot doctor in degeschiedenis met een proefschrift over de houding van de Antwerpenaars tegenover de Joden in de periode1880-1944. Voor zijn proefschrift ontving hij zowel de Hubert Pierlot-prijs als de Prijs van de ProvincieAntwerpen. Hij werkte in de jaren 1980 een aantal maal mee aan de BRT-uit

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