Just a 1/4 inch does a lot to KA signal strength [Archive]

View Full Version : Just a 1/4 inch does a lot to KA signal strength

bonscott87

04-09-08, 02:04 PM

I'm just posting this to help people that might want to realign their dish. It doesn't take much on the KA sats to improve (or worsen) your numbers on the KA sats.

I had gotten a new Slimline in December to replace a failing LNB on an AT-9 (long story, you can search for my postings if you really want to know). Anyway, putting the dish up in the 15 degree cold and snow was fun to say the least and it wasn't all that steady. A good wind would knock it off alignment. Luckily it's just on a pole in the backyard so swinging it back was easy. Annoying though. I eventually wrapped duct tape around the thing and that kept is from moving other then a couple blizzards.

Now fast foward and it's finally getting warm out. Duct tape has pretty much disintegrated and it's Thunderstorm season. Dish gets out of wack a couple days ago after a strong wind storm.

So anyway I take it all down and tighten it all up properly.

Now to my point....

My trusty old DirecTivo in my patio is my alignment tool as I can see it from the outside. Get a 91 on 101 TP2. Good. Before I really tighten it down I go downstairs and check the HR20 for signals. Eh. Upper 80s/Low 90s for the most part, I've seen better but it's good enough.

But I get to 103c and it's all mid 70s and low 80s. That's bad. I know I can get a LOT better then that.

So I go up and nudge the dish to the left about an 1/8th to a 1/4 inch. The DirecTivo "jumps" up to 93. Not a huge improvement but that's as high as it will go.
I go down to the HR20 and numbers on 101 are all low/mid 90s now. So a decent improvement.

Go to 103c. Holy cow. Solid mid 90s across the board! Tighten that baby down! :hurah:

So that long story was to remind that the KA band is narrow to peak and just a slight tick one way or another can drastically improve your signal strength.

Good luck to you all and your signals.

veryoldschool

04-09-08, 02:20 PM

the fine tuning adjustments are there for just this reason. :)

bonscott87

04-09-08, 02:37 PM

the fine tuning adjustments are there for just this reason. :)

You know, those dither adjustments still confuse me. I've never used them so far. I've either been real lucky or it is possible to tune it in if you try hard enough. Frankly I didn't try all that hard and just slapped it up there and I get mid 90s across the board. Luck perhaps. :eek2:

veryoldschool

04-09-08, 02:58 PM

You know, those dither adjustments still confuse me. I've never used them so far. I've either been real lucky or it is possible to tune it in if you try hard enough. Frankly I didn't try all that hard and just slapped it up there and I get mid 90s across the board. Luck perhaps. :eek2:
I just did a Slimline install and started out "the old way" for the 101. Then I locked down the pole clamp and moved over to 103 and the fine adjustments, where I turned them enough to see a drop off and then the other way to the same drop off and half way back. Work pretty well, so I locked everything down.

Canis Lupus

04-09-08, 04:33 PM

I did this as well. I didn't actually "know" what I was doing, but I did get a few more points "turning some knobs" :lol:

houskamp

04-09-08, 05:08 PM

so who want's to do the math? 1/4" = ?degrees at 22k miles = how far off? :D

veryoldschool

04-09-08, 05:29 PM

so who want's to do the math? 1/4" = ?degrees at 22k miles = how far off? :D
I think the 1/4" is relative to the mast. :lol:

glennb

04-10-08, 09:10 AM

I put my AT9 dish up in October of 2006. I got pretty good signal strengths and called it good. I went back up on the roof last summer and fine tuned it. I went thru the whole fine tuning procedure and followed it to the letter and it really made a difference in signal strengths.

I get a kick out of the people that say - Peak it with one of the satellites and tighten all the bolts. You can do a lot better if you fine tune it.

RobertE

04-10-08, 09:20 AM