[Hallicrafters] SX 101A hum

[David C. Hallam]

I just cured the hum in my SX-100 by replacing the 6BA6 50.5 KHz amplifier
tube.  It had some type of grid emission.  One of the first times with a
tube tester I have ever believed what it indicated.

David
KC2JD/4

> -----Original Message-----
> From: hallicrafters-bounces at mailman.qth.net
> [mailto:hallicrafters-bounces at mailman.qth.net]On Behalf Of Andy
> Bullington
> Sent: Tuesday, February 05, 2008 10:18 AM
> To: hallicrafters at mailman.qth.net
> Subject: [Hallicrafters] SX 101A hum
>
>
> It's winter project time so I've decided to revisit my SX 101A. I've
> realigned it with good results but on using headphones I'm noticing an
> annoying hum. It doesn't seem to be a tube , there is a 60 cycle
> hum even in
> standby mode. Using a speaker the hum isn't as noticeable but
> still there.
> The overall audio sound is very smooth and better than my NC303
> but the NC
> 303 is hum free. I've long ago replaced all the paper caps and
> electrolytics
> and also some out of spec resistors. At the same time I did all
> that work I
> replaced the power cord with a 3 prong. I'm wondering if I did that wrong.
> Any help for a poor technically challenged musician would be much
> appreciated. Here's where I stand: I get hum even in standby or with the
> audio turned all the way down or the audio tubes removed. It's
> not run you
> out of the room hum, but it shouldn't be there. Is it something
> in the power
> supply? Thanks in advance.
>                      Andy W1AWB
>
>
> ______________________________________________________________
>
>
>
>