José Luis Flores is graciously providing a
free Excel spreadsheet for performing mixer spur analysis - The Distances Chart.
I downloaded and ran it, and it looks very nice. Although the author claims it is
a new concept, Collins Radio invented the format many moons ago, and in fact, as
far as I can tell, my
RF Workbench software from the early 1990s was the first to implement
it in code. I have been considering doing this in Excel for along time, but thanks
to the hard work of Senõr Flores, there is no longer a need. Maybe I'll take a few
extra naps instead.
Featured Product Archive
The inventions and products featured on these pages were chosen either for their
uniqueness in the RF engineering realm, or are simply awesome (or ridiculous) enough
to warrant an appearance.
| 1 |
Star Wars weapons are a step closer to reality
thanks to Wicked Laser's new Spyder III Pro Arctic Series. The high intensity blue
laser module is actually part of an image projector system - it just happens to
resemble a lightsaber (yeah). News reports of the unit quotes the company's website
as warning that the 1 W output "...will blind permanently and instantly and set
fire quickly to skin and other body parts..." It appears the "set fire quickly"
part of the
warning had been removed by the time I visited the site for verification.
Still, its 445 nm blue light generates a beam that exceeds safe exposure levels
by a factor of 75x. That is a wicked laser. For just $200, maybe I could use it
to fry the squirrels that are robbing Melanie's bird feeders. Hmmm...
This week's product is a little different than most in that it requires
you to construct it yourself. Designer Dan Davies wrote to me about his simple but
effective anti-theft device for use in automobiles, snowmobiles, airplanes, etc.
It is a device called the "G-Spot" that splices in series with the ignition wire
that requires the operator to tough it prior to starting the engine. The security
feature is simple - you have to know where it is and that is needs to be touched
for enabling. A nicely done video is provided showing to to assemble the device,
so the DIYers out there can tackle it without fear.
Here is an iPhone that is guaranteed to not
have an antenna problem. In fact it might just have the cleanest signal around even
though they feature just one bar... of soap, that is. LOL, really, folks, I'll be
here all week. Also available are BlackBerry, Droid, Pre and iPod soap bars with
various scents. Not in
the market for iPhone soap? How about a Antenn-Aid for your iPhone 4? "We're getting
a new order every minute," claims the inventor.
If you still have not been able to part with
your retro turntable, but all your old vinyl LPs are too worn to play, you might
be glad you kept it. A German company called
Production has created a technique for making a hybrid disc with a standard
CD on one side and pressed vinyl record on the other. Techno DJ
Jeff Mills has created
a combo version of "The Occurrence" that sells for $35. It is currently sold out
- likely from all the publicity like what it is getting here. The guy's a bit weird
(UFOs, etc.), but it sometimes takes "out of the box" [of reality] thinking to come
up with this kind of an idea.
a little bit different tack, this week's Cool Product is no product at all. This
is worse than the current epidemic of gray market items, in that at least with the
gray market, you actually get a functional - albeit illegal manufactured - version
of what you need. In the case of the Intel Core i7-920 μP seen here, a lot of effort
went into creating an elaborate faux version that looked amazing real... right up
to the point it was removed from the box. The contents turned out to be an nicely
done picture of the μP / cooling fan and some lead weight. Even the holographic
Intel sticker on the box looked authentic.
5-21-2010Spur Charts are all the rage these days. AWR
led the way a couple years ago with a contemporary version of the mixer intermodulation
spur graph in their Visual System Simulator software. This white paper on
System Planning discusses the use and advantages of the format.
Here's how it works. One axis is the input frequency divided by the LO frequency.
The other is output divided by LO. Each line plots a single spur product, 1x1, 1x2,
2x1, 2x2, 2x3, etc. Then, a box is constructed that represents the frequency boundaries
of the input / output realm. Any spur line that crosses through the box is an inband
product. This allows you to visually determine not just which products lie inband,
but also how close surrounding spurs are. Nice.
If there was ever a product designed for the
purpose of guaranteeing at least one new candidate for the Darwin Award, this has
got to be it. Were it not for the accompanying serious video from the DoD, you might
suspect the power harvesting "Bat Hook" was a joke. It is designed to be tossed
over an overhead power line so that field operators can gain access to electrical
power. With a properly trained user, this device undoubtedly provides a very convenient
way to recharge batteries or power emergency equipment. Still, keep an eye on the
2012 award honorees.
This is a slick new
product by Narda Microwave-East. Their Model 743-60 step attenuator provides attenuation
of 0 - 60 dB in 10-dB steps via a thumbwheel and direct readout. It covers DC to
18 GHz with a deviation of ±1 dB or less from 0 to 40 dB, and no more than ±1.5
dB to 60 dB of attenuation. Resetability is less than 0.05 dB, VSWR is less than
1.5:1, and temperature stability is 0.0001 dB/dB/°C. The attenuator can handle RF
input power of 2 W average and 200 W peak. The 743-60 can be panel-mounted.
6-4-2010In a sort of electronically incestuous manner,
this really cool clock uses analog multimeters to effect an analog multimeter themed
Alan Parekh designed and built this really slick clock to look
like a plus-size Simpson 260 analog multimeter. It uses three small analog multimeters
to display hours, minutes, and seconds. A μcontroller calculates the current required
to position the analog meter needles per the time of day. This is a really great
way to mix old and new technologies - akin to the
clocks. Unfortunately, the mini-meters are an offshore brand, which mutes the
nostalgic je ne sais quois just a bit. Maybe make a label to put over the names
Spectrum Analyzer Uses 256-Point FFT
USB ports are used for a lot of things, from
powering keyboard lights, communicating with wireless devices (via a dongle), to
even the original purpose like interfacing to a wired peripheral. So, why not use
the USB port to charge batteries? USBcell batteries have a built-in USB connector and charging circuitry
all within the form factor of a AA battery. The NiMH cell is rated for 1.2v at 1300
mAh. Pretty cool indeed.
Here is a unique service that offers produces for sale without charging a fee.
There are currently more than 700 items listed. Clients include both private parties
and dealer; however, dealers are limited to offering used or new old stock (stuff
not currently in production). SecondHandRadio.com has been around for a couple years,
and advertises in ARRL's QST magazine. Since there is no middle man fee, prices
are the lowest possible for test equipment, electronic components, radio gear, vintage
TVs, and more. The website gets its funding from advertising, so as with similar
websites (one in particular comes to mind), please be sure to visit those advertisers
and support them if possible.