[Hallicrafters] SX-111 "Demons OUT!"

[Mike Everette]

"Put 'cha HAAAAAANNNND on th' Radio..."

The SX-111 has been healed! Partially at least.  A
number of demons have been exorcised but a few
remain... Their name is ColdSolderJount, and they are
Many.

However, I actually got the receiver to work tonight,
after finding out that about half of the 150 volt
tegulated B plus line was disappearing, through a cold
solder joint.  Prodding it with a screwdriver produced
a nice blue spark, and lotsa rush noise.  I fixed the
joint, and Voila!  It started working, and audio
quality on SSB is outstanding.  Selectivity, when
cranked down to the 2 KHz position,  approaches that
of my trusty Heathkit SB-102 with its crystal filter. 
And the SX-111's notch filter is superb.  Stability of
the HF oscillator, after a 15-minute warmup, is
decent.  Sensitivity is amazing.  With ten feet of
wire hanging off the antenna terminal, it hears just
about anything the SB-102 does, using the "real"
antenna and tuner, at least on 80 and 40; and plenty
of signals on 20 and 15.  10 meters seems quiet, but
the calibrator is strong... probably band conditions.

The S-meter action is not what it should be.  This
could either be due to another bad solder joint or
something to do with the AVC mods.

I still have to go gunning for a few more demons (with
a Weller D-440).  In the process I plan to reverse the
poorly-executed mods and restore the original AVC and
RF gain circuitry.  But at least I have "heard the
noise" now... the sweet sound of success!  And the
dial lights up real pretty too.

73

Mike WA4DLF




		
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