Two LNBF alignment question

[Keith Brannen]

We'll I went out last night at 7pm and tried to touch up HTN's mux when it went to the dogs like clockwork. What I ended up doing was messing up my alignment to the max and couldn't get it back where I wanted.

Been there, done that, still haven't learned! In fact, I was out last night myself fighting with SCETV which, until the last week or so, has always been fairly steady at 30 (threshold low 20s or so) and has usually been viewable 80 to 90 percent of the time (in clear/party cloudy weather), has now gone into the toilet. It was jumping between 15 and 30, so out I went, minor adjustments to no avail, and the signal degraded as time went on. Will be out again today, once the signal gets back closer to the 30 mark. As you say, no point in trying to adjust when 12 to 15, unless the dish is way off!

 

[tvropro]

AMC 4 to AMC 1

Well I decided today I had enough with HTN on AMC-4 and now pointed that LNBF at AMC 1. Getting 75 Q on those special channels. I'm happy 6 degree spread and good Q on stuff I want so G-19 and AMC 1 is the ADTH's new home. The bracket works quite well at 6 degrees

At least I won't be watching cliff effect every night. :rant:

 

[tvropro]

Been there, done that, still haven't learned! In fact, I was out last night myself fighting with SCETV which, until the last week or so, has always been fairly steady at 30 (threshold low 20s or so) and has usually been viewable 80 to 90 percent of the time (in clear/party cloudy weather), has now gone into the toilet. It was jumping between 15 and 30, so out I went, minor adjustments to no avail, and the signal degraded as time went on. Will be out again today, once the signal gets back closer to the 30 mark. As you say, no point in trying to adjust when 12 to 15, unless the dish is way off!

I kinda went gonzo again today on my setup. I first decided to see if I could get AMC-1 by sliding the bracket. Low and behold success. Then I said well lets see what happens if I play with azimuth and elevation, did that messed things up so I remembered the position I had the dish in and somehow got lucky and put it back in the right place. Then I left az-el alone and made all adjustments with the feeds and bracket and got things working quite well on G-19 and AMC-1. Then said DON'T TOUCH IT! this time I listened to myself. And went to enter in some manual pids on well you know what.

I have a good spread on the lnbf's now and the screwy AMC-1 skew is opposite of G-19 as seen in the photos. I have to give that bracket points. As it does work and quite well

 

[Keith Brannen]

Then said DON'T TOUCH IT! this time I listened to myself.

LOL! Have said that many times myself (and now and then listened, at least for that day). Usually say that after screwing it up and finally getting back (or close to it) where I started, or where it was best at one time during whole tweaking session!

 

[tvropro]

LOL! Have said that many times myself (and now and then listened, at least for that day). Usually say that after screwing it up and finally getting back (or close to it) where I started, or where it was best at one time during whole tweaking session!

I guess we all have that I think I can make it better mentality. At least for me it can get me in trouble where I spend countless hours correcting my screwups.

Unless a problem arises I think I'm done for a while. I was thinking about realigning my bud again, did it a couple months back. I get 99Q on most and everything is 100% fine. But it's that I think I can make it better little bugger creeping out in my head. Right now I say "Leave It Alone" but who knows that may change down the road.

 

[Mr Tony]

LOL! Have said that many times myself (and now and then listened, at least for that day). Usually say that after screwing it up and finally getting back (or close to it) where I started, or where it was best at one time during whole tweaking session!

done that countless times

 

[tvropro]

The next idea's in my head for that dish will be to skew the entire dish and add a threaded rod elevation adjustment. That would really make it top shelf.

 

[tvropro]

Adjustment screws

Here's an undershot of the bracket to see how easy it is to adjust the cradles on the lnbf for spread.

 

[SatelliteAV]

Remove one of the two securing screws and slightly pan the LNBFs left and right on the reflector. The straight on approach is fine when the LNBFs are in a tighter setting, but you will notice a signal improvement on the wider spacings when the LNBFs can be individually panned to optimize the collection.

 

[Anole]

keep up the good work:

The next idea's in my head for that dish will be to skew the entire dish and add a threaded rod elevation adjustment. That would really make it top shelf.

Now yer talkin' ! - :up
Though, didn't the ADTH dishes come with that?

Couple of years ago, I did some calculations on what thread pitch and how many degrees you got, for a turn of the screw.
If that's well documented and you can find it, maybe it'll give you and your machinist some encouragement.

Also, how 'bout a fine azimuth adjust with a big screw?
That should help ya zero in on the buggers!

 

[tvropro]

Remove one of the two securing screws and slightly pan the LNBFs left and right on the reflector. The straight on approach is fine when the LNBFs are in a tighter setting, but you will notice a signal improvement on the wider spacings when the LNBFs can be individually panned to optimize the collection.

Brian, I actually tried that with my AMC-1 LNBF, it did absolutely nothing, since that one is pushing the limit more (I'm favoring G-19). I think the next step is to get the whole dish to skew and also put a threaded rod for elevation adjustment. Then I need reflector extensions.

 

[tvropro]

Now yer talkin' ! - :up
Though, didn't the ADTH dishes come with that?

Couple of years ago, I did some calculations on what thread pitch and how many degrees you got, for a turn of the screw.
If that's well documented and you can find it, maybe it'll give you and your machinist some encouragement.

Also, how 'bout a fine azimuth adjust with a big screw?
That should help ya zero in on the buggers!

I really like the way my BUD adjusts elevation vs these mickey mouse ku dishes. That's why a threaded rod adjustment like a bud would be tops.

One thing the ADTH has going for it is the massive rim on the reflector, no flex.

 

[Anole]

My mistake, here's the adjuster I was thinking about:

Lak7 shows Bob Jones University dish & elevation adjuster rod:
http://www.satelliteguys.us/c-band-...tures-dish-hunting-2008-a-14.html#post1495561


And while I'm not recommending it . . . (but maybe you can get an idea from ... )
Here is something we came up with in an old conversation with JsatTV for his 1m Fortec dish:

JsatTV and his trouble with elevation adjustment on Fortec dish:
http://www.satelliteguys.us/free-ai...-fortec-star-dish-elevation-2.html#post889050

also:
http://www.satelliteguys.us/free-air-fta-discussion/97232-problems-results-re-fine-tuning-1-meter-fortec-star-dish.html
http://www.satelliteguys.us/free-ai...h-stab-hh-120-motor-tips-lessons-learned.html

 

[tvropro]

Interesting

 

[Anole]

screw that elevator:

The JsatTV/Fortec threaded rod (above) pulled from the top of the dish mount to adjust elevation.
That was needed due to the geometry of the mount and hardware.
It came from a seed of an idea by Bill190 (who we nicknamed: TurbuckleBill) who suggested using a turnbuckle.

Here's a much earlier idea by DirtyShame, back in 2005.
His mount geometry demanded he push from the bottom with his big screw.
Since then, many have improved/refined the idea and posted numerous variations.
I just don't have them bookmarked, but perhaps they'll chime in with links, and give you additional ideas.

 

[tvropro]

Just an update

Been monitoring signals at 6 degree's apart on the new bracket. Been solid with no problems. So I guess the new design was a success.