Цифровой КСВ/Ваттметр, охватывает КВ и УКВ диапазоны. Позволяет без переключения коаксиальных кабелей измерять параметры (КСВ и мощность) как на КВ, так и на УКВ, содержит два датчика. Имеет встроенные часы, с возможностью выбора четырёх различных часовых поясов. Показывает измеряемую мощность ВЧ-сигнала в режиме РЕР или AVG, отображая её на цифровом дисплее с подсветкой. Внутренняя система защиты позволяет избежать повреждение прибора при высоких значениях КСВ, или при превышении допустимой мощности. Есть возможность питания от установленных внутрь батарей.
Модели 800-й серии производились в Японии в период между 1992 и 2000 годами .По причине сложности изготовления и достаточно высокой цены для КСВ-метра производство было прекращено. Переход с аналоговых методов измерения на цифровые (с применение PIC контроллеров) вытеснил с рынка эту серию замечательных КСВ-метров для радиолюбителей. По своим функциям и возможностям DP-830 в себе сочетает DP-810 и DP-820.
The DAIWA Dp-830. Digital SWR and Power Meter.
Simultaneously measure power and SWR from 1.8 to 525 MHz.
There's always been a surefire way to tell a hard-core ham. He's the one with the expensive wattmeter. A quality wattmeter, with all those elements and the case and everything, can easily cost more than a cheap HF rig . You can be sure that if someone shells out that kind of money for a piece of test equipment, he's really into ham radio.
Fortunately, the people at DAIWA have made owning a quality wattmeter a little easier for the rest of us non-hardcore types. The OP-BOO series of wattmeters sport top-of-the line features, accuracy equal to the industry standard , and a price that won't blow the ham budget. The DP-8 10 covers 1.8 to 150 MHz, at 0. 1 to 1500W, and has a list price of $265.95. The DP-820 covers 140 to 525 MHz, at 0.01 to 150W, and lists for $295.95. The deluxe DP-830 covers both of the above bands, and throws In a four-lime-zone c lock, for $385. 95. All three units read SWR from 1:1.0 to 1:5.0, and measure PEP as well as average power. T he units have a power reading accuracy of 7% of full scale for average reading s, and 12% for PEP readings . Readings are displayed on a 2- 1/2 dIgit LCD dissplay. Six AA batteries power the meters, and a power lead is included if you want to power the unit with your own 8-to-15-volt supply.
Wide Frequency Coverage
The classic problem with wattmeter design concerns the need to use the unit on a wide range of frequencies. This is certainly the case for the radio amateur-even an entry-level ham may find the need for power measurements at 28 MHz and 146 MHz, quite a range in itself. As the frequency increases, the capacitance and inductance inherent in the sampling circuits changes, causing inaccurate readings. This has traditionally been solved in one of two ways. The first method is simply to limit the design frequency of the instrument. As an example, most wattmeters found in the average ham shack are designed for the HF bands, say 2 MHz to 30 MHz. These will be relatively accurate over most of the range, and tend to be a little less than accurate up near 10 meters . The second method involves changeable sensing elements. These elements, often called "slugs," are built for a small band of frequencies. As the frequency of in te rest is changed, so is the slug, ensuring a correct read ing (as long as the correct element is used).
The DP-B30 takes somewhat of a combination approach to the problem. It uses two separate sensing elements, one for 1.8 to 150 MHz and one for 140 to 525 MHz. The proper connections to each element are made via the back panel-two "N" connectors for UHF, and two "50 -239" connectors for the HE Both transmitters can be left hooked up at all times, and a front panel switch selects one element or the other. Other front panel functions include the TIME selector-tapping t his button selects one of four different time zones. Set one to local, one to GMT, one to the buddy you have that eked with, and the last one to .. ??? Whatever, it's there if you need it. A nice feature of the time function occurs when the unit is hooked up to an external supply. When left in the TIME mode, the unit kicks In to read power as soon as the transmitter is keyed, then switches back to time mode. (One of those .feature s you' re glad t hat somebody thought of ) A BAR GRAPH switch toggles the 15-segment bar graph on and off. An $WR BEEP function causes the unit to beep in different ways, depending on the level of the SWR. MusiCally- inclined hams will find a chart in the instruction sheet that relales the different SWR levels to the musical notes that will be produced. For example, an SWR of 1.30 equates to three ~D sharps" followed by one "E ttat." While most of us will use this function only as an ongoing alarm system-anythi ng other than one beep means troubl&-this is an extremely valuable feature fo r sighHmpaired operators, or anyone who wants to rapid ly tune up an antenna for minimum SWR without having to see the meter. The front panel controls are rounded out with a PEP/AVERAGE switch, a POWER switch, and recessed time set controls. The physical construction of th is unit leaves noth ing to be desired . Both RF sensing units are enclosed in metal housings, mounted inside a stylish metal cabi net. Simply pi c king up th e DP-8 30 is enough to convince you that this is a quality unit. The unit looks good enough to warrant a permanent spot on the opera ting shelf, but is tough enough to be used mobile, or In a service environment.
Operation of the DP-830 was very straightforward. Simply pop in the six AA batteries (yes, they're Included) hook up the transmitter(s) to the appropriate connectors, set the clock, and you're in business. The unit was well within specification when compared to a lab standard wattmeter. In actual ham shack use the unit performed flawlessly. The bar graph meter was very responsive, and would be quite useful for tune-up operations . The ability to see both forward power and SWR simultaneously is a real plus, although a reflected power reading is not available. The unit autoranges, and perhaps the only feature missing is a "range hold" switch. For those of us who operate right around 150W (the point where the unit switches from W to kW) it would prevent the unit from flopping between 149W and 0 .151 kW, and the corresponding change in the bar graph.
The only weak point to the DP-830 concerns the documentation, wri tten both in Japanese and broken English. Considering all of the starving technical writers around, it's amazing that DAIWA didn't hire one to give their manual the once-over before it hit the press. The operation of the DP-830 is mostly self-explanatory, so this is more a matter 01 mild amusement than serious concern . (However, at one point after changing the batteries my unit "woke up" with no display! Nothing I could think of corrected the problem, so as a last resort I read the instructions. Luckily, I found this passage: "Please push the RESET switch when the any Informations are not displayed completely o r incompletely on LCD," Hmmmm. Well, at least I knew there was a RESET switch. I pored over the pictorial and found the switch, accessible through a screw hole in the bottom of the chassis. Sure enough. it corrected the problem, just like the instructions said.) Another somewhat startling aspect of the instruction sheet concerns the final page. Most of the instructions are printed with each page split down the middle, Japanese on the left, English on the right. However, at the bottom of the last page is a box filled almost entirely with Japanese, and what looks like a spot to fill in the serial number, date, and other pertinent information. The only English text in this box is the statement "This warranty valid only in Japan." Hmmmm. I did notice a separate Warranty Registration Card, discussing a one-year limited warranty, ready to be sent to Electronic Distributors, inc., in Virginia. I gave EDCO a call , and found:
1) some very friendly people ;
2) that the DP-830 has a one-year warranty;
3) that EDCO performs DAIWA warranty repairs right in Virginia-you won't need to take your wattmeter to Tokyo for repair, UPS can take it right to Virginia.
Not that that appears likely. The DP-830 looks like a unit that's well-built enough to last for years, and well-designed enough to make you want to hang on to it for that long. The DP-800 series is distributed by Electronic Distributors Co. of Vienna, VA, and Is available anywhere DAIWA products are sold.
Larry R.Antonuk WB9RRT