[Mesh] pallet of high gain (11dbi) directional wifi antenna's up for auction

Thu Nov 3 18:50:41 PDT 2016

no if it's a diplexer, it's called a diplexer on both ends.

"The diplexer is a different device than a passive combiner or splitter."

https://en.wikipedia.org/wiki/Diplexer

if it's a splitter, it's described here

https://en.wikipedia.org/wiki/Power_dividers_and_directional_couplers

the devices are very different.  A diplexer divides a port by frequency (above
a certain frequency goes to one port, below goes to the other port) and a
splitter just doubles or halves impedance.

On Thu, 3 Nov 2016, Martin wrote:

> So if it's used on one end it's called a diplexer and a splitter on the
> other but it's the same device under the hood.
>
> Common uses[edit
> <https://en.wikipedia.org/w/index.php?title=Diplexer&action=edit&section=1>]
>
> A diplexer allows two different devices to share a common communications
> channel. Typically, the channel is a long coaxial cable, and a diplexer is
> often used at both ends of the coaxial cable. The plan is feasible if the
> two devices operate on different frequencies. The plan is economical if the
> diplexers cost less than running a second cable.
>
> Diplexers are typically used with radio receivers or transmitters on
> different, widely separated, frequency bands. A single city radio tower
> might have a police department antenna on 460 MHz and a fire department
> antenna on 156 MHz. A diplexer at the top combines the two antenna signals
> to the single coaxial feedline, and a second identical diplexer inside the
> building separates the feedline signals to the two dispatch radios. Some
> diplexers support as many as four antennas or radios that work on different
> radio bands.
>
> Diplexers are also commonly used where a multi-band antenna is used on a
> tower, with a common feedline. The diplexer will split the two bands inside
> the building (such as VHF and UHF systems combined with a diplexer onto a
> common antenna).
>
> On Thu, Nov 3, 2016 at 5:21 PM, Jake <jake at spaz.org> wrote:
>
>> Martin,
>>
>> a diplexer is a device to feed one antenna from two transcievers, since it
>> splits signals according to their frequencies.
>>
>> https://en.wikipedia.org/wiki/Diplexer
>>
>> you might be thinking of a splitter.
>>
>> John, i have a really nice 2.4GHz directional coupler by Narda, it has four
>> ports unlike the slightly similar one in this picture:
>>
>> http://www.recycledgoods.com/media/catalog/product/cache/1/i
>> mage/1000x/af097278c5db4767b0fe9bb92fe21690/n/a/narda-
>> microwave-corp.-3002-30-coaxial-directional-coupler-2.0-ghz-1.27.jpg
>>
>> you can borrrow it if you want, I also have attenuators and stuff like
>> that.
>>
>> -jake
>>
>>
>> On Thu, 3 Nov 2016, Martin wrote:
>>
>> John,
>>>
>>> The coupler you got is probably a diplexer - a device to feed two antennas
>>> with one cable.
>>>
>>> To do the testing that you're thinking of requires a directional coupler
>>> like this: http://www.ebay.com/itm/Mini-Circuits-Coaxial-RF-Direc
>>> tional-Coupler-ZADC-13-2000-1-13dB-SMA-50-Ohm-NEW-/291379146
>>> 740?hash=item43d78ceff4:g:A0IAAOSwqu9U2rgN  The seller claims that the
>>> units were tested to 2800 MHz and worked.  This is a pretty good deal.
>>>
>>> For the noise source you can use one of these: http://www.ebay.com/itm
>>> /DC-12V-0-3A-SMA-noise-source-Simple-spectrum-external-
>>> tracking-source-DY2-/172150915301?hash=item2814fe80e5:g:OaUAAOSwI3RW-t7N
>>>
>>> You don't need a spectrum analyzer - a Hack-RF or similar SDR will do.
>>> Connect the noise source to the directional coupler input and the antenna
>>> to the coupler output.  Attach the SDR to the coupler's coupled port.
>>> With
>>> your favorite SDR software tune your radio to mid-band (2.442 - 2.447
>>> GHz).  Note the receiver power level.  Reverse the antenna and noise
>>> source, repeat measurement.  The larger number is the power delivered to
>>> the antenna, the smaller is power reflected back from the antenna.  You
>>> can
>>> use an online calculator like this http://rfcalculator.mobi/
>>> vswr-forward-reverse-power.html to calculate VSWR.  The ideal VSWR is one
>>> and an antenna with greater than three should not be used.
>>>
>>> Although the antennas are only rated to 2.2 GHz they may be usable at 2.4
>>> GHz.  Check the VSWR.
>>>
>>> The antennas are probably useful for hams (there's a 902.005 MHz through
>>> 927.995 MHz band).  I can ask around and see if there's is any interest.
>>> You might want to put one one ebay and see if there's a market.
>>>
>>> --Martin
>>>
>>>
>>> On Thu, Nov 3, 2016 at 1:14 PM, John Fitz <johnfitzeecs at gmail.com> wrote:
>>>
>>> Dang, well I picked up the pallet of antennas and it looks like they're
>>>> the CELLMAX-EXT-CPU which only cover 806–960 MHz and 1710–2200 MHz :( .
>>>> Hey but on the plus side, they contain tee couplers that are rated for
>>>> the
>>>> full 698–960 MHz and 1710–2700 MHz. I've needed a 2.4Ghz coupler for a
>>>> while now and that alone was worth the minimum bid for me. With one of
>>>> those, a noise source and a spectrum analyzer, I can start characterizing
>>>> Wifi/Bluetooth antennas.
>>>> The antenna design is relatively simple and pretty cool looking. It would
>>>> be interesting to try and simulate the design and see how much would have
>>>> to change in order to extend the range. Also, if anyone wants to build a
>>>> phase arrayed radar system...
>>>>
>>>>
>>>> On Fri, Oct 28, 2016 at 6:57 PM, Marc Juul <juul at labitat.dk> wrote:
>>>>
>>>> Are you sure these cover 2.4 GHz. There are multiple versions of the
>>>>> CELLMAX-EXT and e.g. the CELLMAX-EXT-CPU seems to not cover 2.4 GHz
>>>>> while
>>>>> the CELLMAX-EXT-CPUSE does cover 2.4 GHz:
>>>>>
>>>>>   http://www.commscope.com/catalog/wireless/product_details.aspx?id=151
>>>>>
>>>>>   https://www.tessco.com/products/displayProductInfo.do?sku=396652
>>>>>
>>>>> if we're sure they cover 2.4 GHz then we'd love to get them! I'd pay up
>>>>> to $100 in that case
>>>>>
>>>>> On Fri, Oct 28, 2016 at 4:55 PM, Jake <jake at spaz.org> wrote:
>>>>>
>>>>> pallet of high gain (11dbi) directional wifi antenna's up for auction:
>>>>>> https://www.auctionbdi.com/listings/details/index.cfm?itemnu
>>>>>> m=1158888078
>>>>>>
>>>>>> Fitz says they can probably be won for $25 and i think he's willing to
>>>>>> bid on them for sudomesh
>>>>>>
>>>>>> so if sudomesh wants them, they should tell Fitz how much Sudomesh will
>>>>>> pay for the lot.  140 pounds of antennas.
>>>>>>
>>>>>> Fitz, did you have a datasheet on these antennas?  I believe i recall
>>>>>> they were wideband in the 900MHz and 2.4GHz bands?
>>>>>>
>>>>>>
>>>>>> -jake
>>>>>> _______________________________________________
>>>>>> mesh mailing list
>>>>>> mesh at lists.sudoroom.org
>>>>>> https://sudoroom.org/lists/listinfo/mesh
>>>>>>
>>>>>>
>>>>>
>>>>>
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>>>>
>