[R-390] C-103 cap replacement

[Bob Weiss]

On Tue, Aug 14, 2018 at 5:21 PM, Bob Weiss <bobweiss1967 at gmail.com> wrote:

> For the 390A, I generally open up the "bathtub" capacitor by first
> drilling a 2 small holes in the underside. Leave one open for a pressure
> vent, and thread a wood screw or sheet metal screw into the other for a
> handle. Clamp the can in a vise,and unsolder the bottom cover with a
> propane torch, while pulling the cover loose with a pair of pliers on the
> installed screw.
>
> The old guts will pull out of the metal can pretty easily, and a new 47
> uF/50V cap can be installed inside the can. The terminal lugs have hollow
> grommets in them which can be uncovered by melting the existing solder, and
> then threading the new cap leads through and resoldering.
>
> You can reinstall the bottom of the can by tack soldering it back if
> desired, but it is completely invisible when the cap is reinstalled in the
> chassis, and can be left off if desired.
>
> I use a similar technique to restuff C551, the 2 uF AGC cap on the IF
> deck.  Those are usually a bit messier, though, as they are oil or wax
> impregnated, rather than dry electrolytics. The same technique also works
> to open up the RFI filters, to replace the caps with smaller values for
> GFCI compatibility. I use .01 uf X1Y2 rated ceramics here, rather than the
> 0.1 uf papers originally used.
>
>
>
> On Tue, Aug 14, 2018 at 2:47 PM, Fred Stillwell <fred.s43 at frontier.com>
> wrote:
>
>>  Good afternoon all,
>>    What is a suitable replacement for:    C103, 10 mfd. 300vdc oil filled
>> cap. B+ line, in the R-390/URR ?This is the big round grey  cap mounted on
>> the chassis near the front.
>>  In the  R-390-A,  C103, 50 mfd. @ 50vdc oil filled bath tub style, on
>> the cathode bias line ?
>> I have several R-390/URR  with the original oil filled caps and  2
>> R-390-A thathave damaged C-103 caps.  I'm thinking electrolytic in both
>> cases.  Any ideas ?
>> Thanks and 73's
>> FredAA8S
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>
>