Help! Local radio signal coming through my new Yamaha TSR 7810

[marym]

Hi everyone,
I've just installed my 2nd Yamaha TSR 7810 receiver after Yamaha told me to try a replacement. It is replacing an old Onkyo TXSR 804 that was having HDMI issues but it never had this signal bleed through issue. I am less than 1/2 mile from an AM/FM broadcast tower.
We have tried the receiver with individual components, just speakers, speakers 1 at a time, plugged into grounded strip or in the wall. There is a very faint sound when there is only the receiver & speakers, but when we plug in either the cable or the TV (or both) the radio gets a lot louder. Same with the phono.
We are ready to return this second Yamaha unless we can fix this. Yamaha support says we've tried everything so they have no solution.
Does anyone know if there is a brand that's especially not susceptible to this?

 

[vsound5150]

Hi everyone,
I've just installed my 2nd Yamaha TSR 7810 receiver after Yamaha told me to try a replacement. It is replacing an old Onkyo TXSR 804 that was having HDMI issues but it never had this signal bleed through issue. I am less than 1/2 mile from an AM/FM broadcast tower.
We have tried the receiver with individual components, just speakers, speakers 1 at a time, plugged into grounded strip or in the wall. There is a very faint sound when there is only the receiver & speakers, but when we plug in either the cable or the TV (or both) the radio gets a lot louder. Same with the phono.
We are ready to return this second Yamaha unless we can fix this. Yamaha support says we've tried everything so they have no solution.
Does anyone know if there is a brand that's especially not susceptible to this?

You could try a shielded speaker wire it's cheap enough. If you can find one wrapped with foil inside and also the bare grounding wire. The challenging part is finding some place to ground the bare wire, just one end needs to be grounded. The speaker wire may be acting as an antenna any noise jumping on a grounded speaker wire should disappear to ground, in theory it should.

If no solution you may have to consider purchasing separates/pro equipment receiver with balanced (XLR) connections designed for long cable runs and noisy environments.

 

[lovinthehd]

You could try a shielded speaker wire it's cheap enough. If you can find one wrapped with foil inside and also the bare grounding wire. The challenging part is finding some place to ground the bare wire, just one end needs to be grounded. The speaker wire may be acting as an antenna any noise jumping on a grounded speaker wire should disappear to ground, in theory it should.

If no solution you may have to consider purchasing separates/pro equipment receiver with balanced (XLR) connections designed for long cable runs and noisy environments.

You don't ground speaker wire generally (and could be dangerous to your amp), that's a line level interconnect that is shielded/grounded (like XLR, which may give some relief over long distances, not too likely on a short connection like between a separate preamp and amp are normally placed). Some say they've gotten relief from twisted pair speaker wire with strong nearby radio signals. Found this article http://electronics.stackexchange.com/questions/24508/what-does-the-third-wire-on-this-speaker-do

 

[Bucknekked]

for the life of me, I know there is a smartass answer/joke in this situation somewhere.
It involves tin foil hats and dowsing rods.
But I can't seem to put it together.

So whatever the link that lovinthehd sent you suggests, do that while I work on my punchline.

If you can't solve it yourself, and lovinthehd can't solve it, I guess we have to go with these two.

 

[Johnny2Bad]

You get Radio Frequency Interference when you plug into the cable, the TV, or the phono.

All are separately grounded interfaces.

Your solution with the turntable is to experiment with the grounding. There is no "right way" to do it; fear not. Is there a separate ground lead from the turntable to a ground lead on the phono preamplifier on your receiver? Does the turntable have it's own phono preamp built in?

As for the video, you can kill the ground loop with a transformer. Do you connect the cable to your receiver, than connect the receiver to the TV?

An antenna is simply a piece of wire of a certain length. Without going into details, for every radio signal there is a specific length of wire that will act as an antenna. Your first solution, then, is to change the length of the cables you use to connect everything up.

Don't bother with the speaker wires. They are very much unlikely to be the cause of the problem.

 

[TLS Guy]

This is a difficult situation. There are no easy solutions.

Clearly you have some RF coming in from the speaker leads. It is the negative feedback circuit feeding the signal back to the early high gain stages in the power amp. Detection and demodulation occurs because semiconductor junctions if OP amps just like transistors and tubes are among other things diodes. So it acts like an old crystal radio.

This speaker wire issue is easy to deal with. You buy some ferrite rod and wind about 10 turns of copper enamel wire round it. You scrape off the enamel insulation at each end and connect in series with +ve speaker wire at the receiver terminals. You need to make one for each speaker lead.

However it is obvious that the signal input leads are also acting as antennas and the radio signal getting detected and rectified by the input op amp.

The way to deal with that is to shunt the inputs with caps in the range of 1000 to 3000 pF. This shunts the RF signal but is too low a value to cause audio band HF loss.

Now I have a feeling that even the digital leads are picking up this interference. This would mean that the caps will have to be placed right at the first analog OP amp chip input.

This will require skill and experience and void warranty. You can try and sort out the analog connection by placing the cap inside the RCA plugs on the end connected to the receiver.

However in my experience this usually only works when the cap is placed right at the detecting rectifying component. This used to be a much bigger issue in the old tube days. In my student days, my apartment was very close to the main BBC TV mast at Crystal Palace. I got lots of experience getting rid of the TV audio from my amps!

As others have suggested using equipment with a balanced connection might help. You will still need to deal with the speaker issue though.

The unit will have to have perfectly balanced connection and the cable and connector quality high. The whole system depends on the live connections, +ve and -ve being identical through out, so that the signal is picked up equally in the +ve and -ve lines and so perfectly cancelled at the input stage. The problem is that I suspect this RF is getting picked up by the digital interconnects somehow. This is strange and not something I have heard of before.

Lastly these issues are fickle. You would find that some receivers would pick up radio masts that others would not and vice versa.

In the end you will likely have to just send back and order receivers until you find the one that does not pick up detect and rectify this radio transmitter's signal.

The good news is that most receivers will not pick up that signal, but likely you could find a station that would get picked up by every receiver on the planet if it was close by.