Freshh approach in the hot UWB field
592266
Author Schantz brings a dramatically different approach to the understanding of very wide band antennas - which are critically important in UWB technology. It is well illustrated, and is steeped in historical background which aids the understanding of antenna development. The volume introduces an intuitive but rarely seen space-time energy flow diagrams to bring an understanding of stored and radiated fields.
437601
The transmitting feature is good, but I am still testing the receiving feature. Hope that it can work for my desktop.
3334785
The high band has much less range than the standard 2.4Ghz band, which is one of the main differentiators of this model from the less expensive ones.  A couple walls and about 30' before performance struggles in my home. At that range I still get "excellent" signal strength using the standard band.  I also bought this model for the USB port to add an external drive.  Otherwise, easy initial configuration, did the firmware update, and no problems - great unit.
4721254
Easy to use right out of the box.  Great caller ID display.  Easy to review calls, erase previous calls, etc.  Holds a charge forever.  Have used it off the charger stand for 2 hours and still not even low on battery.  Crystal-clear reception.  Home base for the unit is 115 feet away.  Used in the garage, too, 220 ft and still a strong signal.  Can't go wrong if you own a Uniden system and want to add a remote unit.
2116557
The 900+ pages of this new book by Ulrich L. Rohde and David P. Newkirk covers a wide range of topics related to its title.  It should serve as a valuable reference to all engineers working in the field of wireless systems and its related components.  It also provides extensive sets of  relevant up-to-date references and related patents.
The book begins with  a quick overview of the radio channel and the various modulation schemes  used in wireless systems, providing useful definitions of commonly used  terminology.  Then, switching from system level, the authors quickly  progress to components and building block discussions for the rest of the  book.
A detailed review of active device models (large signal and small)  for various diodes, bipolar and Si and GaAs field-effect transistors are  followed by SPICE-, and noise-parameter extractions, including a new  modeling approach for low-voltage operation.
The most extensive chapter  (260 pages) of the book deals with design considerations of RF/MW linear,  low-noise, high gain  and (nonlinear) power amplifiers.  Several  illustrative examples are given, including a wide range of commercially  available device and amplifier datasheets.  This chapter also covers AGC  amplifiers and voltage-tuned filters.
The last three chapters cover  mixers, oscillators and synthesizers and their related CAD methodologies.  The Ansoft Serenade programs is used for all illustrative examples. The  book concludes with two Appendixes: one discussing HBT models, parameter  extraction and validation and another on multiharmonic load-pull techniques  and their applications in power amplifier and frequency multiplier designs.
979431
With RTL2832U and R820T chips you can start experimenting with SDR in a couple of minutes. Good value for price.
263551
Heck and Hall have done a fantastic job in summarizing both the theory and practice of solving today's SI issues. The math behind topics such as linear network theory, frequency-dependent dielectric effects and filter design for equalization is rigorous, yet ample space is set aside for practical guidance as well. Of particular note is their thorough treatment of hot PCB SI topics as dielectric loss and surface roughness modeling, and preservation of causality in transmission line models. Transmitter and receiver equalization (DFE and CTLE) are well-described, as are analysis techniques such as peak distortion and bit-error rate. Finally, their summary of response surface modeling (RSM) approaches to desgn of experiments (DOE) is perhaps the first and certainly the most comprehensive overview of those methods as applied to PCB SI design available today. A book well worth purchasing if you are involved in SI modeling, SI simulation or PCB design.
1210930
Soft install required - that's one thing my tech said.  You need to find the best placement of the interior receiver and "sandwich" the signal.

I have spent the past week trying one location and decided to reposition everything to maximize invisibility and provide a good vehicle coverage shell.  I definitely recommend you turn on the decibels in Field Test mode.  I saw a gain of 20db when the unit was activated - so it does work.  Worth noting is that if you're running lots of apps on your phone, eliminate the ones you don't need running (background apps) and you'll see your decibels improve.

I bought this for a cross-country, into another country drive and to provide a moving hotspot for my passenger to do work.  I suppose a review would be better after the drive but wanted to share my experience with this product.  Last note - do check out the AmazonWarehouseDeals.  I bought my unit as a working return and saved $$$ -- basically and upgrade from the cost of the lower model.
2675331
This product is a winner!
I purchased this wifi detector with the intention of minimizing use of my cell phone based 3G wifi hot spot while travelling the country in our RV.  The rationale is to save the plan data limit for times when no open network is available.  We live in a rural area with the closest homes over 250' away.  I was able to detect open and usable network signals from four different sources on the periphery of my property.  This would range from 50 to 100 feet from neighboring structures.  I found that a signal was available to my workshop that was equal in strength to the one from my home.
The one thing missing from the instructions is to hold the detector vertical and by the bottom to avoid shielding the antenna and missing signals.  With the quick scan time and easy refresh you can determine the optimimum location for best access.
2854009
NETGEAR WAC 720 provides effective and super-fast wireless coverage for small-to-medium business and different other venues, at an affordable price.  Here are some of the main features of this access point:
-Reliable and fast coverage up to 300 feet coverage with 2 streams of 2x2 (transmit and receive) internal antennas with the alternative of adding exterior 2.4GHz/5Ghz antennas.
-Fast concurrent ac mode wireless speeds between 2.4GHz (300Mbps) and 5GHz (867Mbps), which are backward compatible with 802.11b/g/n network devices.  For the fastest speeds AC wireless cards and devices are needed.
-One of the greatest advantage of the NETGEAR WAC720 besides ultra-fast speed, is the ability to connect up to 10 access points in ensemble mode to cover thousands of feet of building space.
-Other features include: Providing high-speed internet access to multiple users, comprehensive security with WPA and WPA2 and MAC address Access List, power over ethernet (802.3af) for ease of deployment, a simple and intuitive graphical user interface, Bonjour Gateway to support Apple devices, 24/7 technical support, and life-time warranty.

-Setup: Follow these basic steps as provided in the quick setup guide.  First, configure your network connected computer TCP/IP settings (IP to 192.168.0.210. and Subnet Mask to 255. 255. 255. 0.) Second, connect the ethernet cable from the WAC720 to your computer and turn on your computer. Third, connect WAC720 to an 12v DC 2.5 A, turn it on, and log in to the WAC720 at the 192.168.0.100 address to do the desired configuration.  If you have a PoE switch you don't need the DC adapter.  All these steps shouldnt take more than 10 minutes.  After the setup, reverse your computers TCP/IP to obtain the DCHP automatically.  Finally, mount the WAC720 to your desired location, preferably on the center of the ceiling.

Performance:  The NETGEAR WAC 720 has been up and running for several days without any problems.  It provides ultrafast wireless to a 50x50 (2500sq. ft.) fellowship hall with the signal going at least 25ft. outside to a playground.  One visible improvement is HD video, which is very fast.  This access point definitely met our expectations, by providing internet access to an area not covered by the wireless router.

One disadvantage is that it did not include the DC adapter and the external antennas, but any 12V 2.5A will work. I definitely recommend this product to anyone looking for the latest in business dual-band high speed wireless internet access.  The price is very affordable ($292.99 right now on Amazon).
(Review by Paul Botica for the NETGEAR F&F Program on 12/22/15)
281409
fabulous fun and quite handy for experimenters...i use mine under GNU/Linux and the gqrx sdr application - installation went smoothly (you'll need to add some ppas, or you can build from source)

just using the short antenna included with the dongle, i was able to quickly and easily pull in local county FM radio and NOAA freqs (see pic)

five thumbs up!

and even better: adding direct_samp=2 to the I/O device string under I/O prefs, then restarting the app, you can do HF scanning (ham  bands) without the need for downconverter!

p.s. do *not* have this dongle anywhere near your transmitter! you'll be sorry!
3840997
I have been using the UAP for several years and have been very happy with it. I decided to try the UAP-AC Lite. It is even better. Easy to setup and I have a great signal in the whole house.

The AC is significantly smaller than the older UAP (see photo). They also gave you more room to connect the wire and redesigned how the wire comes through the unit which is even better. You can tell ubiquiti really pays attention to design.

Great product.
1940762
Mpow has come out with an update generation of these bluetooth earbuds. So this is the update. The sound quality has improved and is a little more bass heavy. Its not comparable to something like Beats when it comes to bass quality, but for only $25-$30, you cant find anything that beats this. The build quality is a little more durable, the design stays relatively identical to the previous iteration and didn't break like the first two pair of the Swifts that I had. Still no carrying case, but the audio quality enhancement is sufficient enough to call it a worthy upgrade.
570672
This radio has taken the wildly popular UV-5R and improved it aesthetically with a stronger case accented with metal faceplate.

Be sure to order a USB programming cable (Compatible with a Kenwood interface if you already have one). Grab the latest copy of Chirp, you will want the most recent nightly build as the release version does not yet support the Plus model. Programming a channel without using the software interface would be incredibly time consuming.

Pros:
Outstanding battery life
Convenient LED flashlight
Multi Color display is surprisingly helpful (background changes to match radio state
Sturdy combination metal/plastic casing
Part 90 Compliant
Price!

Cons:
Not Part 95 Compliant (Yes it is capable of transmitting on these bands)
Belt clip requires a screwdriver to attach/remove
Scanning channels is VERY slow

Please note that the unit is FCC Part 90 compliant but not 95.
This means you can use this radio on Amateur and Business bands to transmit but can only (legally) receive on the FRS, GMRS and MURS services.
3331264
We currently use three of these handheld units and plan to purchase a fourth. Here in rural southwestern Ohio, where there are lots of hills and woods, the 1 watt output of these radios provide a one mile range reliably. While traveling in convoy on long and unobstructed stretches of highway, the range is greater. They are used infrequently and have provided communications for five weekend long events over the past two months. For well under one hundred dollars, I did not expect much. These units exceeded my expectations.
While the manual that comes with the radio is not very detailed, vender support is outstanding. I had a question regarding charging the batteries and received a reply within one business day. They recommended charging for 24 hours when new or totally depleted and overnight for normal daily use. These radios use commonly available rechargeable AA batteries and not the expensive type found on many amateur and commercial handheld radios. In other words, no special order for replacement rechargeable batteries. Also, at need, regular alkaline batteries may be used. (Attempting to charge the alkaline type batteries will damage the unit) The rechargeable batteries supplied work surprisingly well. We keep our transmissions short and to the point and regularly operate for two days and more per charge, especially if we turn them off for the night. These radios are extremely easy on the batteries while receiving and only draw the batteries down appreciably while transmitting.
I hope to acquire the matching Dakota Alert MURS transmitters to provide wireless and portable security at remote locations. Allowing us to monitor the area around the vehicles or camp while in the woods etc.
These radios are not water resistant nor do they provide military grade shock resistance. These radios are not "industrial strength", but neither is the price. They do provide all five of the unlicensed MURS frequencies while many others only provide one or two operating frequencies. They are affordably priced with great customer support from the vendor, Home Controls / Home Security 4 Less. In summary, good value for the money.
2441995
This book is a very refreshing book with a unique approach to radio receiver design.  Don't be fooled by the title, "Building  Your Own Transistor Radios".  This book is almost auto biographic.  It takes many of the author's boyhood experiences with simple crystal radios and relives that experience.  However, with 35 years in the industry and over 70 US patents, he can now gives a much more thorough analysis of how and why the simple crystal radio works and how to improve it.

The author then proceeds to improve the performance of a simple crystal radio.  Covering the analysis of amplifiers, mixers, and filters and using these building blocks to construct his "super radios".  A unique chapter is given on "Inductorless Radios". Using Gyrators as inductors, Mr. Quan shows several radio architectures using op amps to construct gyrators (and thus inductors) and build successful high performance radios.  There is even a chapter on how to make your own signal generators for testing these circuits.

The book can be described as broken into two sections.  The first section for the casual hobbyist who wants to improve his/her understanding of radio receiver design and a second section for the more advanced radio engineer.  The second section on analysis of distortion and noise is more typically taught at the graduate level at most engineering schools.

The Chapters on Software Define (SDR) radios takes the reader from superheterodyne architecture to the present state of the art SDR radio using I and Q of a radio signal.  He goes on the say, "With I and Q you can demodulate anything."  Although one does not need to understand all the trigonometry involved in deriving many of the equations, Mr. Quan takes a step by step approach to the derivations.  This approach is lacking in most radio text books.

Last, Mr. Quan covers a chapter on bipolar noise with real life examples and numerical calculations for common components and configurations.

This is a very refreshing book and most of it can be read not as rigorous college engineering text book but more like a "novel" for the radio hobbyist.
901091
I identified the need over a year earlier. I'm getting a bit older. When we have a fan running in the same room as the TV, I am finding myself missing some spoken dialog. The white noise masks the sound, particularly when the person drops their volume. It's not a problem with my sound system; I'm using a very clean soundbar with subwoofer. The highs are being clearly and crisply transmitted.

To solve the problem I ran a headphone extension cord across the room and plugged in a variety of devices: over-the-ear headphones and in-ear earphones. In each case, I consistently pick up all dialog-- and to my surprise-- gain better stereo placement.

But the extension cord across the bedroom had to go! I started looking into wireless solutions. TDK introduced an excellent sounding wireless headphone/transmitter combo. It uses a lag-free proprietary RF technology. But customers were not happy with the battery-only power-- and the flimsy battery compartment cover. I also prefer standard solutions that allow for interchangeable parts.

Bluetooth seemed like a good idea but my early experiments showed that there was too much lag. It was irritating how out of sync the audio is when watching TV. It took a lot of research before I learned about aptX technology and how some aptX-equipped devices implemented the low latency protocol. Now that I found the appropriate technology, I discovered many products implementing aptX low latency. Which one should I choose?

After reading customer reviews here on Amazon, I concluded that Avantree would probably be the best vendor to buy because they offered a variety of products in this niche. I read comments for their various products and concluded that the Saturn Pro was the most appropriate product. On the TV side, one can provide power continuously if one wants to. (It's rechargeable, but who wants to regularly charge yet another device if you don't have to?). It's lightweight so I can use it with in-ear earphones in bed. It can switch between transmitter and receiver modes in case I decide later to use it in other ways with other audio devices.

Once I discovered that Avantree offered a 2-pack at a lower per-unit cost, I clicked on the "Add to cart" button and sighed in relief. My search was over. But would it work well for me? The customer reviews were strong, so I kept my fingers crossed. I just plugged in the unit (which had already been set to transmitter mode) into my AV Receiver's headphone jack. I took the earphones from my hiking backpack and plugged them into the other unit (already set to receiver mode). Turned on the TV and AV receiver. Powered the two Avantree Saturn Pros. It worked. Immediately. I watched the lips of the TV personalities. There was no discernable lag.

If you're convinced by my experience, just make sure of one very important detail: this product is not equipped for optical audio input or output. So if your TV or home media system only provides HDMI or Toslink outputs, this is not your solution. (And unfortunately this is going to be the case with most TVs these days.)

If you have any of the most common analog audio outputs on your TV, soundbar or audio/video receiver (RCA or phone jacks), this is a viable solution. In the box are cables and adapters for RCA and mini phone jacks on your TV side. So the only reason you'd need to buy an adapter is if your receiver uses the larger old school phone jack.

Because this 2-pack is already pre-paired with switches set, you only have to determine which unit is the transmitter. Look at the slide switch on the Saturn Pro. Plug that unit into your TV, soundbar or A/V receiver.

Maybe you're only casually interested in this technology. But if you have elderly friends and family members, this solution could bring immense happiness into their lives. And if they live in your home, it might introduce peace and quiet. Or if you're watching TV in bed at night with your mate trying to snooze off, this will bring all kinds of peace into your relationship.