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A little while back there was a heads-up and ensuing discussion on
this list about a 500mW 802.11b/g amplifier that Dick Smith New
Zealand sells. Well I bought one. This is the item in question:
http://www.dse.co.nz/cgi-bin/dse.storefront/40577b840d495de4273fc0a87f99071e/Product/View/XH6825
[1]

I ordered it in early February and received a customer code from the
website but no email confirmation. After a month I just assumed that
the order didn't go through. Then on 10th March it arrived. The
invoice is interesting as it appears I haven't been charged NZ GST on
the item, even though the "tax code" says that I have. I paid NZ$264
for it, which is AUS$240. I also bought a 7dBi magnetic mount antenna
for NZ$40.89 and postage was NZ$25.11. The grand total was AUS$298
charged to my credit card.

The Amp has a RP-SMA connector on the antenna side and a standard-SMA
connector on the radio side. Included is a SMA-to-RP-SMA RG-316
pigtail so you can plug the amp into your AP. The Amp runs on a 6V DC
supply - don't know what the current draw is though. The manual claims
a 17dB increase in transmit gain and a 10dB increase in receive gain.
Interestingly, the Longreach 1 watt amp claims a 15dB increase in
transmit gain and a 16.5 increase in receive gain.

I've been putting the amp through it's paces, and have compared it to
my Longreach 1 watt amp.

I have a Superpass 8dBi omni on top of a 13 metre mast at my node -
Node GMR. It was connected to a SVEC AP inside my house, and I used to
have the Longreach amp inline - in locally powered mode. I shelled
into Node GES and ran Wavemon. He has a 13.5 metre mast with a 25dB
conifer on it pointed at me. We run on Channel 4.

Here are the Figures from Node GES

SVEC/NO AMP

SVEC/LONGREACH

SVEC/DSE-NZ

Link Quality

54/92

80/92

78/92

Signal Level (dBm)

-66

-53

-55

Noise Level (dBm)

-100

-100

-100

Signal-Noise Ratio (dB)

+34

+47

+45

I now use a Minitar as my AP, here are the figures:

Link Quality

78/92

Signal Level (dBm)

-53 (dips into -52)

Noise Level (dBm)

-100

Signal-Noise Ratio (dB)

+47 (dips into +48)

As a control I also ran my laptop in my office with an Enterasys card
(using the internal antenna) and ran Knoppix STD on it. Here are the
wavemon figures:

SVEC/NO AMP

SVEC/LONGREACH

SVEC/DSE-NZ

Link Quality

20/92

28/92

27/92

Signal Level (dBm)

-75

-65

-66

Noise Level (dBm)

-93

-92

-91

Signal-Noise Ratio (dB)

+15

+27

+25

These figures from my office are a bit rubbery because I was sitting
right next to the laptop and there was a lot of fluctuation. I did
stare at the screen for a long time however and wrote down the most
stable figures.

I don't have a SMA-N-type pigtail yet so I can't plug the amp into
any of my cards. So I have yet to run wavemon on an interface that
actually has the amp plugged into it. I plan on doing so soon so I can
get a good idea of the noise figure of the DSE amp.

Any other suggestions for testing? -- DanFlett [2] 170304

Links:
------
[1]
http://www.dse.co.nz/cgi-bin/dse.storefront/40577b840d495de4273fc0a87f99071e/Product/View/XH6825
[2] http://melbournewireless.org.au/?DanFlett

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