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Onelasttime
New member
Username: Onelasttime
Post Number: 1
Registered: 8-2011
| | Posted on Friday, August 05, 2011 - 4:34 pm: | 
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Ok so I have an amp I just purchased in the mail to me. It is very old tubed base amp. I am planning on replacing all the cap's and diodes. I want to upgrade them. I am going to install 1N5408 3 amp Diodes based on what another person has done.
My real question has to do with capacitors. First can I replace the electrolytic caps with Japanese solid cap's? I have done this on some computer power supplies and other portions of old mother boards and it has been great for durability and better regulation of the power.I do not know enough about tube amps to know if I have to stick with electrolytic caps or if I can replace them with solid models?
I am trying to put it back to better then stock condition. I am also going to buy new tubes in matched pairs for it.
If it matter it is a Kris Power Pump and it is currently working and I would like to set her up to be working great 25 years from now!!! |
Tech833
Moderator
Username: Tech833
Post Number: 2017
Registered: 8-2002
| | Posted on Sunday, August 07, 2011 - 12:06 pm: |
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A tube-type amplifier has high voltage inside (potentially thousands of volts DC), so if you truly don't know about tube amps, don't do anything.
When you replace power supply caps in a tube amp, you need caps that can handle the voltages present. Computer caps are usually rated for 50 volts or less.
Too much to type. Take it to someone who knows about tube electronics. Don't any of your ham contacts know any hams who would help? Most hams are eager to help other hams.
Your radio 'Mythbuster' since 1998
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Onelasttime
Junior Member
Username: Onelasttime
Post Number: 10
Registered: 8-2011
| | Posted on Monday, August 08, 2011 - 6:56 pm: |
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I understand I am going to be talking about caps in the 450+ volt range.....I have seen some pretty beefy solid caps though. But I had not thought about that. I guess I will just use Sprague(sp) Atom Electrolytic Cap's......
I used to work on Transmission Power Lines 1000Volts and less is kids stuff. I will use a resistor to slowly discharge the caps before I touch anything....Just because I do not know tube circuitry does not make me stupid....LOL
I have worked on TV's before and those are even more dangerous. Who on earth can afford what a good Tech demands to do such work?????
In fact I suspect that Copper get's a lot of people that check th box for Tune,Expand and Align because it is dirt cheap. When I was aprenticing at an Electronic Repair Shop it is $39 to Align a AM radio and $69 to Align a SSB or Export radio......if no parts needed to be added to expand a radio then it was included but if any parts where needed those wold be billed in addition to the base rate. That was back in 1991/1992 I can not imagine things have gotten cheaper.
The only thing I have to worry about is the cap's I am not dumb enough to poke around inside with the power running!
I am also going to install saftey cap on the power side so that if it fails it fails in a safe way so no shock's from the cabinet or fire burning down the house!
Thanks for pointing out that glaring detail I failed to think about which was the voltage limits of most solid caps.
Anyone know how far into the tank circuit I need to go to add taps for 12 and 6 meter's?? |
Dirty_diaper
New member
Username: Dirty_diaper
Post Number: 1
Registered: 8-2011
| | Posted on Saturday, August 13, 2011 - 1:23 pm: |
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Mr. Onelastime, you must be like me. Sometimes I ask questions to re-inforce my already decided actions, kinda just to hope my friends will give me a little moral support. You seem capable to do the work required, and like a momma bird, push you out of the nest. LOL Anyway, good luck on your project, I use mostly tube equipment, and try to do a lot of the work myself. That seems to be part of the hobby I thought. I was told by a person once that if a turtle didn't stick his head out, he couldn't cross the road. Damn the torpedoes! Full speed ahead! Have fun, Email me if you want to compare notes sometime, D.D. in S.C. said that. |
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