[Hammarlund] Old Hammarlunds

[rbethman]

The SP-600 J, not JX came out in 1951 with no crystals.

The first diversity version was done by Northern Radio.  SP 600 J11 is 
what the dataplate has on the turret cover.

They have one heck of selectivity!  One part non-crystal, then the 
remaining is a variable crystal type.

Bob - N0DGN

On 4/12/2011 4:00 PM, Glen Zook wrote:
> You have to remember that many of the SP-600 receivers used by the military were the JX- versions that could be crystal controlled as well as the tunable feature.  Those JX- versions were usually used with crystal control for things like RTTY circuits.
>
> Glen, K9STH
>
> Website:  http://k9sth.com