2600A small burst of static / sparkles with switches or moving joystick

[rmzalbar]

Hi all,

 

I've pulled my old Atari out of storage, and gave it a refresh job with all new caps from the Console5 kit, trigger input protection, new jack, new 7805, and the TIA resistor color boost. It's a Rev 12 2600A.

 

Well, on firing it up, it works perfectly, but gives a smattering of interference sparkles visible on the screen when any of the following switches are triggered. is this normal?

 

RESET

SELECT

Joystick 1 or 2, any of the four cardinal directions.

 

Fire button does not do this, nor does any paddle activity.

 

The interference is just an instantaneous blip of a smattering of sparkles, it does not disrupt modulation, it's just visible. This is standard TV RF output to a CRT television.

 

My primary concern is that it is doing something unhealthy and should be filtered out. I understand the 2600's RF output is very weak, and any interference tends to be seen in the display, so that may mean the spikes from the controller/switch input are basically nothing.

 

If it's not a concern, but isn't normal and/or can be fixed, I would be interested in doing that too.

 

I've tried jumping in capacitors across various lines to see if I could change it, including across the capacitors I've replaced just in case I got unlucky and swapped in a bad one. I've also measured my voltage brick (10.5v loaded on the transformer, and 4.998v after the regulator) but no luck so far. Any suggestions?

 

Thank you,

 

It did clean up nice:

Edited May 11, 2019 by rmzalbar

[rmzalbar]

The joystick-induced static went away when I replaced my switchbox/coax F terminator combo, with a direct RCA female-to-male F connector adapter. Excellent picture now (well, excellent for RF anyway.)