Radio W4KAZ

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2018 RSGB IOTA as K4Z from Cape Lookout

Operating IOTA for 2018 solo again.  Once again from the cabins at Cape Lookout, IOTA NA067.  Original plan was to use wire yagi from June 2018 QST article.  Weather changed plans….

As it turns out, lots of things were different.

Original plan:

The original plan was to operate on batteries at 100w using the K2 as the station.  Original antenna plan was to set up wire yagi’s for 40/20/15 using three telescoping fiberglass masts at ~30 feet height.  The wire yagis were to be based on design from 2018 June QST article(ref?).  An additional mast was going to be set up for 10m/80m, using a 10m dipole that I would base load for 80m with a K2AV style folded counterpoise.

Revised Plan:

The weather took a prolonged turn for the wet and nasty about 10 days before the event, and forecasts for IOTA weekend were maybe even a bit worse.  On the drive down to the dock the on Friday I hit light rain a couple of times.  Also a short shower as I exited the ferry onto the Island.   No lightning, but radar showed active storms offshore.  So the original antenna plan was trimmed to bare minimum – a single mast with multiple dipoles.  And a plan for quick disconnects if things got worse.

After setting up the antennas and station, quite a bit of time was burned debugging a couple of mistakes, a mixup with the feedlines and a 40m dipole with a bad connection.  Temps were about 30C, with a continuous ocean breeze.  So it was a long hot day, but not as uncomfortable as either 2017 of Field Day 2018.  But tiring, so not much radio play.

Operating Conditions:

1200Z Saturday morning – Scarf up some breakfast after a restless night of broken sleep.  A quick trip outside to tension the dipoles and eyeball local WX conditions.  Lots of cloud cover, brisk wind, but no rain or lightning.  Nice.   Turning on the radio – “OK – what’s wrong?”  Very few signals heard, all very weak.  Spent time checking to see if something was broken.   Eventually worked a few, but not having fun.  This was a real discouragement, as I had a lot of success with essentially the same set up just a month earlier for ARRL Field Day.  Was not counting on not hearing any EU stations in the morning.  Was also not counting on having such difficulty working US stations.

Spent some of the down time scouting some of the other cabins as potential sites for future trips, and a good bit of time on the beach.    Tried a couple of times in the mid/late afternoon to get runs with domestic stations, but zero success.    Starting to seem like a S&P affair.   Tuning the bands at around 1630Z it was starting to seem like there was more activity, so finally settled in for a short run on 20m CW.  WX was starting to look bad so I decided to take a break for a short siesta.  Decided I’d make a decision after getting some rest and food.  Another 20m run from 2030-2130Z and only 30 or so Q’s.  Bleh.  Unable to run on SSB after several attempts over the late afternoon.

2400Z and the WX is OK overhead, but storms over the mainland and radar looking worse.  Forecast is calling for major storms overnight and in morning.  Here is where a bit of bad planning caught up with reality.  The return trip on the ferry was scheduled for 1300z Sunday, which would have been a bit rushed in good weather.

So I decided to pull the mast down and yanked the plug on the operation.   This turned out to be a Very Good Thing.  Sunday morning brought a heavy storm with lots of lightning.  Better to watch it from inside than try to fool with antennas in that.

What Worked:

The plan for setting up the yagi’s would have been workable in this cabin area.  There was enough room for everything needed.  Batteries and station equipment, all FB.  The ‘basic’ food plan was fine.

What Broke:

The trip reservations – not nailed down far enough in advance.  The 40m dipole – must have a break in one of the wire legs.  The operator – Poor CW skills, and not sleeping sucks!

_____________CW          __                     PHONE

BAND      QSOs      Point      Mults  QSOs      Points      Mults

80            0             0               0               0           0            0

40            0             0               0               1           5             0

20           57          415           10             19         155          6

15            4             30             2               1             5             0

10            2             10             0               1             5             0

625          X             18 =          11250

points                     multipliers  score

NT4D Estate Items For Sale

This page will be used to list photos of items for sale from NT4D, SK late 2016.

The following items are for sale from  NT4D.

Alpha 87A – $3400

Good condition Alpha 87A

Good condition Alpha 87A

Drake MN-2000 #1  – $200

Drake MN-2000 #1

Drake MN-2000 #1

Drake MN-2000 #2 – $200

Drake MN-2000 #3 – $200

Drake MN-2000 #2 and #3

Drake MN-2000 #2 and #3

RBN Spot Counts, CQ WPX CW 2017

To get an idea of the efficacy of the Red Pitaya skimmer set-up, I pulled spot counts from the RBN via screen grabs off of the ‘Spots Analysis Tool’.  During the 2016 contest the skimmer station at W4KAZ was run with softrocks as the skimmer SDR, skimming only 160m/80m/40m/20m.  15m was better during 2016 than 2017, but the softrock for 15m was not reliable enough to run during a contest.

With that caveat, the W4KAZ spot  counts from 2017 are quite a bit better than those from 2016.  This reflects skimming 6 bands in 2017 as well as improvements  due to Red Pitaya vs Softrocks(2016 skimming was for only 160/80/40/20)

Spot counts from RBN for the CQ WPX CW of 2016/2017.  They are grouped by continent and sorted from high to low spot counts.

There are 4,489,640 total RBN spots for the period of the 2016 contest.

There are 4,431,759 total RBN spots for the period of the 2017 contest.

http://w4kaz.com/images/pages/skimmer_spot_counts_wpx_saturday.htm

http://w4kaz.com/images/pages/skimmer_spot_counts_wpx_sunday.htm

Despite a similarity in the total number of spots, the spot distribution shows the counts for Europe significantly higher in 2017 vs 2016.  In North America, the spot counts on

Mast Hoisting & IOTA Pages

For some reason this info never was documented here, so for my own uses, here it iz.  A few links about surplus masts, falling derricks, and IOTA.

Mast base fitting for falling derrick, and photos of falling derrick test.

Photos from 2010 IoTA, mast photos.

IOTA 2007

IOTA 2008

IOTA 2009

IOTA 2010

 

WPX SSB Prep

The 2011 NR3X Multi Single from N1LN.

And 2014 WW4LL, most local M2 leader.

Skimmer File Extracts Summer of 2014

File extracts for three summer contests from four skimmer stations for May 2014’s CQ WPX and June’s JARL All Asia and ARRL FD.  The files are by skimmer spotting station and are sorted in datetime order.

Spots from K1TTT

Spots from W1NT

Spots from W4KAZ

Spots from KM3T

CW Skimmer Station for WPX CW 2013

Some repairs to the skimmer station set up have been made after losing the 20m and 10m softrocks.  Both were probably damaged due to modifications I made to the voltage regulation circuits.  That appeared to eventually fry the QSD chip, which is the heart of a softrock.

The 20m skimmer was replaced completely with a new softrock lite.  10m is pending re-work, but replacement would probably be the best bet.

So for WPX 2013 there are five bands available, 160m through 15m.  These will be active during WPX intermittently.  I intend to bring them up and down based upon my own operating.  The skimmer will be down when I am operating.

Other changes made to the skimmer station include loading windows XP onto the Optiplex 360 that had been running windows vista.  Vista was able to run one instance of CW skimmer, but was not able to support two instances simultaneously due to sound card conflicts.  Windows XP does not seem to have a problem with the two sound cards, and is an OS supported by CWSkimmer(Vista is NOT supported by skimmer).

 

More on Xonar DX Experiments

A thread over on the softrock user group list spurred the curiosity…..: http://groups.yahoo.com/group/softrock40/message/68324

G4ZFQ has  RightMark test data for a high end Xonar D2X card, as well as several others.  An internet search found other RightMark tests of several other Xonar cards, all of whose test data show curve trends remarkably similar to those of the D2X, albeit with somewhat worse IMD, spurious, and noise figures.

The curiosity is the test data shows a roll off on the frequencies above 50khz.  The nature of the loopback test is an issue, but it also seems likely that using a sound card as the source may be having an effect on the test results at the higher edges of the sound card frequency response.  But signal generators as input to the tests shows the same general trend.  SDR at wider bandwidths pushes at these edges of a ‘sound’ card’s ability….So perhaps the SDR software is compensating for the expected performance drop-off at frequencies above audible levels?

The Test- (Pertinent Excerpt from list post):

Having not yet thought of a better way to do a meaningful real-world test on the sound card with what is available in the KazShack, I fired up the 80m softrock on the xonar DX.

Test condx:
Transmitting a cw signal(a string of dashes at about 18wpm) at 5w into a dummy load on separate radio, noting the SNR readings obtained by CW skimmer from the SoftRock center frequency(353395x) to its upper limit. With the xonar DX set to 192khz scan rate, the actual upper limit on the readings was 3629.60. SoftRock connected to normal antenna system, a NE facing K9AY with W7IUV pre-amp. In summary, a sound card test using the SoftRock system as input source.

fq….—-SNR(dB)
3534.5—-42

3543-3593-42-40

3603——37
3613——35
3623——32
3629.6—-36

After CW skimmer collected a bit of data, the SNR readings above 3600 improved to 37-39.

So the worst case for CW skimmer(as currently configured) using a Xonar DX is being 6db less sensitive at the upper edge of the 192khz bandwidth than it is at the center. That is actually a lot better than I expected for an audio device pressed into service outside normal audio ranges (and I already liked the Xonar DX).

My curiosity is now nagging me to run the same tests on all of the other in-shack cards more methodically at their maximum scan rates(mostly 96khz), and to find a lower level outside signal source. I’ll try to recruit a fellow in the near field who will better be able to generate a low level test signal.  It would be useful to see what happens at the band edges when the best copy close to the center of the SoftRock’s scan range starts out at 20dB, 10dB, or 6dB SNR.

But with the WX here improving, all of that might not happen for several months.
😉

Engineer the Possible…

Skimmer Station

Added a new page to the skimmer station fun facts list.

The new page describes observations from using several different sound cards for both music and as the interface for SoftRock software defined radios and the CW Skimmer software.

Re-purposed HyperDawg as Antenna Launcher

Ran across the hyper dog ball launcher a couple of years ago, and the potential for re-purposed applications as an antenna launcher for hanging antenna supports seemed obvious.  It is not as much fun as a pneumatic launcher, but it sure is easily understood by any boy of 8.  No air pump required.

The modified hyper dog 
The hyper dog ball launcer modified to launc lines for antennas Photo of tennis ball modified for use as line launcher

The normal slingshot type Wrist-Rocket/Crossman slingshot launcher has served the purpose for years, but not always without problems.  A 1-oz(28g) lead weight works, but not without a relatively high rate of mis-fires, line tangles, and “Oh S**t!” moments.  The hyper dog is a lot less likely to draw whining complaints from those inclined to wring their hands and moan about things that don’t really concern them..”See, its just a tennis ball.  Now p**s off!”

The hyper dog has a much larger pouch designed for use with tennis balls.  A slight bit of hacking to the hardware gives a nice re-purposed tool for lofting lines into all of those beautiful deciduous biological antenna supports lining the back yard.  So far it has been a lot more reliable in actual usage than the ole trusty Crossman, although Field Day proved its not impossible to Dork Up.  [You Know Who You Are….lol]

The reel deal:

Here the body was altered by adding a cheap spin-cast zebco reel picked up for $2 at a yard sale.  A spinning reel or open faced casting reel might be better, but I have used the zebco’s since I was 6yo.   Being more familiar with the Zebco quirks and limitations is useful. For most, a spinning reel is probably the best option.  10 or 12lb test line has proven the best choice over the years – light enough to fly, strong enough to pull, and not impossible to break if it becomes hopelessly snarled at altitude.

The reel is simply attached below the ball carrier with a couple of hose clamps.  That was later wrapped with an ugly mess of electrical tape just to reduce the number of exposed sharp edges.

Yes, the tennis balls work FB.

To modify the tennis balls, they were  just drilled with a 9/64 bit.  A loop of 1/8th braided nylon cord is secured to a small hardware store drywall toggle bolt/spring bolt. Then just cram the bolt/cord through the hole, reaming the hole out slightly if needed[leaving most of the loop of cord hanging out!].    The base of the cord is sealed at the hole with a goop of liquid nails or hot glue or some-such.  The loop of cord is about 6 inches long(~150mm), and the spring bolt serves the same purpose it normally does by providing a large area preventing pull-out.  After drying completely – good to go.

The tennis balls seem to be a good compromise between weight and a non-destructive & non-threatening projectile. [Just don’t try to pull them back up through the tree-too fast!].   The ‘trick’ to success with it seems to be making sure the cord on the tennis balls clear the end of the slingshot.  It seems to work best when the corded end of the ball is facing  up(i.e., at the top of the pouch when pulled back for a shot).

What’s the catch?

The only genuine problem I have with it is that it has a “long draw”.  Being impishly short my arms are not long enough to get the maximum performance out of the rig.  But despite that it works much better than the regular slingshot with fewer snags and mis-fires. It easily sends the tennis balls up to about 90 feet(~30m).  The canopy here prevents anything higher, so no real top-end found yet.

I suspect golf balls would be the ultimate high-flying projectile for rural locations.  Too much window glass and nervous-Nelly neighbors around the home QTH for me to try golf balls here.   A day-break early morning experiment for the future…. 😉

There is somebody here on the east coast marketing these re-branded as antenna launchers, and asking $80.  See Radiowavz Hyper Hanger, now $90USD….

Too easy to homebrew from the $22 Amazon original to peel out 80 samolies 90 GreenStamps, but it is there as an option. (!~yikes~!)