[Hallicrafters] Very slow warm-up for SX-62

[Todd, KA1KAQ]

On Sat, Jul 10, 2010 at 12:42 PM, Carl <km1h at jeremy.mv.com> wrote:
> Unplug the radio and do a full recap as well as checking for out of
> tolerance resistors. Otherwise you risk burning up the power and audio
> transformers.
>
> This is the hardest, along with the similar SX-42, Hallicrafters to work on.
> Its not for a first timer.


SX-28 is a bear, too!

After doing as Carl suggests (especially the audio output and power
supply circuits), go to the tubes. Weak tubes can indeed cause low
audio, but so can a mismatch in speaker impedance. They can also cause
the slow warm up symptoms you describe as it takes them longer to
build up some level of functionality due to their depleted condition.

A tube tester is excellent for checking things like dead shorts, gas,
and so on, but won't necessarily guarantee a 'good' tube. Couple years
back I had some issues with a 75A-4 after changing a weak tube with a
NOS JAN replacement. I checked it twice on the tester, it looked
great. It was only after I placed another tube in its place that the
radio worked properly again.

~ Todd,  KA1KAQ/4