| Author |
Message |
    
Dave1
Junior Member
Username: Dave1
Post Number: 24
Registered: 9-2005
| | Posted on Friday, September 09, 2005 - 11:53 am: | 
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I have an old Astron RS-20A Regulated Power Supply lol Regulated my Butt the volts go from 0.81 to 15.50 and keep rolling up and down any of you out there know how this can be fixed short of dumping it in a lake to swim with the fish it has been driving me nuts
its only my backup one but would like it to work again
Dave |
Artie_bee
New member
Username: Artie_bee
Post Number: 1
Registered: 7-2005
| | Posted on Friday, September 09, 2005 - 1:23 pm: |
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Do the output variations occur with load attached? |
Dave1
Junior Member
Username: Dave1
Post Number: 25
Registered: 9-2005
| | Posted on Friday, September 09, 2005 - 3:00 pm: |
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with it and without it
it will hold 13.8 for a little while when I adjust it then bang its gone a rolling |
Chad
Intermediate Member
Username: Chad
Post Number: 435
Registered: 11-2004
| | Posted on Friday, September 09, 2005 - 11:34 pm: |
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Something is wrong in the current limiting section, I'll betcha! |
Fusebreaker
Intermediate Member
Username: Fusebreaker
Post Number: 149
Registered: 3-2004
| | Posted on Saturday, September 10, 2005 - 5:25 am: |
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it sounds like a capacitor and prolly the main one AKA the big boy that stabalize`s the current just my thought |
Dave1
Junior Member
Username: Dave1
Post Number: 26
Registered: 9-2005
| | Posted on Saturday, September 10, 2005 - 9:19 am: |
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well if its thai big sucker then I think its time to put the old bugger down to rest because its cheaper to buy a new unit than replace that thing this is about 25 years old and I think I got some use from it lol |
Artie_bee
New member
Username: Artie_bee
Post Number: 2
Registered: 7-2005
| | Posted on Friday, September 16, 2005 - 10:31 pm: |
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Was just researching some 1000uF 's at work. They're about $20.00 at Newark.
Is the PS a linear or switcher? |
Dave1
Junior Member
Username: Dave1
Post Number: 37
Registered: 9-2005
| | Posted on Saturday, September 17, 2005 - 9:16 am: |
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I think its a switcher I will have to look and if its not I will write and let you know
Thanks
Dave1 |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 632
Registered: 9-2004
| | Posted on Saturday, September 17, 2005 - 9:38 pm: |
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if its 25 years old chances are its linear.
and in working condition it is still worth way more than a capacitor.
im gonna guess that the voltage regulator is weak or gone.
i dont know if its a transistor or an IC, but i'll bet replacing it will work. old caps can also be a problem. you can find them cheaper. mouser is a good source.
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Twowatt
Member
Username: Twowatt
Post Number: 63
Registered: 7-2005
| | Posted on Sunday, September 18, 2005 - 12:23 am: |
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i just ordered a 4900uF 50V cap for $2.00 this week from fair radio. you should get at least 5 of them for ur supply, imo. |
Dave1
Junior Member
Username: Dave1
Post Number: 38
Registered: 9-2005
| | Posted on Sunday, September 18, 2005 - 10:35 am: |
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Ok going to try to fix this  I think I need this part but I dont know where to get it. Its a General Electric 86f4043m1 (the last number could be an I but the eyes dont see that good) 33000UF -10 +75% 25VDC 30 Surge 85C Max Ambient this part is 4 1/2" long and 2" wide with 2 screws on the bottom that make the connection and hold it to the board so if you know where I can find one please let me know
thanks
Dave  |
Goat373
Junior Member
Username: Goat373
Post Number: 38
Registered: 3-2005
| | Posted on Sunday, September 18, 2005 - 4:20 pm: |
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i have a GE 86f1197na 14000 UF -10+75% 30vdc 40 surge 85 c max ambient sitting right here if you have a use for it, i know it dont cross but i figured id let ya know i had it |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 644
Registered: 9-2004
| | Posted on Sunday, September 18, 2005 - 9:48 pm: |
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just re-read an earlier post.
try going to rad shak and getting a can of "freeze spray". the people working there wont know what the heck you're talking about but they have it. with the other cans of stuff.
turn on the power supply and when it starts doing its thing (rolling), spray a small shot right at the voltage regulator. if the problem goes away for a bit andthen returns then its probably the voltage reg. and when it heats up, it goes out.
try it, it's cheap, and you'll use it again.
matt |
Bigbob
Senior Member
Username: Bigbob
Post Number: 2216
Registered: 12-2001
| | Posted on Monday, September 19, 2005 - 6:40 am: |
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If you can find a junk cash register,man will it have the cap for you.I got a cap out of one it's 25 volts and 100,000 uf,hows that for filtering.Won't work on my supply cause it's working volts is 26 after rectifier,but went to radioshack and got 10 4,700 uf caps at 35 volts and bundled them in paralell,works great,but clip leads short and tie together with 14 ga. automotive wire,other wise it can't keep up with current surges.Bigbob |
Chad
Intermediate Member
Username: Chad
Post Number: 449
Registered: 11-2004
| | Posted on Monday, September 19, 2005 - 8:44 am: |
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Freeze spray is an expensive version of a bottle of "canned air" turned upside down 
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Dave1
Junior Member
Username: Dave1
Post Number: 40
Registered: 9-2005
| | Posted on Monday, September 19, 2005 - 9:27 am: |
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Well I would never figure how to set them up like that so the search is still on but thanks for the thought Bob I will have to look in some junk stuff I might find one
Dave |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 650
Registered: 9-2004
| | Posted on Monday, September 19, 2005 - 4:47 pm: |
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chad, ive only done that on accident, good to know!
dave1, picture two 14ga. bare wires about 12" long, laying parallel about 2" apart. lay the caps perpendicular to the wires and solder them on. picture a ladder where the rungs are the caps.
matt |
Dave1
Junior Member
Username: Dave1
Post Number: 42
Registered: 9-2005
| | Posted on Monday, September 19, 2005 - 5:34 pm: |
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I have a Galaxy 33 I will use as a test after I put them in because I dont want to kill a good radio |
Kid_vicious
Advanced Member
Username: Kid_vicious
Post Number: 656
Registered: 9-2004
| | Posted on Monday, September 19, 2005 - 6:39 pm: |
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remember kids, always test your mods on a galaxy radio first. that way if it doesnt work, you havent lost a radio, you've gained a parts bin!!!
matt |
Chad
Intermediate Member
Username: Chad
Post Number: 451
Registered: 11-2004
| | Posted on Monday, September 19, 2005 - 6:54 pm: |
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If you have a scope you can check for ripple on the rails of the caps before the regulator. A DVM on AC mode will also tell you ripple voltage.
The less ripple the better, unloaded you should see way less the 1/2 volt. Ripple does freak out regulation circuits. If the voltage rise and fall is peroidic (constant on and off fore the same amount of time) then ripple can be to blame, if it's only under load regardless of current, (like a 1A load) it could be a malfunction in the current sense/limiting circuit.
Chad |
Yankee
Advanced Member
Username: Yankee
Post Number: 919
Registered: 7-2003
| | Posted on Tuesday, September 20, 2005 - 12:22 am: |
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Astron still makes this supply, me I would take it to a good radio tech. It is worth having fixed.
Astron power supplies are highly rated within the amateur radio crowd. A good used Astron supply is worth quite a few bucks and they are very good. |
