My First Atari - Inductor help

[Adran]

So I recently got given my first atari console - a 2600jr - from a mate after getting his main console running and working properly. I consider this a good score as its the first Atari I've seen in my neck of the woods (even checking second hand game shops which had nada). Anyways I ended up with the console, 2 games and 1 joystick and no power cable. 

 

I've since repaired the joystick to have tactile switches in it so it's usable again and made up a power cable to spec and then an adaptor for the rf cable so I could use it as it didnt have the switchbox. 

I've tested the unit and gotten picture and sound, however the picture is snowy/staticy after being tuned to channel 3 @ 61.5MHz, so I tried adjusting the L6 rf inductor and found that the inside part of the inductor you adjust was crumbling. 

I was wondering if anyone had the specs for the inductor in question or the Service Manual for the 2600jr or I wait until I get the composite video mod componets and remove the inductor per  the instructions for my board.

I'm also planning on getting a recap kit from console5 for it as well

 

Many thanks in advance and its nice to be here :3 

 

p.s quality image is from before I played with the RF, which improves it but still isn't great 

[Voxel]

Take a peak here it may help:

 

 

[Adran]

8 hours ago, Voxel said:

Take a peak here it may help:

 

 

 

Do the junior and the regular 2600 use the same inductors though? 

Thanks

[Voxel]

The appearance is different but both have two wires which can be spaced enough to solder, and hot glue can secure.  However it's height that would concern me as the Jr is smaller.

 

From distant memory (very), it's the same circuit design though optimised in the Jr.

 

You'd be wanting 20uH in a video circuit like this and that's a ballpark value. As with a lot of component tolerances you'll need to make adjustments and your inductor is adjustable to allow that compensation in the video circuit.

 

In this case Atari has a 15uH inductor in the VCS, so the max you can go up to is 15uH if you need it.

 

I'd rather cover myself with 20uH, but it's the same basic video circuit so 15uH should work.

 

If you do some research on Inductors you'll see how basic they really are (a coil with a core), that allows DC, and stops AC. It's a choke.  You may decide to source a non Atari part rated at around 15uH based on cost, that fits in the case.  You may even get the confidence to fix the one you have.

 

Wait it out until you find a donor machine, or go with a value of 15uH to 20uH.

[Adran]

6 hours ago, Voxel said:

The appearance is different but both have two wires which can be spaced enough to solder, and hot glue can secure.  However it's height that would concern me as the Jr is smaller.

 

From distant memory (very), it's the same circuit design though optimised in the Jr.

 

You'd be wanting 20uH in a video circuit like this and that's a ballpark value. As with a lot of component tolerances you'll need to make adjustments and your inductor is adjustable to allow that compensation in the video circuit.

 

In this case Atari has a 15uH inductor in the VCS, so the max you can go up to is 15uH if you need it.

 

I'd rather cover myself with 20uH, but it's the same basic video circuit so 15uH should work.

 

If you do some research on Inductors you'll see how basic they really are (a coil with a core), that allows DC, and stops AC. It's a choke.  You may decide to source a non Atari part rated at around 15uH based on cost, that fits in the case.  You may even get the confidence to fix the one you have.

 

Wait it out until you find a donor machine, or go with a value of 15uH to 20uH.

 

Thanks for the help, I appreciate it, I might end up going with a composite mod if the inductor end up too hard to source.