Thursday, November 30, 2017

In Memoriam: WL7F SK

Just before Thanksgiving, Wes Jennings WL7F, age 52, was killed when his snow machine was struck by an SUV near his home on the Parks Highway about 25 miles west of Fairbanks. The contest community has lost a good one. Wes could be a royal PITA, but I admired his energy and tenacity. He was brilliant and quickly leveraged his prime RF location into a top contest spot. Off grid. Low power. He took many risks, from free-climbing his tower in the middle of winter to the accident that killed him. He was a wild man, and I shall miss him immensely.

http://www.blanchardfamilyfuneralhome.com/notices/Wesley-Jennings

Sunday, October 8, 2017

Field Day 2017

Naturally, FD propagation conditions were not very good, but that didn't stop an intrepid dozen from setting up and giving it ago under the KL2R banner. (KL7CDA was the GOTA station.) We picked a new venue at the Pleasant Valley Community Center, which is just about 7 miles east of the club station. Many thanks to John AL7ID for arranging to have the building during the weekend. Although a tri-bander was erected, only 20m proved workable. Dale KL7R rocked satellites handing out AK for a lucky few. The 6m setup really didn't prove helpful, but it wasn't for lack of trying.  Many locals are on 6m FM now.


KL7R supervises tri-bander assembly.

WL7CW tweaks and cinches.

Oh, the joy!

KL7CDA GOTA: KL4HT, two visitors from MD (ham calls missing) , KL7B, and KL1JP.


Saturday, October 7, 2017

Busy Bobcat

The tower is approximately 100 feet from the shack, and for years the cabling was only half-buried and subject to breakage. We also host the local wireless ISP equipment on the tower.  A snowplow snagged the internet cable and a coax in January. Laying new cable in thigh-deep snow at 30 below is not a great thing to be doing. A plan was thus hatched with the ISP owner to properly trench between the tower and shack just after Field Day. He has some dandy toys, not the least of which is a Bobcat skidsteer with proper attachments.  It was a 14-hour day, but conduit and spare underground cables were the result.





Time Flies Like a Banana Peel

Seriously, the time has slipped past way too easily since the last blog post in March. Here we are in early October, and one might think there has been almost no radio action since then.  Well,, nearly, but not quite.  Here's part one of the re-cap:

Visalia DX Convention

This was a riot, although a smaller gathering than in 2016, which was some kind of record. Without checking official numbers, I heard roughly 750 people attended this year. Last year it was closer to 900-1000. In spite of having a bout of flu, I attended more technical and contesting-oriented sessions. IMHO the DXpedition sessions become incredibly redundant: "It was hard. We made lots of contacts. Send money."  But I digress. See what you missed: IDXC 2017 Program. The dinner was well-attended, and many laughs were had, both intentional and unintentional. Our table mates were from Canada (VE3CFK and XYL), Colorado (N7VZ and W7UM), and Colombia (HK3W). Fun!





Saturday, March 11, 2017

Propagation Sanity Check

This morning we received an email from Finland!  It's always nice to hear from our "neighbors" across the north pole.  I know we share a common bond when it comes to tough propagation.

Hello, Sirs.
It is quite foolish to ignore JT65 spotter on.
The whole of Europe called on you.

None of the answer does not come from there.

OH4SS, Matti

I was certainly sorry to miss the opening.  

So it would seem Matti is implying one shouldn't run JT65 spots to PSK Reporter if not in the shack. Now that's an interesting point of view, and one I haven't encountered before.  I think we have a little disagreement here with Matti, but maybe there are others out there who feel the same way. 

"Foolish"?  Let me explain my rationale.

Followers of the blog -- are there any? -- will know there are special challenges the ionosphere lays on us in the high latitudes.  What they teach you in radio school about propagation being basically reciprocal is total nonsense above 60 degrees or so.  It's actually hard to figure out when openings may occur.  The second element to this puzzle besides geomagnetic instabilities is the rapidly changing daylight in the Far North.  In Fairbanks, daylight changes 6-7 minutes per day throughout much of the year.  That has huge implications for HF, as one week is literally completely different from the next.

Sooooo...here at KL2R we make frequent use of spotting software and other tools to monitor the bands. That includes CW Skimmer reporting to RBN and WSJT-X reporting to PSK Reporter.  The data is helpful to other hams who are anxious to see when the bands are open to Alaska.  What's not to like?

The other reason we frequently run receivers and spotting software when the shack is unattended is to gather data for serious technical analyses.  The data sets are useful for comparing station performance, for instance.  JT65 actually yields quantitative results on received signal-to-noise ratios from various locations.  We can compare, say, AL7ID just a few miles away.  Even better, years of study have clearly demonstrated the myth of reciprocal propagation.  Approximately 80% of the time, the KL2R signal SNR will be about 6-10 dB worse at the remote station than received here.  What that means in practical terms is that when we receive JT65 at around -15 dB (good by most standards), the other station is likely to receive us at very marginal levels, if at all.  So there you have it.

Finally, let me just say presence on PSK Reporter is not the same as a call for CQ.  The spotting network does not substitute for actual RF.  So who's "foolish"?  I suggest those who would call a station without hearing their signal.  Whatever the mode, many Europeans have a bad habit of throwing out their callsign into the ether in the hopes the DX will log them, like a message in a bottle. It's remarkable that within hours of working a pileup I will get requests by email, like "Please tell me if I worked you."  Seriously?  If I worked you, you would know it.

Friday, March 3, 2017

Experience with SDRs

A couple of years ago, N1TX was sufficiently impressed with the QST review of the FiFi SDR from Germany to order a kit and put it together.  After experimenting with it as a standalone receiver, an RF Space IF-2000 board was added to one of the FT950s.  The FiFi then became an integral part of operations, providing bandscope functions and feeding VE3NEA's CW Skimmer.  HDSDR was used to drive the FiFi, and HDSDR was kept in sync with the logging and CAT software through Omnirig.  It proved very effective, and a second FiFi was added to the FTdx-5000MP.  No interface board is required, since the FT5k radio has an IF output port.  The guidance provided by G4ZFQ was invaluable to setting everything up.

The FiFi is a "sound card" SDR and a good entry-level package.

Of course, while the FiFi, SDR-Play,  Soft Rock, and others like it are somewhat plug-n-play, soundcard-type SDRs have inherent limitations due to the way frequency conversion and filtering are implemented.  Note I said "somewhat plug-n-play".  The need to tweak multiple parameters to derive optimal performance and calibration can be a pain.  

Enter Brad Forker KC7JLU, who contacted us in 2016 to discuss installing a remote SDR in Fairbanks.  I was intrigued by a system set up so anyone in the world could tune in to the Alaska receiver via the internet and sdranywhere.com. Soon the CloudIQ was delivered from RF Space and connected to the KL2R antennas.   

The stand-alone “Cloud” mode includes a built-in internet server. In this mode, the radio performs the tuning and demodulation of signals and transmits the demodulated information back to a PC, OS-X, Linux or Android client anywhere in the world.  Control, display, and audio information can be supported over a modest internet connection.  There were few issues with streaming and control, which was used to great success during KL7FWX Skywarn on-air activities in December.  Lower noise levels and better antennas at KL2R yielded positive results. Download the RemoteSDR client to listen. Note: The unit is now on an amplified loop antenna at WL7CW's hilltop location.

A few brief experiments with the SDR in IQ mode were very convincing.  In this mode, the CloudIQ streams raw 24-bit IQ data at 1.8 MHz to software like SpectraVue running on a machine on your LAN.  Wired and wireless rates are sufficient, but streaming this amount of data over the internet may not succeed. (Hence, the Cloud mode).  However, run on the local network as either a stand-alone receiver or IF receiver, CloudIQ adds some powerful capabilities.  Having a completely independent, wideband receiver in the shack is advantageous.  Driving a radio these days without a bandscope is like flying blind.  Spectravue also allows for synchronization to a local PC-controlled transceiver for true point-and-click ability to select frequency, bandwidth, and mode settings.  We added a second CloudIQ to the FTdx5000 as an IF receiver.  It works great with the FT950 + IF-2000 as well.

One thing not tested yet with the CloudIQ is CW Skimmer.  The FiFi feeds IQ data via HDSDR into a VB-Audio virtual audio cable "connected" to the skimmer for monitoring 24 kHz bandwidth.  It is not clear from brief internet searches how to feed IQ data from CloudIQ.  Another concern is whether or not it is possible to maintain the SpectraVue bandscope function with point-and-click tuning while operating in skimmer mode due to port limitations and conflicts.  Even without CW Skimmer, it's a nice asset during the contests.