[Boatanchors] Halli SX-111

[Mark K3MSB]

Hi Dick --

Replace all the BBOD and all the electolytics.   There are two kinds of old
electrolytics and old paper caps -- those that are bad and those that WILL
go bad and take something made of unobtanium with them.

I completely recapped my SX-101A last winter, replaced all out of tolerance
resistors etc, and what a perk up in the old girl!    My SX 111 MK 1 hasn't
been recapped yet (only had it 23 years now....) and it's a great
performer,  but I know I'm just askin' for it as the saying goes....

Several years ago I worked out the math concerning the series resistance of
the older caps as it was mentioned that it was actually considered in the
original circuits.   I posted that stuff on the old AMWindow, and nobody
commented on it.  So,  either nobody understood it or it was OK.  My
conclusion was that the increased series resistance of the original caps
didn't really need to be considered when replacing with more modern caps.

I replace all BBODs, electrolytics etc during a restoration.  Save the
originals by the way.  Replacing all the BBODs with (say) OD's really isn't
an authentic restoration,  it's an electrical restoration.  If and when I
sell any of my old stuff,  the buyer will have the option to have the old
caps incase they want to restuff them and reinsert them into the circuit.

Also,  do NOT unsolder the old caps;  snip them and leave a pigtail and
solder onto the pigtail.

http://www.k3msb.com/twiddle/twiddle.html

There is a lot less change of damaging solder lugs.  Also, since I use
non-authentic Sprague OD's,  I don't want the next owner to have to unsolder
original solder connections another time and risk damaging the lugs.    If I
were going to restuff the old BBODs, then I would indeed unsolder everything
and "do it right".   Take a look at

Your mileage and others may vary.... to each his own....

73 Mark K3MSB

Mark K3MSB

On Sun, Aug 23, 2009 at 1:03 PM, Richard W. Solomon <w1ksz at earthlink.net>wrote:

> I just acquired a Halli SX-111 that should clean up nice after I
> get rid of all the desert dust !!
>
> Any problem areas I should look at before I start applying power
> (of course after checking/re-forming power supply caps).
>
> I notice some caps that look like next generation BBOD's, they
> seem in good shape. Do they suffer from the same fatal disease
> as their older counterparts ?
>
> 73, Dick, W1KSZ
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