Ku + C together on 7.5ft mesh using quadraport LNBF setup

[i4tas]

Switched out the Norsat dual Ortho setup for a Quadraport prime focus C, Ku LNBF this weekend. After messing around in this hobby for 9 years now, trying offset LNB's and several flavors of BSC621 I'd say the quadraport LNBF is the ideal solution (never tried the Bullseye II). My dual ortho setup was perfectly tuned and pulling in nearly everything a 7.5 foot dish can, so my goal was to adjust the quadraport to the same cband specs and hope the Ku signals would be good enough.

Information on the Quadraport:
http://www.atci.com/simulsats.html
http://www.idyd.com/page/view.asp?code=14&idx=134

4 outputs C-H, C-V, Ku-H, Ku-V. Two power circuits that need 15-24 V. It is designed for simultaneous reception on large dishes, where the LNBF slides on rails. I had to make my own mounting system from aluminum stock. Not much of a scalar ring. Apparently they are made differently for dishes based on focal point and f/D ratio, I have know idea what mine is set for.

I am using a modified Spaun SMS5802NF Compact 5x8 Powered Multiswitch to combine and power the 4 ports.

Results: Everything on Cband seems to be the same. CBS 29860 HD 422 feeds, everything on Galaxy 16, CTV, NBC/Telemundo, GCI on AMC7. Ku has been quite good. Able to get everything on AMC21 and 97W. I even get good Ku on SES-2, WTTG and LPB, come in.

For the most part all transponders will tune in at one exact spot with the actuator/vbox (C and Ku), but I only have 2 or 3 clicks of leeway (dual ortho seemed to be wider beamwidth, meaning 3-5 clicks of leeway).

To do... investigate more signal across the arc, figure out how to weatherproof and power Spaun switch at dish OR investigate stacking solutions and in house power supply for LNBs. SES cband issues... Also noticing lower than normal Strength reading on certain satellites (not signal / quality), thinking there could be issue with cband noise. EDIT: SES-2 issues were azbox / luken related. Still need to adjust a bit more to get CBS 9/10 transponders. Changing out multiswitch for one with lower noise / weatherproof housing.

 

[KE4EST]

Nice project thanks for the pics.

 

[kodaz]

very nice and good pics of that feed.

 

[FaT Air]

The feed side reminds me of the National ADL RP1-CKU feed I used to use. Similar but not exactly
That beast must have set you back some moola.
Reducing Sidelobe reception can sometimes be had by setting the F/D on the feed a bit higher than what is calculated. .36-.4 instead of .34 for example. At the cost of some gain.
UGH. Appears to be not adjustable by what I see.
ref: http://adlfeed.com/fp_feed_pat.htm

 

[kodaz]

does that ku waveguide extend past that first step in the c-band sortof scalar? if so, bout how far?

 

[radio]

I'm not clear on how this would be powered by today's FTA boxes on the 13/18 volts...can you help explain?

 

[Magic Static]

He uses a modified multi-switch to power the LNB(S). I use a modded switch to power 4 PLLs on a Bullseye II. The FTA box can't tell the difference . The multi-switch still senses what the receiver wants and switches to the correct LNB.

 

[radio]

Could this concept work for the older Birdview highblock LNB's where voltage was fed UP the horizontal side only, but always "on?"
These were the later ones, compatible with anybody's receiver. I've always wanted to play with one of these and FTA, but didn't know
if a power/polarity self-switching system could work! I have a bucket with many multi-switches in it....if that can be made to do the same!

Just dreamin' ...probably easier just to get one of the new PLL C-band LNB's and call it done, take Ku off the big dish.

 

[Magic Static]

I'm not familiar with the BV stuff. But yea, all my LNBs are always on.

 

[Titanium]

Same here. Running 18Vdc+ to LNBs at all times.

 

[i4tas]

The C and Ku power systems are independent and are powered via either of their output ports. So any multi-switch will work as it will get the 18 Volts from the H port (no power inserters needed like Bulls Eye 2). As it turns out my modified power inserter is not needed, but I did this because my previous setup needed it.

Yes the Ku waveguide extends into the "sort of scalar" part of the feed, about 80 mm further than the start of the cband feed.

I might try adjusting the focal point by adding longer screws and then counting turns on all four bolts... might be a PITA to do.

 

[Hockeynut]

Nice lookin setup there i4tas..So you see no loss on the tp`s with an SR of 29860 compared to a dual Cband ortho?..Curios how much did this quadraport set you back?

 

[richyrich]

Yes, great project; reminds me of all the waveguide lights the mountains have. In the early days they just used waveguide (expensive)! The 18/14 switch can provide the power inside on the bench; and both to all signal amplifications need to travel both pipes (after you use waveguide x 4 and bring the cable to the other 4 lnb's seperating h/v into the 4 selections) is the solution! The 4 waveguides attach to "siphoning waveguide; each a cut of the 4!

You have to add 4 cuts into the feedhorn; micro error (each size); just like double isolated zorcitals@); all that is added is the diode ssssa class slitter at the switched ! No wonder the diode splitter was now required !! It was desired first!!!

 

[i4tas]

Nice lookin setup there i4tas..So you see no loss on the tp`s with an SR of 29860 compared to a dual Cband ortho?..Curios how much did this quadraport set you back?

Results are mixed right now... IU bball game came in great on sunday (G28 29860 TP). The fronthauls of CBS on G19/G28 were not decoding tonight... CrazyCat and Prof saw the signal around 11 dB which apparently is not enough. I never had the best luck with CBS before either, depending on what TP they transmit my results vary. If my 7.5 footer was and 8 foot dish, i think I would get them.

Adjusted the LNBF tonight with a laser pointer, the only signals that wouldn't lock are the CBS TPs on G19/G28. Will keep on trying, I am very close to decode. Ku is much improved now, really no issues on any satellites that have clear LOS.

I have not noticed these for sale online anywhere. I found mine cheap (under $100) on surplus auction.

 

[richyrich]

Tp's that shoulda been ret. were working the whole time worked for 20 more yeare tp's; the accuracy is directional

 

[primestar31]

Tp's that shoulda been ret. were working the whole time worked for 20 more yeare tp's; the accuracy is directional

You need to spin your keyboard around, and stop typing on it while it's upside-down.

 

[KC9TIK]

It looks to be one expensive and hard to find LNBF assembly but... I like it.