Quote:
Originally Posted by glen4cindy
I actually have this setup working right now. I have a quad LNBF that I am going to hook into a DiSEqC switch this spring to get circular FTA. Right now, just the one cable going out to the motor and the dish. The 2nd receiver is slaved to the first receiver. I leave the rear power switch on both receivers in the ON position. I can use EITHER receiver but not BOTH at the same time. Either receiver can move the dish.
Lets say that receiver #2 is on G10R and receiver #1 is on G25. The first thing that happens whenever I power EITHER receiver on using the front panel ON/OFF or the remote button is the dish moves to whatever was the last sat being watched.
I know this limits my viewing, but, my family does not watch FTA unless I am watching it, and I cant be in two places at once, so there is no chance of overlap.
I've not tried to power both receivers on at the same time because I don't know what the outcome would be. My thinking is that IF I tried to turn #2 on while #1 is on, that #1 would keep any DiSEqC signals from being passed to the dish.
With a quad, only one receiver could move the dish, but, how then would the 2nd receiver know which satellite it was pointed at? For this reason, I have chosen just to slave two receivers, which works great for my setup. |
This topic came up recently in another thread, but I think it deserves more discussion. What is described above depends on doing something that most tvro hobbiests think is a bad idea, and that is to slave receivers without using a DC-block between them. Conventional wisdom basically says that when you have 2 receivers that are trying to send DC-voltage down the coax, sometimes at different voltages, that it is possible or likely to have a conflict between the 2 power supplies, ie one trying to keep the voltage at 13V and the other trying to keep it at 18V. Some people claim that doing this can result in damage to one or both of the receivers, so they recommend using a cheap DC-block between the receivers. I, like most hobbiests, don't know whether any damage to the receivers is possible, but I decided long ago that it sounded safer to just put in the DC-block, and not worry about possible damage.
In the above example, the likelihood of damage might be reduced because both receivers are not powered on at the same time, or at least they aren't supposed to be. I don't know if this reduces the likelihood of damage or not, because you are still feeding voltage into one of the "off" receivers.
However, apparently the above seems to work, so I can't argue with success. But the decision about whether to do that or not should be made with the knowledge that you may be feeding current back into one of your receivers. It should also be made with the knowledge that depending on where your receivers are relative to your TVs, there may be other options that don't involve any risk.
In my case, I slave receivers off other receivers, but I use DC-blocks between them. This means that basically only one receiver can control each dish, and the slaved receivers have to watch whatever satellite/polarity the main receiver is tuned to. This doesn't hamper what I can watch, even though I watch in a different room from the receivers, because I use those RS pyramid remote extenders. It does, however make it a bit complicated to tune the slaved receivers at times though. For example, my main (big) dish is controlled by an analog receiver, I have my Fortec Ultra slaved to this receiver after a DC block. I then have a
Twinhan 1020a slaved to the Ultra, and either a Broadlogic card, a Fortec
Mercury, or a DSR 4200 DCII receiver slaved to the
Twinhan. For the Ultra, before I can tune in any satellite, I have to tell the analog receiver to move the dish and change to the proper polarity. Before I can tune anything on either the
Twinhan or the Broadlogic, 4200 or
Mercury, I need to set the Ultra to either C or Ku, because the Ultra controls the DiseqC switch which chooses the band. It gets a bit complicated at times, but it works, and it works without me needing to ever leave my recliner, which is upstairs in the living room, even though all the receivers are in the basement.
Similarly, my 3' dish has a quad lnbf, and a
SG2100, both of which are controlled by my Fortec Lifetime receiver I slave this receiver to any of the above mentioned receivers, ie either my 2nd DSR4200, or sometimes to the
Twinhan or Broadlogic or
Mercury, again with DC-blocks between each receiver. And again, before I can watch anything via the slaved receivers, I need to first tune the Fortec Lifetime to the proper satellite/polarity. Again, complicated, but it can be done without the need to have multiple receivers controlling the same dish.
I know that in some cases, because of the location of the equipment, that what I do won't work, but I just wanted to suggest that there are usually other options to consider to avoid connecting receivers without a DC-block.
As an afterthought to the above, one might ask, why would I use the slaved receivers if I need to be able to view the main receiver to tune them? Good question, and if I just had 2 equal set top boxes, it wouldn't be logical. But in my case, each of my receivers does something different. I use my
Twinhan for all "quality" viewing and recording, but use the Fortec receivers for casual viewing and TIVO recording, I use the Broadlogic for spectrum scans, and the 4200s for DCII viewing. If I just had 2 STBs, there really wouldn't be any need for slaving. I'd just run the signal from the main receiver to different rooms.
Anyway, just some alternative ideas.