DiSEqC & 22KhZ

[elgemcdlf]

I am going to be putting up another 8.5' dish possibly this weekend. I currently have a BSC lnbf on a dish on that end of the property tied to port 1 of an external DiSEqC switch. The latest addition will be feet away from this dish. Can I run a 22Khz switch between the BSC lnbf and the DiSEqC which will be used to switch between the two dishes on that end of the yard? The new addition will be running a standard type feedhorn/lnb combo. Both dishes will be used for C Band only.

[wejones]

Originally Posted by elgemcdlf

I am going to be putting up another 8.5' dish possibly this weekend. I currently have a BSC lnbf on a dish on that end of the property tied to port 1 of an external DiSEqC switch. The latest addition will be feet away from this dish. Can I run a 22Khz switch between the BSC lnbf and the DiSEqC which will be used to switch between the two dishes on that end of the yard? The new addition will be running a standard type feedhorn/lnb combo. Both dishes will be used for C Band only.

Signal wise, even though DiseqC is modulated 22khz, it is not supposed to interfere with 22khz devices, or visa-versa. At least in theory. I guess that's all assuming that the 22khz switch passes 22khz. I have seen problems though with the 22khz switch in a DTV system. 3 sat DTV systems use a 22khz switch to select lnbfs, and once I left DiseqC on, when trying to tune transponders on my DTV dish (actually was tuning GOL or NASA from the Dishnet sats while using the DTV dish), and the video kept going on and off every few seconds. I found out that the DiseqC signals were switching the 22khz switch on and off. I'm a bit confused by that, because I've since seen that the DiseqC signals are stopped once there is a lock, so I'm not sure why they continued.

[lumpkin666]

That should work just fine unless you have something terribly goofy going on outside the scope of a normal setup.

I've got a similar setup at my mother's house and have no probs

[elgemcdlf]

Would there be a preference to which side fo the switch went to which dish? Ie powered side to BSC621-2 or to the lnb or no difference at all?

[lumpkin666]

Since you're using a BSC621-2, it won't matter. The BSC621 (the other model) uses a 22k tone to switch between C and KU, and although you can bypass the tone switch (as I did) and use either a diseqc or tone switch with unique ports to each of the two outputs (although it seems you are bypassing and just using C-Band anyhow). It seemed to me that the C-Band port would not give a good signal when I had it on the 0mhz leg of the 22k switch. Since the c-band side is also the side that you use if you want to use the internal switch (and the internal 22k switch is set to enable the C-Band side with 22k), I'm thinking the 0k tone was confusing the internal switch on the 621. That's not supposed to happen, but that's the only explaination I have for what I was seeing (not that this matters for your scenario, but maybe someone else coming through with the BSC621 standard lnbf will find that info helpful)

So, in short, either leg of the 22k will work for either lnbf.

[wejones]

Originally Posted by lumpkin666

Since you're using a BSC621-2, it won't matter. The BSC621 (the other model) uses a 22k tone to switch between C and KU, and although you can bypass the tone switch (as I did) and use either a diseqc or tone switch with unique ports to each of the two outputs (although it seems you are bypassing and just using C-Band anyhow).

Thanks for clearing that up. I was under the impression that both the 621 and 621-2 used DiseqC... mainly because that is what the "manuals" that you find on the Sadoun web page says. However after reading your post, I notice that the links at the Sadoun page for both 621 and 621-2 both lead to the manual for the 621-2. I looked up the manual for the 621 at
http://www.dmsiusa.com/documents/621-manual.pdf ,
{Even though the first image says 621-2, this is for the 621}
and I see that you are correct about it using the 22khz.

I am starting to wonder how many posts regarding this LNBF (particularly some I've made) have been in error because they were based on this incorrect manual link found at the Sadoun site. Like it seems like Bibber was having problems getting one band???

How did you bypass the switch on C-band? Did you take the lnbf apart? Ie isn't the switch internal? I know you can bypass the Ku side, since it connects via a coax jumper, but I wasn't sure if you could bypass the switch on C-band.

Originally Posted by lumpkin666

It seemed to me that the C-Band port would not give a good signal when I had it on the 0mhz leg of the 22k switch. Since the c-band side is also the side that you use if you want to use the internal switch (and the internal 22k switch is set to enable the C-Band side with 22k), I'm thinking the 0k tone was confusing the internal switch on the 621. That's not supposed to happen, but that's the only explaination I have for what I was seeing (not that this matters for your scenario, but maybe someone else coming through with the BSC621 standard lnbf will find that info helpful)

So, in short, either leg of the 22k will work for either lnbf.

Well, I'm confused by what you're saying above. The manual says 22KHz gives Ku, and the "0" side (which is the absence of the 22khz tone, not the presence of a 0 khz tone) gives C-band. I think the switch will definately give you some insertion loss whichever leg you go through, which is why I asked about how you bypassed it, but I didn't expect it to be that noticable. Some of these switches now say that they have a 2 or 3 db insertion loss, which seems to be a lot. I've not noticed that much loss with my old diseqC switch. I wonder if what you noticed was caused by noise coming in through the un-used Ku switch port?

[lumpkin666]

Originally Posted by wejones

I am starting to wonder how many posts regarding this LNBF (particularly some I've made) have been in error because they were based on this incorrect manual link found at the Sadoun site. Like it seems like Bibber was having problems getting one band???

Yeah, the first one I did last month had me scratching my head before someone pointed out my error by pointing me directly to the main distributor's site where it shows the diff.

Originally Posted by wejones

How did you bypass the switch on C-band? Did you take the lnbf apart? Ie isn't the switch internal? I know you can bypass the Ku side, since it connects via a coax jumper, but I wasn't sure if you could bypass the switch on C-band.

I really didn't bypass it, but I was told by several sources that you simply bypass the internal switch by not connecting the KU side of the switch to the jumper. I am not sure whether the internal switch is "smart" enough that it realizes this or not. I assume that it's really not as smart as we'd hope, and that's why I was having problems on one leg of my 22k switch.

Originally Posted by wejones

Well, I'm confused by what you're saying above. The manual says 22KHz gives Ku, and the "0" side (which is the absence of the 22khz tone, not the presence of a 0 khz tone) gives C-band. I think the switch will definately give you some insertion loss whichever leg you go through, which is why I asked about how you bypassed it, but I didn't expect it to be that noticable. Some of these switches now say that they have a 2 or 3 db insertion loss, which seems to be a lot. I've not noticed that much loss with my old diseqC switch. I wonder if what you noticed was caused by noise coming in through the un-used Ku switch port?

I was typing from memory, so it may have been exactly opposite (the 0k side caused me troubles?) I'm not positive without going out and looking at how things are setup (and that setup is at mom's. I'm using a much more complicated setup of 0/22k ecoda and multiple diseqc and multiple mover arms on my home setup. I still think the loss was due to the fact that I was pushing the opposite khz signal to the C-Band side of the switch, because it got much better when I swapped sides.

[wejones]

Originally Posted by lumpkin666

I really didn't bypass it, but I was told by several sources that you simply bypass the internal switch by not connecting the KU side of the switch to the jumper. I am not sure whether the internal switch is "smart" enough that it realizes this or not. I assume that it's really not as smart as we'd hope, and that's why I was having problems on one leg of my 22k switch.

Oh, Ok. Yeah, I don't think that it is really being "bypassed then, because the signal is still going through the switch. I was hoping that maybe they had some internal jumper that could be moved or something.

Originally Posted by lumpkin666

I still think the loss was due to the fact that I was pushing the opposite khz signal to the C-Band side of the switch, because it got much better when I swapped sides.

What kind of signal problems did you observe? I'm wondering if it may be similar to what I observed with the DTV switch? Ie since I had diseqC commands going down the coax, the signal was turing on and off because the diseqC commands are 22khz. They are supposed to shut off when you get a lock, but for some reason they weren't. But if you're getting a periodic breakup, it could be that the internal switch is just turning on and off, not that the signal is really bad.

[lumpkin666]

My problem was simply that the signal would not lock. It would bounce back and forth from 0 to about 50 very quickly (50 still being low for what it should have been).