Profile for JM > Reviews

Personal Profile

Content by JM
Top Reviewer Ranking: 196,960
Helpful Votes: 11

Learn more about Your Profile.

Reviews Written by
JM

Show:  
Page: 1 | 2 | 3
pixel
20pcs Solder Finished Prototype PCB for DIY 5x7cm Circuit Board Breadboard
20pcs Solder Finished Prototype PCB for DIY 5x7cm Circuit Board Breadboard
Offered by CraftStore
Price: £2.44

1 of 1 people found the following review helpful
5.0 out of 5 stars Really useful optional extras for micro-controller boards, 8 Mar. 2015
Verified Purchase(What is this?)
These small PCBs do not have strips but have just the individual holes encircled with copper. This permits maximum flexibility of the use of the holes but one has to be careful to limit the amount of heat from the soldering iron as the copper circles have only small resistance to lifting off the boards.

They are ideal for developing small experimental circuits for use with Arduino and other micro-controller boards as they have an identical pitch with the connectors on these boards. The value is exceptional.


50PCS NE555P NE555 DIP-8 SINGLE BIPOLAR TIMERS IC
50PCS NE555P NE555 DIP-8 SINGLE BIPOLAR TIMERS IC

4.0 out of 5 stars Exceptional Value Timers, 8 Mar. 2015
Verified Purchase(What is this?)
The 50 pieces of the NE555P offers exceptional value for money. My reservations are that the printing on the chips is only just visible and I cannot be sure that these fully comply with the manufacturer's specifications.


BlackBerry Pocket Leather Case for 9720 - White
BlackBerry Pocket Leather Case for 9720 - White
Offered by B2B TRADING
Price: £5.88

5.0 out of 5 stars Good quality Blackberry Case, 8 Mar. 2015
Verified Purchase(What is this?)
This provides extremely usable protection for my Blackberry phone with an optimum amount of padding. The white colour is neutral and allows it easily to be seen.


TP-LINK TL-SF1005D 5-Port 10/100Mbps Unmanaged Desktop Switch
TP-LINK TL-SF1005D 5-Port 10/100Mbps Unmanaged Desktop Switch
Price: £5.86

0 of 1 people found the following review helpful
1.0 out of 5 stars An undeliverable item, 19 Dec. 2014
Verified Purchase(What is this?)
I have been unable to assess this item as I was told it was "undeliverable".


Emartbuy® Vision Slim Line Nokia Lumia 730 Dual Sim / Lumia 735 Compatible PU Leather Horizontal Black Pouch Case Cover ( Size 3XL ) With Belt Clip
Emartbuy® Vision Slim Line Nokia Lumia 730 Dual Sim / Lumia 735 Compatible PU Leather Horizontal Black Pouch Case Cover ( Size 3XL ) With Belt Clip
Offered by emartbuyuk
Price: £3.99

2 of 2 people found the following review helpful
5.0 out of 5 stars An expensive looking case that has a belt loop fitting, 19 Dec. 2014
Verified Purchase(What is this?)
The case fits my Nokia Lumia 735 well. The phone fits snugly while enabling easy insertion and extraction. The leather material is soft and supple and looks more expensive that it is. For me, the all important feature is the belt loop at the back, affording a safe and secure horizontal mounting on a belt.


Oscillator Circuits (Newnes Circuits)
Oscillator Circuits (Newnes Circuits)
by Rudolf Graf
Edition: Paperback
Price: £38.99

4.0 out of 5 stars A Simulating Source for a Large Variety of Oscillators, 1 Nov. 2014
Verified Purchase(What is this?)
This stimulating book covers a wide variety of oscillator circuits using many different active components such as transistors, Op-amps, MOSFETS, TTL and CMOS ICs, Function Generators and even Unijunction Transistors and SCRs. Where sources are involved, these are clearly labelled and referenced at the back. These are frequently amateur radio and electronics magazines and manufacturers' data books. Apart from organising types of oscillators via the use of chapters, there is no fixed format for explaining the action of the circuits. The modes of operation of some are described in great detail whereas others have only a cursory mention. But this is not the point with this book as where it excels is the sheer variety of ideas put forward, such that it acts as more of a cook book promoting experimentation around the given circuits.

There are eight chapters, with such titles as Audio oscillators, Crystal oscillators (a large section of the book), RF oscillators and Voltage Controlled oscillators. The great majority of the circuits use transistors, digital ICs and Op-amps. Some are simple one or two device designs, whereas others, such as a morse code encoder, are just part of a larger circuit. Having tried several of the circuits myself, I have to say that almost all are designed to operate at specific frequencies, especially in the 1 MHz to 100 MHz. range. If the reader has a particular frequency in mind, some experimentation may be needed to alter the oscillation frequency. As has been mentioned earlier, explanation of the circuit design is very variable, so getting a circuit to work can be simple or more involved. Significantly, the writer does offer many helpful additions for some, including formulae and graphs to make it easy to modify the circuits for specific purposes. Interestingly, some designs are labelled "self-starting", so one can glean from that, there are some which are difficult to start!

However, overall, I have never seen such a large and varied selection of oscillator circuits in one volume, that are given in such a practical and interesting way. It is not only a valuable reference for such circuits but also acts a stimulus for ideas. For me it drops a star rating due to the variability of how it treats the different circuits.


Braun Men's Quartz Watch with Grey Dial Analogue - Digital Display and Black Rubber Strap BN0159GYGYG
Braun Men's Quartz Watch with Grey Dial Analogue - Digital Display and Black Rubber Strap BN0159GYGYG
Price: £140.00

3 of 4 people found the following review helpful
4.0 out of 5 stars An impressive analogue and digital watch for the price, 5 Oct. 2014
Verified Purchase(What is this?)
I wanted a watch to supplement to supplement my Longines automatic watch, specifically it had to have an alarm function. Initially, I considered a Casio which had analogue and digital displays, but was unimpressed by the resin casing and low brand status.

This Braun was the same price as the Casio and provides just enough functions to meet most most situations, but without swamping the user with little used facilities and having difficult to navigate menus and sub-menus. Date, Chronometer, Alarm and 24 hour display are all available, together with backlighting for the digital LCD display. It is supplied with Black, Grey or White dials, the digital numerals being in black except for the black dialled one, which are in a light colour. The case is metal and the strap is made of rubber.

I am impressed with the readability of the dial. The three hands are easy to differentiate in dusk conditions but unfortunately the backlighting does little to brighten the digtal display, serving only to change the character colour from black to turquoise. A two year warranty is supplied

Surprisingly, the watch is quite thick and of substantial weight, about the same as my Longines. By contrast, the equivalent Casio is very much a thin featherweight. The only thing that detracts from the quality of the watch is the strap, which, I am sure, will have a usefully long life, but is customised for the watch and is quite thick and difficult to bend. A standard leather strap would have been a good finishing touch. Other niggles are the American style digital date format and the rather abbreviated instructions. But as the menu is logically laid out, has limited menu choices and is almost self-explanatory, the latter is not a problem. The two buttons are quite stiff to operate, but this is a good thing as they are unlikely to be pressed accidentally due to the gyration of wrist movements. The alarm is, by no means, loud, but it is of a frequency to which the human ear is very sensitive so it should be enough to even provide a wakeup call if needed.

Overall, it is a very impressive watch, it has a modern sort of Art Deco style, has good brand status, boasts the most important digital facilities you would expect and is good value for the price. It is a pity about the strap though, but I suppose i will get used to it.


Tower's International Transistor Selector
Tower's International Transistor Selector
by T. Tower
Edition: Hardcover
Price: £11.99

0 of 1 people found the following review helpful
5.0 out of 5 stars A Definitive Transistor Reference Source, 29 April 2014
Verified Purchase(What is this?)
This transistor data reference manual has all one needs to find out the most used characteristics of a transistor. It is comprehensive, covering both the old germanium devices as well as silicon transistors and includes comprehensive listings of European and American numbers, dating back from the earliest devices of the 1950s to those of recent manufacture. The format is extremely readable with the exception of the physical form illustrations and pinouts, placed at the back of the volume. These are rather confusing and time consuming to wade through, and the diagrams are small. However, all the information is there, so it still merits the full five stars. This must be the standard work on the subject.


Nokia CC-3068 Protective Shell Case for Lumia 520 - Yellow
Nokia CC-3068 Protective Shell Case for Lumia 520 - Yellow
Offered by You Want GPS
Price: £3.40

5.0 out of 5 stars Fancy a Psychedelic Mobile Phone?, 20 Mar. 2014
Verified Purchase(What is this?)
I bought this to change the look of my rather mundane white appearance of my Nokia Lumia 520. I was initially somewhat confused as to the definition of "a shell". Was this an add-on cover or did it replace an original part of the phone's casing. It was the latter I was looking for, and the latter it turned out to be. It was a simple task to remove the original and just clip on the new, bright yellow, case. To the stranger, it appears that I now have a new phone and have joined "the jet set". The makeover was well worth the small cost and was easy to fit. A matching case is also available.


Photographer's Guide to the Panasonic Lumix LX5: Getting the Most from Panasonic's Advanced Digital Camera
Photographer's Guide to the Panasonic Lumix LX5: Getting the Most from Panasonic's Advanced Digital Camera
by Alexander S. White
Edition: Paperback
Price: £16.95

4.0 out of 5 stars A well researched book, 20 Mar. 2014
Verified Purchase(What is this?)
This a manual that is thorough in its contents and is easy to understand. Unlike the official dounloaded manual from Panasonic, the functions of the camera are straightforwardly explained such that it is even suitable for bedtime reading. My one reservation is that the photographs, showing certain of the controls, are rather constricted and small, which contrasts with the very clear text. Overall, a very valuable adjunct to the camera which greatly enhances one's enthusiasm for the camera itself.


Page: 1 | 2 | 3