Observations with a slaved Traxis 3500 to Big Dish

[linuxman]

I saw Sharpee's thread about a Traxis with C-band, but didn't want to hi-jack his thread, so I started this one.

I bought a used Traxis 3500 from Stogie last week and hooked it up as a slave to my 4DTV, partly because I wanted to get used to using it, and partly because I wanted to confirm how well I have that dish set up.

Got everything hooked up and started setting up the Traxis. It is a little different than what I am used to, but I have now learned my way around the setup screens pretty well.

The Traxis likes diseqc 1.0 if you only have 4 ports on the diseqc switch. It doesn't like 1.1 unless you have uncommitted and committed switches.

It also requires that you have LNB on even if the LNBs are being powered by another receiver. With LNB off, the diseqc functions don't work, and you get C-Band signals coming through the Ku side.

I am having another issue with horizontals being scanned in as verticals, and verticals being scanned in as horizontals. A lot of duplicates.

I think that has more to do with the position of the feed-horn. I have mine set at the 10:30 - 4:30 position maybe even leaning towards the 9:00 - 3:00 side which works great with the 4DTV since it has control of the polarity and skew and you can adjust it any way it needs to be. I think, and this is just a thought, that the Traxis looks at it like it is extra skew and reacts accordingly.

I think I will probably have to make the feed-horn a little more towards the 12:00 - 6:00 position to satisfy any DVB receiver that doesn't control polarity. More like an 11:30 - 5:30 position. That would probably eliminate all duplicates.

The problem could be eliminated perhaps if the Traxis had a method to scan one polarity at a time which it doesn't, at least I couldn't find it. To me that is a serious drawback in it's firmware and I will be addressing that with Tim at DMSI.

I got the Traxis for one major reason. It has a pin-point accurate and rock solid meter along with fast and accurate blind scanning. I am getting tired of unhooking my Pansats to go up to the roof to fine tune dishes. I have plenty of old analog receivers that I can take up there to move the dish with the Traxis slaved to it for that job. I might get a spare VBox for that job too.

If all goes as planned, this unit will be slaved to the spun aluminum dish when finished and the pc tuner slaved to it for blind scanning and recording. It will be very easy to unhook and hook back up. Hopefully in another 6 months I will have the Fortec Passion, or the Pansat 9200 for that job, and the Traxis will only be used to fine tune dishes.

On the plus side, the dish seems to be tuned pretty well. It actually works better with Ku than with C-Band. I also was able to input a strong C-Band transponder for IS-9 (PAS9) at 58W and scanned in the channels there. I was surprised to see some actual stuff for the 4DTV there too.

I am not going to make any changes to the dish until I see whether I get the solid Birdview that I am "tracking in the hunt". If I get the solid BV, the perfed BV will be sitting in this spot.

If you think I am incorrect about the duplicate channel issue, or have a different thought, please let me know?

Fred

 

[mikekohl]

Go into the Antenna Setup mode and carefully go down the list of parameters until you get to the bottom. There is a choice of H/V, V or H polarities.
If you set for V or H instead of H/V, it will scan only one polarity as listed,
and label all scanned channels as being on that polarity. You can change it
back to H/V when finished.

Or if your 4DTV or other receiver is actually doing the polarity control,
make a switch to the other polarity by changing the channel on the 4DTV
just as the Traxis receiver's scanning count reaches 49%; in the H/V position it will normally switch from H to V scanning at 50%.

Good luck!

 

[linuxman]

Hey Mike!

Go into the Antenna Setup mode and carefully go down the list of parameters until you get to the bottom. There is a choice of H/V, V or H polarities.
If you set for V or H instead of H/V, it will scan only one polarity as listed,
and label all scanned channels as being on that polarity. You can change it
back to H/V when finished.

I had thought about trying both of those options, but didn't know if you could change the settings on the satellite and then come back to it and change it to something different.

Or if your 4DTV or other receiver is actually doing the polarity control,
make a switch to the other polarity by changing the channel on the 4DTV
just as the Traxis receiver's scanning count reaches 49%; in the H/V position it will normally switch from H to V scanning at 50%.

I had thought about trying that idea too, but was afraid that it might switch at the wrong time.

I will give both options a try and see which works best. It will certainly save me having to re-orient my Co-Rotors.

As always, your advice and knowledge are very much appreciated.

How have you been? Haven't seen you post much lately. Been back to Siberia lately? Would love to read any more stories you might have.

Thanks,
Fred

 

[linuxman]

Okay, I deleted all the channels on G3 C-Band, and all the transponders and tried option 1 above.

In the satellite setup screen I punched the menu to tell it that I only had H available, scanned, went back in and told it that there was only V available, and scanned, then went back in and changed it to both, and all is working well now. No duplicates!

If that process can be accomplished with existing settings, all that needs to be done is set up the steps in the firmware to allow individual polarity scanning of the satellite.

Thanks again Mike,

Fred

 

[Diamond Jim]

Fred,

The first thing to do is set your 4DTV TP on the polarity you want to scan. With the 3618 it would ask you which polarity you wanted. If I wanted to scan H, I would put the 922 on an H TP and set the 3618 on H and scan, then change everything to V and scan again.

On the other hand, the 3688 does not give you an H or V option so I do what was suggested, set the 922 on H and at 50% switch it to V. Seems to work pretty good, both polatities get scanned with no duplicates.

I have found out with the 3688 that on a TP scan it does not make any difference what poliarity it is set on, it will scan what the main reciever is set to. When I scan a TP with the 922 polarity set on V the 3688 will read it on H. I will change it to V just so I will have and accurate reading. When I first got it I was looking at channels I knew were H but the info screen said V. That's when I figured out to set the 3688 to match the 922.

I was told not to pay any attention to the slave, just put the main on the polarity you want.

Clear as mud, right?

 

[linuxman]

HeHe!

Thanks Jim! I think I've got it figured out now. I haven't tried the switchover at 50% yet, but might give that a whirl.

There is always something new to learn with these things.

Fred

 

[Diamond Jim]

Yea, I was all screwed up, so I ask about the same questions. I like the 3688, but the 3618 was more user friendly. The 3688 has what I think are a lot of unecessary steps that were by passed in the 3618. The 3688 is a second generation box and I don't understand why they didn't combine what they had with the 3618 to the new stuff they had for the 3688. They are two completely different boxes. When I got the 3688 it was like I had never done this before. Took about a week to get my s**t together. Now I am like a duck in water.

 

[linuxman]

I know what you mean.

I think you hit the nail on the head when you described un-necessary steps.

But as long as it will get the job done, what's another step among friends.

Fred

 

[voomvoom]

When I scan C-Band on my Pansat using the 4dtv as polarity controller, I have to put the 4dtv on an H polarity first (because the Pansat does H first), and watch the Pansat untill it is through with the H, and then change the polarity on the 4dtv to V, while the Pansat continues to scan (now doing V), and continue to watch the Pansat and when it gets through the V, then switch the 4dtv back to H, while watching the Pansat continue with part 2 of it's scan (now on H) and when the Pansat is through with H then switch the 4dtv back to V and watch the Pansat as it finishes off it's scan of the V side.
"Pheeew....." nothing to it!

Al

 

[linuxman]

Hey Al,

Thanks for the tip! It's been a while since I had one slaved to an analog, and I just have to get used to it again. If I was a newbie, it would be very confusing if I didn't know those channels were duplicates.

Fred

 

[linuxman]

Well I tried the switch-over from H to V while scanning, and I am getting pretty good at doing that and it seems to work with no duplicates.

One thing that I found that I like with the Traxis, is that I can dump all the TPs and channels after scanning very easily so it is possible to scan for "all" and dump everything if nothing is found real quick.

The picture quality is good and switches from PAL to NTSC seamlessly.

Fred

 

[Diamond Jim]

Fred,

I was playing with the 3688 today, which I think is very close to a Traxis, and I tried scanning one FR. I watched the red bar and it stopped at 50 per cent. That tells me if I would have flipped it to the other polarity it would have kept going. This convinces me that changing polarities at the 50% point will have it do both sides on a blind scan.

 

[linuxman]

You are right Jim.

I have been playing with that today, and if you watch closely and change at the 50% mark fast, it will switch over and no duplicates.

Just upgraded to the AC3 fix, and re-scanned AMC3 and the AC3 works perfectly on the PBS channels.

Fred