[Drake] unknown capacitor in Drake 2B

[Garey Barrell]

Joe -

Probably added by someone to compensate for a high ESR section in the 
four-section can.  NOT a good idea, since if one is dried out, the 
others aren't much better and/or far behind!.

The "twist-lok" cans are pretty well unavailable anymore, and NOS ones 
are most likely not worth the effort to install them.  There are two 
ways to go about it.  One is to remove the old can, cut them open, and 
"re-stuff" the cans with modern tubulars.  Capacitor technology has 
improved to the point that the reduction in size for a given capacitance 
makes for plenty of room.  A good description of the process is at

<http://www89405.temp.w1.com/DrakeArticles/TechTips/FilterCapacitorRebuilding.htm> 


The other approach is to just cut the terminals off the bottom of the 
can, mount tag strips, and wire the new caps in under the chassis, 
leaving the can in place for appearance.

I have also seen where someone mounted an octal socket in place of the 
cans, and then built up a stack of tubular caps on an octal plug.  
Nothing wrong with this technically, but it looks pretty sloppy.   If 
you rebuild the cans or mount new caps under the chassis using 105 
degree Celsius rated caps, they'll last another 30 years or so.  
Probably longer than you will want the receiver, so making them plug-in 
really isn't worth the effort.

73, Garey - K4OAH
Atlanta

Drake C-Line Service Manual
<http://www.k4oah.com>



Joseph Trombino Jr wrote:

> My regrets....I mis-spoke.....the cap goes from the cathode of V10 to 
> ground.  This 80mfd cap is separate from the 4 section can electrolytic.
>
>                                    73, Joe W2KJ
>
>
> ----- Original Message ----- From: "Joseph Trombino Jr" 
> <w2kj at bellsouth.net>
> To: "Drake list" <drake at mailman.qth.net>
> Sent: Tuesday, September 27, 2005 3:20 PM
> Subject: [Drake] unknown capacitor in Drake 2B
>
>
>> Hello Drake Experts and Afficionados:
>>
>> I am currently checking the electrolytics in the Drake 2B receiver 
>> for possible replacement and notice an unknown electrolytic cap 
>> (80mfd at 450VDC) going from pin 7 (CATHODE) of the 6X4 tube (V10) to 
>> ground.
>>
>> This is not shown in the schematic nor the pictorial of the 2B.
>>
>> Is this cap some kind of Drake mod or is it a "ham" mod and what 
>> purpose does it serve???
>>
>> Many thanks for any info y'all can provide.
>>
>> I will be using the 2B with my newly refurbished HT37 for a vintage 
>> SSB station, hopefully in the very near future:-)
>>
>>                                    73, Joe W2KJ
>