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The Fisher TA-600 Rebuild Thread

Alright did a bit of soldering after breakfast. Replaced the other (3) 0.1uf coupling caps and the 25uf lytic. Now to move along to another area. I am making a note of the ceramic cap whose lead I broke moving around. That will have to be ordered and replaced at a later time.

I spoke with Tom at Hayseed Hamfest today about the custom can caps for the top. Just need to get him a few more measurements and those will be on order.


Pic of replaced coupling caps.

P1010086.jpg
 
Now I'm going to move on over to the cardboard can cap underneath the chassis.

Here is a before pic of the area I'm working on.

P1010087.jpg


Here's the cluster of caps I put together to replace the old can. Should fit right in there nicely.

P1010088.jpg
 
Finished homemade replacement for cardboard can cap by soldering 47K resistors in place. All that's left to do is insert caps into place and solder appropriate wires to cap leads.

Edit: Forgot to add, the stock can's ratings were 30uf@300V, 30uf@300V, 10uf@200V, 10uf@200V 85C. The caps I'm replacing it with are 33uf@400V, 33uf@400V, 10uf@350V, 10uf@350V 105C.

P1010089.jpg
 
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kpaxfaq:

I know this is bit premature at this stage of your rebuild but, I'm wondering about your dial glass.... The stencil on mine is perfect, yet the inside of the glass is covered with a layer of dust that's really tough to get off. I've started to remove the dial glass several times and chickened out. Bending the tangs on the dial bezel to remove the glass kinda freaks me out. The dingy glass takes away the looks of an almost perfect receiver.
 
dsndblm said:
kpaxfaq:

I know this is bit premature at this stage of your rebuild but, I'm wondering about your dial glass.... The stencil on mine is perfect, yet the inside of the glass is covered with a layer of dust that's really tough to get off. I've started to remove the dial glass several times and chickened out. Bending the tangs on the dial bezel to remove the glass kinda freaks me out. The dingy glass takes away the looks of an almost perfect receiver.
Click to expand...

dsndblm,

I have the same issue. I was thinking of getting some longer cue-tips and trying to detail behind the glass best I can...I have no plans of bending those metal holders to remove the glass. I'll get it the best I can and I'm sure it'll look fine. Dial glass for these 600's don't grow on trees like they seem to for the 400, 500, 800. Come to think of it, I don't think I've ever seen one on flea-bay unless you bought the whole unit. A little dust will add some character :D

Kory
 
Further progress to report...

I removed the old cardboard can cap and replaced a 0.022uf cap nearby while the area was clear. I noted which color wires went to which values of the can so installation of the new cap cluster would be a breeze.

P1010090.jpg


Here is the replacement cluster of caps installed in place. I'm very happy with how they turned out.

P1010091.jpg


I think this will wrap up work for today. Time to get some fresh air outside before work this evening. I should be picking up where I left off sometime tomorrow night. :smoke:

Kory
 
Just saw this thread. As another TA-600 owner, I find this very interesting. Nice work so far. :thmbsp: I think I'd be VERY careful on cleaning that dial glass, like was said, they don't exactly grow on trees. ;) Maybe some compressed air, but I think I'd leave Q-tips & paint brushes out of the equation.
 
Thanks for the kind words guys. I learned 100% of what I know now from Audio Karma so I owe it to all the members here. When I joined in December 2009, I didn't own a solding iron or even know caps went bad! It's been a long continuous journey to read, learn, and apply the knowledge but the hard work has been paying off. :yes: This hobby inspired me to go back to school full time for my BSEE which I begin this summer.

My inspiration for this thread was that it seems there are many great threads showing people progress on projects along the way but hardly any that really spell it out step by step showing before and after pictures. My hopes are that someone intimidated by working on their own gear (like I was for quite some time) could view this thread and realize it's really not all that difficult. I also will be re-doing my MPX-100 and a Fisher 800-C soon which I will also be documenting in this same fashion. :thmbsp:

Stay tuned for more progress either tonight or tomorrow! :smoke:

Kory
 
It's great that you are taking the time to share your progress with others. Keep the posts and pics going.
 
Further progress to report...

Replaced this 0.047uf@250V cap with 716p 0.047@400V cap. It's not pretty but it's securely soldered in there. Some of these tight spots are impossible to completely remove old leads and redoing the joint without heating/removing all the resistors around it. I'm avoiding that at all costs.

Before

P1010092.jpg


After

P1010093.jpg
 
Now moving towards the front of the unit. I am going to replace the 0.01uf@250V cap with a 716p 0.01@400V cap. Then I will note the polarity of the big 100uf@150V lytic' cap and replace it with a 100uf@160V cap.

Before

P1010094.jpg


After

P1010095.jpg
 
Since I dove right into the project, I never took a picture of the actual unit from the top. I had to flip it over to measure the top cans for Tom Hayseed and figured I'd snap a few pics. I think I've decided on white LED's to replace the bulb lamps so I don't have to worry about them for a really long time. Doesn't hurt that they look nice.

P1010096.jpg


P1010097.jpg
 
The one real benefit to this work is how nice this is going to be when it is done.
You will have much to be proud of kpaxfaq.
Time consuming to do it right, but well worth it. You'll be able to take the bottom cover off and show the work with pride.
 
Update:

Tom Hayseed got back to me today with some quotes. I had measured the diameter as 1" on the can caps, Tom said they are most likely 1 3/8" which I need to confirm when I get home from work tonight.

Here's the specs he came up with for the replacement cans...

"The replacement for the 40/40/40 uF @ 350/250/250V cap would be a 47/47/47 uF @ 450V 105C unit. This can would cost $27.25.

The replacement for the 40/40/20/20 uF @ 400/350/200/200V can would be a 47/47/22/22 uF @ 450V 105C unit. This can would sell for $27.95.

Shipping and handling for the order would be $7.95.

At the present time, the lead-time has been running about 3-4 weeks."

I like those specs! Especially the 105C temperature ratings with the cans being near the rectifiers like that. Can't hurt at least in the long run :dunno:

Hopefully I'll have some time to tackle the remaining caps towards the faceplate of the unit tonight. They are all that are left on the TA-600. Next on the restoration queue is a Fisher 800-C and then a pair of Sherwood S-1000II mono blocks with 7189's in PPP for 36 watts each :D
 
I'm trying to source the ceramic cap I busted the lead on in my earlier work. The Fisher parts list say it is "15uuf N75 1000V Ceramic". Through google I can't find anything showing specifically what 15uuf is. Is it Picofarads?

Edit: I'm answering my own question but I'd assume it is just like mmf means picofarads.....I just want to confirm.
 
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From what I've read uuf is an older notation for mmf. You are correct that mmf means picofarads. Allied Electronics, Mouser or Digikey will surely have the cap.
 
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