[Hammarlund] Rebuilding a derelict SP-600 receiver

[Roy Morgan]

Bill:  Comments in line below:

> On Sep 12, 2020, at 1:30 PM, William Radmer <bradmer at comcast.net> wrote:
> 
> Greetings,
> 
> This is my first post after joining the group a few weeks ago.

Welcome.  There is lots of experience with the SP-600 here.
> I am
> rebuilding an SP-600 R-274C  purchased several years ago

Hooray - great to see another one being restored.

> ..(it was full of the infamous "Bumble Bees of Death”)

You no doubt learned that there are some inside the IF or mixer cans.

> RF section requiring the most effort to remove for service.

Sounds like “previous owner damage!”

> At this point, the rebuild is almost done! 72 capacitors have now been
> replaced …. bringing AC power up slowly on a variac  while checking the B+ voltage.

NOTE! !!:  THE filter choke may be leaking to ground.  One suggested repair by insulating it from chassis is NOT a good idea.

NOTE2!!  DO NOT “bring it up slowly on a variac”. You risk frying the transformer.  Details later.


> If no other problems come to light,  full alignment of the receiver will
> finish up the rebuild.

NOTE 4!! :  DO NOT try to set linearity by bending the tuning cap plates.

More later.

Roy

Roy Morgan
K1LKY since 1958
k1lky68 at gmail.com