Strange Issue with my Ham it Up

[opendous]

Google Groups lost a message:

I recently purchased my ham it up and have been playing around with
it and   have noticed a weird problem that I'm not sure if its an issue
with the device or something else.

Firstly it works in the sense that it upconverts, and I can easily tune in
the standard AM radio stations around.  I can even receive a bunch of
short wave radio stations.  However it seems that when i start to move
up to around 127MHZ and above I get a strange interference that is
clearly cyclical, its hard to describe, but is easily observable when
viewing for  SDR#.  In the screenshot I've attached, you can see in
the waterfall the lines that are caused by the interference.

Any clues to what might be causing this would be great.
Thanks
Chris

[Opendous Incorporated]

image

[opendous]

  The interferance (horizontal lines) is very strong and every few seconds.  It could be that the Upconverter power supply regulator is overheating, turning off, then turning back on with a burst of power.  Does IC1 (SOT23-5 package) to the left of the socketed oscillator get uncomfortably hot?  Are any of the ICs uncomfortably hot?

  A more likely explanation is that some broadband noise source is activating periodically such as a motor.  Is your computer and/or antenna close to an Air Conditioning unit or electric heating element?  Is there any sound associated with the noise spikes?

[opendous]

  Does the wideband noise only exist at Upconverted frequencies (~2MHz) or also at 127MHz?

  If you can also see it at 127MHz with a direct antenna connection to your RTL-SDR dongle then it might be a local transmitter.  127MHz falls into Aeronautical Mobile in the US and it could be powerful enough to overwhelm the Upconverter's filters if you are close enough and your antenna is good.
http://en.wikipedia.org/wiki/Frequency_allocation

[Andrew Pepper]

I bought my upconverter in 2013 (v1.0), and I'm finally getting around to trying to use it !

I don't seem to be getting any voltage to the Oscillator. I have 5v at the USB connector.

There are also 0V at the switch in either positions. It's almost as if the switch is shorted somewhere. Measuring between centre and each of the legs of the switch I get a dead short.

IC1 gets VERY hot to the touch.

Any suggestions what else to look for ?

[Opendous Incorporated]

> I don't seem to be getting any voltage to the Oscillator.

> ... IC1 gets VERY hot to the touch.

There is a short somewhere.

[Andrew Pepper]

Problem solved. The switch was the cause of the dead short. I replaced that and it's working great.