RF Modulator no sound

a_hockeynut

SatelliteGuys Pro
Jan 26, 2006
264
0
Rochester, Minnesota
Wasn't sure where to post this, so trying here.

I have a setup where I want to send a signal from a DVR recorder from downstairs to my TV set upstairs.

I have used an RF modulator to do this with my other TVs, and it worked great. In fact, it still works great with my other TVs, but for some reason I cannot get sound to come through to my new LG LED TV when sending through the RF modulator via the A/V jacks. If I send a coax signal on through, I get sound no problem.

I talked to a guy in Best Buy about it, and he had no clue.

I tried scanning all channels to see if it was because manually defining channel 3 on the LG tv was causing the issue. It scanned in as both an analog 3, and a cable channel 3. However, still no sound when I try sending via the A/V jacks of the RF modulator.

Could it be my RF modulator is only sending mono sound? Do I need a newer RF modulator?

I will try attach a photo of the RF modulator I have.

Anyone have any ideas?

I may try calling LG technical support, and see if they have any ideas.
 

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jayn_j

Press On Regardless
Supporting Founder
Sep 29, 2003
10,691
3,301
Sheboygan, WI
You have three components in the chain and one of them is not passing the audio.

1. Did you connect all three signals to the modulator? Red and white audio in addition to the yellow video? Confirm you are getting video at the TV in this setup.
2. Have you confirmed that the modulator is working with a different TV in this exact setup?
3. You also said that the LG works when you connect the RF output of the recorder directly to the antenna input of the TV.

#1 tests the connection path.
#2 tests the output of the recorder and the modulator
#3 tests the RF input of the TV

I don't see how you would pass all three of these tests and not have audio at the TV. I think something that is not working as you say it is. You are on the right track by eliminating components from the signal path one at a time as that will tell you which one is causing the problem.

Even if the modulator doesn't pass MTS stereo, it should still work passing a mono audio signal. That's not the problem.

I have to ask why you are messing with the modulator though. Why not simply use the RF output of the recorder? You will not get any better signal by making the signal path more complicated.
 

a_hockeynut

SatelliteGuys Pro
Jan 26, 2006
264
0
Rochester, Minnesota
You have three components in the chain and one of them is not passing the audio.

1. Did you connect all three signals to the modulator? Red and white audio in addition to the yellow video? Confirm you are getting video at the TV in this setup.
2. Have you confirmed that the modulator is working with a different TV in this exact setup?
3. You also said that the LG works when you connect the RF output of the recorder directly to the antenna input of the TV.

#1 tests the connection path.
#2 tests the output of the recorder and the modulator
#3 tests the RF input of the TV

I don't see how you would pass all three of these tests and not have audio at the TV. I think something that is not working as you say it is. You are on the right track by eliminating components from the signal path one at a time as that will tell you which one is causing the problem.

Even if the modulator doesn't pass MTS stereo, it should still work passing a mono audio signal. That's not the problem.

I have to ask why you are messing with the modulator though. Why not simply use the RF output of the recorder? You will not get any better signal by making the signal path more complicated.

Forgot to mention, yes, I do get video, just no audio.

I am splitting the coax coming out of the modulator OUT, and the other TV receiving the signal has the video and audio.

Also, the same coax coming into the LG LED TV when the DVR is turned OFF is getting the signal from the coax (the output of my digital TV converter box), and then has video and sound just fine.

I played with it some more this morning, and I do seem to get a clicking sound.

I was hopeful that I could scrap the RF modulator and just hook up to the coax out on my DVR, but that is only pass through (it does not send the DVR signal, it only passes through what is coming on the COAX IN of the DVR). That is why I had the RF modulator in the 1st place.

At this point, I may have to call LG tech support. I had this hooked up to the TV I moved downstairs (a newer plasma), and it worked fine.

It seems my new LED TV is more sensitive. I also thought maybe it was some type of copy protection going on, but it seems the video would be messed up then.
 

jayn_j

Press On Regardless
Supporting Founder
Sep 29, 2003
10,691
3,301
Sheboygan, WI
Yes, the copy protection would affect the video and not the audio.
This is a strange one, and I am sorry I can't really help further. Not sure what is happening.
 

lakebum431

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Have you closely looked at the various audio options on the TV and the DVR? First what type of DVR do you have? There could be audio options that let you chose between the types of audio it is outputting (I know the Dish receivers let you do this (DD, line, etc.). Try each of those options. Second, look for the same type of settings on the TV. See if any combinations make a difference. Without knowing the models of those two components I am not sure what the specific options would be.
 

raoul5788

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Have you tried connecting only the television you are having issues with? Don't split the cable, just go from the modulator to the tv. You might have an issue with the signal being too low to detect.
 

harshness

SatelliteGuys Master
May 5, 2007
16,887
2,929
Salem, OR
As the audio is adjacent to the video in the frequency spectrum, there's very little chance that you're going to get one without the other.

The issue is almost certainly one of TV configuration since the other TV works fine. I'd be looking for something insidious like having the TV set for SAP or having its internal audio disabled.
 

a_hockeynut

SatelliteGuys Pro
Jan 26, 2006
264
0
Rochester, Minnesota
Thanks for all the input.

I tried hooking a DVD player straight into the RF modulator (instead of my DVR). Just get video, No sound.

I tried hooking the coax out straight into the TV (no splitter). Just get video, No sound.

I tried resetting the TV. No change.

I tried LG customer support. They told me since the TV gets sound for everything else, it must be the RF modulator device and I should contact the manufacturer. Ha, I bought this RF modulator like 15 years ago. I told her the RF modulator works on all my other TVs, it has to be the TV. She says TV gets sound for everything else, must be RF modulator. Round and round we went, without any resolution. I asked them to try an RF modulator on the TV in their shop and to let me know their results. Will see if I hear back from them.

I am convinced it is the TV. I have gone through and tried different sound options on the TV, no luck.

For now, I am going to use my HAVA device to pipe my DVR to the upstairs TV, since now I can hook my laptop to the TV upstairs directly with HDMI. It ties up my laptop when we want to watch something I have recorded, but will work for now. I also tried my portable hard drive with recordings from the HAVA, and they played fine on the new TV as well (so I could just transfer my DVR recordings to the portable hard drive and play them on the new TV, thus not having to slave the laptop).

I am tempted to have them try an RF modulator in a retail store on this TV to see if it is just me or the TV. Maybe LG will try it and get back to me.
 

RRich

New Member
Mar 25, 2012
1
0
Nor CA
having same issue with a vizo 22" LED..
my old samsung (5+ years old) worked 100% fine off an RF Modulator...
went to put in new tv and picture fine, sound was 100%garbled - and not audible - so i do get some sound
i even tried "direct connect" to the HDMI port to ensure not a defective TV....it worked flawless.
i even tried to put another cable in back of rf modular ( vs current 50 ft run) ....used a 4 ft wire to no luck
Might have to go back to old tv ?? all i need is a slave off the 'Main tv " in the house...
I tired all the settings on the tv no luck ..i thought it was a shielding issue with the new tv ,,,but that doesnt seem to make sense...
 

harshness

SatelliteGuys Master
May 5, 2007
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Salem, OR
Are you people minding the fact that you can choose whether you're sending on "AIR" or "CATV"???

You must be absolutely certain you've configured both devices for the same type of channels.
 

a_hockeynut

SatelliteGuys Pro
Jan 26, 2006
264
0
Rochester, Minnesota
Are you people minding the fact that you can choose whether you're sending on "AIR" or "CATV"???

You must be absolutely certain you've configured both devices for the same type of channels.

I tried letting the TV scan through everything (AIR and CATV), didn't make a difference.

Ultimately I found a solution by putting the RF modulated signal into my old VCR, and then hooking the VCR A/V cables to my new TV. Strange I know, but it works!

This allows me to not have to switch between my antenna and my RF modulated signal as well, so in the end I was happy with this solution.
 

raoul5788

Studebaker driver
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Dec 28, 2004
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I tried letting the TV scan through everything (AIR and CATV), didn't make a difference.

Ultimately I found a solution by putting the RF modulated signal into my old VCR, and then hooking the VCR A/V cables to my new TV. Strange I know, but it works!

This allows me to not have to switch between my antenna and my RF modulated signal as well, so in the end I was happy with this solution.

Since a vcr has an rf modulator built in already, why not just use it without the other modulator?
 

a_hockeynut

SatelliteGuys Pro
Jan 26, 2006
264
0
Rochester, Minnesota
Since a vcr has an rf modulator built in already, why not just use it without the other modulator?

I am converting my DVR in the basement from A/V to coax, then the coax goes upstairs where normally I had the coax plugged directly into the TV, but now had to come up with this other method such that I can get the signal from the basement to the upstairs TV with both video and sound.

Of course if my DVR had COAX out I would not have to do all this.
 

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