[Premium-Rx] TCI 8174 spectrum display

[Steve Burney]

Hi Frank,

 

I've done something similar with my 8174. I installed a 455KHz to 12KHz DRM
converter (connected to a couple of header pins on the board marked 455KHz,
probably the same spot you see in the schematic) and ran that out to a BNC
in the hole you mentioned.

While I haven't decoded any DRM transmissions (haven't had a good enough
signal on them), I have used the Dream software in analog mode to demodulate
all the regular modes. It works quite well. I haven't played with it for
awhile, but you've got my interest up again!

 

Steve 

 

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From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org] On Behalf Of Carcia, Francis A HS
Sent: Monday, October 30, 2006 9:15 AM
To: premium-rx at ml.skirrow.org
Subject: Re: [Premium-Rx] TCI 8174 spectrum display

 

Hi All,

 SK #8400-5006 

Look at the right side  page 7 of the receiver schematic. TP1 at R152 looks
like a good spot to take 455 KHz out of the radio.  This could drive a soft
rock 6 board. It may require a resistive termination at the input of soft
rock. Say 50 ohms making a 26 dB attenuator. There is plenty of gain at this
point so should be able to drive the soft rock board. This board needs
unregulated power for an internal 5 volt regulator. I think about 40 ma so
could put it inside and use internal power. Then I/Q to the rear panel. A
simple interface to tp1 and a new coax would keep the radio stock without
modifications. Either way this would make a cool interface to a sound card
and a number of software packages. Even flex radio software would work since
it was modified to work with softrock. I like I2PHD software because it does
not require 60 meg of bill gatesware to function. fc 

 

  _____  

From: premium-rx-bounces at ml.skirrow.org
[mailto:premium-rx-bounces at ml.skirrow.org] On Behalf Of Carcia, Francis A HS
Sent: Monday, October 30, 2006 11:15 AM
To: premium-rx at ml.skirrow.org
Subject: [Premium-Rx] TCI 8174 spectrum display

Hi All, 
I notice the back of my 8174 has a plug over a hole for a BNC connector. I'm
thinking a BNC could be added and a connection to the  455 KHz IF.. This
signal would be connected to a soft rock converter to make I/Q to a sound
card. Then run software like I2PHD to get a spectrum display and as an added
feature compare demodulation with the internal DSP.  I bet you could get
wider bandwidths for AM

limited by the internal IF filters. 
 I'm sure the soft rock converter could be installed in the radio with a
stereo connector on the back for an even cleaner set up.  

Now to bring myself to break the chassis cover seal.    frank 

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