[Hammarlund] SP-600 Cabinet

[Richard Knoppow]

----- Original Message ----- 
From: "Stanley Adams" <stanleybadams at yahoo.com>
To: <hammarlund at mailman.qth.net>
Sent: Tuesday, December 13, 2011 6:24 PM
Subject: [Hammarlund] SP-600 Cabinet


> The original SP600 often would come in a black steel 
> cabinet and there would
> be air louvers on the side and top.  But no holes near the 
> bottom or under
> the chassis where the air could flow, my 600 JX works a 
> lot better out of
> the cabinet where it is cooler and the dial divisions for 
> accuracy stay
> within a half of division to one division on the top band, 
> to me that is
> awesome.  Each division represents 10 kc.
>
> I wonder if I Greenlee punch out some holes for air to 
> circulate in the
> cabinet as I do not have room nor the desire for a rack.
>
>
> Stan Adams
> Memphis

    I've never seen an original SP-600 cabinet like that but 
earlier Super-Pros did come in standard desk cabinets. The 
original SP-600 cabinet is in a gray wrinkle finish a bit 
darker than the panel. These are extra-long cabinets; the 
SP-600 chassis is too long for a standard 14" deep rack 
cabinet. The original cabinets have square perforations on 
the sides and top and underneath along the sides of the 
chassis, they are very well ventillated. The older Super-Pro 
for rack mounting came with a wrap around chassis cover with 
no perforations at all in it. I think the idea was to 
provide shielding but the receivers run very hot in them. 
Perhaps they were meant to be ovens to help stabilize the 
frequency but the receivers ordered for cabinet mounting did 
not have them at all and were in ventillated desk cabinets. 
Same with the power supply. Rack mount SP-600 receivers came 
with a bottom cover, not supplied for the cabinet model, and 
with a single cover over the top of the chassis to prevent 
things from falling into it. This was just a flat sheet 
fastened at the four corners with a plastic gasket along the 
front. It did not close the sides at all. I have only once 
seen a receiver where this cover was not missing. The bottom 
cover may be important for shielding. Both are easy enough 
to make.
     BTW, there _were_ instrument cabinets made that will 
accomodate the depth of the SP-600. My JX-17 came in one. 
Its painted green and has no perforations and obviously came 
from something else.


--
Richard Knoppow
Los Angeles
WB6KBL
dickburk at ix.netcom.com