Best RF Connection to old TV

[old_tv_nut]

1) Yes, the 75-300 ohm transformer is the correct thing.

2) The signal from your modulator should be strong enough to overcome RF radiated interference, even though the 300 ohm connection is not as well shielded as a coax cable. So, this could require some investigation to see how the interference is getting in.

Regarding going via coax directly to the tuner, it maybe doable, but you need to provide a schematic and/or pictures of what's in the set that connects the 300 ohm screw terminals to the tuner coax input.

Questions: Does the set have separate 300 ohm screw terminals for VHF and UHF? Are you sure you are connecting to the right ones?
Are you sure the tuner has a coax input, or could you be looking at the tuner's IF output cable?

[vol.2]

Thanks

Originally Posted by old_tv_nut

2) The signal from your modulator should be strong enough to overcome RF radiated interference, even though the 300 ohm connection is not as well shielded as a coax cable. So, this could require some investigation to see how the interference is getting in.

Okay. Well I don't get the interference all the time. I usually see it during the day and evening, but if I'm using it late at night it seems to go way. My thinking is this is the time when less people are using devices that might cause interference.

Regarding going via coax directly to the tuner, it maybe doable, but you need to provide a schematic and/or pictures of what's in the set that connects the 300 ohm screw terminals to the tuner coax input.

This is the coax that goes from the VHF tuner to the antenna block. I ohmed it out to the inside of the block, and it connects to the antenna/external switch through a capacitor.




This shows the location on the antenna block where that coaxial cable (from the VHF tuner) goes to:

Questions: Does the set have separate 300 ohm screw terminals for VHF and UHF? Are you sure you are connecting to the right ones?

Yes it does and yes I am. I know how to do all that and I wasn't making any mistake about it.

Here's the antenna block and the VHF tuner: