SX-100 question

[George Maier]

You might consider taking a tip from the SX-99, which has the same problem,
but has a built-in cure.  It's the same exact tube line up in the audio
pre-amp and amp, but lacking the variable IF bandwidth, Hallicrafters added
some audio shaping to the output stage. Where the SX-96 and SX-100 have a
response switch to control the IF and SSB shift, the SX-99 has a tone
switch. In the "high" tone setting, there is an .0022uF cap to ground from
the plate of the 6K6-GT, no .001uf accross the xfmr.  Actually the .0022 is
always there.  In the "Med" tone setting, a .022uF cap in series with a 15K
1W resistor is added across the .0022uF to ground, to kill some of the
highs.  In the "low" tone position, only the .022 is added accross the
.0022, which really kills the highs.  I find the Med best for most
listening, whether AM or CW, as the high is just as you describe it. Just
maybe, the .022 and 15K might do the trick.  I plan to try this in my own
SX-100 once I get it into restoration mode.
Good luck...
George - K1GXT

-----Original Message-----
From: Boat Anchor Owners and Collectors List
[mailto:BOATANCHORS at LISTSERV.TEMPE.GOV]On Behalf Of Darrell, WA5VGO
Sent: Monday, June 02, 2003 9:31 PM
To: BOATANCHORS at LISTSERV.TEMPE.GOV
Subject: Re: SX-100 question


I've never heard one that didn't sound like that. I've never spent any
serious time attempting to track it down, but it's not in the audio stage.
I'd look in the detector or AGC.

73,
Darrell, WA5VGO



>But the receive audio just has this edge, it's tiring to listen to.
>Almost sounds like crossover distortion in a solid state amp. Low
>frequencies sound distorted too. 6K6GT is biased normally. Still sounds
>like it's overloading slightly on local AM stations too.
>
>What's the opinion of you SX-100 owners? Is the receive audio even
>"good" on these receivers? I'd classify it as poor....I know it's only a
>5khz IF bandwidth, I'm not expecting Hi Fi, but this just doesn't sound
>"right".

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