My First Composite Mod

[Hank Rearden]

Getting ready to put the composite mod on a 4-switch that I recently acquired. I've watched a ton of videos and checked out a few installation guides and it looks like something this novice should be able to accomplish.

 

Question: To have a cleaner look, why not remove to the RF modulator completely? I've seen a few people do it but mostly they just cut the pins and break it off or move it aside. In the 2 cases they both seemed to struggle getting it to come off. Why is that? Seems you could also desolder the transistor as well.

 

Also, I have a second unit coming and it has a very static heavy picture. Can someone link me to a troubleshooting guide for that issue? I will pull the whole thing apart and clean it up first then would like to go point by point to get it fully functional again.

 

Thanks in advance!

[mojoatomic]

Replace C242 (C241) .1uf, C243 2200uf 16v, C214 & C207 4.7uf 50v. Check/replace A203 LM7508 voltage regulator, make sure it has a good curve. Check 9v supply, make sure it's close to 9v. Be prepared to replace the RF cable on the unit.

[+Nathan Strum]

Replace C242 (C241) .1uf, C243 2200uf 16v, C214 & C207 4.7uf 50v. Check/replace A203 LM7508 voltage regulator, make sure it has a good curve. Check 9v supply, make sure it's close to 9v. Be prepared to replace the RF cable on the unit.

 

 

Where do you order your parts from? A list of parts with order numbers would be nice to have for people needing to repair their 2600's.

[mojoatomic]

 

 

Where do you order your parts from? A list of parts with order numbers would be nice to have for people needing to repair their 2600's.

Well, mostly large parts houses in my case. I'd be happy to post the part numbers from where I mostly purchase from, but truthfully, it's not cost effective to order that way unless you do it in large quantity. My normal order is 100 caps plus for each value, and then multiples of that for the caps that are used in greater ratios - for example 4.7uf, .1uf, etc - point being, that's where the price break comes in. The 2200uf caps aren't $3 each anymore when purchased in quantity. They will also give vastly superior pricing if you have a business license on file in most cases.

 

That's why I generally post part's with descriptors, so people can source them on their own at vendors of their choosing, but in reading your post, I think I could probably do a better job of it. I'll try to give better descriptions.

 

Here's the breakdown..

 

Normal parts from a HUGE supplier - Digikey, in single repair quantities...

 

All prices are in USD. Index Quantity Image Part Number Description Customer Reference Available Quantity Backorder Quantity Unit Price Extended Price 1

493-14399-ND CAP ALUM 2200UF 20% 16V AXIAL

0

Immediate 1

Lead Time 2.33000 $2.33 2

493-6100-1-ND CAP ALUM 4.7UF 20% 50V RADIAL

2

Immediate 0

0.26000 $0.52 3

1572-1186-ND CAP FILM 0.1UF 10% 250VDC RADIAL

2

Immediate 0

0.36000 $0.72 4

LM7805CT-ND IC REG LDO 5V 1A TO220-3

1

Immediate 0

0.62000 $0.62 Subtotal $4.19 Shipping Estimate Sales Tax unknown Total unknown

 

 

But here's the deal breaker... their only shipping option is -

 

U.S. Postal Service Priority Mail* - -

$7.40

 

 

Total cost? $11.95

 

Which brings me to my next thought... would anyone want these supplied at a cheaper shipped cost, to make these repairs easier? Let me come up with a set shipped price for the US and see if anyone's interested. I need to weigh the parts and double check pricing. Other countries might benefit from local shipping.

Edited February 10, 2017 by mojoatomic

[Hank Rearden]

Replace C242 (C241) .1uf, C243 2200uf 16v, C214 & C207 4.7uf 50v. Check/replace A203 LM7508 voltage regulator, make sure it has a good curve. Check 9v supply, make sure it's close to 9v. Be prepared to replace the RF cable on the unit.

 

Well, mostly large parts houses in my case. I'd be happy to post the part numbers from where I mostly purchase from, but truthfully, it's not cost effective to order that way unless you do it in large quantity. My normal order is 100 caps plus for each value, and then multiples of that for the caps that are used in greater ratios - for example 4.7uf, .1uf, etc - point being, that's where the price break comes in. The 2200uf caps aren't $3 each anymore when purchased in quantity. They will also give vastly superior pricing if you have a business license on file in most cases.

 

That's why I generally post part's with descriptors, so people can source them on their own at vendors of their choosing, but in reading your post, I think I could probably do a better job of it. I'll try to give better descriptions.

 

Here's the breakdown..

 

Normal parts from a HUGE supplier - Digikey, in single repair quantities...

 

All prices are in USD. Index Quantity Image Part Number Description Customer Reference Available Quantity Backorder Quantity Unit Price Extended Price 1

493-14399-ND CAP ALUM 2200UF 20% 16V AXIAL

0

Immediate 1

Lead Time 2.33000 $2.33 2

493-6100-1-ND CAP ALUM 4.7UF 20% 50V RADIAL

2

Immediate 0

0.26000 $0.52 3

1572-1186-ND CAP FILM 0.1UF 10% 250VDC RADIAL

2

Immediate 0

0.36000 $0.72 4

LM7805CT-ND IC REG LDO 5V 1A TO220-3

1

Immediate 0

0.62000 $0.62 Subtotal $4.19 Shipping Estimate Sales Tax unknown Total unknown

 

 

But here's the deal breaker... their only shipping option is -

 

U.S. Postal Service Priority Mail* - -

$7.40

 

 

Total cost? $11.95

 

Which brings me to my next thought... would anyone want these supplied at a cheaper shipped cost, to make these repairs easier? Let me come up with a set shipped price for the US and see if anyone's interested. I need to weigh the parts and double check pricing. Other countries might benefit from local shipping.

I'd be interested in a kit of the recommended parts to fix my static issue. Of course I don't even have it on hand yet but will know for sure next week.

 

On a side note, what type of store would sell parts like these now that Radio Shack no longer exists?

[mojoatomic]

If your looking locally, find out who supplies the local repair shops. In Memphis, where I am, the only one left is Bluff City Electronics. I'll buy there if I'm in a hurry, but they can't compete on price for my normal stock parts.

 

I checked my bulk pricing and shipping cost - I can do the parts for $7 shipped, anywhere in the continental US. Think I'll put an ad in the marketplace tomorrow.

[+Nathan Strum]

Very cool. I'll be sure to take you up on that. (And some of these would be nice, too... if you'd be willing to part with any. )

[mojoatomic]

Very cool. I'll be sure to take you up on that. (And some of these would be nice, too... if you'd be willing to part with any. )

 

Man! You saw those?

 

That was a weird find, up in the loft - forgot all about them for years, who would have known back then that people would need them?? Glad I kept them! Guess I could part with some :-)

 

What I was looking for, I didn't find... But I know I still have them somewhere - about 500 820pf polystyrene audio caps for the 2600.

Edited February 11, 2017 by mojoatomic