Directivo interference with emulation

[cokekid]

I am getting alittle bit of interference with my DirecTivo unit while running emulation.. Im not sure if this is the right place to voice this problem, but i will give it a try... Any one else have this problem? Any solutions?

I see lines going from right to left and if i turn my receiver volume up, i can hear a hiss sometimes.. Never happened on my Sony A2

[BubbaJ]

you could try running a wire with true ground to the chassis of the dtivo.

[BubbleLamp]

How close is the PC to the Tivo/TV/wiring? PC's generate a lot of RF interference.

[peters62]

I have my DTivo setting ontop of my computer and have no interference at all it may be your cables I use actuall serial cable between the computer and the emu board I have hear people having problem when they use phone cord as cables no shielding.

[BubbleLamp]

Originally posted by peters62
I have my DTivo setting ontop of my computer and have no interference at all it may be your cables I use actuall serial cable between the computer and the emu board I have hear people having problem when they use phone cord as cables no shielding.

Good point, silver satin phone cord makes a GREAT antenna!!

[cokekid]

My computer is about 3 feet away from it.. and I am using serial cable not phone cord... I am also using monster cable to connect to the receiver.. so I know its not that..

[Tico]

Taken from another site:

Hi FRIENDS --- The simple fact is that emu circuits work with high frequency signals. The harmonics of those signals can extend up into the RF (Radio Frequency) range. The keys to eliminating unnecessary harmonics are multifold.

The first thing is to start with a properly designed emu. Those based on the MAX232 family of chips have transmitter sections with controlled risetimes that meet the specifications of RS 232 (serial port spec). The often misused 1489 chip does not have any transmitter sections. The receiver sections (which are used as poor substitutes for transmitters) do not have controlled risetimes. Signals with uncontrolled risetimes contain a lot of unwanted RF harmonics.

The next step is to minimize the radiation of those harmonics that are left. Shielded cable can help as can Cat 5 cable with the extra conductors grounded at one end only. The goal here is to make the emu to PC wiring into a poor radiating antenna. The 2 piece Stealth wedge boards have a second radiating antenna between the 2 sections. The ferrite donuts that I've mentioned in earlier threads will suppress some RFI (interference) from being introduced into the radiating antenna(s). They can also be used in severe cases to suppress unwanted noise from being picked up by all the other wiring associated with your IRD. Sometimes simply separating (moving wires) potential transmitting antennas from all other possible receiving antennas will solve the problem. Avoid if you can, push on F connectors and the cheaply made, poorly shielded cable assemblies that use them. It should go without saying that all connections should be tight and secure.

Another solution would be to use the S video connection or RCA video jacks if your TV has those connections. Those inputs are usually well filtered from unwanted RFI.

Another path where RFI can sneak into your TV, VCR, or IRD is through the power wiring. The noise filter circuits which are usually included in UPS's (Uninteruptable Power Supplies) can be effective in those cases. Better quality outlet strips such as the Isobar that include noise suppression as well as the more common Transient Voltage (surge) suppression can also help.

The best approach in any unwanted noise situation is to eliminate as much of it as practical at the source. After that, the goal is to minimize the RFI sensitivity of your other equipment to the harmonics that are left over.

I realise that a comprehensive post such as this one is bound to be copied to forums other than *****.com. Permission is granted to repost in complete UNedited form only.

Dr. Bob

[RxMan]

Are you using Pitou? I assume that you have at least the minumum amount of CPU horsepower. I used to get pixelations and microfreezing when I tried Pitou with a 133mhz computer. It runs SLE with no problems at all.

[cokekid]

no im running sle.... it has nothing to do with the program... dunno.. i will check...

[BamaRocket]

In my experience, this is almost always the piece of cable out from the receiver to the TV. If it's one of those push on deals, throw it away. Get a good cable. Solves 99% of these problems.

Good luck

[TheOne]

Originally posted by cokekid
My computer is about 3 feet away from it.. and I am using serial cable not phone cord... I am also using monster cable to connect to the receiver.. so I know its not that..

I would not assume that just because it's monster cable it's not the problem. Monster's great, but not indestructible. I would start by swaping that out first.