[Hallicrafters] SX-117 info

[Alf Fisher]

Jeff,
Another thing you could check is the voltage on the cathode pin 7 of the 
output stage V12 across the 120 ohm resistor R79.
The manual quotes 3.6 volts so if there is excessive current flowing, that 
voltage will be higher.
The coupling capacitor C96 (known here as 'That capacitor') is only a 1nF so 
not usually troublesome but depends on the make and type.
If capacitors in that location are leaky, they will cause the grid volts to 
go positive causing increased plate current and the likelihood of damaging 
the output transformer.

73,
Alf
G3WSD

----- Previous Message ----- 

> According to the information I have the input voltage design was for 
> 105-125 volts AC so that should not be a big concern.  What may be more of 
> a concern is leakage of the electrolytic capacitors in the power supply or 
> any others that are in the set.
>
> The transformer should be adequate for the receiver and will run warm.  Be 
> sure the capacitors are in good condition and look for any other improper 
> drain on the HV.
>
> Jim
>
> W5JO
>
> -----Original Message----- 
> Looking for some first hand knowledge.  I just picked up a SX-117 with
> matching speaker.  After replacing three tubes, and doing a cursory
> alignment, I am VERY happy with this new rig.
>
> I have a point of concern however -- it seems like the power transformer
> runs quite hot.  My digital thermometer reads 149 degrees F after about
> 30 minutes of operation.  It doesn't appear to go past that, so I
> suppose that is a good thing.  I'd appreciate anyone's thoughts or
> experiences on that.  I will hook it to a bucking transformer to bring
> the AC input down to 110 and see how that goes.
>
> Second, the tuning dial has a bit of a slip in it.  It's only momentary,
> and not reproducible at any specific point.  It also seems to diminish
> after the radio has heated up.  While it isn't a problem now, if it is
> something that can easily be addressed I'd like to deal with it before
> it becomes a catastrophic failure.
>
> I believe the one I have is the "E" revision.  I have the original
> manual. Any recommendations that will improve longevity or performance
> are greatly appreciated.
>
> Jeff
> WB3JIH
>
>
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