Saturday, March 13, 2010

F5K Noise Abatement E71A, TM27CC

Above is a shot of the 5275 mile path between me and E71A in Bosnia

I've been playing around with a new video screen capture program. This morning I was listening to E71A on 80CW and decided to make a recording of him vs my noise, to demonstrate how well the F5K does at reducing the noise. I used to have a very low noise floor at this QTH but over the course of the last 9 months or so things have gone from good to bad. If it weren't for the capabilities of the F5K I would be sunk.

The station starts out in a 250hz bandwidth and I add noise blanking and go to 25 hz, then add the second receiver in diversity mode then go to diversity plus mode using the phase gain pad (the green bulls-eye)

There are thunder storms out in the ocean and up in NC and SC.

You can hear the difference for yourself. (If you are using firefox, you can increase the size of this video by holding down CLT and using the mouse wheel to increase the size and if you look closely you can see the mouse cursor flying around the screen changing different settings)


E71A 80M CW, 2 verticals about 3/4 wavelength apart

You can hear E71A and I also note when I peak the station he is talking to (lower left corner) I open up the noise again and then turn every thing back on, note the increase is SNR near the end of the video when I enable the "plus" feature. My antennas for this band are 2 verticals separated by about 3/4 wavelength I made the contact and on my 43ft vertical at 100W I was 559 and on my 66ft vertical at 1500W I was 599. I was about an hour into his daylight.

I next switched to 160M, tuned up my diversity antenna, and heard some early risers in EU. G3JMJ was booming in but went QRT before I could record him. I next heard TM7CC in France
a 4500 mile path, and made a recording of him.

This was just after the terminator flew over his head. In this video you can see the storm static is considerable. On 160 the antennas are only 3/8 wave separated so you can see a much greater beam steering interaction between antennas when using the plus mode. He came back first call and gave me 599. Again I go through all the noise abatement features except NR. NR does help some on static noise but I find the improvement is nothing like the improvement from the noise blankers and the filters and diversity and the beam steering that the plus feature offers


TM7CC 160M CW 2 resonant verticals about 3/8 wavelength apart

I belong to the Florida Contest Group and on their reflector (private reflector) there has been a discussion regarding how some fellow wants to configure the K-3 he intends to purchase. Most of the discussion revolves around a 400hz roofing filter followed by a second 400hz IF filter. Given my noise situation, my noise floor on 160M is at best -100dBm at 400hz and it drops down to -115dBm at 25hz. Just one pair of 400hz filters adds $260 bux to the cost of the radio. Its like I now live on a different planet. I can't even imagine living with something as pedestrian as a 400hz bandwidth

The software is called Debut video capture software and I am using the free version. Thus far its the best package I have found and the audio is very good. To make the thing track audio and video I had to reduce the frame rate in Debut to 15fps and I increased the frame rate in PSDR to 30fps