my mini bud :-)

Hello
Everybody seems to be putting their two cents worth so here are a couple of pennies more.
I've been using a old convert 1.2m dish I was given 2 years ago the begining of my C-band life.
Have been enjoying every mininute of it. It uses a DMX-741 Lnb C and Ku band, and a modified Sg2100
motor, being that the dish weighs 48 pounds. I won't bore you with the mods to the motor but it does the
job and has proved to be very reliable to say the least. I used the conical scalar ring at first and played with
the standard scalar next. The results I received with the conical were the best of the two but not good enough
for all the Sats. meaning Fox, Reels, and many other low power transponders. I also found there to be a 1/2 degree
spread on some of the Tps. so scanning them in would take a couple of tries by moving the motor left and rigth that 1/2
a degree. I'm sure this is because it is an off set dish an has a little boarder Q than a prime focus dish. Also experimenting with the correct positioning of the Lnb leaves a fine line in receiving a transponder or not.
I did a lot of reading on dish design and scalar rings first thing I found out about the Lnb is the plastic cap that covers
the thoat of the Lnb if removed made a difference of 10 points on the quality reading it depends how dense the plastic
cap material is and with a small dish every db of gain is very important so I replace it with a piece of Kapton material
which now is like a clear window to the signal passing threw.
Next came making my own scalar ring there may be some sceptics out there but I experimented for many hours
trail by fire and came up with a very interesting scalar ring design made from a stainless salid bowl with focial point in
the right position which gathers a lot more energy at the Lnb's focial point making a substancial quality gain on the receiver.
Here are a few pictures so don't give up on your experimenting because you can receive most all the Sat's. with 1.2meter
dish I'm at the 3450 foot level this helps with a clear view. I use a Open box S9 and have and try many others so far this is
the best all round receiver, I have 2 AzBox receivers on the way from China should be here Monday want to try them
to so what they are like $180.00 each deliveried free shipping. Anyway that's my spare change on the subject.

ps sorry spelling that's not my best subject. I guess entering pictures may not be a good subject either I'll try.

Hello again
How do I go about attaching picture files to my text file.
Thanks

Thanks for your Post :-)
After you click on reply, click on the go advanced button and you will see a picture icon that will let you browse on your computer to your pictures.
Im going to take your suggestion and ill remove the plastic cap. Is the plastic cap just there to protect the inner tube from rain or does it have a use?

The cap is just there for rain. Interesting observation though, never thought to pull the cap off as always thought most plastic was pretty transparent to microwaves (it is the plastics with fluoride or chlorine that have dielectric properties that are microwave reactive, plastics that are largely just hydrocarbon have little dielectric effect on microwaves).

Yep, the best spot for me seems to be into scaler--actually closer to 3/4 way to first ring than 1/2. when I pull off the scaler the signal drops pretty quick, can't really push the ring further back much but the rate of change is slow and decreasing Q. Tried a bunch of positions and where I end up is always pretty much the same. The LNB ends up further forward than one would expect too, I set up the mount so that I could move it back at first and ended up reversing everything to get more forward. The focal point is just inside the front end of the tube of the LNB.

Read the Paul Wade stuff on satellite dish scalers and have been thinking of trying a few designs out, measured the standard conical horn scaler of a standard offset Ku band LNB thinking that it might be the better match than just a stepped ring scaler, but from what Wade says (or how I read it anyway) the design of the scaler shapes how much of the edge of the dish you see and a flat scaler should see more of the edge than stepped or conical and so should give the greatest signal. Clearly more is going on than I know right now.

just a update =
i went out to the dish to remove the lnb plastic cap and it didnt change anything in quality.I pushed the lnb towards the dish and the quality droped. i pushed back the conical scalar and it didnt change anything. So i brought back the lnb back even more then the original place that it was at the begining and i pushed the scalar ring right at the edge of falling off.
I got ennought of a quality gain that im getting realz on 91 with a snr of 10 on the s9 openbox :-) i didnt have it before so im happy. im watching event horizon at the moment :-)

I tried removing the cap too--no change in readings.

Gain for a 1.2M dish is about 1.5dB higher than my 1M (1.2/1 squared== 1.44 linear)--so where I have readings around 50 Q I would expect you to get readings around 70 or so. And you should be able to get those sats that you have 40dBm contour or higher. Assuming similar Q meter readings in both boxes of course.

the cap is for more than rain, with out the cap you will have bugs and spiders in it and then you will have a real problem.

can you post a photo of your motor setup, thanks.

Thumbs up to all the posters in this "mini-bud" thread!

Yes a big thumbs up, this is good testing, this is also why I asked for its own section, so this will not get buried the BUD section.

Hi everyone,

I just wanted to update you guys on my c-band project. I successfully switched dishes. My initial reaction to the switch is slightly happy in some areas and slightly dissapointed in other areas.

1st of all i had to order a new tube for the sg2100 motor because the u-bolt mount system for the geosat is not compatible with 42mm tubes.
even with the 50mm tube i got here at fridge i had to add 2 washers and some material around the tube-please see attached pictures.
without the washers the u-bolts were still extremely loose on the 50mm tube.

Now for the result. I got 43 channels on 91w with the geosat compared to 22 with the winegard. but the added channels are mostly 4:2:2 that i cannot watch. I wished to be able to receive fx however i still cannot pick up at transponder. Last night i was able to pick up reelz however after work today I lost the transponder even after bumping the motor some. Maybe it will come back after sunset. But please note that i did not play around lots with the lnb placing. Maybe if i play more with the placing ill be able to add some more power to reelz.
TP 3720 went from 56% max on the winegard to 71% max with the geosat.

On Anik F3 i was able to add 3 channels the cox sports channels that i was not able to receive with the winegard. Also the virgin island 10 channels are a bit stronger so no more pixalation.

I added the 421 lnb last night so i havent had time to do lots of testing but this is the results up till now with the two sats 91 and Anik f3.

I will have to add the spitfire on the side with the av satellite sidecar kit and hopefully ill get some better results then with the winegard

Great photos and a great job on the adapting.

One hint, put the flat washers under the lock washers, it should go, mounting bracket, flat washer, lock washer, nut.

And as for the spacing material is it weather proof?

If not then go get a piece of 2" EMT conduit and cut to length, then (this is a pain to do) you split it down the middle with a hack saw, then you can use it as a spacer, if this still tends to move around you could drill and use a through bolt (2 1/2" x 1/4") this keeps things nice and tight.

Thanks Terry,
your right about the washers thanks for the suggestion, im giving my winegard to my dad and allong with the motor. I have a motor on the way with a 55mm tube that should help allot with the spacing issue. the material on the tube came with the winegard kit, im not too sure why it came with the winegard kit but im sure its weather resistant.

Its 8:40pm now and the reelz tp is now comming in with 90% signal and 25% quality. Thats just with the sun going down. with the kids in bed im going out to try and max out the signal. I love this project :-)

It is fun to see what you can get with this stuff--often a frustration/mystery that you can get some, but you wish for others. Still you do get programing that you would not get on KU band.

And with the right rotor you can do some stellar listening to some of the intergalactic noises from some of the local Quasars, Cassiopeia is one that is fun to listen to late at night.

I had a friend (sorry to say he has passed on) that modified an old 10 footer with a HAM satellite tracking rotor and a multi element antenna, he covered all the sky 360 degrees and 0 to 90 in elevation. this would be fun but the Yaesu G-5500 rotor is big $$$.