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[aprssig] Ham uses for a 1.2m Ku-band dish?

Scott Miller scott at opentrac.org
Wed Jun 18 05:27:04 UTC 2008


Lots of good info, thanks.  Mine's a 1.2m dish, so not quite the same 
configuration.. looks more like this one:

http://www.truennetworks.com/Images/DISH.jpg

Anyway, I'm off to Croatia, so I'll worry about getting it off the roof 
when I get back.

Scott
N1VG

Greg D. wrote:
> Hi Scott, Stephen,
> 
> My neighbor moved recently, and I rescued their Hughes "DirectWay" Internet dish from the bin (with their permission).  I haven't gotten it totally apart yet, but enough that some initial observations can be made.  I suspect that it's similar to the unit you have, at least as far as the RF side of things is concerned.
> 
> The receive LNB has a sticker on it claiming "11.7-12.2 ghz", so this is a bit outside of the ham band.  Judging from the construction, it looks like it's circularly polarized, and is fed with about a 3/4" round waveguide.  According to another Ham, it appears to have what he called a "ceramic oscillator" or something like that, feeding a mixer for a low-gHz IF.  He guesses the IF out is in the 1 to 2 ghz range.  Since there's not a lot of filtering, and nothing is crystal controlled, we suspect that it should not be too hard to re-tune down to the 10-10.5 ghz range.  It somewhat depends on whether the LO injection is on the high or low side, hopefully low.  He's also worried if the waveguide is the right size.
> 
> The transmit side of things appears to be linearly polarized, and at a higher frequency (guessing by the constrictions in the feed pipe).  I haven't opened the full Tx module (didn't have a Torx screwdriver handy), so I don't know what's under the shield inside.  Outside the shield are a bunch of parts, nothing resembling a transmitter...  Their website talks about it putting out a couple of watts.  
> 
> I haven't opened up the control box yet.
> 
> Some pictures, below.  Any additional hints would be appreciated!
> 
> The whole dish.  Looking on the website, the new ones seem to be round; hopefully, they haven't changed the electronics part...  http://home.wavecable.com/~ko6th/IMG_0115.JPG
> 
> Side view of some of the plumbing.  LNB is at the left, and the back of the feed horn is to the right.  The transmitter is piped in from below.  We are guessing that the lumps in the plumbing between the "T" and the LNB is a filter of some sort, keeping the Tx from frying the Rx.  The crud on the parts is the remains of a rather large wasp nest that was waiting for me inside the plastic hood.  http://home.wavecable.com/~ko6th/IMG_0123.JPG
> 
> Outside of the LNB, with the round flange for the waveguide, and one of the feed probes.  The other one is on the back side of the PCB, coming down from the top (up from the bottom on the next picture).   http://home.wavecable.com/~ko6th/IMG_0131b.JPG
> 
> Inside the LNB, with the cover and shield removed.  The feed is on the right, and we believe the LO is the round doughnut thing just to the lower left of center.  There's a set screw on the shield cover that comes down over the ring, to adjust the frequency.  There's one filter section in the middle that might need tweeking.  The IF comes out the upper left. http://home.wavecable.com/~ko6th/IMG_0130b.JPG
> 
> Transmit module, with the inside shield still on.  Haven't done much analysis on this yet...  Where did I put that Torx?   http://home.wavecable.com/~ko6th/IMG_0132b.JPG
> 
> So, I turn it back to you guys... What should I do with this?
> 
> Greg  KO6TH
> 
> 
> 
> 
> ----------------------------------------
>> Date: Tue, 17 Jun 2008 13:18:00 -0700
>> From: wa8lmf2 at aol.com
>> To: aprssig at lists.tapr.org
>> Subject: Re: [aprssig] Ham uses for a 1.2m Ku-band dish?
>> 
>> Scott Miller wrote:
>>> We're shutting down an office and there's a surplus 1.2 meter Ku-band 
>>> HughesNet dish on the roof.  Is there anything interesting that can be 
>>> done with it in the ham world that'd justify breaking out the rappelling 
>>> gear to take it down?  Not that I've ever really needed a good reason to 
>>> acquire radio gear and/or rappel down buildings...
>>>
>>> Scott
>>> N1VG
>>>   
>> 
>> It would make a seriously long-range WiFi antenna.    Put a waveguide 
>> "Cantenna" or a *Hawking **HWUG1 USB WiFi* "dongle" at it's focus.  The 
>> HWUG1  (details at 
>>  > 
>> is a very useful gadget for these kinds of applications.
>> 
>> 1)     It comes with a half-wave "rubber duck" whip that is removable, 
>> revealing a reverse-polarity SMA jack that lets you easily connect 
>> external gain antennas.   
>> 
>> 2)     Since the device is a USB-connected external radio, you can 
>> locate the transceiver at the antenna and connect it with just a 
>> few-inches-long cable pigtail, and run a USB cable back to the PC. Saves 
>> serious coax loss at 2.4 GHz.
>> 
>> 3)     The device is so small and lightweight that you can Velcro it to 
>> the back of antennas for quick lashups.
>> 
>> 4)     The supporting control software produces an actual real-time 
>> analog RSSI (Received Signal Strength Indicator - i.e. "S-meter") 
>> display calibrated in actual dBM received, instead of the usual crude 
>> cellphone-style 5-bar signal indicator that lags far behind actual 
>> signal changes.  Makes it a LOT easier to aim, tweak and peak 
>> directional antennas. 
>> 
>> 
>> 
>> 
>> --
>> 
>> Stephen H. Smith    wa8lmf (at) aol.com
>> EchoLink Node:      14400    [Think bottom of the 2M band]
>> Home Page:          http://wa8lmf.com  --OR--   http://wa8lmf.net
>> 
>> NEW!   World Digipeater Map
>>   http://wa8lmf.net/APRSmaps
>> 
>> JavAPRS Filter Port 14580 Guide
>>   http://wa8lmf.net/aprs/JAVaprsFilters.htm
>> 
>> "APRS 101"  Explanation of APRS Path Selection & Digipeating
>>   http://wa8lmf.net/DigiPaths
>> 
>> Updated "Rev H" APRS            http://wa8lmf.net/aprs
>> Symbols Set for UI-View,
>> UIpoint and APRSplus:
>> 
>> 
>> 
>> 
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> 
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