[Hammarlund] SP-600

[Stanley Adams]

Hammarlund made an AVC Modification in later years that you can implement to
your radio.  It is one of the later issues of the 600 on BAMA, or Jammin'
Andy's site, Hammarlund site, etc.

After you recap your unit and verify all your resistors, there is something
else to remember about these radios.  You must bear in mind that they were
primarily designed to copy voice, CW and especially RTTY half way around the
world, so they are sensitive to the max.  Even with a properly aligned IF
system and you cannot just peak the first IF section on these radio's, they
really need swept tuned or the old fashioned stagger tuned; you will have to
back down the RF Gain a bit, especially on AM broadcast stations.  With the
constant highly compressed over 100% positive peak RF envelope, you will get
a little sideband slicing if you allow all of it to go through the radio.
So back the RF gain back a little.

Restoration time on these animals is measured in weeks or months not hours.

But in the end, you will have one of the radios ever built by American
hands.

Stanley Adams
Memphis