[Hallicrafters] Need Help With SX-101 USB Problem

[Mark K3MSB]

Hi Richard

I have an SX-101A and have exactly the same problem you're experiencing.

I've had my receiver for about 15 years and it started to do this about 5
years ago.  I swapped the USB crystal with the one in my SX-111 and the
problem went away.

It came back last winter.    USB works fine when the radio is turned on,
but cuts out after a while.   Switching between USB and LSB sometimes
helps;  mostly not.

I recapped my receiver several years ago and also did the cleaning with
DeOxit.    Obviously, that didn't help.

I think the only way to fix the problem is with an alignment as K9AXN
mentioned.   Parts go out of tolerance after 50 years, and I'm not
surprised part of the converter needs tweaked.     I suspect heating of a
component and the resultant change in value is what is happening.   What
you could do it try some freeze spray, but the offending part may be in the
converter subchassis which would make it rather difficult to get to.

I don't know if you need an entire alignment or not;  it's been many moons
since I cracked the manual.

73 Mark K3MSB



On Wed, Jul 15, 2015 at 5:07 PM, richard <ramnaz at peoplepc.com> wrote:

> Hello.
> Have a SX-101 that  when I go from USB to LSB & then want to go back to
> USB it is Dead but if I pull the 12AT7 tube out & put it back in then the
> receive in USB comes back on or if I turn the on & off many times then the
> USB receive comes back on yet the LSB never goes out.. Any body have this
> problem & if you fixed it can you tell me how? I have even put a small fan
> inside & that does nothing .
> Thanks Much
>  Richard
>
> Richard Morris
> ______________________________________________________________
> Hallicrafters mailing list
> Home: http://mailman.qth.net/mailman/listinfo/hallicrafters
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Hallicrafters at mailman.qth.net
>
> List Administrator: Duane Fischer, W8DBF
> ** For Assistance: dfischer at usol.com **
>
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>