Forum

  • http://www.sniffwifi.com/2012/02/wipry-spectrum-is-great-but-its-all.html
    http://newsblaze.com/story/2011091208190200002.pnw/topstory.html

    I would be very cautious about using this device. Ben has a very interesting blog and has raised some important issues here.

    I went on their website and had a look around. Make sure your speakers are turned down if you listen to the ?music? on the video !!

    Under the specifications/Q + A section, we have:

    ?Amplitude Range: -40dBm to +20dBm????!!
    In other words, according to their own specs, - 40 dBm is the minimum signal level that the unit will accept !!

    In order to protect internal circuitry, prevent false readings at high power etc, spectrum analyzers are often fitted with internal attenuators, and sometimes external attenuators are required. That is all fine and valid. However, from the photo, there is no sign of an external attenuator ( a kit is supplied ). As Ben points out, the unit is displaying a power level of greater than 24 dBm. Apart from the obvious AP issue, displaying a power level greater than what their own specs say certainly raises eyebrows.

    If you look at the Q and A section, we have the following:

    ?What is the gain of the supplied antenna?
    The gain of the supplied antenna is +1dBm.?

    That?s pretty scary. If that was a spec from an ?el-cheapo? AP , they may be slightly forgiven, but for a manufacturer of a device that is supposed to be used for accurate measurements, that?s a definite red flag.

    Antenna gain can only be measured relative to another antenna ( isotropic, dipole etc...dBi , dBd etc ). The term ?dBm? refers to an absolute power measurement made relative to one milliwatt in the same measurement impedance.

    They are a step in the right direction with the whole I-Pad business ( cursors are a great idea, ?slide your finger along?, as per the video etc ), but.........

    If ( "If" not being the right word ) they?ve messed up the whole calibration description/marking, that needs to be sorted out ASAP. It?s a real pity. The rest of it doesn't look too shabby at all.

    Dave

  • On a purely "gut feel" way, with no scientific "backup", I often get a feeling for the way things are, by looking at a company's website. One thing that always puts a red flag up for me, is when there is no phone contact or live chat etc:

    http://www.oscium.com/contact

    Now, with some of the big companies, it has gone the other way, as they don't want too many customer enquiries. Using the Internet, you can usually track down a number that is "hidden". Last year, a major, very well known supermarket near us was not paying attention to people removing shopping carts from their location. They ended up near us, littering the place. I ended up taking them back nearly every day. I had called the manager umpteen times, no reply.

    One day, a bunch of little kids got in one and pushed it across a busy road. A car flipped them. They ran away. Called the company and left a message. Nobody replied. Tried calling their corporate numbers, and couldn't get hold of anyone. Dug into the Internet and found the phone number I was looking for. There's always someone who publishes what you need. The first thing the bloke said when I called was "How did you get that number ?". Told him what had happened, and that if I saw one more cart, I'd call the local TV station and say that if anyone's kids got injured due to that company's negligence, "they should sue them into the ground". Within two days, I got a bunch of calls from the manager of the local store....he'd a technical problem with his phone.....they put RF locks on all the carts and had patrols to remove any strays. Their "empire" is still growing by the way.

    Dave

  • We updated the Q&A typo, and although we don't have live chat, we work very hard to quickly respond to all questions (even those that aren't directed at us, such as this post).

  • Can you explain what is going with the power levels mentioned by Ben ? That is a very important issue.

    One of the reasons that I mentioned the contact business is that when I first saw the name of the device, I almost automatically thought it was WiSpy ( a well established product ). It isn't. It's WiPry.

    WiPry, WiSpy.

    I then go on the website and find no phone number, no e-mail, no physical address ( I eventually managed to find all of that after "digging" through the internet ).

    When I find a product named almost identically to another well known and respected product, it certainly raises my "interest" level.

  • Regarding the wider range of Ben's device, the power level is calibrated to a conducted source at the time the product is manufactured, which translates into a slight variance in each unit that is shipped. The unit that Ben was using had a slight wider range than the expectation we set for our customers (which caps out at 20dBm).
    Regarding the power differential, we have requested that Ben exchange his unit out so that we can look into this more. We?d love to be able to help address it.
    Regarding the naming of WiPry, we?ve been awarded a trademark by the US Patent & Trademark office.
    Regarding the address, thank you for the suggestion to add this to our site. At your request, we have added it to our website (on the page labeled about).
    Regarding live chat, although we?ve considered adding this, our accessibly can?t be the issue given that we are having this conversation. If we?re attentive to those that don?t contact us directly (like a comment on a forum), how well do you think we service those that contact us directly?

  • "Regarding live chat, although we?ve considered adding this, our accessibly can?t be the issue given that we are having this conversation. If we?re attentive to those that don?t contact us directly (like a comment on a forum), how well do you think we service those that contact us directly?"

    Well, I don't quite think we can quite make a deductive jump from one to the other, as we are not comparing apples to apples. All marketing and sales departments use tools like "Google Alert" etc to give almost instant notifications if their product is mentioned "anywhere" on the Internet. "Pop-ups" appear on that person's I-phone or I-pod or whatever. They will immediately scan the post and say "Positive or Negative ?". If negative, it doesn't take long for someone from that company to reply on that forum or whatever. There are many people from different manufacturing companies who do not post on this forum, in terms of starting a new topic, but read whatever is said about their company. I have no problems with that. It's the way of the world.

    A forum is a public place, where all sorts of eyes are watching.

    But what about Joe Public who calls up and asks for help ? Nobody is watching that communication exchange. Your responses could be lightning fast, or could be dreadful. Basically nobody would be any the wiser, unless that person decided to communicate that, after the fact.

    So, I don't think we can say that because you guys responded here very quickly, that a person contacting your support group would receive the same speed of response ( and importantly, accuracy of reponse ) etc. It may be that you do indeed provide rapid and accurate service, but one cannot determine that based on responses here, on a public forum.

    Going back to the whole power issue here. You guys have stated that the minimum power level that your unit will accept is ? 40 dBm. Is that correct ?

    Dave

  • Ben Millers blog mentions several dB measurements, quoted to hundreths of a decibel, e.g. -36.25 dB.

    I really doubt that a device this inexpensive can accurately measure to better than 1/2 dB, at best.

    Reporting dB levels to two decimal places is almost meaningless in a practical setting anyway. At WLAN power levels, differences less than 1/2 dB make no practical difference. Especially once the radio is connected to an antenna.

    I am not quite sure about the utility of this device for a WLAN administrator or site surveyor. Its lower sensitivity level is much too high. But if you love to experiment and the input power range meets your needs, it sounds like an excellent investment.

  • Yes, Wlanman, I agree about the decimal places. It is in respect to some other issues that I hope they respond to, one at a time, starting with the specified minimum input level.

    "Amazing
    ...I ripped the package apart in a fury of excitement. It's beautiful. I can't wait to show my professor, the equivalent unit in our lab weighs about sixty pounds.... Thanks Oscium?

    http://www.oscium.com/products/wipry-spectrum-spectrum-analyzer

    The ?equivalent unit?????.

    Dave

  • Our (outdated) Spectrum Analyzer weighs about 50 lbs. and with all the bells and whistles was over $80k new. Still over $50k for the equivalent new gear.

    My WLAN tester was about $42k. . Somehow I don't see anything, including my Wi-Spy that I really like BTW, being equivalent to any true lab gear.

  • Yes, that's correct. To have that statement about being "an equivalent" is not only misleading, it's wrong, period. If you were going to buy a Toyota Corolla and someone put a comment up on the Toyota website saying ?I can't wait to use this ?..the equivalent Ferrari in my garage weighs so much more..."

    A Toyota Corolla and a Ferrari are not the same. Each has it's own niche. Each costs what it costs because of what each can do. You get's what you pays for.

    A small handheld unit is NOT the equivalent of a desktop analyzer, in any way, shape or form.
    This does not mean that one is ?better? than the other etc. They simply cannot be compared like that.
    Spectrum analysis is a complex subject. I?ve worked with analyzers for my entire working career. Ranging from small Anritsu handheld units to large units costing anywhere up to $120,000 dollars for specialized signals analysis. Looking at my logs, I?ve taught over 2,300 people worldwide on the theory and use of a range of different analyzers. I?m still learning about them. One thing I can say for certain is that statements on ?the front page? about ?being equivalent? can put the wrong idea in someone?s head who is perhaps new to the whole subject.

    When someone is not used to how spectrum analyzers work, and exactly what the specifications mean ( and that in itself is a whole complex subject ), statements such as ?the equivalent unit in our lab weighs about sixty pounds....? can be highly misleading.

    I do not like this at all, and would hope that Oscium remove that comment and put something else up instead.

    Each analyzer has features and specifications ( frequency range/accuracy etc etc ). These are always directly proportional to the cost of the box.

    Dave

Page 1 of 3