# VCR RF output bad signal



## william lan (Nov 1, 2012)

*VCR RF playback interference*

My sony VCR SLV-ED1 tuner via rf signal shows horizontal lines interference on tv. It can record TV programs through its tuner but playback through RF output with horizontal lines interference too. The same recorded material works well with another vcr with the same set up and cables. I suspect the sony RF output signal. Please advise how to remedy or repair. Thank you.


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## octaneman (May 13, 2009)

Hi william Ian


You'll need to open your VCR and inspect the pcb layout for cold solder joints or bloated capacitors. If everything checks out OK, your tuner will require replacement.


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## JimE (Apr 16, 2009)

Please don't start multiple threads for the same subject/problem.


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## Done_Fishin (Oct 10, 2006)

there is every possibility that your rf output is very close to another broadcast that is being transmitted and your interference is coming from there.
I would suggest that you play back a pre-recorded video and see if you have any interference whilst it is playing back. To see if the signal clears up remove the antenna cable to see if there is any difference in signal quality.

Look at the back of your video to see if your RF output is on the VHF band or the UHF band .. VHF used to be around channel 2 or 4 whilst UHF was in the region of Channel 36 and adjustable. It may well be that you need to adjust to another channel that has no other transmitters broadcasting on or near it.


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## william lan (Nov 1, 2012)

Done_Fishin said:


> there is every possibility that your rf output is very close to another broadcast that is being transmitted and your interference is coming from there.
> I would suggest that you play back a pre-recorded video and see if you have any interference whilst it is playing back. To see if the signal clears up remove the antenna cable to see if there is any difference in signal quality.
> 
> Look at the back of your video to see if your RF output is on the VHF band or the UHF band .. VHF used to be around channel 2 or 4 whilst UHF was in the region of Channel 36 and adjustable. It may well be that you need to adjust to another channel that has no other transmitters broadcasting on or near it.


Thank you for the suggestion. Yes. The interference persists when played back a prerecorded video but clears off when antenna cable is removed. I prefer the antenna cable to be permenantly fixed as I need to watch one channel while record on another using the VCR tuner. The funny thing is it still records good RF signal which is proven by playing back in another machine.
There is no choice of RF selection at the back of VCR as the VCR is electronically tuned. I have to tune the TV RF to receive the VCR signal. Presently I choose TV channel 0 and channel 13 to watch VCR playback. Does it make any difference if I choose different TV channel to tune to VCR?


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## Done_Fishin (Oct 10, 2006)

Most videos I ever worked on / repaired had a switch if they worked on VHF RF output or a trimmer if the RF output was on UHF 

VHF if memory serves me correctly was channel 2 changeable to Channel 4 whilst UHF was preset to Channel 36 UHF but adjustable from about channel 30 to channel 40 using the trimmer.

The adjustment was made at the back of the VCR by the RF in / out BNC's and also had a "TEST" switch which put vertical white bars out on the RF channel selected in order to "spot" the channel being broadcast & fine tune the TV to the channel.




















in the case of a VHF modulator flip the switch and retune your TV to the VCR on the new Channel .. 

if you have the UHF modulator try searching for a channel without the VCR running slightly up & down from the current channel looking for a channel with minimum interference. then power up your VCR and adjust the output using that trimmer to the channel that you have just found. It will be much easier if you operate the test signal switch to give out those "Bars" I mentioned earlier or play back a tape without your aerial input connected.


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## william lan (Nov 1, 2012)

Done_Fishin said:


> Most videos I ever worked on / repaired had a switch if they worked on VHF RF output or a trimmer if the RF output was on UHF
> 
> VHF if memory serves me correctly was channel 2 changeable to Channel 4 whilst UHF was preset to Channel 36 UHF but adjustable from about channel 30 to channel 40 using the trimmer.
> 
> ...


Thank you for taking much trouble to post images to help solve my problem.
At the back of VCR, apart from RF in and RF out, there is a switch to choose PAL/NTSC. In front of the machine there is a button for 'one touch tuning RF channels' which I am trying out to work around with the downloaded manual. Every time I press the button it requests to 'wait'. I presume it searches the channels automatically.
Other buttons are 'color system', 'easy timer', 'program' with 'tracking'


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## Done_Fishin (Oct 10, 2006)

Can you give me a link to the manual you downloaded .. the one touch button is only for programming the VCR with all stations that can be found and would normally have nothing to do with programming the RF out


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## william lan (Nov 1, 2012)

Done_Fishin said:


> Can you give me a link to the manual you downloaded .. the one touch button is only for programming the VCR with all stations that can be found and would normally have nothing to do with programming the RF out


Exactly that one touch button is to auto tune programs on the VCR. Anyway, the link is as follow. regards.

SONY SLV-ED1,4,7,8PL Service Manual free download, schematics, eeprom, repair info for electronics


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## Done_Fishin (Oct 10, 2006)

Sorry for the delay in response .. the manual you linked me to was a very simple service manual and not a user manual .. in fact I was unable to find a user manual for the VCr but I did find another more comprehensive service manual which only states that you should set your RF out to either Channel 3 or 4 depending upon which one is being used by any broadcasting station. basically this means that the output is fixed and that you should use channel 3 if channel 4 is in use by a station or vice versa. If both are being used pick the one that gives you best reception. 

Since this problem only showed up recently it could be that a new broadcaster has come on the scene or that the RF modulator has developed a fault allowing that interference to appear. During y searches for a solution to your problem it came to my attention that you have been searching yourself quite well but without much success. 

Possibilities that you might want to consider if you have a friend who is an Electronics Technician .. 

1. try replacing the RF modulator with an exact replacement

2. try replacing the RF modulator with a similar modulator that has a UHF output (assuming that your TV can receive UHF signals). This might mean that you would have to "hang it outside the VCR" , after removing the old one, for testing purposes.


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## william lan (Nov 1, 2012)

Obviously you have helped narrowing down my problem. I will try out what you have suggested. Changing a new RF modulator is one of the options. I would get a friend for a second opinion before proceeding to purchase a RF modulator. Thank you for the patience and help. I appreciate it very much.


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## Done_Fishin (Oct 10, 2006)

Glad to have been of service & help. Let us know the outcome if you manage to solve the problem.

:wave:


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