100MHz Upconverter Issues

[dmp250net]

I purchased one of the 100MHz upconverters from Amazon, but it appears to not be working.  I plugged my cheap 300 Ohm loop antenna up to the RF connector, then connected my RTL2832 USB dongle up to the IF connector (there is no OUT connector on my board).  Toggling the switch shows no difference in the spectrum of HDSDR when tuned around 100MHz.  The light next to the USB port comes on when the board is plugged up.  The light on the OUT side does not come on.  Is there something wrong with my board?

Thank you!

-Dave

[Opendous Inc.]

>Toggling the switch shows no difference in the
>spectrum of HDSDR when tuned around 100MHz

First thing to check is whether the oscillator is firmly seated and
in the correct orientation. The following video has a quick intro to
setup.
http://www.youtube.com/watch?v=Rnof4xGkdAo

Let me know if this fixes things.

>there is no OUT connector on my board

This has become confusing all around. The antenna input is RF, the
Upconverter/Passthrough output is IF, and the Noise Source is OUT.
The Noise Source is an optional unfinished circuit included to not
waste PCB space. Disregard it until the day you come across the need
for an RF noise generator.

>The light next to the USB port comes
>on when the board is plugged up

That is the correct operation, it denotes power is being supplied to
the board.

[Opendous Support]

When switching between Upconvert mode and Passthrough mode with the
toggle switch, there should be some effect when you are tuned to
around 100MHz.

The oscillator should be aligned dot to dot and inserted firmly. It
will sit about 1/10" (3mm) above the socket due to its long legs,
which is fine.

Please also check that all your connectors are firmly (but not
forcibly) tightened and that you have the correct polarity on all
connectors (SMA and not RP-SMA).
http://en.wikipedia.org/wiki/SMA_connector
http://www.microwaves101.com/encyclopedia/connectortorque.cfm

[dmp250net]

Thank you for the resonse.  Sorry for the late reply.  I tried removing the crystal and re-seating it, but that didn't help.  While playing around with it I found out that the area around the USB port was getting really, really hot to the touch.  almost enough to burn my finger.  After that, I sent an E-Mail off to the guy I bought it from and asked to have it returned.  Is that an issue that has been seen before? 

Thanks again for the help!!

[Chad]

I'm having the exact same problem. Toggling does nothing. I see the spike at 100Mhz, but am not getting anything in the MF/HF range. 

[Opendous Inc.]

When you tune your DVB dongle to 100.006MHz and toggle between
Passthrough and Upconvert mode, do you see a clear spectrum difference
as in "Upconvert_to_Passthrough_Switch.jpg"?
http://groups.google.com/group/opendous/attach/5bc69c7ec95dcabe/Upconvert_to_Passthrough_Switch.jpg?part=2&view=1

If yes, then the issue is not with the power supply or LO
oscillator. It looks like Dave's issue is related to a USB connector
short. It is turning out to be very fragile.

If Passthrough and Upconvert are clearly distinguishable then more
debugging is required. Do you have anything that can generate a
signal somewhere in the 1MHz to 60MHz range? An oscillator, a MCU
development board with clock output, a signal generator. The idea is
to attenuate the signal to less than 0dBm (25dB attenuator is
guaranteed to work if signal is 5V or less) and tune to it using both
a DVB dongle directly and then through the Upconverter to pinpoint
where the problem is.
http://www.random-science-tools.com/electronics/PI_attenuator.html
http://code.google.com/p/opendous/wiki/Upconverter_Testing#Conversion_Losses

What kind of antenna are you using? Are all your connectors SMA or
is it possible you used a RP-SMA connector or adapter somewhere?

[Opendous Incorporated]

Chad's follow-up message somehow got deleted.

On Sunday, December 9, 2012 Chad wrote:

My problem is solved. Something must have been wrong with
the adapters I was using. I bought some new sma male
connectors and made a couple new cables and that did the trick.
I can clearly see the shift when I flip the switch.
Thanks for the great hardware!

[dmp250net]

I got my new one today, and after a cable change it all appears to be working fine.  Not much in my area after about 115MHz (after upconvert).  Might be time to make a new antenna.  Thanks for all the support!