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Messages - M R I

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1
This was a waterfall image test to see the viability of playing music with the bandwidth lowpass filter set and at the same time being able to send images from above the lowpass cutoff frequency.

Thanks for picking them up.

OK. Here's another idea: images on the LSB and simultaneous music on the USB.

If I go that way I would do independent sideband stereo sound with images on both sides.

2
This was a waterfall image test to see the viability of playing music with the bandwidth lowpass filter set and at the same time being able to send images from above the lowpass cutoff frequency.

Thanks for picking them up.

3
Equipment / Re: New to me R75
« on: August 11, 2023, 0502 UTC »
I run power SDR interfaced with IF stage and CAT control functions on a modified HF transceiver. I can use the VFO knob to tune with tracking.

I also have the R75 that developed audio distortion. I traced it down in the -5 volt power supply circuit that uses a 555 IC as a DC to DC converter to a bad capacitor causing a low output voltage.

4
SDR - Software Defined Radio / Re: KiwiSDR future/replacement?
« on: July 15, 2023, 0058 UTC »
Nice. I am glad you tried it. I mostly listen to my transmitter in IQ mode. I find it sounds better because in sideband the kiwi has preemphasis. It is not needed on my transmitter since I run preemphasis.

5
SDR - Software Defined Radio / Re: KiwiSDR future/replacement?
« on: July 14, 2023, 2322 UTC »
With my transmitter bandwidth down to 10Hz I can hear a non GPS frequency locked kiwi off by a few hertz when monitoring my station and use headphones that have a very good low end responsive. Even without a wide bandwidth transmitter If you listen in IQ mode you can hear the zero beat drift with stereo headphones if not exactly on frequency.

6
General Radio Discussion / Re: AM STEREO
« on: June 28, 2023, 0557 UTC »
Transmitting in ISB stereo with suppressed carrier is effectively DSB mode. I mostly transmit in sideband anyway. I may get around to working on this at some point.

7
SDR - Software Defined Radio / Re: KiwiSDR future/replacement?
« on: June 19, 2023, 1327 UTC »
I use 1Hz resolution adjustment when the kiwi or receiving station is off frequency. You just enter the 1Hz digit as a user. The digit will not show up in the display but will change.

8
The RF Workbench / Re: Oscilloscope recommendation?
« on: June 18, 2023, 1951 UTC »
I still use HP and Tektronix analog scopes with storage that still are very useful. I also have a Tektronix digital that works in the gigahertz range.

9
General Radio Discussion / Re: AM STEREO
« on: June 17, 2023, 1802 UTC »
Give it a try on shortwave and see how well it works for you. I have been working on a method with two independent sideband channels that would not be subject to propagation fading. The receiving method would be on SDR with standard available modes like dual receiver function.

10
General Radio Discussion / Re: AM STEREO
« on: June 17, 2023, 0452 UTC »
Unfortunately the phase method of C-QUAM that was designed for the the local AM broadcast band canít keep the stereo and center channel from constantly drifting called platform motion on shortwave. This is because of signal propagation fading causing phase distortion. This makes it just about useless unless you are transmitting closer to the receiving station especially during the day or have no phase fading.

11
General Radio Discussion / Re: AM STEREO
« on: June 15, 2023, 0026 UTC »
I modified a Sony ICF-2010 receiver by bringing out the both left and right channels to line level output from original CQUAM stereo synchronous AM detector IC in the radio. This with the switchable wideband Hi Fi AM filter mod sounds great. One of the best SAM stereo detectors holding lock into the noise without distortion especially on shortwave.

12
General Radio Discussion / Re: DaveP passes
« on: April 28, 2023, 0102 UTC »
I enjoyed Daveís posts on my station. The last one from 25 meters. He will be missed.

13
Hello Dickweed. Nice signal and audio tonight.

14
If you are still checking. I came back on the air. I was shooting for Japan. Thanks for checking.

Good strong S5 here now.

Thank you.

15
I hear this station very well along with radio romania international. One of the best signals on the 19-25 meter bands.

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