[Collins] 30L-1 Electrolytics

[Dr. Gerald N. Johnson]

Look at Mouser catalog pages 823 to 826. One of the limits is ripple 
current and the more compact the capacitor the less surface area it has 
to dissipate heat from the ripple current. The higher capacitance part 
will make the peak ripple currents larger (though the time shorter) and 
I see in Cornell Dubilier that the 105 C rated caps have a lower ripple 
current rating than the 85C even though some of the high temperature 
caps are titled "high ripple current" their ripple current ratings are 
lower.

The Vishay/Sprague axial lead Atoms on page 865 I like for vintage 
repairs because they have the surface area to dissipate heat like the 
originals and Sprague was a favored vender half a century ago.

Larger capacitors will improve the voltage regulation, at the cost of 
higher peak currents the original rectifiers may not be able to handle, 
at the cost of a greater capacitor temperature rise, and difficulty 
fitting into the volume available.

The upgrade boards have been created because the caps to upgrade the 
original boards don't exist.

73, Jerry, K0CQ, Technical Adviser to the Collins Radio Association.

On 1/19/2012 10:46 AM, Byron Tatum wrote:
> Hello-
>      Can someone recommend to me a good replacement electrolytic for the 30L-1
> 100 uFD @ 450 VDC ones? I do not wish to replace the existing PC board with one
> of the upgrade boards at this time.
>      I was looking at the axial lead capacitors (Mouser, Newark) and there are
> not many offered above 100 uFD. I am wanting to use higher capacity ones such as
> 220 ufd. Is it necessary to use radial lead units on the existing board?
>
>      Any advice appreciated.
>                                  Thanks, Byron WA5THJ
>