reversing lnb poarity

[brucedawg1]

reversing lnb polarity

looking for informatiion on reversing the polarity of circular lnbs. From what I have read channels and providers determiine whether its a V or H but its the lnb dielctric placement that has to be changed too change the polarity. I purchaasea T-55 and have my older lnbs from an ecliptical dish. Lookoing for any pictures that show the guts of an lnb or the changes made to the dielectric placement. As far as lnb makes...not positive but one is a focus and digiwave and I think a royal.

thanks

 

[FaT Air]

??? If your LNB's are mounted to a feedhorn, the dielectric plate is in the feedhorn throat. Usually the feedhorn incorporates a servo to move the probe to get the other polarity. Most Ku LNBF's have 2 probes, one for each polarity. Which polarity(probe) is selected is determined by the LNB voltage. In each instance the dielectric plate does not need to be repositioned.

have my older lnbs from an ecliptical dish

Maybe asking what you're trying to do, and the model numbers of your "older lnbs", which could actually be LNBFs, would result in better answers.
O, BTW:

 

[Jim S.]

A T-55 is a toroidal dish with a Gregorian reflector element. Since it has an extra reflector, the handedness of circularly-polarized signals gets reversed. It sounds like he wants to hack up some existing LNBs for a Dish or DirecTV subscription rather than buy the reversed-polarity ones that the dish manufacturer sells.

 

[xtgold]

snip snip here,snip snip there.
there was once a pdf on converting old lnbs.
In my archives somewhere.You had to cut circuit traces and re-wire.

 

[Smith P.]

snip, snip, snip ...

You can't rewire it - have you seen dtv/dish LNBFs inside - see posted pictures in my posts a few years ago? Reprogramming switch matrix chip, but you should have knowledge...

 

[xtgold]

you swap h and v control
the pdf had pics

 

[xtgold]

jpegs

actually it was a series of jpegs and not a pdf.
Original author unknown, type lnb unknown.

 

[Smith P.]

I recall these pictures ...

Definitely not DP type, but looks like as old 'legacy' circular dish LNBF.

Let me get that box with my 'lobotomized' LNBFs ...

 

[SatelliteAV]

If the toroidal dish and a regular circular LNBF and is to be used with a FTA receiver, it is easy just to exchange vertical transponders to be horizontal and horizontal to vertical or erase all transponders and blind scan. No need for modifying the LNBF.

 

[Smith P.]

I think it's not the purpose this time - ppl like to use T-55/90 for support pay TV after FTA.

 

[brucedawg1]

Just had a chance to get back to this message. I have been trying to lock in on one Sat first using a T-55 dish. What I'm trying to accomplish is...... to get 82w,91w,110w, 119w, and 129 in ont. Im using an elevation of 34 shew at 71 and azimuth of 127. Played around with this with a signal meter and i seem to have a signal of 95 percent b no quality.. I have a nano premium receiver using sat 110 and tp of 12282. Im only using one lnb for now to get just one sat in first. The lmb is an emp model N88k Freq 12.2-12.7ghz l.o. 11.25ghz an I.F of 950-1450mhz and the noise is 0.3db. I have been just reversing the tp polarity on the nano from V to H for vaious tp. Signal is always hi but no Quality. Either this lnb wont except the changed polarity or theres more to polarity changing then meets the eye. Anyone getting these sats using a T-55 and what lnbs are you using for each i guess is my question? dont mind buying new if the lnbs work. Cheep isnt always good but again if it works. thanks for any help

 

[Smith P.]

it works for reversed LNBFs

 

[Mikey11]

If the toroidal dish and a regular circular LNBF and is to be used with a FTA receiver, it is easy just to exchange vertical transponders to be horizontal and horizontal to vertical or erase all transponders and blind scan. No need for modifying the LNBF.

best advice here....all you need to do is blind scan....your receiver will set the polarity on its own

 

[Larry1]

What are you trying to receive from these satellites?

What I'm trying to accomplish is...... to get 82w,91w,110w, 119w, and 129 in ont........ I have a nano premium receiver

 

[Smith P.]

What are you trying to receive from these satellites?

Dish and Bell programs, I think the 'nano' employ IKS.