Noisy Audio

[Gregb]

I have noticed that when I use one of these low cost RF modulators with a vintage TV they cause a lot of noise in the audio. Is there anyway to get around this or at least minimize it to some degree?
Its not the set because using on older model VCR the audio is crystal clear.
Thanks

Gregb

[Findm-Keepm]

Hum, static, or hiss? Hum is easy - better power supply filtering. Static and Hiss could be harmonics, spurious transmission, or bandwith issues.

I've got a cheapo Radio Shack RF Modulator that gives a herringbone pattern in the picture on tube sets - it's not there on my solid state sets. If I swap the AC plug (pull it out of the socket and rotate 180), the herringbone goes away. Some awful AC filtering I guess, but sound is unaffected - at least to my s**tty ears.

Cheers,

[Gregb]

It's not power supply hum, its like that sound you get on a high contrast picture like text and it follows the video.

Gregb

[Findm-Keepm]

Ah, the buzz of AGC action. Sometimes an inline 3dB or 6dB attenuator solves that easily. I have two 3dB attenuators, left over from a time when the cable company signal would overload the old/cheap Silvertone color sets. We'd place them in line with the cable input (after the cable box) and solve the buzz/bending/contrast shift of overloaded IFs. Worked every time. The older Oak boxes they used here put out 300-800uV of signal, w-a-a-y too much. Try and inline F-fitting based attenuator and see if it helps. You can also make one.

Cheers,