Friday, September 26, 2014

It All Makes a Difference

Tonight I was listening and watching the ZD9XF Tristan Da Cunha & Gough Is pileup on 40M

He had them spread out over about 9 khz and was working the entire 9 khz.

The band was fairly noisy.  With 25 hz filters he was virtually un-copyable 

The noise floor was -99 dBm at 25hz.  I decided to give min bandwidth a try

At 10hz I had a -110 dBm reading for a noise floor

You can see his peak signal strength was -104 dBm at 10hz, 5 dB under the noise at the 25 hz bandwidth.  At this level he became readable BUT at this level tuning has to be exact 

3 hz makes a difference.  Tonight I added a FlexControl to my DDUTIL setup giving me the ability to tune easily in 1 hz steps 

The FlexControl marry's with DDUTIL and gives a wide variety of control options to the radio.  Its other feature is it is persistent and does not loose control with change in focus

I was involved in the design of this device and it is quite powerful and plastic to its functionality. 

I use a second FlexControl on my 6300.  I guess there is still a debate raging over knob v. no knob in SDR but for me this device is perfect and I highly recommend it.  

I already had ZD9XF in the log on a few bands including 40M so I didn't turn on the transmitter to add to the QRM.

Speaking of the 6300 I switched the 40M vert over to that radio to see how it compared.  ZD9XS was about equally copyable but the 6300 only goes to 50hz bandwidth.  I used APF and adjusted the AGC-T to compensate.

The signal strength was virtually identical at -102 dBm average, but the noise floor was about -104 dBm with the wider filter so the signal to noise was a bit worse on the 6300.  This is one of those cases where pulling out all the stoppers did make a difference, but I could have made the contact on either radio.

Here is a shot of the pileup in all of its raging glory.

Good times!  I notice 80M is starting to pick up a bit as well as 160M  

73  W9OY

Monday, September 22, 2014


There is the usual controversy over on EHAM regarding the noise blanker performance especially in the Flex 6xxx series.  Since I own both a Anan100D and a Flex 6300 I thought I might publish a picture of the 2 noise blankers in action

(click the pic for increased resolution)

My friend Steve K5FR of DDUTIL fame added a digital readout of the Flex 6300 S meter.  I prefer this to the S meter readout for this kind of discussion since the readings are exact.  The readings on the 6300 are -98 dBm reducing to -117 dBm or a 19 dBm improvement in the noise floor.  In the Anan 100D we see a -20 dBm improvement, -89 to -109 dBm.  A virtual dead tie which is well within the margin between the two radios.  Both radios show a greater than 3 S unit improvement average, 4 S units on peaks.  I tried both noise blankers on the Anan but didn't see a numeric difference between the two.  This data is of NB 1 which is my normal choice.  

This test was performed a 14:30 local on 30M using the same antenna, a full sized 80M 1/4 wave vertical tuned to the 30M band with a MFJ 998 tuner.   Both radios are on CW with a 450hz offset and 100 Hz filters.  No other noise abatement is employed.  The dummy load (no antenna terminated in a high quality shielded 50 ohms) noise floor on the 6300 is -130 dBm and on the Anan 100D, -117 dBm.

FWIW here is a pic of the lightning map in my area at 14:30

I'm on the east central coast of Florida right under that big yellow/red blob of lightning.  I am running the latest alpha version of SSDR and the latest general release of HPSDR/firmware.  Personally I can't kick about being able to receive S0 to S1 signals in the middle of a huge thunder storm.  I present the data unvarnished so you can draw your own conclusions.

73   W9OY

Saturday, September 20, 2014

4th Century

This finishes up 40M DXCC for me.  I hope to hear them on other bands especially 80 and 15.  

They are playing in the Scandinavian contest and plan to be active for a week 

73  W9OY

Sunday, September 14, 2014

2nd Century

I hit my second century tonight

It was a race between 17M 30M and 40M.  17M won out with some amazing activity.  Hopefully within the week I will close out 2 more centuries.  Ham radio is a total blast.

I just tried to work RI1ANC on 15 and I had to publish this grayline pic

As he blasted into daylight in 30 seconds he went from -94 dBm to -122 dBm  

73  W9OY

Thursday, September 11, 2014

Peering into the Noise

A large aspect of working DX is being in the right place at the right time.  TY1AA in Benin came up on 30M this afternoon at 1936Z (15:36 local).  30M at this time of day and this time of year is very much like 40M, noisy as heck.  Here is a shot of daytime 30M with the noise blanker off

Note the bright green waterfall and the S meter.  You aren't hearing Benin through that!  Here is a shot with the NB on.

A clear 12 dBm improvement.  Increasing selectivity to 25hz bandwidth further improves S/N by 20 dBm compared to no noise blanker.

Copying at 25hz however requires being dead on in terms of freq.  

I still can only copy the Benin station only occasionally but I expect he will build as nightfall progresses

Spot Collector in DX labs gives some clue to the pileup

This reporting station states he worked TY1AA "up 2"   So I look at the panadadapter/waterfall and sure enought you can make out a pileup about 2khz wide

This is confirmed on skimmerfall

You can just make out about signals about 2 khz wide almost perfect bookends.  As I write this I can hear the Benin station continue to build.  Before he was nonexistent now he is 3/3, its 20:36Z 

The latest spot collector report is 


So I'm going to start mashing the key with my measly 200W and see what happens

Update:  9-12-2014 After all that I was never able to get him.  He was working a wall of Japanese and almost no USA.  Today I flipped on 17M and using skimmer had him in the log in 3 calls (less than 5 minutes)

Like I said "right place right time"  Now let's see what I can do about this ZD9XF joker on Tristan da Cunha 

73  W9OY 

Monday, September 8, 2014

Sable Island

CY0C is on the air.  It's a one day DXpedition to Sable Island

This year apparently the focus is 17 and 30 on CW.  I've been listening to the station build all afternoon and he is now in the -100 to -95 dBm range

Good enough for government work!  The pileup is fairly massive and he has good propagation to Europe and NA.  You can see and hear the propagation by listening to the stations he is working and also by looking at the skimmerfall (a couple pics below)

You can see all the red dot DX spots in EU.  The panfall looks like this

A pretty massive wall of RF and about a 6khz pileup.  Skimmerfall looks like this

I tried tail ending for a while but that didn't work so I just watched the 599 pattern in skimmer.  His freq was 18075 and he was starting at 18077 and moving up, but not every contact he might tarry on a given freq for half dozen contacts before moving on up the band.  Usually somewhere around 18080 he would flip back down to 18077 and like cream slowly rise to the top

It took a while maybe an hour but I finally bagged him at 1959Z actually a few minutes earlier since I wanted to grab a few screen shots prior to logging him

He is supposed to be on 30M at some point so B.O.T.L.  (be on the lookout)!!  I was glad to nab him since my propagation in this direction is usually not too good

73  W9OY