[Hammarlund] No more BBoD's in this SP-600

[Roy Morgan]

At 04:04 AM 6/3/03 +0000, Phil Atchley wrote:
...I'll continue on to the next stage, checking tubes and forming the
>filter caps preparatory to checking the operation of the unit since it
>hasn't yet had any power applied.

Phil,

Check for leakage in the filter chokes (unhook the lead feeding B+ to the 
rest of the radio.)

One failure of the SP-600 is leakage in the tar itself: the choke becomes 
leaky and puts an increasing load on the B+ supply.  The "fix" offered in a 
Hollow State news article some years ago to insulate the choke case from 
the chassis and run it that way is dangerous in my opinion.  Don't do that.

Also:
While you are at it, move the power transformer primary tap from the 115 
volt pin to the 120 volt pin.. Then you radio wil run a bit cooler and the 
tubes will last longer.  (If only more of our fine old radios had such a 
tap on the transformer!)

Roy


- Roy Morgan, K1LKY since 1959 - Keep 'em Glowing!
7130 Panorama Drive, Derwood MD 20855
Home: 301-330-8828 Work: Voice: 301-975-3254,  Fax: 301-948-6213
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