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Fisher 500c

OK!!! GOOD SHOW. NOW, get some CRC QD ELECTRONICS CLEANER (NON-RESIDUE). Home Depot has it. Read the thread on cleaning the tuning capacitor. Then spray the Tuning capacitor itself (the fins). This will clean off any stuff thats on it, and flush out the crap the deoxit loosened. Once it's dry, touch up the bearings/clip joints with de-oxit again, test it out and if tuning is good, button it up, and celebrate with your favorite beverage.

Larry
 
Just an update: got the unit, and man, its dirty. I've been reading up and so far I've deoxited all the switches and pots, and I've cleaned all the tube sockets and tube pins, and I'm still trying to get all the dirt and dust off of the chassis, and that is quite a job. I am at the point now where I'm considering the Baking of the unit that is in the tube amp care thread. haven't gotten brave enough to do it yet. but it does seem the last thing I can do on my own. the next step is to test the tubes. I've been keeping my eye out for tube testers on sale, as well as asking some local peeps if I can use theirs. when I get the tubes tested, then its time for the variac. thats right, I havent even plugged this thing in yet. not sure if it works at all. lol!! but thats ok, I'm patient, and determined. it will work at some point. I'll try and throw up some picks of the half cleaned unit for those interested. lol.
 
We're all with you keithpgdrb.
Welcome to a special club.

So far, ya done good.
If you have access to a variac, connect it up and bring it up slowly after the bake-off. By the time you hit 70 volts, you should hear something.
That'll satisfy your curiosity.
Use your nose and eyes as diagnostic tools.
 
audiodon said:
We're all with you keithpgdrb.
Welcome to a special club.

So far, ya done good.
If you have access to a variac, connect it up and bring it up slowly after the bake-off. By the time you hit 70 volts, you should hear something.
That'll satisfy your curiosity.
Use your nose and eyes as diagnostic tools.
Click to expand...

I was reading up on some of the diy variacs using lightbulbs because I am an impatient man. anyone have an opinion on these?

also, how many of you have baked your unit?
 
Baked many. Never had a problem. Just don't overheat it. Melting the tar out of the transformers would make a mess.....:thumbsdn:
 
To bake,
Flip it upside down, run the oven no higher than 160 for up to four hours.
Vent the house when done, with the oven door open. It'll smell like warm old electronics.
 
Hey all,

well, life took a few turns, but now I'm back to the project. sorry about no pics yet. I'll have to do that for ya'll. so, here is the update.

Have continued to clean the chassis. and today, I got the tubes tested.

Faired pretty well on the tube front. All of the really expensive tubes tested strong, which left me to only replace about 6 tubes, which I ordered, and ended up costing maybe 35 bucks. Thats not too bad.

so, the baking, and the variac is the next step. I did ask a question about the diy variac/dim bulb tester. that seems like it would be pretty easy to put together, because I dont have a variac. has anyone used this method? is it ok to go this route? what are your thoughts vs an actual variac?

[Edited to remove references to old merged threads.]
 
Last edited by a moderator:
Fisher 500C Rehab project

[Edited to remove references to old merged threads.]



12/29
I did the baking today. My oven sucks, so the temps were all over the place. I think I did my best to monitor so that it didnt get too hot. so all in all, I did a half assed baking job today. one more thing down. variac/dim bulb next. dont know what I'm doing here. any help?
 
Last edited by a moderator:
When you finally get the dim bulb started, withthe 500C don't go less than a 60-75W bulb, or it will be too small a bulb. You want the bulb to be able to dim AFTER the caps charge for a second or two. If the light stays bright the unit has a problem OR the bulb is too small.
 
You might wanna see if Fisherdude can merge your threads and drop 'em in the Fisher forum. Then everyone can follow along and help easily.

Are you planning on recapping your 500C?
 
Jailtime said:
You might wanna see if Fisherdude can merge your threads and drop 'em in the Fisher forum. Then everyone can follow along and help easily.

Are you planning on recapping your 500C?
Click to expand...

the plan at this point is to see if the unit is functional. after that, I will do what needs to be done to have this baby sing for another 40+ years. so yes, I do plan on a recap, just not right away. I'll replace what needs to be done, then take it from there.

and yes, FISHERDUDE, could you merge these threads and put them in the Fisher forum? I meant to put it there, and lost my mind.
 
keithpgdrb said:
the plan at this point is to see if the unit is functional.
Click to expand...

That's the way to go about a restoration. Find out what works, what doesn't. Then you have a baseline to work from, if you screw something up during restoration, it's much easier to figure out when you know what worked before.

You're gonna love that 500C when you get it finished.
 
Jailtime said:
That's the way to go about a restoration. Find out what works, what doesn't. Then you have a baseline to work from, if you screw something up during restoration, it's much easier to figure out when you know what worked before.

You're gonna love that 500C when you get it finished.
Click to expand...

Yeah, I really cant wait. its driving me nuts. I'll probably put together the dim bulb tester tomorrow, and try out the amp. see if it blows up or not. but more on that later.
 
Ok, I built the dim bulb tester. I have to see if it actually works, then I can try it on the amp. So, I am basically going to try to use this like a variac to bring up the juice slowly as is suggested in the "vintage tube gear care" thread. I picked up a bunch of bulbs because I know I will need some for starting up a couple vintage radios my father in law has. so.. I have a 15, 40, 60, 100, and a 150. larryderouin suggested starting between 60 and 75. would this be ok to do, and to leave on for an extended amt of time?
 
also, I know to take out the 4 big power tubes in the beginning, but am I supposed to have the rest of them in when I'm bringing up the voltage?
 
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