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Please mention you saw it in Monitoring Times!
2000 Reviews: CCRadio vs. GE Superadio / Icom W32 Transceiver as a scanner / The Ramsey FM-100 Stereo Transmitter / Low Cost Hardware for GOES Reception / Nil-Jon Scanner Antennas / Ramsey Mobile RDF System / Super Select-A-Tenna / AOR Antennas / Protek 3201 RF Field Analyzer
Index to scanner reviews by Bob Parnass
1999 Index to review columns: Scanner Equipment, Magne Tests, Computer & Radio, And More
Review by Bob Grove
Medium wave (standard AM broadcast band) DXing (long-distance listening) is a specialized hobby, separate from shortwave listening. General coverage communications receivers, perfectly acceptable for the SW listener, commonly attenuate their sensitivity in the MW band to avoid the consequences of local strong-signal overload, and loop antennas are often invoked to reject ambient electrical noise or null interference from co-channel broadcasters.
Off-the-shelf consumer radios are hardly adequate for the hard-core MW DXer; they suffer the maladies of poor sensitivity, broad selectivity, imaging, strong-signal overload, and dismal frequency accuracy. And, just for kicks, they rarely allow the use of an external antenna.
For many years a popular favorite among MW DXers was a Radio Shack receiver with TRF (tuned radio frequency) design; it was a hot receiver, and many aficionados were disappointed when the product was discontinued.
More recently, the GE series of Superadios, now in their third generation, have been accepted as the standard of comparison for medium wave broadcast listeners, primarily because of its legendary IF (intermediate frequency) filtering. Now there is a new kid on the block: the CCRadio, made by Sangean under contract with C. Crane Co. of Fortuna, CA, and reviewed in MT Feb 1999.
Is the CC hype louder than its performance, or is this newer model a serious threat to the GEÕs lofty position? At nearly three times the price of the GE ($159.95 vs. $59.95), does the CC offer that much more? LetÕs take a quick overview of their cosmetics and features, then a more discerning look at their relative performances under actual listening conditions.
The smaller CC (11ÓW x 6-3/4ÓH x 3-1/2ÓD) is finished in charcoal gray
matte, while the larger GE (13ÓW x 9ÓH x 3-1/2ÓD) exhibits a glossier black
and chrome highlighting. Both radios offer separate bass and treble tone
controls, headphone jack, telescoping whip (longer on the GE), and dual
AC/battery power supply. Both provide screw terminals for an external AM
antenna (the GE also includes terminals for FM), a top-cabinet push/push
power switch, and a right-side-mounted tuning dial. But thatÕs where the
similarity ends.
The GE sports a traditional analog slide-rule dial, while the CC offers a backlighted LCD which has an alarm clock/sleep function and 20 memory channels (5 in each of 4 bands) in addition to its mandatory frequency display.
The accurate and informative LCD wins hands down over the old analog dial with its loose calibration. The GE offers automatic frequency tuning (AFC) on its FM mode, required in older variable frequency oscillator (VFO) designs to prevent tuning drift. The CC, being frequency synthesized and utilizing phase locked loop (PLL) drift cancellation, does not require such compensatory circuitry.
Like modern automotive radios, an up/down autoseek feature searches out signals at the press of a key.
While the GE offers conventional AM/FM coverage (530-1700 kHz/88-108
MHz), the CC adds seven weather channels (162.400-162.550 MHz) with severe
conditions alarm, and TV audio for channels 2-13.
This one is a little tricky. The CC is admittedly designed for talk radio, so its IF and audio filtering are contoured to favor the more limited range of voice frequencies. The GE does a much better job on music with its choice of wide/narrow filters and separate, larger woofer/tweeter speaker system in a larger enclosure. Although the printed specifications show the CCÕs audio output rated at 1.8 watts for 10% THD (total harmonic distortion) versus the GEÕs 700 milliwatts (unspecified THD), both radios deliver approximately the same acoustic sound levels before going into distortion.
While the sound of the GE on music is more transparent with richer bass
and crisper highs, the CC music performance is certainly listenable, but
clearly favors the human voice. Both sets offer considerable tonal equalization
with their bass and treble controls.
We noticed no remarkable difference in either AM or FM sensitivity between
the two sets, although other observers report slightly better weak AM signal
reception on the GE. Weather band reception on the CC was roughly equivalent
to that of a hand-held scanner, remarkable for a multiband portable. Reception
on this range is undoubtedly helped by the frequency-resonant 16Ó whip
antenna.
The ability of a receiver to reject interference from adjacent channels stations is critical to AM DXers. While the GE offers two selectivity choices, the wide is unjustifiably broad given the poor fidelity common on medium wave; as a result, only the stronger signals will be heard with that selection, swamping weak, adjacent-channel broadcasters. The narrow position certainly improves adjacent channel selectivity, but does not compare to the sharp skirts and ultimate attenuation of the CCÕs filters.
On the other hand, using the internal AM loop antenna to null interference
is much sharper on the GE, and at nighttime, image interference from 60
meter (5 MHz band) shortwave signals are quite prominent on the CCRadio
using its own whip.
If you require a portable with good fidelity, excellent adjacent channel AM selectivity, and favor listening to distant talk radio in crowded band conditions, the CCRadio is a clear choice, and tosses in weather band and TV audio as well.
If you are looking for a more economical AM/FM radio with better-than-average
performance and outstanding music quality, the GE Superadio III should
prove quite satisfactory.
CCRadio, $159.95 plus shipping from C Crane Company, 558 10th St., Fortuna, CA 95540 2350; ph. (800) 522-8863.
GE Superadio III, available from MT advertisers including Grove Enterprises, PO Box 98, Brasstown, NC 28902; ph. (800) 438-8155 (Price $59.95 plus $5.95 shipping).
By Gary Webbenhurst AB7NI
Wow! This is a great scanner!
That is the conclusion I have arrived at, after evaluating my new Icom W32A amateur transceiver. Like most ham radio operators, I keep waiting for the "perfect" handheld transceiver (HT.) Over the years, I have owned more than a dozen radios from all the major manufacturers. They all have their advantages and disadvantages. But I think I finally found one that comes very close to perfection.
Here is my checklist of the features for the perfect HT.
1. The alpha numeric display must be large and easy to read.
2. Display and keypad must be brightly backlit.
3. Audio speaker must be adequate to the task for clear, crisp sound.
4. Display of the battery's current voltage status.
5. A real time clock display.
6. Good mechanical battery release button.
7. Extended wide band receive coverage.
8. Computer programmable.
9. Direct keypad input.
10. Small cheatsheet and/or a summary of instructions.
11. Easy to understand programming booklet.
12. A good antenna for the intended ham bands.
13. The keypads must be large and spaced for the average fingers.
14. True dual band capabilities.
15. External power jack.
16. Standard earphone and microphone connection.
Until now, only the Yaesu 530 came close. But, alas, my 530 has died and good used ones are impossible to come by. Thus I began a new search. Now, there have been many really good HTs. I loved one model, but it had a fatal flaw: The battery release button had a 100% duty cycle. That meant that every time I went to slide the radio unto my belt, the battery would come loose and fall to ground, usually damaging the battery pack.
Applied to the checklist, the W32A is good for 15 out of 16. (No
clock.)
While I was evaluating the W32A as a ham transceiver, I noticed that it had many features that would make it a very good scanner. Here are several features of the W32A that are really handy for the scanner enthusiast:
¥ Expanded coverage of 108-135AM, 136-199, 300-399, 400-599 and 600-999
MHz
To enjoy these ranges, one can perform a simple keyboard modification
of holding the SQL and Band buttons down, while powering on the radio.
Of course, we all know that just because the radio displays a certain frequency,
that is no guarantee that the radio can actually receive such a frequency.
I had mixed luck in the TV audio range. Depends on the antenna and literally
how you hold the radio. I could move the radio from vertical to horizontal
or three feet from the previous location and now the station came in clear.
Other times nothing. Reception on the aircraft and 800Mhz range (cellular
blocked) was excellent. You can check the internet for the hardware modification
to open the transmit frequency range.
¥ The radio can be configured for dual display (and simultaneous
scanning) of Very High Frequencies (VHF) and Ultra High Frequencies (UHF.)
The choices include the following combinations:
Wx/VHF 10 preprogrammed weather channels 136-199.995
VHF/UHF 108-135.975AM 300-399.995
VHF/UHF 136-199.995 400-599.995
UHF/UHF 435-454.975 600-999.990
This is a true dual band radio! Image the possibilities. You can
scan the aircraft frequencies on one side, the ham bands or public safety
on the other side. Listen to the audio of the five o'clock TV news while
also listening for a ham buddy on the two meter band. Or monitor your favorite
440 MHz repeater while simultaneously scanning the fire department channels.
How many scanners will do that?
¥ Another great feature is the five programmable search ranges. These begin with memory channels M1A (lower) and M1B (upper). The others are shown below with the particular ranges I wanted on the VHF side. Of course you could program anything you wanted.
My favorite setup for the VHF side:
M1A 145.110 M1B 147.995 Ham repeaters on two meters
M2A 118.950 M2B 128.000 Local airports
M3A 151.145 M3B 151.465 Park Rangers and forestry
M4A 153.740 M4B 154.445 local fire departments
M5A 154.650 M5B 156.150 local police departments
UHF possibilities:
M1A 440.000 M1B 450.000 Ham repeaters on 440
M2A 406.000 M2B 412.000 Trunked military systems
M3A 412.000 M3B 419.900 Various Federal Agencies
M4A 453.050 M4B 453.975 local public safety
M5A 460.025 M5B 460.625 local police/fire departments
To use this feature, you simply press Scan while in the Variable Frequency Oscillator (VFO) mode. It will begin searching in the first range 145.110 to 147.995. To search any of the other ranges just press 2, 3, 4 or 5. This is way too easy! Even my brother-in-law figured it out! UHF has its own five search ranges.
¥ You can select the scan pause mode for each of the five ranges. Choices are: 15 seconds, 10, 5 or carrier activated. I prefer carrier activated so as not to lose any radio traffic.
¥ An excellent cheatsheet and an easy to understand instruction programming booklet
¥ CTCSS (Continuously Tone Coded Squelch System). An impressive list of 50 different PL tones. You can use the correct tone squelch to keep out the annoying intermod noise and unwanted signals. Set the radio to a frequency in VFO mode, activate Tone Squelch, then press scan and the radio will search for the correct tone. Cool!
When set to a specific frequency and tone squelch pocket beep, it will ring like a phone (or other sounds that you can program.) This also means I can use the W32A to act as a CTCSS activated pager ? great if you are a volunteer firefighter or Emergency Medical Service (EMS) person.
¥ 100 memory channels for the VHF side and another 100 for UHF, plus the 10 memory band scan edge channels for both VHF and UHF.
¥ A special memory channel, the Call channel. This allows one button touch access for your favorite frequency on VHF and UHF. While my ham buddies and I refer to this as the "Charlie" channel, it is in reality a two meter ham radio simplex frequency. You can program anything you desire.
¥ A power saver feature can be activated to reduce the current drain while in manual mode.
¥ Automatic power off at 20, 40 or 60 minutes. This is great, because I often forget to turn my radio off. No more dead batteries for this guy. This feature can also be toggled on/off.
¥ The display backlight can be set for 5 seconds or on/off toggle. This is a great feature. If you are monitoring in poor light conditions, you can keep the backlight on continually until you decide to turn it off. The four LEDs draw minimal current from the battery. If you are using an external power source, the backlight is not an energy concern.
¥ Keypad beep tone can be easily disabled or reactivated.
¥ Select step size. Available in any of these kilohertz steps: 5,10,
12.5, 15, 20, 25, 30, 50!
¥ Select LCD contrast setting.
¥ Ten preset NOAA Weather channels.
¥ Display can show frequency or channel number plus an eight digit alpha
numeric (AN). The potential here is great. If the local police have
8 channels, I program them into the radio's Channels 1-8. On the 8 character
AN label, I can use anything I want such as South, Records, SWAT, Chase,
Downtown, car-2car, on-scene, white, blue etc.
I can also use the common abbreviations such as SO for Sheriffs Office, CP for Command Post, DOT for Department of Transportation, CDF for California Division of Forest and Fire Fighting. DNR for Department of Natural Resources, HP for Highway Patrol, SP for State Police, FBI etc. Thus I end up with a display reading ÒCH 1 Downtown.Ó
¥ When used with the CS-W32 software and connection cable, the W32A can be programmed from a create-your-own database of frequencies. You can program the receive frequency, transmit frequency, PL tone, offset etc. You can have several databases. I have one for each of the major geographical areas I visit. I also have one just for airshows. You can trade data files on the internet. I have several to swap!
¥ And finally, extra cost battery pack and alkaline battery case
are available. Size and feel are good: not too big, not too small.
Belt clip and handstrap are included. It has a large and easy-to read display,
and priority channel feature.
¥ The W32A does not do trunk tracking. You can use the conventional
method of locking out the 800MHz data channels.
¥ No 30-54 MHz low band coverage.
¥ There are no banks like a conventional scanner. You have a bank of 100
memory channels on each side and you can lock out (skip) any channels you
desire.
¥ No cellular coverage, but who cares?
¥ The scan rate is good, but not nearly as fast as other scanners and radios.
¥ No clock! Oh well. Many agencies now give the time as part
of their radio procedure. Car: "Adam 56 is 10-8"
Dispatcher: "at 10:32"
Street price of the Icom W32A is around $300.
Next time you are in the market for a scanner, consider an amateur radio transceiver. You don't have to be a licensed ham to buy amateur radios; just don't transmit. Ah, what the heck -- get your license.
Professional
FM Stereo Transmitter
Review by Thomas James Arey
If
you have been following the radio press for the last year or so, you are
aware that there is a boom in interest in low power broadcasting. There
is growing interest in the hobby community about the practical and fun
uses of unlicensed Part-15 transmitters. (FM broadcast signal with a field
strength not exceeding 250 microvolts/meter measured at a distance of three
meters from the transmitter (FCC rule 15.239))
Others
are testing the limits of the existing law (broadcast pirates) and still
others have supported a total revamping of broadcast law to allow low power,
affordable, licenses. The FCC's recent decision to allow low power broadcasting
-- consistent with its on-going move toward deregulation in all the radio
services -- make these very exciting times, indeed. (See this month's Washington
Whispers and American Bandscan columns.)
While
these transmitters continue to serve the needs of many hobbyists at very
reasonable prices, a couple of years ago Ramsey answered the call for a
more sophisticated FM transmitter to meet the needs of this growing aspect
of the radio hobby. The no-compromise FM-100 provides studio quality audio
signals and a level of transmitter control not found in other lower cost
units, while remaining a legal Part-15
transmitter.
The
FM-100 is more than just a transmitter; it contains all the essential aspects
of a complete broadcast station short of the actual the signal sources.
The unit includes two line inputs and one microphone input, all with a
high level of audio signal filtering and signal mixing controls. Further,
the microphone line has Automatic Gain Control (AGC) to prevent overloading
should you have the uncontrollable urge to start shouting like Wolfman
Jack. Both channels also have LED readout audio level meters so you can
see just what your signal is doing.
All
of these efforts in design serve to allow the user to produce the highest
quality signal free of the distortion and noise sometimes experienced by
Part-15 listeners. Properly used, the audio quality of your signal should
rival that of most any commercial station.
The
25 mW (that's milliwatt, not megawatt!) FM stereo transmitter is the response
of Ramsey's years of technical experience to what their customer base wanted.
For
places outside the United States where higher power is legal, this unit
can be purchased with a 1 watt RF output module. Export units connected
to gain antennas have been known to cover several miles with their signal.
(But don't try this at home in the US, kids...The FCC still frowns on folks
tweaking their equipment beyond Part-15 standards.)
Frequency
control is state of the art, Phased Lock Loop-controlled. The output frequency
is displayed on a large, easy to read, Light Emitting Diode (LED) display.
Frequency adjustment is as simple as the push of a button.
The
unit comes in a sturdy metal case with a silk screened front panel. This
goes a long way toward making the whole package look very professional.
The
FM-100 can be purchased in a fully wired and tested version; however, I
opted to break out the soldering iron and build the kit. Over the years
I have built many Ramsey kits. I have always been impressed with their
attention to detail, particularly where beginners are concerned. While
the FM-100 could be considered a moderately advanced kit, anyone who knows
which end of a soldering iron to hold and who can follow clear, step-by-step
directions should be able to build a fine project.
The
Ramsey kit manuals rival the standards of the long departed Heathkit books.
Complete parts inventory check lists are included along with check-as-you-go building
steps. There is also a large-format parts placement guide that you can
follow along as you do your work.
The
Ramsey folks also take the time to teach you about the circuit as you go
through the building process. By the time you are done, you will not only
have an FM broadcast station, you will also have the ability to tell people
how the thing works.
Recommended
building time for a beginner is listed at 24 hours. This is about right.
Since the construction is based on a series of circuit groups, it was easy
to build a section or two through to completion in an evening.
Given
the attention to detail of the manual, I had no reason to be surprised
when the unit fired up the first time without any problems. Ramsey seems
to have anticipated many of the common problems associated with construction
projects and they tend to give a lot of extra support where it's needed.
I
have had previous experience with both the FM-10a and the FM-25. While
these remain great entry level units, the FM-100 is clearly head and shoulders
above either of Ramsey's previous offerings. I had to let my next door
neighbor know that there wasn't a new station in town.
My
most routine use for the FM-100 remains getting signals from my home stereo
system out to a "boom box" by my backyard pool. The possibilities,
however, go far beyond that. The FM-100 would make a great basic setup
for a school radio program. The manual alludes to the fact that the unit
can be used as a front end for "carrier-line" use but reminds
people that they should seek a qualified engineer to make this happen.
Before
you take to the airwaves, the Ramsey manual gives complete practical comments
on the proper, legal use of this transmitter under the current regulations.
This includes a list of Frequently Asked Questions that show they have
been keeping their ears tuned to their customers over the years.
The
world of hobby broadcasting is growing every day, but even with the newly-enacted
low-power regulations the number of potential new licenses may not exceed
1,000. Why wait? Start broadcasting, legally and with the cleanest signals
on the airwaves, using Ramsey's FM-100s.
-
by Lawrence Harris -
My
backyard comprises a dish and antenna farm, but nothing stays in one place
for long. One day the washing line/mast support has a vertically polarized
log periodic antenna fitted at the top for monitoring satellites; the next
day this may be replaced by a multi-element yagi pointing at GOES. For
the last few days it has supported a VHF antenna that is pointing upwards,
then westwards, now southwards (for testing polar satellite reception).
Meanwhile, the dishes on the ground get moved about, dependent on test
requirements.
The
units that I have recently had under test comprise an active feed and a
downconverter. In isolation, these components are unlikely to be of much
use to anyone, but as new additions to a weather satellite (WXSAT) system,
they are invaluable. This article provides the background to their use
as the essential parts of a low-cost GOES WEFAX system.
The
newcomer to monitoring satellites has a bewildering choice. The cheapest
systems are likely to be commercial satellite television receivers, where
bulk production means lower costs. However, thanks to NOAA (the National
Oceanic and Atmospheric Administration) we also have several weather satellites
that provide interesting alternatives! There are two different groups of
satellites (constellations) available for monitoring. I suspect that most
WXSAT monitors started with the polar orbiters -- currently NOAA-14 and
NOAA-15. These (as the type suggests) orbit earth in near-polar orbits,
and therefore pass over every point on earth three or four times each day.
To
receive signals from these WXSATs, you need a suitable 137 MHz band antenna
and receiver. The units must be specifically designed for WXSAT use; general
purpose utility antennas and receivers are unsuitable due to the special
nature and content of WXSAT signals. Forget the discone; although these
allow you to tune to the 137 MHz band, special characteristics (for example,
the NOAA WXSATs provide right-hand circular polarization) mean that reliable
reception may be limited to an occasional minute during high elevation
passes. A crossed-dipole, turnstile or quadrifilar helix antenna are amongst
the most popular choices for reception. WXSAT receivers are also highly
specialized, requiring a wider-than-normal bandpass, together with tight
filtering for optimum reception.
Perhaps
you have a complete polar orbiting WXSAT set-up and have been monitoring
NOAAs-14 and -15, in addition to Resurs 01-N4 and Meteor 3-5. What else
do you need for GOES reception? Two -- maybe three -- items. Before I detail
these, let us take a brief look at history.
There
are grounds for being grateful for decisions made decades ago. Despite
their significant differences in operation, the decision was made to provide
a satellite downlink of low-resolution imagery from geostationary weather
satellites in a format compatible with automatic picture transmission (APT).
This is the image format of the polar orbiting WXSATs. Both types (with
few exceptions) provide low resolution pictures in which image data is
amplitude modulated on a 2.4 kHz carrier. The image data is a signal representing
the measured brightness of a small component of the scene below the satellite.
This
modulated carrier then frequency modulates the main radio frequency carrier.
In a visible-light image, high modulation means dark levels (sea), and
low modulation means white (cloud). Land generally falls in an intermediate
range of gray levels.
This
unique form of signal processing is the reason that receivers of special
design are essential for good reception, and means that a system that can
receive and produce pictures from most polar orbiting WXSATs, can also
produce them from geostationary WXSATs -- including Meteosat-7 for European
users, and GOES for American users. The only compromise is that a receiver
for polar orbiting WXSATs normally has an intermediate frequency (i.f.)
bandwidth a little wider than that required for geostationary WXSATs --
to allow for Doppler effects. Doppler effects are not observed from geostationary
satellites -- under average conditions!
These
two components -- the active feed and downconverter -- cannot achieve much
on their own (or even together). They are designed to be additions to a
polar orbiter receiving system that will already include a 137 MHz receiver
and decoding system. Such receivers sometimes include an additional connector
for 137.5 MHz to take a feed from a downconverter.
You
also require a suitable dish to receive the signal. Contacts tell me that
supplies of old Primestar dishes are often available for the taking, due
to obsolescence. Even if such a dish is unavailable, a home-made dish should
not be out of the question. When I first decided to set up a receiving
system for 1691 MHz back in the mid-1980s, buying a dish was impossible.
Satellite television was in its infancy and such dishes were very expensive.
I decided to construct my own, after realizing that at this frequency,
surface accuracy was a minimal problem -- imperfections of over 1cm were
acceptable! I built a 1m diameter dish using chicken wire, supported by
a wooden frame. I fitted a downconverter, and immediately found a signal
from METEOSAT -- EuropeÕs geostationary WXSAT.
Software
is required to decode the telemetry. The necessary facilities are almost
certainly included with your current NOAA-Meteor-Resurs program; look for
a GOES option.
My
original feed for 1691 MHz reception was passive; it consisted of a cylindrical
feed fitted with a small dipole. Because of the low signal strength, I
had to fit a microwave amplifier. This new "active feed" device
is almost revolutionary in providing a signal suitable for direct input
to a downconverter without the need for a preamp. This is indicated by
its specification:
Specification
Feed
gain 6.0 dBi
Preamplifier
gain 14.0 dB (giving a total gain of 20 dB)
Noise
figure <0.5 dB
Voltage
supply 6 to 16 Vdc at 20 mA current.
The
majority of system noise is added at the first stage; this active feed
provides 20 dB gain with no more than 0.5 dB noise figure.
Price
$89 ex postage
Downconverters
are commonly used in radio ham environments; this unit converts the amplified
1691 MHz signal from the active feed into a 137.50 MHz equivalent for transport
to the receiver. It is a work of art! The input connector is a standard
N-type plug for use at 1691 MHz; the output is an F-type socket. Little
is likely to go wrong with it. It should be given protection from the elements
by fitting in a small enclosure to keep out rain, especially around the
connectors.
Specification
1691
MHz input, 137.50 MHz output
Gain
33dB nominal with 2dB nominal noise figure
Power
input 6 to 16V d.c. at 40mA nominal current
Power
output (if selected) 50mA at the N-type socket for powering the active
feed
Price
$135 ex postage
For
testing purposes, I used a small off-set dish in order to provide worse-case
conditions -- those possibly met by anyone confined to using a small dish.
Setting up required the routing of cable from the dish/active feed to the
downconverter, and then indoors to the computer. A 5m length of cable is
supplied for the feed to downconverter, and this should be used without
cutting or other modification. You will need to provide cable for the 137
MHz run; the specifications provided with the system suggest that up to
100m of either 50 or 75ohm cable can be used. I fed some low-loss 50ohm
cable through already-prepared feed holes leading to my computer room.
The
system worked from switch-on. The dish has to be pointed at the satellite,
and this can readily be achieved by monitoring audio from the WXSAT receiver.
Two satellites are available -- GOES-10 is located over longitude 135 west,
for west coast coverage, and GOES-8 will be found at 75 west, for the east
coast. A helper can be invaluable for the process of either adjusting the
dish position or monitoring the audio -- but I achieved this on my own,
so help is not essential.
My
backyard is in Peverell, Plymouth, UK, so I used the system on Meteosat-7
-- the equivalent of GOES-8. A look at the transmission schedule for GOES-8
and GOES-10 shows a near continuous sequence of images from not only the
original GOES satellite, but also images originating from Meteosat-7, NOAA-14,
and the other GOES.
The
schedule ensures that formats of specific regions are transmitted at regular
intervals. Because these have identical content (only the clouds have moved!)
they can be animated. Software normally has an "animation" facility,
and this provides the best guide to nowcasting and forecasting that can
be obtained. Even using the three-hourly images from GOES-8 that are transmitted
by Meteosat-7, Europeans can monitor weather changes over America. A selection
of GOES images are shown here.
With
all satellites, you either receive them near-perfectly, or they are of
little interest. No-one wants to view noisy images, or to have to spend
time using software to "clean" them. This system provided virtually
noise-free images throughout the test period. One minor "hiccup"
happened when a gale blew the dish a few degrees in azimuth, causing enough
signal loss to suggest that the system had failed because of the rain.
Close examination immediately revealed that the pointing was several degrees
off. Re-adjustment corrected this and the system continued to operate flawlessly.
For permanent use, it is advisable to fix the dish to the ground, rather
than merely resting weights on the mount support legs as I did!
The
pricing of these units brings GOES WEFAX imagery right into the domestic
market. Fifteen years ago I paid the equivalent of over $200 for a downconverter,
and the system also needed an expensive preamplifier. It is encouraging
to see such products arriving at these prices.
The
two units (feed and converter) are manufactured by Timestep Weather Satellite
Systems and retailed by Swagur Enterprises (now defunct - ed, 2004). Check-out the Timestep site at: www.Time-step.com
Prices
given above were those applicable at the end of 1999; please check in case
of changes.
Frequencies
- polar
NOAA-14
transmits APT on 137.62 MHz
NOAA-15
transmits APT on 137.50 MHz
NOAAs
transmit beacon data on 137.77 or 136.77 MHz
Meteor
3-5 may transmit APT on 137.30 MHz when in sunlight
Resurs
1-4 transmits APT on 137.85 MHz
Frequencies
- geostationary
GOES-8
and GOES-10 use 1691 MHz for WEFAX
By
Bob Grove
A
relative newcomer to the consumer antenna marketplace is Nil-Jon, offering
several models for TV and FM broadcasting, amateur, and scanner listening.
We decided to take a look at two wideband scanner antennas since the promotional
literature issued by the company gives them rave reviews.
The
Big Base
It
seemed fair to compare the big base model with two perennial favorites,
the Channel Master 5094 Monitenna and the Antenna Craft Scantenna. Both
of these antennas have so far been unbeaten for wide frequency coverage,
excellent reception, and low cost. Their receiving performance and architecture
are virtually indistinguishable.
With
the Nil-Jon selling at nearly three times the cost ($129.95 vs. $49.95)
of its two competitors (which include 50 feet of coax as well), it had
better offer something special.
The
Nil-Jon is shipped as a semi-kit, roughly a dozen element pieces, interconnect
cables, splitter, boom, and a bag of nuts and bolts. Using the enclosed
(old edition) directions to sort parts and then assemble the rig took about
half an hour. The new manual is a vast improvement.
The
competitorsÕ antennas come fully assembled, requiring only fanning out
the elements which then latch into position. All three antennas require
attaching their respective balun transformers and U-bolt brackets. Common
tools (screwdriver, pliers, etc.) are required to assemble the antenna.
The
marked difference between the Nil-Jon and its two competitors is its use
of three independently fed elements. While the competitive antennas are
essentially comprised of a single vertical element with parasitic elements
hinged to it in an ÒXÓ-like configuration, the Nil-JonÕs three separate
vertical dipoles are mounted on clear acrylic plates and spaced wide enough
to avoid interaction which could skew the omnidirectional pattern of the
antenna.
The
piping used for the elements is seamless aluminum conduit (3/4ÓD, .035Ó
thick) bearing the millÕs stamp; this is much larger than used in either
of the competitors, and gives it an edge in the durability department.
It is rather crudely cut, however, giving the ends of the tubing a ragged,
home-brew look. But that doesnÕt affect its performance.
The
elements are off-center fed like the Grove Omni, resulting in a balanced,
high-impedance feed point, matched by three conventional VHF/UHF TV balun
transformers. Three lengths of F-connector-fitted RG6/U coax route the
signals from the balun transformers to a three-way VHF/UHF TV splitter,
connected in reverse as a signal combiner. The combined signals are then
led to the receiver or scanner via the ownerÕs F-connector-fitted cable.
We would recommend anchoring the longest of the three interconnect cables
to the boom with PVC electrical tape to keep it from flapping in the wind,
possibly subjecting it to premature failure.
So
How Does it Work?
To
do a fair comparison, the Nil-Jon was mounted in the same position as a
Scantenna, separated by several feet to avoid incorrect readings resulting
from interaction of the elements. Using an Icom R7100 receiver as the test
instrument, several steady carriers were selected in the 30, 90, 120, 150,
160, 300, 420, 450, and 860 MHz bands.
After
a reading was taken from the Scantenna, the coax lead-in was switched to
the Nil-Jon. Just to confirm the results, the coax was then reattached
to the Scantenna and signal strengths were again measured. Unexpectedly,
within visual limits, every signal was identical on all frequencies!
No
attempt was made to measure characteristic impedance or VSWR. Transmitting
into the antenna is probably possible if the power is low, limited primarily
by the small components used in the transformers and splitter.
The
Bottom Line
In
order, the flimsiest construction is the Scantenna, although its history
shows very little damage from wind and weather -- most damage is incurred
from rough handling during shipping! It is made from rolled and seamed
aluminum tubing of the TV antenna variety. Next, the Monitenna, which is
assembled from seamless tubing and is more durable. Both antennas reflect
typical assembly line construction and finishing.
Strongest
of all is the Nil-Jon with its heavy-gauge tubing and heftier boom, in
spite of its homemade appearance. While we noted no difference in signal
reception among the three contenders, the Nil-JonÕs durable construction
may give it an edge under severe wind load conditions.
The
Mag Mount Mobile
This
was a pleasant surprise. The appearance of the HD-V/U-Super-M mobile antenna
itself is unusual, with three slightly-different-length VHF-Hi band whips
all radiating upward at an angle from the base (see photo). At first glance,
one might think that the purpose of the separation is to prevent interaction
which might degrade a broadbanding design, similar to a dipole cluster
of different lengths, each resonant at a different frequency.
But
there is an added advantage to this design. At higher frequencies, as an
element becomes electrically longer, the radiation and reception pattern
starts to favor the ends. By angling the whips downward, this pattern is
also lowered toward the horizon. Now the extra length has gain over the
quarter-wave whip, providing better performance. And angled downward, the
antenna cluster is less likely than a comparative single vertical element
to strike overhead obstacles.
The
Bottom Line
So
does it really do this? You bet! The Super-M was compared to an 18Ó whip,
the Grove ANT-30 Stealth, and even a cellular gain antenna, all popular
favorites for scanner monitoring as well as VHF/UHF transmitting.
In
every case, the Nil-Jon Super-M equaled or outperformed the contenders,
sometimes by a substantial amount! And even though the manufacturer advertises
it for 140-170/400-480 MHz communications, for receiving purposes, it works
well past the 800 MHz band.
The
antenna consists of three black-enameled and rubber-tipped elements (16Ó
to 18-1/4Ó), a machined brass base, and a Larsen 3-1/2Ó magnetic mount.
A 12-foot length of RG-58/U coax terminates in a PL-259 connector for attachment
to two-way radios; an optional UHF/BNC adaptor is required for scanners.
HD-SCAN-WB-OMNI-F
base antenna, $129.05 plus shipping.
HD-V/U-Super-M mobile antenna, $64.95 plus $7.50 shipping.
From Nil-Jon Antennas, PO Box 764, Amherst, OH 44001; ph. (440)
989-2295. Web site www.nil-jonantennas.com;
e-mail pfb@eriecoast.com. By
Bob Grove Radio
direction finding (RDF) antennas find myriad uses in communications, from
locating sources of intentional or incidental interference, to homing in
on downed aircraft beacons. Amateur radio Òfox hunts,Ó locating hidden
transmitters, are a popular pastime in some radio clubs. Members often
use those talents to find repeater jammers. Classical
systems use loops, Adcock arrays, Yagi (beam) antennas, and other manually
rotated antennas to determine target bearings from the operatorÕs position.
But automatic direction-sensing antennas with a compass-bearing readouts
are certainly easier to use, and often more accurate. Doppler
schemes use multiple antennas, arranged in a circle and electronic sampled
hundreds of times per second by a rapid switching circuit. Comparing signal
arrival times at the different antennas is automatically translated into
direction and displayed on a control panel as a digital bearing or, more
often, as an LED in a circle representing a compass rose. While
commercial Doppler RDF systems can be very expensive (often thousands of
dollars), Ramsey Electronics has recently released an inexpensive kit.
The DDF-1 Doppler Direction Finder is based on a circuit published in QST
magazine (April/May 1999 issue), contributed by WA2EBY. A single
Doppler RDF system can be operated over a wide frequency range, as illustrated
by the advertised 130-1000 MHz span of the Ramsey. However, proper positioning
of the whips at different frequencies is critical for accurate bearings,
meaning that antenna lengths and separations must be changed for wide frequency
excursions. The
DDF-1 display contains an array of 16 LEDs, and is capable of resolving
bearings within 22.5 degrees (16 x 22.5 = 360). While this may not be accurate
enough to position a rocket launcher, it is adequate for following and
finding a target transmitter. And a second operator using an RDF at another
location could radio his bearings as well, allowing cross-coordinates to
be plotted on a map for rapid resolution of the targetÕs location. Putting
it Together A 36-page
assembly/calibration manual is included with the kit. Although assembly
is not particularly difficult for an experienced kit builder, calibration
procedures may be rather daunting for someone unfamiliar with radio or
electronics theory. It
is important to have access to an oscilloscope to verify the square wave
pattern of the logic circuits; a frequency counter to measure the operating
frequency of the clock oscillator; a voltmeter to assure correct operating
voltage in the circuitry; and an audio generator to calibrate the signal
level circuitry. The
operator will also need to secure the assistance of a confederate with
a walkie-talkie or mobile rig who is willing to drive around, communicating
with you to coordinate proper positioning and alignment of the rooftop
array and control settings. The
DDF-1 kit contains all the parts necessary to assemble a full system, including
approximately 150 circuit board components, plus miscellaneous hardware.
You will need to supply the coax cable (RG58/U or RG174/U) down-lead and
five-conductor cable (multi-conductor telephone or computer cable will
work well) from the rooftop array to the console. You will also need to
supply the DC cable with a standard power connector, and an audio cable
to connect between the control box and your radioÕs external speaker/earphone
jack. While
the ABS plastic box utilized a professional stick-on panel, the antennas
will look quite homemade. Four copper-clad steel rods anchored to small
circuit boards housed in white-plastic jar lids comprise the antenna array.
Plenty of unimpeded rooftop space will be needed to accommodate the four
whips, spaced a yard apart The
antenna bases are ÒanchoredÓ to the vehicle roof by flexible tape magnets
with barely enough strength to hold them upright. The manual recommends
slow driving speeds, or replacing the magnetic strips with something more
substantial, like speaker magnets. Good idea unless you are satisfied taking
all bearings from one position. In
Operation The
panel consists of a central ring of red LEDs with a center green LED; two
red LEDs indicating low/high audio level; a Power switch; a stop/run Scan
switch; and a normal/reverse Phase switch. There are also three controls:
Calibrate (used to set your initial compass bearing); Damping (used to
average out flutter in the logic circuits); and Audio Level (used to balance
the input level with required speaker volume). After
some fiddling with the controls, we found the system actually quite simple
to use, but the newcomer will need to do considerable experimenting with
known signals to feel comfortable with the variables that accompany any
direction finding effort.
By
Larry Van Horn Needless
to say I was excited when given the opportunity to test Intensitronics
Corporation's latest addition to their BCB antenna product line --
the Super Select-A-Tenna.
I have been using the company's
original offering, the Select-A-Tenna
(both first and second generation models), for several years now.
While it isn't my primary BCB DX antenna, it does an excellent job
when matched up with two of my secondary portable receivers that I use
from time to time -- the
Sony ICF-2010 and GE Super Radio III. To
back track a bit, the original Select-A-Tenna is a passive device that
requires no wires, no batteries, no plugs, etc. It works by simply placing
it next to your radio and turning the large tuning knob to the same station
frequency as your radio. This antenna functions by concentrating the radio
station signal energy in the near proximity of the Select-A-Tenna. If the
radio you use has an internal antenna and is placed in that same near proximity,
the radio and antenna share the same signal concentration and gain improvement.
The manufacturer claims 30dB improvement of signal with the original Select-A-Tenna
and my testing showed that is the case over most of the BCB spectrum. Recently
Intensitronics released their second generation of Select-A-Tenna (Grove
ANT-21). This antenna has the same intrinsic +30dB signal strength improvement
and features of the original version. In this second generation model,
a jack on the front panel allows the unit to either be connected to an
outside long wire and ground, or directly to a radio's antenna and ground
terminals when the radio has no internal ferrite rod antenna (such as in
a communications type receiver). This opens up several receiver options
over the earlier version. Users
in all-metal buildings or campers where AM radio signals do not suitably
penetrate will also find this unit effective, because a long wire outside
antenna and ground may easily be connected directly to the Select-A-Tenna.
This allows outside AM signals to be ported through the Select-A-Tenna
to a ferrite-loop-only receiver. Other
users with radios having only an antenna jack and ground terminals, but
who want an alternative to the long wire and ground, can connect the Select-A-Tenna
directly to the radio using the external antenna and ground cable assembly
that is provided with these antennas. The
brand new Super Select-A-Tenna was developed for listeners who require
better performance working within some very specific AM listening applications. One
of these applications involves coupling older model internal ferrite rod
antennas that don't work well to this antenna to obtain good, high-Q, mutual
coupling. My Sony 2010 tends to fit into this category and the Super-Select-A-Tenna
did show a significant improvement over the second generation model I have
been using with it. This
new model is an active device with additional controls for an internal
regenerative amplifier, and it does require a 9-volt battery (not included)
to operate this unit. Normally, you find regeneration circuits on top end
AM-BCB air-core loop antennas such as the Kiwa. This is a very nice additional
feature to and it works quite well to narrow down adjacent channel splatter
when activated. This
unit has an additional variable 0dB to +10dB gain added to the intrinsic
+30dB mentioned before for a useful gain up to +40dB. While this didn't
really matter much on some of the clear channels station we monitored in
our test (loud is still loud), it was really useful when trying to dig
out a single station from hundreds on the crowded AM BCB graveyard channels
of 1230, 1240, 1340, 1400, 1450 and 1490 kHz. Gain
is not what you always want on these crowded frequencies. In fact it can
be a curse, depending on conditions and your local radio environment. The
combination of directionality plus the ability to adjust the gain supplied
by the antenna to the radio, resulted in a couple of new stations added
to my logbook during our testing. This
unit has both coarse and fine tuning controls (like its more expensive
brother, the Kiwa) for ease of operation at the higher gain settings. It
also has the ability to effectively drive a remote ferrite probe. This
is useful when using the antenna with a large case radio which may prevent
effective proximity coupling and reduce the effectiveness of the Super
Select-A-Tenna. To
recap, this new model may be used in any of four different modes of operation: (1)
Direct near proximity, just like the first and second generation Select-A-Tennas (2)
Ferrite probe near proximity (3)
Direct wired antenna connection, and (4)
External antenna and ground for metal-buildings when using modes 1 and
2. The
new Super model has a high-signal level and low-impedance balanced drive
port for the ferrite probe. This provides the capability to not only drive
the 6-foot coaxial cable and probe, which are included, but the cable may
be extended to as much as 26-feet¨(not included). We found this particularly
useful for remotely locating the Super Select-A-Tenna away from radio noise
sources (including the human kind) or into better signal locations without
having to move the radio itself. (It's hard to make an AC-only rig portable.) I was
particularly impressed with this new version of the Select-A-Tenna as an
owner of both the original and second generation models. This is a significant
improvement over those early antennas, and its four modes of operation
will make the Select-A-Tenna of benefit to an even greater number of hobbyists. While
it couldn't hold a candle to my Kiwa (I didn't expect it to, given the
price differential), it really performed quite well for an antenna in its
price range. If you can't afford a Kiwa, but you want a capable, loop style
antenna for the BCB frequencies, take a serious look at the new Super Select-A-Tenna.
This model (Grove ANT-40) is available from Grove Enterprises (800-438-8155
or www.grove-ent.com)
for $189.95 plus shipping.
By
Bob Grove AOR
SA7000 The
AOR SA7000 is a wideband (30 kHz-2000 MHz) base or transportable monitoring
antenna measuring 5 feet tall (longest element), and about 4 inches wide.
The two vertical elements are conjoined by an impedance matching system
to provide a nominal 50 ohm unbalanced load for the receiver cable (approximately
50 feet, included). It is not intended for transmitting. The
elements are made of durable steel, and the system is easily and quickly
assembled using only a Philips screwdriver, pliers, and an Allen wrench
(provided). Our
Test We
compared the AOR SA7000 with the popular Grove ScanTenna at VHF/UHF, and
a GAP Titan HF vertical for 100 kHz-30 MHz measurements. While the ScanTenna
outperformed the SA7000 by 6-10 dB on all our VHF/UHF test frequencies
between 27 and 900 MHz, reception was quite acceptable. Similarly, at shortwave
frequencies, in spite of the considerable difference in antenna length
(5 feet vs. 30 feet), response of the AOR was only about 10-12 dB lower.
When tuning the 100 kHz-500 kHz LF range, LORAN C and non-directional beacons
came in loud and clear. Years
ago, the U.S. Coast Guard made similar short-element tests and found that
an impedance-matched five-foot antenna was able to hear HF signals 100%
of the time when compared to a full size antenna. This is because the main
limiting factor below approximately 50 MHz is atmospheric noise, becoming
increasingly disruptive the lower you tune in frequency. If an antenna
is long enough to capture enough signal to overcome the receiver's internally-generated
circuit noise, that's all that's required. The
net result is that the background noise is very quiet and S-meter readings
will be quite low when compared to longer antennas, but the signal will
be there above the noise, just as it would be when using a much longer
antenna. Just turn up the volume! The
Bottom Line We
would recommend the AOR SA7000 wideband antenna for general purpose reception
throughout the 100 kHz-2000 MHz range for wide-frequency-coverage receivers
like the AOR AR5000 Plus, AR7000, Icom R8500, PC100/1000, R9000L, WiNRADiO
WR1000/1550/3100/8000 series, and extended-frequency coverage scanners
like the Alinco DJX10T, ICOM R2/3/10, Yaesu VR500, and AOR AR8200. It
is pre-eminently useful as a rapid-deployment field antenna for emergency
and tactical applications. While received signal strengths will not be
as strong as experienced with larger, separate scanner/HF antennas, they
are adequate for local monitoring applications and near-field surveillance
and countermeasures. The
SA7000 is available for $189.95.* SA3000 The
SA3000 is an unconventional discone design intended for mast mounting.
Essentially, it is a composite of several element lengths in an effort
to extend the typical 8:1 frequency range of a discone so that it can accommodate
wideband receivers over the entire 25-2000 MHz spectrum. As with the previously
reviewed SA7000 antenna, signal strength measurements were compared to
those received on the Grove ScanTenna. Overall reception was as good as
that heard on the standard of reference. Predictably,
however, reception below 30 MHz deteriorated rapidly and substantially
(although not as rapidly as on the ScanTenna). This is also characteristic
of discone antennas in general, making VHF/UHF discones virtually useless
for serious listening on shortwave and medium wave. Because
the elements are of various lengths, we suspect that the DA500 may be somewhat
directional, and should be rotated while receiving tests are being made
to find the most favorable compromise position. Directivity should be less
pronounced on those frequencies in which various element lengths overlap
in their frequency coverage. The
elements are made of strong, lightweight, stainless steel tubing; a sturdy
connector block attaches to about 50 feet of coax cable (included) via
a TNC connector. The receiver end of the coax is fitted with a BNC connector.
We would suspect that the antenna could be used for transmitting as well
as receiving over those frequency ranges closely impedance-matched by the
antenna. Although
washers called out on our instructions were missing from our sample, we
suspect that they probably weren't necessary for their intended placement.
We were very impressed with this antenna, both from a standpoint of quality
of manufacture and performance, and would recommend it for general purpose
25-2000 MHz receiving applications. The
SA3000 is available for $129.95.* MA500 For
mobile VHF/UHF monitoring applications, the MA500 magnetic-base antenna
is a strong contender. The same VHF/UHF element found on the higher price
SA7000 is firmly attached to a rugged, strongly magnetic base. About 16
feet of coax cable with BNC connector is included. For
this test we measured its performance against a Nil-Jon Super-M (see June
MT, p.104) and an 18" whip.
Although the Super-M is considerably shorter, we found it performed equally
well against MA500 to perform nearly identically, given variables on the
road. Both antennas outperformed the simple whip.
Ramsey
Mobile RDF System
Super
Select-A-Tenna Review
The
Antenna Line from AOR
The
MA500 is available for $99.95*
=============
*Prices
quoted are all from Grove Enterprises (PO Box 98, Brasstown, NC 28902;
800-438-8155; http://www.grove-ent.com/order)
and do not include shipping.
Three or four years ago, we
reviewed a radical new test instrument produced in Korea, the Protek model 3200.
Now upgraded to a model 3201, we thought it might be time to take another look
at this unusual piece of equipment.
The 3201 is ideally suited
for the installation and maintenance of paging, two-way radio, cellular
telephone, cable TV, and satellite TV systems as well as antenna site
maintenance.
Lightweight (1.4 lbs.) and
compact (4-1/4"W x 9"H x 2"D), the 3201 is intended as a
hand-held, portable, multi-function, field test instrument for the radio
industry, As such, it is essentially a combination spectrum analyzer, frequency
counter, and data recorder with considerable flexibility, and it is extremely
easy to use by simply following its on-screen menu.
With a frequency coverage
of 100 kHz-2060 MHz, direct-entry keypad, and a versatile LCD display, the unit
is designed to operate as a stand-alone instrument or to interface with a
computer and a printer. Software, documentation, and an RS232C cable are
provided.
The
Display
The backlit LCD measures
2-1/2" square (3-1/2"
diagonally), and contrast is continuously adjustable for any lighting condition.
Spectrum
Analysis
The spectrum analyzer mode
is quite user friendly, allowing a choice of sampling steps between 5 kHz and 6
MHz, with 160 total samples per sweep. This equates to spans as small as 800
kHz, to as great as 960 MHz. Unfortunately, the user cannot select resolution
bandwidth.
Sweep speed is quite slow, taking about 13 seconds per span,
making the capture of short-term transmissions rather hit-and-miss. It is most
satisfactory for continuous carriers.
An operating mode may be
chosen which allows simultaneous sweep and audio recovery, affording the user
the opportunity to sample the hits as the sweep progresses across the spectrum.
Automatic scanning/sweeping
is user-programmable, allowing continuous spectrum sweeping, recurrent sweeping
over a range, or scanning discrete memory channels. Scanning speed is 12.5
channels per second.
A rotary tuning knob is
provided, but its rubbery, erratic response mandates the use of an alternative
set of up/down keys.
Audio
Recovery
The 3201 does have the
capability of allowing audio recovery of AM, WFM, and NFM signals; while SSB is
also specified, the low injection level and apparent lack of AGC makes such
signals virtually unintelligible. A tiny, one-inch speaker slot on the rear of
the unit is barely adequate for quiet environments. An external earphone jack is
provided (ear bud included).
Although sensitivity is
excellent (typically 0.5 microvolts NFM), poor dynamic range prohibits serous
monitoring applications. Using the rubber duckie antenna included with the set,
it works reasonably well, but connecting a large, outdoor antenna invites
overload and the attendant mish-mash of mixed signals.
An adjustable squelch level
is visualized by an attendant bar graph, allowing the user to adjust audio
cutoff levels, as well as choose signal thresholds to automatically stop
scanning and searching sequences.
Additional sources of noise
include a variety of self-generated spurious signals (“spurs”) from the
instrument itself. Motorboating sounds, whines, and hisses were commonly heard
at various frequency settings; bringing your hand near the LCD while monitoring
AM at lower frequencies invites a loud wailing from the display’s driver
circuitry.
However, audio monitoring
is not the instrument’s purpose; it is designed for near field measurement of
discrete signals, not for scanning the spectrum for listening purposes.
Up to 1600 memory channels
including frequency, amplitude, and channel identifier, may be stored in 10
banks.
Frequency
Counter
Seven-digit readout with
+/-50 PPM accuracy may be expected from 9-2060 MHz. Sensitivity averages 100-150
millivolts, and acquisition time is a short 0.5 seconds. Up to 10 of these
readings may be stored in memory for later recall.
Bar
Graphs
For data comparison, the
user may select a display of 1, 5, 10, 20, 40, 80, or 160 separate bar graphs.
Two separate signal levels (such as video/sound may be compared on screen in the
comparison mode, or up to 160 different signal levels may be shown.
A printer driver allows a
permanent record to be made of the instrument’s measurements over time.
Power
The 3201 is powered by six
internal AA NiCd cells; optionally, an external source of 12 VDC may be applied
for extended periods of portable or mobile use. Battery operation is rather
short, only about one-half hour with the NiCds supplied with the unit. Recharge
time, though, is short -- about 1-1/2 hours. A wall adaptor is provided.
To conserve power, the
audio section may be switched off during measurements-only use, and the
instrument may be programmed to automatically shut down after 5, 10, 20, or 30
minutes of idle time.
The
Bottom Line
We found the Protek 3201 to
be a highly versatile piece of test equipment, suitable for a variety of field
instrumentation applications where compactness and flexibility are of paramount
importance.
The 3201 comes with
carrying strap, canvas zipper bag, BNC/BNC coax jumper, flex whip, rechargeable
NiCd cells, AC wall adaptor/charger, ear bud, PC software, computer cable,
documentation, and operating manual.
The Protek3201 is $2100
retail from Protek, 154 Veterans Drive, Northvale, NJ 07647. Phone(888)
784-8400, fax (201) 767-7343, email hcprotek@hcprotek.com,
or visit their web site at http://www.hcprotek.com