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eHam Forums => Boat Anchors => Topic started by: WA2MGB on October 30, 2003, 09:39:37 PM



Title: Swan Power Supply & Bad Caps
Post by: WA2MGB on October 30, 2003, 09:39:37 PM

My trusty Swan 117C power supply that kept my trusty 350 going needs new caps.  I checked the specs on the caps in question and the only source I could find is AES at 35.00 each...  I could buy a another used Swan PS at those prices.  Is this worth recapping, or should I start shopping for a replacement?

FYI here are the specs on the cap I need

80/ 475
50/ 475
85  C
073-018 (Mallory stock number)

I need two of these.

Tnx,
Ted


Title: Swan Power Supply & Bad Caps
Post by: KD7KOY on October 31, 2003, 01:43:43 AM
Well..what you can do is run the caps in series..
For example..2 each 220UF @ 250DC would be..er..ummmmm (doing math...)..110UF @ 500 DC (capacitance divided by 2 and voltage multiplied by 2..)..that'll work..; ))
I can't remember if they are 'cans' on the power supply..if they are, you can 'stuff' the cans with the new caps to give it an original look or mount underneath. Cut off the tops of the cans with a dremel, clean it out, insulate your leads and hot glue the top it back on..run the leads out the bottom.
I stuff the cans for old radios. Don't have to but I'm bored..; )
Remember ARROW points to NEGATIVE side of cap.
Switch it wrong and bad things happen..; P
Also, 'Warning Will Robinson'..HIGH VOLTAGE..this stuff bites hard..be careful. Can injure or kill.

Try AES
www.tubesandmore.com
or shop around..the caps are about $4.95 apiece.
Also check for any out of tolerance resistors while your digging through there.
Good luck..


Title: Swan Power Supply & Bad Caps
Post by: WB2WIK on October 31, 2003, 02:12:07 PM
I'd try Mouser, Digi Key, All Electronics and other discount distributors.  RF Parts lists some multi-section twist-mount 450V electrolytic caps from Sprague, Mallory and Sangamo in the $13.95 to $19.95 range.

I'm lucky that All Electronics, who has tons of these kinds of parts, is only a few miles from me.  Rather than look through their catalog, I just drive over there.  Last time I bought 450V electrolytic twist-mount caps, I paid $4.50 each for them...

WB2WIK/6


Title: Swan Power Supply & Bad Caps
Post by: W9GB on November 02, 2003, 05:49:44 PM
" I could buy a another used Swan PS at those prices. Is this worth recapping, or should I start shopping for a replacement?"

Ted -

If you like your Swan - and will keep it for a while - then go ahead and fix this one properly.  

Why go out and buy another problem supply? - That is a "buy a used tire" solution that sucks good hard money to bad decisions.

Greg
w9gb


Title: Swan Power Supply & Bad Caps
Post by: W9GB on November 02, 2003, 05:54:22 PM
If you are looking for another source - you could contact:
Bill Turner, WA0ABI,  
1117 Pike St., Saint Charles, MO 63301.
Phone: 636-949-2210

Bill stocks and customizes specific parts for the antique radio restorers, and may have something:

ELECTROLYTIC CAPACITORS, new,
7/8"DIA. X 3" OR 3 1/4" long, shiney red or blue cover, brown end seal, printed inscription down the length, metal mounting strap with a hole for mounting.
 
33uF-47uF 160 volts, $2.50
33 uF-33uF-33uF 160 volts $3.00
47 uF-47uF-47uF 160 volts $3.50    
33uF -47uF 160 volts 47uF/100  $4.00 with bias cap.  
33uF-47uF 94 uF/100 volts $4.00 (AC/DCbattery sets)  22uF-22uF 450 volts $4.00  (for AC sets)  
22uF-22uF-22uF 450 volts $4.50 (for AC sets,)


Title: Swan Power Supply & Bad Caps
Post by: W9GB on November 03, 2003, 12:41:56 AM
Ted -

Here is a very good tutorial on replacing capacitors in older radios
http://www.antiqueradio.org/recap.htm

w9gb


Title: Swan Power Supply & Bad Caps
Post by: WA1RNE on November 09, 2003, 11:47:06 AM
You should be able to find good quality aluminum elctrolytics with the capacitance and voltages needed at several distrubutors. As the other OM suggested, series and/or parallel them as needed to get the cap. values/voltages needed. But here's a little different swing to that idea that might be a good compromise:

 Purchase some aluminum electrolytics with AXIAL leads. These are tubular shaped that are usually 2-3 inches long and should fit under the chassis. They can be tie-wrapped to other components or with an adhesive plastic tie-down. Get the mechanical specs before buying and compare them to the space available under the chassis.

Then just leave the old metal cans in place for looks. Disconnect them of course......


Title: Swan Power Supply & Bad Caps
Post by: KD7KOY on November 09, 2003, 08:52:00 PM
RNE..Low and behold I just came across a Swan 500C's  and 117..(Doing Swan dance waving hands in the air..)
Coincidence responding to this thread.
The 117 has (at least mine..no scedmatic yet..)
4 100UF@350VDC
1 80UF@150VDC and a
1 250UF@25 VDC
(All paper caps)
All of them axel lead. So should'nt be a problem locating at AES or elsewhere, and dig the old ones out and solder the new ones in.
Ted, you can go 450 VDC (or higher voltage for the others..)if you want and alittle higher in UF..Not a problem.
Diodes are rated at 1 amp 400 or 600 volts.
I will use a standard rectifier diode (1N4007) at 1 amp and 1000 volts.
This one blows the fuse. Have'nt troubleshooted yet but suspect a cap or bad diode(s).
Good luck and keep us posted!



Title: Swan Power Supply & Bad Caps
Post by: WA1RNE on November 11, 2003, 01:38:10 PM
KD7KDY et al:

I redesigned the HV supply in my Viking II using some 1N4007's (several) and some series combination of tubular computer caps (forget values), all on a fiberglass board.  Works great though you wlll end up with a someshat higher HV bus because the losses through the tube rectifers are almost gone, but it's not a problem for the 6146's.


Title: Swan Power Supply & Bad Caps
Post by: KD7KOY on November 12, 2003, 01:06:51 AM
WA1RNE.
Sounds like a good project.
Thanks for a new idea! 73

       


Title: Swan Power Supply & Bad Caps
Post by: WA1RNE on November 13, 2003, 10:36:58 PM
There are LOTS of mods you can make to a Viking II:

I gave the audio driver a little more punch by replacing it with a 6AQ5 and rebiased it as required.
Sounds good but the driver transformer isn't ultimate for the tube's plate resistance, but it's OK and reliable.

Also regulated the screen supply for the 807 modulators, increased the coupling caps in the audio preamp and increased the grid input resistor to around 10Meg (memory?) which is one of the more common mods.

Adding a built in antenna changeover relay with screen voltage control was one of the better convenience mods.

I think I added zener regulation to the 122 VFO too.

You can go nuts with these rigs...I'm more partial to my 32V3 though....did similar stuff to it....