RF Wattmeter and RF Load Selection Guide - Bird Wattmeter -
Telewave Wattmeter - Coaxial Dynamics Wattmeter - RF Load - Termaline Wattmeter - Thruline Wattmeter - RF Power Measurement
The RF Shop Offers You A Wide Selection of New and Used RF Wattmeters
and RF Loads at Affordable Prices
Enter the ChuckMartin.com RF Shop
Coaxial Dynamics RF Wattmeters
The Coaxial Dynamics RF products are high quality, reliable, and affordable and offer an excellent
alternative to the Bird products. The RF Shop stocks a large inventory of new
wattmeters and plug-in elements manufactured by Coaxial Dynamics. The meters are similar in design to the Bird Electronic wattmeters and the
plug-in elements (or "slugs") are interchangeable. There are several models of wattmeters available for
average reading, peak reading, broadband (no plug-in elements required) and other applications. A Two year limited warranty on all Coaxial Dynamics products assures your
complete satisfaction.
Telewave Broadband RF Wattmeters
The broadband Telewave Wattmeters require no
plug-in elements and cover a wide frequency range and power range. If your requirements involve
multiple frequency ranges and power ranges the Telewave wattmeters will be less expensive in the long run.
Unlike the plug-in elements style meters there is no need to purchase subsequent elements as the use of your
wattmeter expands to other frequencies and power ranges. Telewave wattmeter models are available for both HF/VHF
(2-200 MHz) and HF/VHF/UHF (20-1000 MHz). The RF Shop stocks a full inventory of new and used Telewave wattmeters.
The Bird Electronic Model 4304A is similar to the Telewave design and uses a
single, permanent, plug-in element for broadband power measurement fro 25-1000
MHz. The RF Shop normally has several of
these meters available for immediate delivery to you.
Bird Electronic RF Wattmeters
The RF Shop offers a wide selection of used Bird Electronic wattmeters, plug-in elements,
RF samplers, RF Loads, and other RF Products. All used products are fully tested
and you're guaranteed 100% satisfaction. We have the best inventory of plug-in
elements (Bird Wattmeter Slugs) in the world and can provide next day shipping
on all the popular element ranges. We also maintain a very large inventory of new plug-in elements by
Coaxial Dynamics and they are 100% compatible with Bird Model 43 style
wattmeters and come with a two year warranty.
Wattmeters That Require Plug-in Elements
The most economical and commonly used RF wattmeter is the Bird Electronic Model 43.
Bird RF Wattmeters. I've been selling
and using this model since 1967. The Bird Model 43 is the industry standard for in-line wattmeters and is the benchmark for performance and
reliability in RF power measurements. The Model 43 requires
plug-in elements, often referred to as slugs, for the frequency range and power range for which the meter is going to be used.
There is a large selection
of elements available that cover the frequency range from 0.45 MHz to 2.5 GHz in power ranges from less than one watt to
more 10,000 Watts. The Bird Model 43 is an in-line wattmeter that reads forward and reverse power. From these two measurements
it's possible to easily calculate the SWR (Standing Wave Ratio) from the RF load (antenna, amplifier, filter, etc.).
The connectors on the Model 43 can be Type N, UHF, TNC, BNC, etc., and are easily changeable with only a screwdriver required.
Many users purchase multiple connectors and have them available for quick changes when needed.
It's a good idea to have an RF Load available to terminate one end of the
wattmeter if you are going to measure transmitter output power and do not want
to use the antenna as a load. The RF shop has a large selection of
RF Loads
for you to choose from.
Coaxial Dynamics manufacturers high quality RF power measurement products similar to the Bird Electronic
products and provides an excellent alternative to the Bird Wattmeters. The two manufacturer's plug-in elements are interchangeable. New Coaxial Dynamics products are offered with a 2 year limited warranty to assure your satisfaction.
Wattmeters That Do Not Require Plug-in Elements
There are broadband RF Wattmeters that do no not require plug in elements. For
example the Bird 4304A and all of the Telewave wattmeter
products
Telewave RF Wattmeters.
These meters cover a wide frequency and power range without the need to purchase expensive elements.
The meters have front panel
switches that select the power range from 5 Watts full scale to 500 Watts full scale.
Although, these broadband RF Wattmeters are
more expensive initially, you will avoid a lot of expense by not requiring
multiple plug-in elements or slugs in the future.
Telewave, Inc. manufacturers a low frequency (2-200 MHz) and a high
frequency (20 MHz to 1000 MHz) model of this type meter.
You should note that the maximum power of 500 Watts on these style, as well as other RF wattmeters. is the RMS or average
rated power. If you are
measuring single side band (SSB) PEP (peak envelope power) the meter can be used at much greater
than 500 Watts. As long as the average
power is less than 500 Watts it will be displayed correctly on the wattmeter. When measuring RF power of SSB voice transmissions wattmeters will display the average power which is
considerably less than the peak power. In other words, a 500 Watt maximum power
scale will be adequate to measure SSB voice transmissions up to 2000 watts. For more details on this subject visit this link
Power - What's It All About.
To measure true peak power you will need a peak measuring wattmeter like the
Bird Model 43P, 4314 and APM-16. See more on these meters below.
The Most Versatile RF Wattmeter - Bird Model 4410 and 4410A
The Bird Model 4410 and 4410A use special broadband elements to provide multiple power ranges with a single element.
With the Model 4410 only a four elements are required to cover the frequency range of 0.5 to 1000 MHz and power ranges 1 Watt to 10,000 Watts.
This meter provides the ultimate in RF power measurement versatility. The Bird model 4410A is one of our best selling models
and is available in several packages.
For example, the 4410(A) with one HF element (2-30 MHz) has seven full scale power measurement ranges.
1 Watt, 3 Watts, 10 Watts, 30 Watts, 100 Watts, 300 Watts and 1000 Watts. The
Bird 4410A elements as listed separately and are not interchangeable with the
Model 43 elements. If you plan perform RF power measurements at a lot of different
frequencies and power levels the 4410A will save you money in the long run by substantially
reducing the number of elements you will need to have on hand. Before
I discovered the 4410A I was carrying around 15-20 elements to provide coverage for the many
uses that I have for an RF wattmeter.
Click here to enter the RF Shop
Peak Reading RF Wattmeters
Peak measuring RF wattmeters have additional circuitry that allows the meter to capture and display the maximum peak power.
This is especially useful when measuring SSB voice transmission power.
The Bird Model 4314 and 43P are examples of meters with this feature. These two meters use the same elements as the Bird Model 43. Bird Electronic
and others manufacture offer user installable modules that can be installed in many Model 43 meters to add a peak reading feature. Look
under Accessories in the shopping cart to see these products. If you are going to perform RF power
measurements on digital RF signals
you will require a more sophisticated wattmeter such as the Bird 4381, 4391 or APM-16.
The Bird APM-16 employs active circuitry to deliver
accuracy of ± 5% for multiple-access technologies such as CDMA, TDMA, FDMA and
other digitally-encoded communication systems.
RF Sampling Wattmeters
Bird Models 4430 and 4431 and the Telewave Models 44AP and 44L1P
Telewave Wattmeters
have an RF Sampling tap to provide a reduced level sample of the RF being measured. This signal can be used to monitor the RF Power
with an oscilloscope or frequency counter. There are also RF samplers, sometimes referred to as RF sniffers, offered in the Accessories category on the shopping cart
that will provide RF Sampling on most wattmeters.
Accessories
Terminating Wattmeters/RF Load
As the name implies, these wattmeters have a RF termination, usually 50 Ohms.
They are available in a variety of shapes and sizes and can be air cooled or oil
filled. They are typically good to about 100 Watts, however, there are some
models that will handle as several kilowatts, for example the Bird model 694. Adding a cooling fan to the heat radiator can extend the useful power
range of the RF load. The RF Shop offers a large selection of terminating wattmeters and RF loads available at
these two links
Wattmeter RF Load and
RF Loads
In-line wattmeters can be used as a terminating wattmeter by connecting a RF load to one of the RF connectors on the wattmeter.
The intermittent power ratings on these RF loads are much higher than the continuous power rating.
Accuracy and Calibration
Most of the RF wattmeters on our website have accuracies of around +/- 5% of the
full scale range. For example, a 100 Watt meter will have an accuracy of +/- 5
Watts on the 100 Watt scale. At the low end of the scale, say 10 Watts, this
accuracy is not very useful. For low power measurements you should use a low
power setting on the meter or a low power element. There are some exceptions,
for example the Bird APM-16 has an accuracy of around +/- 5% of the reading
instead of the full scale value. These more accurate meters are usually more expensive.
Refer to the manufacturer's links listed below to determine the correct and accurate specifications for any wattmeter.
Calibration of broadband RF wattmeters requires specialized and
expensive equipment. In almost all cases a NIST traceable calibration can only
be performed by the wattmeter manufacturer. The RF Shop checks each meter and element that
we sell for accuracy using high quality calibrated wattmeters and test
equipment, however, this is not a traceable calibration. If you require a NIST
traceable
calibration we can have the product calibrated for you by the product manufacturer for an additional cost.
This usually takes about 2-3 weeks and costs from $75-$400.
Wattmeter Manufacturer Link
Bird Electronic
Coaxial Dynamics
Telewave, Inc
RF Shop Home
email: The RF Shop
RF Wattmeter and RF Load Selection Guide - Bird Wattmeter -
Telewave Wattmeter - Coaxial Dynamics Wattmeter - RF Load - Termaline Wattmeter - Thruline Wattmeter - RF Power Measurement
The RF Shop Offers You A Wide Selection of New and Used RF Wattmeters
and RF Loads at Affordable Prices
Enter the ChuckMartin.com RF Shop
