signal combiner question

[icstephen]

I am planning on dropping D* in a week or so and am going to use only my SC & FTA setups, I am wanting to connect the FTA & SC seperatly each through a vcr to the tv. Ok here is my question is it possible to put one vcr on chanel 3 & one on chanel 4 and then run them through a combiner (like a perfect vision PVDP3 combiner/diplexer or the Sadoun combiner/diplexer) and then be able to switch between chanel 3 & 4 on the tv to view the respective service? Also it states one port dc pass would this couse a problem for the vcr or is that only for satellite operation?

Thanks

 

[cablewithaview]

I am planning on dropping D* in a week or so and am going to use only my SC & FTA setups, I am wanting to connect the FTA & SC seperatly each through a vcr to the tv. Ok here is my question is it possible to put one vcr on chanel 3 & one on chanel 4 and then run them through a combiner (like a perfect vision PVDP3 combiner/diplexer or the Sadoun combiner/diplexer) and then be able to switch between chanel 3 & 4 on the tv to view the respective service? Also it states one port dc pass would this couse a problem for the vcr or is that only for satellite operation?

Thanks

I've tried something like that before but it didn't work out to good. One interfered with the other. I would probably go an A/B route. Also if your TV has a separate a/v jack, you could switch between it and the RF input. DC pass is for the power to feed back to the lnb/lnbf so you would not want anything between the receiver and the dish.

 

[icstephen]

I was afraid of that, I currently have a 4 channel switch now, but it is a pain in the backside to get up and switch it all the time...oh well I may try it to see how bad it is but I'm sure it wont work. I wish I had the money to get one of those things that allows you to put things on different channels.

 

[cablewithaview]

I have a four channel a/v switch I have to get up and switch but I run it through an a/v sender to another TV so I control everything from one point.

 

[Todd Humphrey]

You can combine 3 and 4 using a signal combiner rated for adjacent channel operation.

http://www.audio-discounters.com/201-030.html

(I am not promoting that company, just using it to show the item)

The devices you are looking at are not intended for combining two adjacent channels. They are intended for combining two freq bandwidths very far apart.

When combining adjacent channels you must filter each to reduce the bandwidth of each, other wise they will interfere with other. This is why you never see adjacent channels being broadcasted in one area. The exception is channel 4 and5, but they are not adjacent on the freq spectrum (go here for more detail http://www.dbsinstall.com/Broadcast/vhf_uhf_freq_list.asp ).

A SC-3 or SC-4 will mix the intended channel into normal off air signals. This is intended to be used to mix any channel 3 or 4 into an off-air antenna system. The pathway carrying the off-air is routed through a freq trap to remove all traces of the desired channel, either 3 or 4. The pathway carrying the mix in channel is routed through a bandpass filter. This only allows the intended channel to pass through thereby removing all signals not 3 or 4.
The two are then mixed, allowing channel three to sit side by side with 2 and 4, or channel 4 is allowed to sit side by side with channel 3.

There are adjustments to control the input level of the desired channel. Both input levels must be close, otherwise you will see some bleed over. These are cheap, and sometimes are not the best option but when they work, it provides a nice convenience.

 

[ctechguy]

I was thinking of doing a similar thing and have read up on a few products. If your receivers are next to each other Channel Vision and ChannelPlus both make devices that would do what you want. They come in different models depending on how many inputs you want and each allows you to choose a channel for each input. I found a link to the channelplus two input which should work for you if your receivers are in the same place. If not you would need two 1 input modules and a combiner. The vhs might work, but i have heard you should leave a gap of channels between the two inputs. ChannelPlus 2 Input Link

 

[AntAltMike]

You can combine 3 and 4 using a signal combiner rated for adjacent channel operation.

http://www.audio-discounters.com/201-030.html

(I am not promoting that company, just using it to show the item)

That product is not a grade of combiner that would satisfy most people in that application. They are basically alternate channel combiners being marketed as adjacent channel combiners to help them sell better. Very few people will bother to return such an inexpensive item.

The cheapest way to combine two satellite outputs into one RF cable is to use the channel 3 or 4 output for one, and an inexpensive UHF modulator for the other(s). There are lots of satisfactory consumer-grade agile UHF modulators available for $40 each, and on eBay you can sometimes find them priced closer to $20 per channel.

 

[Todd Humphrey]

I agree, but the question was

"...is it possible to put one vcr on chanel 3 & one on chanel 4 and then run them through a combiner (like a perfect vision PVDP3 combiner/diplexer or the Sadoun combiner/diplexer) and then be able to switch between chanel 3 & 4 on the tv to view the respective service? "

I answered the question.