# Stereo RF Modulators?



## GnatGoSplat (Feb 22, 2003)

My house has a strange setup where each CATV jack in every room is daisy-chained off an adjoining room via splitter inside the wall box. I decided to take advantage of this strange wiring by connecting my Dishnetwork 301 receiver's RF output to the CATV jack to send the signal to TV's in other rooms.

This works great and the picture is sufficiently clear - not as good as SVideo, but good enough. However, I noticed the RF output from the 301 is mono.

I've seen many RF modulators on Ebay advertised as being stereo, or having stereo input. Indeed, they have separate L & R audio inputs. Does this always mean the RF modulator is modulating a stereo signal that the TV's tuner can decode, or are these RF modulators simply mixing L+R and sending a mono audio signal? One RF modulator in particular I see on Ebay a lot is the Recoton DVD647. Anyone know anything about these, or have any brand/model of RF modulators that DEFINITELY modulate stereo?


----------



## JohnH (Apr 22, 2002)

I have several which have L & R inputs, but none of them are stereo. There are stereo ones available. I do not have a list off hand. The price would be substantially higher than the mono ones.

The Recoton is not likely stereo at the price Amazon has them for
http://www.amazon.com/exec/obidos/ASIN/B00005T3FO/inktomi-ceasin-20/ref=nosim/104-9477210-9135908


----------



## JohnH (Apr 22, 2002)

Some possibles here:
http://www.smarthome.com/av_mod.html


----------



## yomama (Nov 3, 2003)

Actually all VCR, DVR, or SAT receivers have mono RF output. 

I have been looking to get one of these for awhile, and this is the best price I found so far http://www.buy.com/retail/electronics/product.asp?sku=90120322&loc=111&sp=1


----------



## boba (May 23, 2003)

CE labs is Cable Electronics Labs from Garland TX. they are partnered with Motorola I believe to make chips that will be built into satellite receivers for stereo output. That price is a very good price on that modulator.


----------



## GnatGoSplat (Feb 22, 2003)

This is the cheapest one I've found so far.
http://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=15-2525

An owner of one has verified that it does output stereo.


----------



## yomama (Nov 3, 2003)

Great price on that item...I will have to check it out. I will be pleasantly surprised if this does output stereo sound through the RF connection. This would mean it is taking a ch 3/4 modulated, non-stereo RF output from a Sat receiver and turning it into stereo with this device, and then output through the RF in stereo ? While reading the owners manual, I could not see where it indicates as such, as the CE Lab unit does.


----------



## GnatGoSplat (Feb 22, 2003)

I don't think the Radio Shack modulator accepts an RF input. I think you have to plug in either a composite or S-Video cable and regular L & R audio cables to it. It then outputs that as RF. I haven't verified that it's in stereo, but someone on another forum said it does output stereo.

If you're already using the A/V outputs on your receiver like I am, that just means you'll also need some Y-cables.


----------



## yomama (Nov 3, 2003)

GnatGoSplat said:


> I don't think the Radio Shack modulator accepts an RF input. I think you have to plug in either a composite or S-Video cable and regular L & R audio cables to it. It then outputs that as RF. I haven't verified that it's in stereo, but someone on another forum said it does output stereo.
> 
> If you're already using the A/V outputs on your receiver like I am, that just means you'll also need some Y-cables.


BUT, that defeats the purpose of wanting a simple one cable configuration....RG6 coax, for both video AND stereo sound, and I thought that was the OP ? of using the existing CATV jacks and the RF out from the receiver to send to other rooms. Maybe I read the OP wrong :scratchin

Yes the RS unit does have an RF input...at least their manual shows one.
http://support.tandy.com/support_video/doc70/70740.pdf


----------



## rcbridge (Oct 31, 2002)

I dont know if your receiver has more than one set of composite or s outputs. You must use the composite or S video from the receiver and the l/r audio then feed that modulator, take the output of the modulator and feed it through your cable system. 
If it doesn't have 2 sets of composite or s you will need to purchase another device
to split the composite signal.


----------



## GnatGoSplat (Feb 22, 2003)

yomama said:


> BUT, that defeats the purpose of wanting a simple one cable configuration....RG6 coax, for both video AND stereo sound, and I thought that was the OP ? of using the existing CATV jacks and the RF out from the receiver to send to other rooms. Maybe I read the OP wrong :scratchin
> 
> Yes the RS unit does have an RF input...at least their manual shows one.
> http://support.tandy.com/support_video/doc70/70740.pdf


I only need a simple 1-cable RG6 configuration from RF modulator unit to the remote TV in the other room. The number of cables between the receiver and RF modulator is irrelevant, at least to me.

In fact, I don't think it is possible to somehow extract any kind of stereo signal from the mono signal that comes out of the receiver's built-in RF modulator. Basically I won't be using the built-in RF modulator at all and only using the external stereo RF modulator.

I think the RS unit's RF input is only used as an antenna pass-thru.


----------



## yomama (Nov 3, 2003)

GnatGoSplat said:


> I only need a simple 1-cable RG6 configuration from RF modulator unit to the remote TV in the other room. The number of cables between the receiver and RF modulator is irrelevant, at least to me.
> 
> In fact, I don't think it is possible to somehow extract any kind of stereo signal from the mono signal that comes out of the receiver's built-in RF modulator. Basically I won't be using the built-in RF modulator at all and only using the external stereo RF modulator.
> 
> I think the RS unit's RF input is only used as an antenna pass-thru.


Thanks for the clarrification :righton:


----------



## md_paul (Jan 21, 2003)

Based on other units available for sale, the Radio Shack unit seems priced too cheap to have the abililty to encode MTS stereo audio into the RF output. If someone here buys one, please let us know if it actually works! It's an excellent deal if it does. 

- Paul


----------



## SSW_Exposure (Jan 28, 2004)

I would be more confident if the _'One Page Owners Manual'_ for the RS unit actually said "*Stereo RF Output*" somewhere.

I also agree that the RF input is just a 'pass through', as you can not make true stereo from mono. At best you might get something that may be called 'dual channel' (or something of the sort).


----------



## rcbridge (Oct 31, 2002)

GnatGoSplat

I just looked up your receiver, in addition to the RF jack you have composite video and audio outputs which are STEREO, you need to take those composite
outputs (RCA) and feed them to the Stereo modulator mentioned above from Radio Shack or equvilant, take that modulated signal and feed that into your house cabeling and you will have stereo.
If you have any questions you can post here or PM me and I can explain further.


----------



## JohnH (Apr 22, 2002)

yomama said:


> Actually all VCR, DVR, or SAT receivers have mono RF output.
> [/url]


Well, Chaparral built a couple of C band receivers which had MTS stereo on the RF output.


----------



## rodb (Dec 5, 2003)

Channel Plus has 2 different modulators that are stereo. The older 5645 and the newer SVM-24with s video inputs. I believe Radio Shack use to carry these as their high end modulators. I run two of the mono versions, 8 in, 8 out. I like my system, it is very elegant. The 5645 shows up on eBay occasionally but you do pay a premium for stereo.

http://www.multiplextechnology.com/channelplus/index.html

If you decide on one of their modulators do a Google search on the model number to find the best price. Lots charge full retail on these but you can find it for a lot less.


----------



## yomama (Nov 3, 2003)

boba said:


> CE labs is Cable Electronics Labs from Garland TX. they are partnered with Motorola I believe to make chips that will be built into satellite receivers for stereo output. That price is a very good price on that modulator.


This looks like what you are talking about -
http://www.celabs.net/news.html


----------



## GnatGoSplat (Feb 22, 2003)

Just a quick update: I ended up buying one of the Radio Shack 15-2525 RF Modulators. It DOES encode in MTS stereo. The stereo separation isn't that great, if I disconnect the left channel, there is still sound coming out of the left speaker although it's a lot softer than the right speaker. However, it is definitely stereo sound.


----------

