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New to Tubes...800c score...help restore.

Kory...
Just read your "The Fisher TA-600 Rebuild Thread". Really great stuff.
Will probably just go ahead and replace the whole power supply with the cans from Hayseed and mount the other caps below chassis.

As an aside...I cleaned the underside of the glass with pipe cleaners. Just dusted really as it's impossibile trust any cleaning fluid with that old screen printing.
martin
 
bdblkta said:
I have always read that Jim McShane uses much higher quality parts and also includes the multi caps needed but does not include detailed instructions such as the Metalbone kits.

In an ideal world I think it would be best to get the McShane kit and see if you could figure most out and have those here help with anything you cannot figure out yourself (or maybe someone could get you some instructions).

McShane's Kit is more expensive but only by about $40 over what you would be paying out for the Metalbone plus Hayseed parts.
Click to expand...

He's already completed the metalbone kit which uses good quality parts itself, so buying another kit is unnecessary. I was a little skeptical until I installed one recently for someone. It's sonicaps, 716p orange drops and Nichicon electrolytics.

I'm sure McShane's kit is very nice because he doesn't endorse junk. I'd be curious to hear what parts he prefers.

Kory
 
Ordered the can caps from Tom at hayseedhamfest.com this morning.
Will order caps for underside tonight once I certain of what I need.
martin
 
So just what do I need to order to finish off the power supply since the multi section cans are in the works at hayseed?
martin
 
marloubow said:
So just what do I need to order to finish off the power supply since the multi section cans are in the works at hayseed?
martin
Click to expand...

From the sound of it you just need a single cap 220uf@250V or higher. I'd also replace the resistors associated with the cans while you're at it.

I'm getting crushed here at work tonight, I'll come back later and give you the specific resistor values if you want.

You're going to be glad you did it right when you're done and can do more listening and less worrying :music:

Kory
 
Yes...that would be great to have a list of all I need so I can order in one shot.
Maybe add a variable resistor pot?
martin
 
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Kory is right, you'll be set for a few decades after all the work is done. It's great that you are doing it right! It's a great feeling to be able to turn one of these vintage receivers on, have it run for hours on end with no hot transformers or component failures.
 
Tonight I worked on reading schematics..."looking" at them might be a more accurate term. I am far from reading them.

So I thought I would try to find the resistors associated with the power supply that I will need to change.

So tell me if I got it right.

Apowersupplypre14revised.jpg


Apowersupplypre12revised.jpg



audiodon wrote "Use metal film or metal oxide resistors in the power supply (only). They're very stable, even when heated."

I'm guessing you're refering to R129 & R121?

martin
 
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Also...
Can anyone tell me about these two resistors. As hard as I tried I could not find these or any resistors tied to the screen grid (the lead connecting pins 4 & 8 on each output tube, to and from each tube) on the schematics.
Of course I'm "looking" at the schematics, not reading them.

powersupplypre10copy.jpg


And please. please...If I call a component by the wrong name or in error in any way, please correct me.

Martin
 
And...
This capacitor C118 was not addressed in the metalbones kit.
It seams to be tied to TV circuitry.
Is it a non issue?

Thats all.
Martin

powersupplypre15.jpg
 
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Martin

Can you scan and attach a copy of the power supply schematic? If so the components can be marked.
 
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Martin, you found em'! Just make sure you observe their wattage ratings in the service manual which can be found on this site. AKdatabase.com

The 470ohm green ones are 3watts, I use 5 watters when I replace them and they're still smaller than the originals. With today's modern resistors being smaller you could actually just use 1 watt metal oxides or metal films and you'll be fine for the rest. A 10k pot is fine for bias adjustments. Do you have some 600V rated wire on hand? You'll most likely need some when you re-do the power supply. Some of the wires connecting to it have no extra length and when you cut/strip you won't be able to reach where it went on the can anymore. Also, some I've come across are a little brittle, so I just replaced it completely.

Those resistors near the OP tubes don't need replaced. I've made a habit of replacing that big green 7 watter with a 10watter for a little cooler running since they're like 50 cents but it's by no means a must.

As usual I'm on the run here and must get to work but if I can a little later I'll take a closer look and see if I missed anything in my post! I'd like to create a project for you on mouser.com and send you the link. Then you just need to click "order" and it will put everything in your basket. Hell I think I still have my "Fisher 800C" project there saved. I'll check soon and get back to you this evening.

Kory
 
Yes...by all means "create a project". I'll take help where ever I can get it.

I was looking at Drew Bolce's "Individual Bias Adjustment Mod" schematics.
His was for a 500c. Should be the same for the 800c as well...yes?

If I were to go that route. Would you also include your recomendation for the 10k pot to use (since your there), wheather it's the one at the bias supply or the 4 at the output tubes.

Thanks
martin
P.s. About time I ponyed up.
 
Finally had some time to poke my head in here for about 10 minutes. I told this to Martin in a PM but I'm working 70hrs/week now and just started a summer math class everyday in the morning so I'm falling off the radar temporarily with homework coming out the wazoo!

I know there's a bunch of you guys who know way more than I do about this gear lurking out there! Can someone give the man a hand? :thmbsp:

Kory

PS: Martin, I apologize I'm leaving you hanging for the time being but I am just crushed right now. I'll be back just not as quick as you might be itching to get answers.
 
Okay...
Everything is ordered for replacing the power supply.
The 2 multi-section cans from Hayseed.
The resistors and the 220uf 350v electrolytic from Mouser.
I also ordered all that I need for a single 10k pot to replace the bias resistor at R119 and the components needed to place individual bias pots at each output tube depending on which direction
I decide to go based on my skill comfort level.
Here is my Mouser order;

Mouser #: ????????????
Mfr. #: ??????????????
Desc.: Metal Oxide Resistors 470Kohms 5% Tol
(Correction - should be 470 ohms, not 470K)
4 @ $??.?? 4 Pending Pending -

Mouser #: 647-UVZ2V221MRD
Mfr. #: UVZ2V221MRD
Desc.: Aluminum Electrolytic Capacitors - Leaded
350volts 220uF 105c 22x50 10LS
1 $3.74 $3.74 1 Pending Pending -

Mouser #: 282-200K-RC
Mfr. #: 282-200K-RC
Desc.: Metal Oxide Resistors 200Kohms 5% Tol
6 $0.19 $1.14 6 Pending Pending -

Mouser #: 660-MO2CT631R123J
Mfr. #: MO2CT631R123J
Desc.: Metal Oxide Resistors 2W 12K 5%
6 $0.14 $0.84 6 Pending Pending -

Mouser #: 647-UKL1H3R3KDDANA
Mfr. #: UKL1H3R3KDDANA
Desc.: Aluminum Electrolytic Capacitors - Leaded
50volts 3.3uF 85c
6 $0.23 $1.38 6 Pending Pending -

Mouser #: 652-3362W-1-103LF
Mfr. #: 3362W-1-103LF
Desc.: Trimmer Resistors - Single Turn 1/4 SQ
10KOHMS 10% 0.5WATTS
5 $0.83 $4.15 5 Pending Pending -

Mouser #: 282-82K-RC
Mfr. #: 282-82K-RC
Desc.: Metal Oxide Resistors 82Kohms 5% Tol
4 $0.19 $0.76 4 Pending Pending -

Mouser #: 262-2.7K-RC
Mfr. #: 262-2.7K-RC
Desc.: Metal Oxide Resistors 2.7Kohms 5% Tol
4 $0.22 $0.88 4 Pending Pending -

Mouser #: 262-22K-RC
Mfr. #: 262-22K-RC
Desc.: Metal Oxide Resistors 22Kohms 5% Tol
4 $0.22 $0.88 4 Pending Pending -

MERCHANDISE TOTAL: $15.65
†ORDER TOTAL: $15.65
† Charges due at this time on items ready to ship.
www.mouser.com/saleterms/
7/7/2011 7:19 PM

Hope I got the correct parts...can someone please confirm?

Below is Drew Bolce's schematic "Individual Bias Adjustment Mod". Believe me, after reading alot of his past postings...this man seem to know his Fishers inside and out. Thanks Drew.

IndBiasSupply.jpg



I guess thats all till everythig gets here.
I am constantly amazed how much info there is in past post...thanks past posters!
martin
 
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Don't worry Kory...it's cool!
I'm not left hanging at all.
thanks
Like I said, there's alot of this stuff covered before. I'm sure it's old news to some. I'll just bet their all kicked back, cooling with the beverage of choice and diggin their fishers....we all have dreams. :yes:
martin
 
P.s Kory you seem like a young man working on the family plan and I can sure respect that. This is all small stuff compared to what your up against these days. You've done more than your fair share here.
thanks
martin
 
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