Default polarity H or V

[N0QBH]

Your own design or ?? Info?? Inquiring minds want to know. Maybe it deserves it's own thread??

Yes, it's my own design, although the idea is not new.
In my case, I'd upgraded to digital a few years back and have used the polarity control on my Uniden 4400, since it's also my dish mover.
However, I found scanning in sats this way kinda sucked as I had to made separate entries for polarity.
This device took care of the problem and my channel list was cut in half
I've been programming and designing circuits for many years and finally got around to this one.
I plan to make the circuit available on my website and possibly sell the programmed PIC micro controller chip that runs it.
If someone is interested in doing a pcb layout, we could have a kit.

 

[FaT Air]

I found scanning in sats this way kinda sucked

Me two, too, whichever. Got so tired of it I broke down and put up a LNBF. And also put in a GBox. Guess, I'm L A Z Y.

 

[pitman1]

@ fat air, what would I need to do to upgrade to an lnbf? does it have to be tied to the gbox? Is this the same as the bullseye feed Ive read about?

 

[FaT Air]

The LNBF is polarity switched via the lnb voltage supplied the FTA box. No servo! Nothing to do with the Gbox which only does the dish moving chores. Gbox takes diseqc commands from the receiver that select a programmed position in the Gbox. Satellite selection and polarity all controlled by the FTA box. 1 remote does it all. If analog reception is also desired, slave it to the FTA box's loop out with a DC Block.

 

[pitman1]

so if I am now using a single pass voltage 2 way splitter and not sending any voltage to the DBS box would I need to remove that and go with a standard splitter with power passing on both sides? Do they make one of these that accepts C and Ku band lnb's? thanks fat air

 

[FaT Air]

The 741 is C/Ku. Uses 22khz to select band. Single coax to FTA receiver. The FTA receiver selects band and polarity. The new LNBF's are integrated LNB(s) and feed, not requiring separate lnbs. Connect the analog to the FTA receivers Loop Out with a DC Block. Don't need power passing to analog. The analog outputs 18v only. That would lock the LNBF on Horizontal polarity. New LNBF's use 13v for vertical. (old school lnb's need 18v all the time, supplied by analog receiver.)
Hard to say which would perform better. LNBF=No signal loss, the splitter (6db+?), to either receiver. Co-rotor may be more efficient. (???)
For one " of these(New school voltage selects polarity, tone selects band) that accepts C and Ku band lnb's? Would require an Ortho-mode feed with 4 LNB's (2 C band, 2 Ku band) and a 5x4 multi switch (modified to supply 18v to each LNB port). No "pre packaged" units. Assembled individually. That's the "Cats meow" performance wise.

 

[pitman1]

you've said a mouthful for sure - let me re read all of that and see if I can make sense of it.

 

[pitman1]

@ fatair - you first talk about the 741 being for c/ku but at the end you talk about a dual C/ku orthmode. which one would I need to convert?

 

[FaT Air]

741 is "Plug and play" LINK If using an ortho, the multi switch needs modification.

 

[pitman1]

so the analog is kept strictly as a dish mover with no polarity control - is it possible to get an inline dc block, I've only seen a dc block on a splitter.

 

[FaT Air]

You got it. Analog is then only used to move dish. I went the extra step, and replaced the analog with a G-box** to move the dish. Now only 1 remote does all the FTA "chores". **G-box or V-boare the two brands names) Google shopping: DC Block If you have the parts, I've used an aluminum box with two chassis "F" connectors. wiring a 100pf cap between the two.

 

[pitman1]

again thanks you've been really helpful. I'm almost sold on the lnbf idea but I have 1 concern. I occasionally have to revert to some analog ITC channels ie.. when you change your jack arm and need to start all over. how would you find anything without seeing those ITC channels to somewhat let you know where you are at?

 

[phlatwound]

Sorry if I misunderstood your question as I just kinda skimmed this thread but......you would use your FTA receiver and look for the digital transmissions on whatever satellite you are pointed at. These can be ITC or encrypted, doesn't matter for aiming purposes.

 

[pitman1]

no prob, thanks for the input. maybe im missing something here but, I mean when you change your actuator you really don't know where you are. If you had ITC picture available you could slowly move the dish around until you started seeing a picture, that is what I meant. to me it would seem alot harder to search for a signal instead of a picture.

 

[phlatwound]

no prob, thanks for the input. maybe im missing something here but, I mean when you change your actuator you really don't know where you are. If you had ITC picture available you could slowly move the dish around until you started seeing a picture, that is what I meant. to me it would seem alot harder to search for a signal instead of a picture.

As long as you know your dish is tracking the arc it's pretty easy.

You most likely know approximately what sat your dish is pointing at just by looking at it, for instance when it is at zenith (highest point in the arc) it is pointing to a sat near your longitude (93W for me). Dishpointer.com is a great website to use to approximate where your dish is pointing also, check it out if you haven't.

You would have a known hot transponder on the desired satellite selected in your FTA receiver, and watch your quality meter while moving your dish. When you see your Q meter jump, if it is ITC you would see video, if encrypted you would see a "scrambled" message, either way you just adjust your azimuth for max Q. You then know what sat you are on and can go from there.

I started in the analog domain in the mid-90s (and I still move my BUD with an old Toshiba 1820 analog) and I origninally thought exactly as you did, that it would be easier to locate with analog. The guys around here got me lined out pretty quick though, and the rest is history.

There are hundreds of digital tps across the arc that are hot 24/7 (C & Ku), it requires a slightly different approach but it's the way to go.

 

[pitman1]

yes I suppose you are correct. I'm just used to doing it the old fashioned way I guess. I also started out in the mid 90's with a Uniden super 4500 which I still use today. It's hard to imagine that receiver not being a part of the system anymore. thanks

 

[waylew]

You should be able to use the lnbf with the Uniden.This is from the manual for a UST 4600 but it is probably pretty much the same as your 4500.
Press and hold menu button for 4 seconds to get to the INSTALLATION MENU ,press 2 to get RF CONFIGURE menu,for an external switch or lnbf press 3 to change switch to EXT.

When you want to see analog just hook the coax to the Uni .I've always found the 2 shopping channels on 135w a great place to set your skew.Gonna miss them when they go dark,whenever that may be.

 

[pitman1]

really? would the uni send the lnbf the differet voltages to get it to switch back and forth horiz and vert. ? that would be cool. I've always started on the 2 shopping channels also and if you move it over to 133W there is a long standing religious channel on transp. 11 which also helps. thanks

 

[waylew]

Yep.LNBFs have been around for quite a while,so most later model analog receivers have the capability.I don't think there's much difference between the 4500 and 4600 so the instructions I gave you should work.

 

[pitman1]

cool. and I still have my uni manual so I can always refer to that also. great info, thanks. now all I gotta do is buy the lnbf and start testing it out.