Ham Radio

Of contesting & computer controlled radios

This is the first post in a series about using the FlexRadio 6700 as an all-out contesting radio. The FlexRadio 6000 series are state-of-the-art Direct Digital Sampling radios but they are different; no knobs, no direct controls and a computer required to operate the radio.  I'm hoping that these articles will provide both perspective and a resource for others interested in exploring the killer performance of this radio.

I made the transition to computer control of my ham station in 2003 after moving to my current QTH and having enough space to put up decent antennas and neighbors far enough away to make RFI mostly a thing of the past.  I started with a station built around a TS-B2000 - the no panel version of the TS-2000 with software control from the PC.  I won't describe this journey here as its document elsewhere in posts on this blog.

Computer control of a radio needs attention to two aspects:

  • Can you control ALL of the radio functions remotely?
  • How do you integrate the radio with your contesting workflow?

The computer control for most radios is via CAT and depending on the manufacturer, you may be stuck with control of a subset of the radio capabilities.  Happily with all the FlexRadio products, there is full control of all capabilities via an extended CAT command set for the radios before the 6000 and a full network API for the 6000 series.

It took precisely one contest with the FlexRadio 5000 for me to realize the importance of contest workflow.  The California QSO Party in 2009 was that contest and within the first 10 minutes, I realized the nightmare of a computer controlled radio when using the same computer for the logging software (in my case Writelog).  Note that it could have been a computer controlled Elecraft, Icom, Yaesu, Kenwood... anything!  Having to mouse the software in focus (accepting keyboard input, mouse commands) from the logging software to the radio and back again was time consuming and a mine field...  typing the wrong key strokes into the wrong window caused havoc.

By the end of the contest I had decided to build what became the FlexControl tuning knob.  This enabled me to command a limited set of the radio capabilies that I needed to access in a contest.  For the most part, I found that access to VFO tuning, RIT & XIT where the most needed.  The FlexControl allows many functions to be controlled thanks to the integration work done by Steve, K5FR with DDUtil.

With the prototypes of the FlexControl and the eventual product, I used my 5000 in many contests - all modes, CW, SSB and RTTY.  I placed well for a station with a single tower - several Call District 6 first places, a couple of records set in the Santa Clara Valley section and more importantly, I had a lot of fun!

When my 6700 arrived I was blown away by the performance of the radio.  Simply without peer!  The receiver is a joy to use and is very easy to listen to - important in a contest when after 48 hours, some radios begin to sound like they have a parott inside - and a raspy parrot at that!

To really leverage the radio, I wanted to take computer control to the limit.  I wanted a separate control panel that let me command all the radio capabilities without creating workflow issues.

Elecraft took an interesting approach to this problem with the K3/0 - this is a K3 chassis and front panel with all the controls... but no RF electronics inside.  Together with a pair of RemoteRig units, you can use a K3/0 to drive a remote K3.  The solution adds about $1200 to the cost of remote control but after a tower, antenna and amplifier, most hams won't bat an eye at that cost.  With decent Internet connectivity the solution works well.

I didn't want a control panel with knobs for controlling my 6700.  A couple of folks had suggested I build a FlexControl on steroids, more knobs, more switches etc.  But a physical device can't readily be configured for specific operating desires.  I wanted total FLEX-ibility!

Back in April this year, I was responsible for the N6V demonstration station at the Visalia International DX Convention.  FlexRadio had generously agreed to provide a 6700 for the station and sent Steve Hicks, N5AC and Jim Reese WD5IYT to help with the station.  During the weekend I spent many hours talking with Steve and Jim - in particular about contest workflow as SmartSDR was still in its early days.  We all agreed that a separate control surface as needed for contest operation.  It didn't take long for the idea of using an iPad as a "soft" control surface came up.

Driving back from Visalia I couldn't get the idea of the iPad app out of my head and after a couple of days back home, I decided to teach myself iPad application development and write one - K6TU Control coming to the app store soon!

The key takeway isn't the app.  The takeay is that contesting with a computer controlled radio - any radio - requires a seamless way of controlling it's operation that doesn't remove focus from the logging software.

It doesn't matter whether its a K3/0 or an iPad with FlexControl thrown in, you simply can't begin to optimize workflow without some independent method of controlling the radio.

Doing well in a contest, let alone winning, DEMANDS optimized workflow:

  • Cut down the number of key strokes
  • Minimize the extraneous information you send (e.g. cut out "please copy", repeating what you were just sent, eliminate unwanted characters in CW or RTTY like DE...  over the course of a contest these add up to HOURS of additional time).
  • Not having to think about controlling the radio - just do it!

For the first time since I began using a remote controlled radio in a contest, I have put the workflow issue of radio control behind me.


FlexRadio 6700 - Latest pre-release update

Kudos to Gerald and the team!  This last two weeks has seen huge progresss on all fronts - stability, features and performance. Radios are now shipping beyond the alpha and beta testers to those who indicated their willingness to take pre-release software.

I have to say things are looking pretty good!

More functionality of course means more to test - so between that and completing some new features on my Propagation as a Serivce web site, I've been busy and not really had time to sit down and compose a new post.  Hopefully this will make up for the delay...

Here's a screen shot of SmartSDR showing the panadaptor and the TX controls.


You can click on the image for a larger image but its easy to see the addition of the equalizer (for both TX and RX), plus the metering and microphone source select.

On-air reports have, without exception, had great comments on the audio quality - in many cases unsolicted which is always gratifying!  Adding some equalization to my different headsets has given me the option of "BBC Quality" for casual contacts or providing sharper audio for DXing or Contesting.

Also shipped with the last couple of updates has been the CAT control for SmartSDR.  This is started as a separate program and runs automatically.  Gone is the need to install a virtual serial port device driver (although it happily coexists with one) as it has a single ended virtual port driver included.  This means you have a single COM port which you can use to connect to sotfware requiring CAT control.

Thanks to Steve K5FR, there is also a new release of DDUtil available from Steve's web site.  This new version interfaces directly with the CAT control for SmartSDR and as before, allows multiple CAT programs to share the CAT control stream.  I've tested SmartSDR CAT with DxLab and Writelog.  I know that it also works with other programs including N1MM logger.

Having DDUtil able to talk to the 6700 and all my other equipment (amplifier, rotor, SteppIR controller etc) has me back to single button band change and a full legal limit automatic transceiver!  I'm really looking forward to getting on the air in a contest with this radio - it really has an amazing receiver!


FlexRadio 6700 - Initial QSO's

This last week I've been test flying the FlexRadio 6700 in a number of QSOs both on HF as well as 6m so I thought I'd give an update on the most recent experiences.

As a reminder I'm still using pre-release software together with the other alpha testers.  Functionality is quickly approaching the release 1.0 level and so on-air testing is now seriously underway.  

My installation is totally remote - all my radio equipment and antennas are located away from the house and controlled via Ethernet.  Audio is handled by a balanced audio link over a spare CAT6 Ethernet drop patched through from the radios to my office in the house.  The CAT6 cable has 4 pairs - two are used for stereo audio from the radio, one for microphone audio to the radio and the last for the PTT line.  For many years I used a homebrew set of balanced audio drivers but early this year, switched over to commercial components made by Radio Design Labs.  Much better fidelity and more audio drive (with gain controls brought to the front panel) make this link a considerable step up on my homebrew effort.

BrandoSince I never got round to training Brando to go and push buttons on command, I spent a lot of effort over the years in station automation.  With my Flex 5000, the CAT port from PowerSDR runs into DDUtil (courtesy of Steve, K5FR) which then handles the different components of the station - amplifiers, SteppIR antenna controller, rotor etc.

The current pre-release of the Flex 6700 software doesn't yet include CAT support (its coming soon!) so I have to go through a few extra steps to handle its operation until CAT is available.

So armed, I've made a fair number of phone QSO's over the last few days.  Mack W4AX (also one of the 6700 alpha testers) and I had a short 6700 to 6700 QSO on Sunday morning.  The bands weren't in good shape with an A index of 58 due to a sneaky CME hitting the Earth's magnetic field and creating a G2 class storm. The severe weather in the mid-West didn't help either - lots of lightning static made for a noisy band.

Mack's business brings him to Silicon Valley from time to time so we have had the pleasure of an eyeball QSO - I mention this because I know what Mack sounds like when he's in the same room - and he sounded just the same during our QSO on Sunday morning - natural and good audio!  I mention this because the TX equalizer we're using has a set response configured in the software - the controls for the equalizer are being externalized as I write this and will appear in SmartSDR shortly.

Late Sunday afternoon, I had a great QSO with Bob K8MLM in Woodbridge, VA.  I was testing on 20m just making sure I had my station control figured out and Bob called me.   Turned out Bob was running a Flex 5000 and so we had a great chat about FlexRadios in general and the 6700 in specific.  Bob was complimentary about the audio from the 6700 and with the bands in better state, gave me 59 once I'd kicked the amplifier in.

Last night (Monday) with the after effects of the geomagnetic storm abated, I checked on 6m before heading to dinner with my wife.  The band was alive and hopping up and down the West Coast and I made a couple of QSO's into British Columbia using the 6700 barefoot.  Tuning down to the CW portion of 6m, I heard WL7N in Ward Cove, AK - located in the sliver of Alaska just to the West of BC, Canada.  Of course, I hadn't hooked up the CW key line from my keyer to the 6700 so sadly a new grid square didn't make it to the log!

A note about SmartSDR and remote control...

Integrating the 6700 into my remote station so far has been very straight forward and easier than the Flex 5000.  In the case of the 5000, I have a computer sitting right next to the radio which runs PowerSDR.  I control that remote computer using UltraVNC over the Ethernet - works great and with plenty of bandiwdth between my home office and the radio, burining 50 Mbps on screen updates isn't an issue.  I can still use my FlexControl to tune the remote copy of PowerSDR as I use the Eltima Serial-to-Ethernet driver to remote my tuning knob.

Since SmartSDR connects to the radio over Ethernet, I run SmartSDR on the computer in the office.  Its a Mac Book Pro running Windows 7 under Parallels 8 for the Mac.  My FlexControl is plugged directly into the Mac and is assigned as a USB peripheral (via Parallels) to the Windows 7 VM.  The whole thing works seamlessly - tuning is smooth with no lag when I stop turning the FlexControl.

Ever time I turn on the 6700 I'm struck by the receiver performance - this radio has good ears!

FlexRadio 6700 - LF reception

Where I live in the San Francisco Bay Area, we have a HOT RF spectrum especially in the AM band.  Using my 160m top loaded vertical as an antenna, the hotest AM radio signal is -8 dBm and there are many in the -10 to -12 dBm range.

One man's entertainment is another man's pollution; operating on 160m from my QTH benefited considerably from adding a high pass filter to cut off the energy coming from the AM band.  Every radio I've operated at this QTH has had increased noise level on the low bands (80 and below) without a BCB filter.

So I was naturally curious how the FlexRadio 6700 would work in this RF environment.

Out of the box, the natural antenna choice for initial receiver testing was the 160m vertical - it captures a lot of signal and functions as a receive antenna over a wide frequency range.  I connected the antenna directly to the 6700 - no in-line filters either in the direct antenna path or the RX filter loop.  This is a harsh real world test for any receiver.

Tuning around the different bands with the FlexRadio 6700 was a surprise!  I couldn't detect any BC band induced spurii even without the high pass filters.  160m had its fair share of QRM from local noise sources - I know what causes some of them (the ones on my own QTH) and others I have a fair idea (the variable speed pool pump in a new construction about a half mile away for example).  But that was it!

Another interesting test for any receiver is to see how its LF performance functions. Although we haven't got low frequency allocations at 137 KHz or 497 KHz yet, hopefully we will in the not too distant future.  I was curious to see how the 6700 would perform at those lower frequencies.

At LF, my 160m vertical is a very short antenna!  Despite that, I've been able to receive a lot of LF stations especially aviation non-directional beacons (NDB).  Most of these beacons serve as navigation aids for instrument approaches into airports.  Many of the US NDBs are being de-commissioned as GPS has rendered them obsolete.  But you can still hear multiple beacons in the LF spectrum from 200 to 400 KHz.

All the beacons have a callsign sent in CW or MCW and I quickly found a good directory mapping frequency, callsign etc to location compiled by William Hepburn of the LWCA - you can find the directory here.

Not withstanding the inefficient antenna I can hear beacons all over the Western states (Arizona, Utah, California, Idaha, Oregon, Washington - all logged) as well as many up in Canada.  I used Google maps to find some of the locations like NDB ZP at Sandspit, BC which I can regularly copy.

Here's a capture of SmartSDR tuned to WL (Williams Lake, BC) which Industry Canada shows on 0.385204 MHz running 500 watts into a 0.5 dBi antenna at 6 meters above the ground.  BTW, a couple of notes about this capture...  

  1. You can see that the radio is in WIDE mode - no bandpass filters selected in the receiver.
  2. The S meter calibration is accurate but ignore the level scale on the panadaptor as its not yet calibrated.


The clip is short - you can only listen to a beacon id so many times!

On the ham bands, the 6700 receiver truly shines!  As I've said before, the radio sounds very clear and its strong signal performance is excellent.  Even with the SteppIR as my primary HF antenna, I can monitor different bands to see if there is activity by using multiple slice receivers - of course a tribander or multi-band HF yagi would allow monitoring with optimum signal levels but wouldn't be as cosmetically friendly!

I'm looking forward to using the 6700 in a contest and also improving my low band receive antennas - the 160m vertical is noisy and this summer I plan to build a receive only 4 square.  That should help my 160m and 80m receiving conditions a lot!

FlexRadio 6700 - out of the box and how it sounds

I’ve been tracking personal milestones in my journey with the FlexRadio 6700:

  • Alpha hardware delivered ✓
  • Alpha software releases ✓
  • Production hardware delivered ✓

For anyone with experience in system development and manufacturing, committing the build of production hardware is no small decision – it simply has to be right!  Of course the science is in the “simply” – just like “oh, it’s a simple matter of programming” – wish I had a dollar for every time I’ve heard that!

So when I got the automated notice from FlexRadio that my production version of the 6700 had been shipped, I was even more excited that when the alpha was shipped…  first customer ship was approaching!

As soon as I got the email alert that the package had been delivered, I hustled home and started unpacking.  Here are some pictures…


FlexRadio ships double boxed – this is the inner box


 Inside – Microphone, Quickstart, GPS Antenna, Power & Ethernet cables

Everyone has seen pictures of the front and back of the radio so I won’t consume bits repeating them here…  but when you get a Signature Version of the 6700, be sure to have a look at the BOTTOM of the 6700.


Truly the Signature Version – K6TU 007!

The home for the production 6700 was ready to go and so I quickly cabled up the unit, installed the latest release of software and was ready for an on air test.

Cut to the chase – How does it sound?

The first real on-air-outing for the Flex 6700 was at Visalia and the N6V demonstration station which I wrote about in the last post.  We had used a Heil PR-781 microphone with no audio equalization and some on-air reports had noted that the audio sounded “muddy”.  Not a total surprise given the voice characteristics of the different operators.

Bear in mind this was alpha software hot off the press!  A scant 3 weeks later, the release I downloaded from FlexRadio for use with the production 6700 has the transmit equalizer operational! Hats off to the software team at FlexRadio – they are a great group of professional engineers!

As a contester, I usually operate with a headset and have been on a seemingly endless quest for one that is comfortable.  I have quite a collection as the real test is a 48 hour contest weekend that doesn’t end with neck ache (from the weight) or a head that feels like its in a vice.

RS60CFThe most comfortable headset I’ve found so far is the Radiosport RS60CF which I purchased from Arlan Communications.  It too has a microphone with a flat response which allows me to choose how I want to sound – BBC quality for casual ragchewing or something with “more punch” for contesting.

With the headset connected to the 6700, I turned on the Monitor, made sure the power level was at zero and hit the PTT.  It sounded very clean with the default profile from my own monitoring.  By the way, did I mention ZERO delay audio?  Testing using the Monitor function on PowerSDR requires a high sample rate and small buffers to minimize the delay between speaking and the audio in the monitor.  There is no delay audible in the 6700 – very nice.

With the 6700 connected to the antenna via my amplifier, I made a test tranmission to set the output power and then started tuning for someone to work. 

The first QSO was with an IT9 in central Italy.  With S8 signals both ways it was a pleasant QSO and got a “nice audio” response to my question about “how does it sound?”

First home QSO with the production 6700 – another milestone to mark DONE!

FlexRadio 6700 experience at N6V

The International DX Convention is held every April in Visalia, California.  In odd numbered years like 2013, a team of volunteers from the Northern California DX Club organizes the convention.  In 2011 and 2013 two friends of mine (John K6MM and Kevin K6TD) were the event co-chairs and asked me to be responsible for the Convention Special Event Station N6V.

A very well attended event, the Convention attracts heavy duty DX’ers and Contester’s from around the world so N6V isn’t a light weight station… legal limit and a good antenna are expected – as is really good radio!

N6V is fortunate to be well supported by a number of key vendors and I am personally very grateful to the following folks who helped me put on N6V in 2011 and 2013.

  • US Tower brings along a heavy duty mobile tower (55’)
  • SteppIR supplies and assembles the antenna on site (DB-18E)
  • M2 Antenna Systems supplied the rotor (Orion 2800) and cables
  • RF Concepts supplied an Alpha 9500
  • FlexRadio Systems supplies the radio (2011 was a FlexRadio 5000)

The 2011 station was a great success – it opened a lot of eyes since this was the first opportunity many people had to operate a FlexRadio transceiver.  Everything performed as expected and many contacts made around the world.

So when I was asked to assemble N6V for 2013 late summer last year… you can imagine what I wanted to do.  2013 N6V was just crying out for a FlexRadio 6000 series radio!

I called Gerald and Greg last October and told them what I was thinking – were they game for it?  But of COURSE was the swift reply.

My 2011 experience was good but had highlighted the challenges of assembling a high performance station in half a day.  We had integrated everything together on site for 2011 and this time planned to pre-integrate before the convention.

With the great cooperation of all the vendors we quickly had a plan in place.  Molly and Joe at RFConcepts agreed to ship the 9500 to Austin so that 9500 support could be integrated into SmartSDR.  FlexRadio already had a SteppIR at their offices in Austin together with the SDA100 controller to help integrate support for it into SmartSDR as well.

Think legal limit transceiver with a resonant antenna from 40 through 10m – no configuration required…  change band, change frequency and the amplifier and antenna follow the radio.

Here’s a block diagram of the 2013 N6V configuration.


We knew that timing would be tight – the FlexRadio 6700 is a sophisticated product and Gerald’s team was determined to build the best product possible.  Like making fine wine, building robust software that can be built on for the long term (as new features are added) can’t be rushed.  You have to get it right from the beginning.

We had agreed to arrive the day before the Convention opened so that we could assemble the station.  In addition to Greg and Don who manned the booth in the vendor area, Steve Hicks N5AC (VP of Engineering) and Jim Reese WD5IYT came to Visalia to assemble the station and look after the 6700.

FlexRadio delivered!  We had a 6700 with support for CW (semi-break in at that time) and SSB with integrated support for the Alpha 9500 and SteppIR antenna!  The 6700 drove the Alpha 9500 to legal limit with about 40 watts or so of input power.

Some things to keep in mind…  this was alpha level software with support for receive (which I’d had for some weeks prior to Visalia) and transmit (which was hot off the press).  Alpha software in this case means that not all features were yet implemented and that not all the SmartSDR controls were hooked to the radio.  For example, in the release of the radio software we used at Visalia, the MIC Gain control wasn’t hooked into the radio – Steve and Jim preset the audio level and we used the power output control to keep within legal limits driving the amplifier.

We didn’t have any shortage of operators!  Here’s a picture we grabbed of some of them:



Radio Performance

To me as a contester and semi-serious DX’er, the proof of a radio is its receiver and how it is to operate (workflow and usability).  I expect a transmitter to transmit – do it cleanly, not get hot and bothered and sound good.  The receiver I expect to perform miracles – it has to handle weak signals right next to monster signals, have killer filters and have audio that I can listen to for hours on end.

I’ve used every major brand of radio in the 40 years I’ve been licensed and a large number of commercial service radios well beyond my check book.

The 6700 is the best receiver I have ever used.

It’s a FlexRadio Systems SDR so by now, while I don’t take them for granted, I expect the filters to be brick wall, no ringing and all the configurability at my finger tips.  Here’s a screen shot from SmartSDR of adjusting a SSB filter on the fly…


The filters perform!  You can pull signals out of a busy band that are really weak – even when parked next to a very strong station. 

It’s not “just” the filters, it’s also about dynamic range.

FlexRadio hasn’t released the dynamic range figure for the 6700 yet but from real world listening, it’s good – very good.  As an engineer and VC I deal with quantifiable objectives – so you may have some idea about how much it pains me to make a qualitative statement. 

The 6700 is simply the clearest radio I’ve heard.

During the CQ WPX SSB event in late March, I took some time during one of my break periods to compare my 5000 with the 6700.  The 5000 is a great transceiver with an awesome receiver –the 6700 just sounds clearer – same station, same noisy band conditions (40m at 9pm PDT) but clearer.  I don’t yet have a good explanation for this but when you use this radio, you will hear what I mean!

I’m really looking forward to using the 6700 in a contest.  I think it will be less fatiguing over a contest weekend and I’m guessing my QSO rate will benefit significantly.

Another comment about the receiver – it handles local high power stations VERY well!  Greg had a 6700 on the FlexRadio Systems booth that was hooked up to a broadband active antenna on the roof of the convention center… maybe 100’ from the tower with the SteppIR and legal limit from N6V.  Greg and Don often had that 6700 tuned to the same band as N6V was operating and only a few KHz away… monitoring a weak signal.  I’ve been at contest stations with brand X (X something other than FlexRadio) where you couldn’t do this because when the transmitter in brand X keyed up, the whole noise floor rose and obliterated the weak.


Transmit wise at Visalia the radio performed well and did its job quietly, no muss, no fuss.  We even had the GPSDO option installed and with the antenna taped to the sidewalk just outside the door, had solid lock.

For the most part we got good audio reports – we had a lot of different operators and a couple of different microphones.  Some operator’s voices together with a flat response studio microphone could have benefited from the TX equalizer but… that wasn’t implemented at the time of Visalia.

Over the course of the convention we made over 500 contacts – all of the QSOs that got logged will receive an N6V QSL card via the BURO.

Sincere thanks to US Tower, Steppir, M2, RF Concepts and especially FlexRadio Systems for their support of N6V.

My personal thanks also go to Gerald and FlexRadio Systems – they generously donated a FlexRadio 6700 as the major price for Sunday mornings wrap up event.  Another Gerald, K0JJ, won the certificate for the 6700 in the breakfast raffle draw.  He is going to be a VERY HAPPY Ham when his radio is shipped (after all the pre-orders!).

The FlexRadio 6700 made the day!

Revelations of a secret FlexRadio 6700 alpha tester

With the imminent shipment of production FlexRadio 6700 radios, I asked the good folks at FlexRadio for the “ok” to start discussing performance and real world experience with the radio.  The reason for the “ok” will become clear below but that’s the extent of it – I’m not paid by FlexRadio Systems and the company doesn’t get to “ok” what I write.

I am one of the FlexRadio 6700 alpha testers – these are my revelations.

About 18 months ago, my phone rang and there was Gerald Youngblood, President and CEO of FlexRadio Systems.  After some pleasantries and chatting about ham topics, Gerald asked if I’d be willing to sign a non-disclosure agreement (NDA) to enable us to discuss future product plans.  In my day job as a Venture Capitalist, I NEVER sign NDA agreements – there are good reasons given the number of business plans I see and at the end of the day, professional reputation and integrity are more important than any legal agreement.  Information stays confidential because of people, not because of paper!  Despite my normal reluctance to sign NDAs, and with radio products a LONG way from my investment activities, I readily agreed.

A couple of days later, NDA signed, Gerald, together with Greg Jurrens (FlexRadio VP of Sales & Marketing) and I started a series of long conference calls and email discussions about the next step in the evolution of FlexRadio products – the 6000 series.

As an engineer, business guy, oh and of course a very active Ham, this was heady stuff – getting in at the concept stage of a new radio was a rare opportunity.  As an unpaid consultant, my reward was to see the 6000 series develop from a clean sheet of paper, through development to product.

I also got to be one of the alpha testers of the FlexRadio 6700 providing feedback on usability, the UI and real world testing.

In the next posts I’ll describe my experiences with the radio from the alpha units, the demonstration station at the 2013 International DX Convention at Visalia, through to getting one of the first production units that have been shipped.


K6TU.NET - Propagation as a Service

There are two reasons why I haven't been posting regularly - last year I was asked to step in as Vice-President & Contest Chair of the Northern California Contest Club.  As a club we decided to go all out for the ARRL RTTY Roundup and the members asked for propagation charts to help with strategy and band planning.

I had produced propagation predictions using VOACAP before and so I volunteered to develop predictions for each of the 5 contest bands for a full 24 hours.  Wow!  It took me forever!  VOACAP runs very quickly on a reasonable CPU computer but generating the graphics required a lot of hand manipulation using VOACAP's image generator and Photoshop.  All in all, it took me half a day to produce all the graphics.

The graphics were a a great success and NCCC won the 2012 RTTY Roundup hand down - setting a new record!  The propagation charts were such a success that the club members wanted them for the next contest - that took me about 6 hours to generate.

At that point, I was hell bent on finding a way of automating the entire generation process - that took me almost 2 months of night & weekend coding but by late March I had it done.  Now generating the predictions took less than 10 minutes using the capabilities of my MAC under its UNIX colors!  Then one of the members asked me if I could get the same thing running under Windows...

By the time I looked at all the different packages I had used, I came to the conclusion that what was really needed was a web service.  With a web service, I could remove the learning curve of customizing VOACAP predictions to a level where it would be as simple as filling in a form and clicking a button.  No learning curve, no software to install.

I started work on K6TU.NET - Propagation as a Service web site at the end of March.  I launched the site into a closed beta in September after 6 months of heavy lifting coding and assembling an industrial grade web site.

I'm delighted to announce that the site went live into production this last weekend.  Stop by and take a look what you can achieve at the click of a button - a good way to do that is to visit the Quick Tour page and see the forms and graphics.

Here are a couple of examples to whet your appetite...

This is an example of the regular prediction you can run - this is a screenshot of a single band/hour combination where you can see the predicted propagation by visualizing YOUR signal strength across the world.


And here is an example of the Contest Strategy Prediction - this is perfect for planning which bands to use for either search & pounce or CQ running during a contest.



K6TU.NET supports many different types of propagation predictions and has both free and premium features.  I hope you will stop by and take a look!


Contest Knob – Announcing the Product

Building the Tuning Knob and getting it working was just the tip of the iceberg.  My sense from the beginning was that if I had a need for a contest control for my FlexRadio based station, others would too!  So it didn't take long before I started thinking about taking the tuning knob from a project to a product.

Building a product for use by multiple different people is a very different proposition than simply building a project.  A project just has to work and seldom is the cost a significant issue.  A product on the other hand has to meet a set of requirements from functionality all the way through to volume production.  

Kevin K6TD and I had been through this many times before – both in our professional life developing products for companies we worked for as well as our own company.  Not only do you have to produce a product but you also have to sell it!

We decided to build the tuning knob with product production in mind, get it working, build enough units to prove out the user requirements and then look for someone who would be interested in producing and selling a product.  Fortunately we had a team of people in Steve K5FR, Kevin and I who knew how to do this and moreover, weren't daunted by the prospect of finding a partner.

It didn't take us long to get the first prototype version designed, built and working!  I guess it's deeply embedded in my genes but the thrill of building something and getting it working never gets old.  Assembling the rev A boards was no exception – we built up a handful and starting giving them to folks we thought would give us good feedback.

We sent one of the boards to Greg Jurrens, the Vice President of Sales & Marketing at FlexRadio Systems.  Greg is an avid VHF operator who also likes to operate contests.  Greg used the tuning knob and really liked it – he liked it so much that he called me and asked if we'd ever thought about turning the tuning knob into a product – BINGO! We had our potential partner!

Over the next few months Greg and the team at FlexRadio gave us great feedback on the knob and we began talking about what be necessary for FlexRadio to take on production and sales.  One thing led to another and eventually FlexRadio assigned Graham KE9H to work with us to turn the tuning knob into its final version.

So today I'm delighted to be able to announce that FlexRadio will be releasing their FlexControl product at the International DX Convention at Visalia, California next week!  FlexControl is the product version of the Tuning Knob designed and built by Kevin K6TD and myself with full software support in DDUTIL provided by Steve K5FR.

Gerald Youngblood CEO of FlexRadio Systems and Greg Jurrens have been kind enough to allow me to provide this preview of the product ahead of its appearance at Visalia.  Greg tells me it will retail for $129.95 and will be available for orders & shipment by the time of the Dayton Hamvention in late May this year.

It's been a great journey and we're delighted at the outcome!

Origins & Refinement of the Contest Knob - II

After my experience with the first generation knob, I realized that a complete re-think was needed for a new knob. Ease of use and low cost were critical coupled with a system design approach to get maximum utility out of the solution.

Kevin K6TD and I have worked together for many years – both for the same companies and also with a number of product ideas we'd commercialized ourselves. Kevin is a very successful VP of Engineering and a serious hardware wizard - so I decided to see if I could rope him into a new project. Despite a busy work schedule, Kevin agreed and we started talking about the specification for the new knob.

A simple list of requirements quickly took shape:

  • Cost effective
  • Simple to use
  • Silky smooth tuning (no tuning detents or lag)
  • Compact form factor
  • USB connected
  • Seamless PC side integration

The need for seamless integration on the PC side was a no-brainer – it was a critical element to get that silky smooth tuning experience and part of the system design to eliminate tuning lag. The logical place to provide this was in Steve K5FR's DDUTIL – "the" MUST HAVE for station integration for any FlexRadio owner. You can find Steve's software on his web site.

DDUTIL is an amazing piece of work. Think about all the different elements that make up a modern radio station (amplifiers, power meters, antenna rotators, antenna controllers, switching matrix, filters, multiple software programs…) that need integration. Integration and automation can simplify and streamline operation. Core to this simplification is getting information from the radio to each of the station components – especially frequency information. DDUTIL sits on the CAT control stream provided by PowerSDR and manages the distribution of CAT data to the station components. You can think of DDUTIL as a CAT multiplexor and station component manager.

I got to know Steve shortly after I purchased my Flex 5000 – I'd decided to add an Expert SPE-1K amplifier to the station and wanted to be able to control it via DDUTIL. The Expert amplifier was on the DDUTIL "to do" list and so I emailed Steve to see what he was planning. The reply email came quickly! Steve was ready to go as long as someone could help him debug the implementation. We worked together to get support for the Expert working and during several long phone calls, found we shared a lot of ideas and common experiences – and had a ton of fun working together!

In a quick phone call to Steve I described what I was thinking and got a resounding "I'm in!" – We had our development team up and running!

Kevin started looking for a cost effective replacement for the optical shaft encoder used in the original project. In parallel, Steve and I worked on defining a control protocol between the new knob and DDUTIL. We opted for a simple control set modeled after the ubiquitous CAT format – simple ASCII text commands with a ';' terminator. The spec for the CAT stream quickly took shape and we started thinking about how to prove out the different pieces of the design.

The first step was to find a development board using the same PIC that Kevin had selected as the core of the system. We opted for a development board sold by Futurelec, a company based in Asia – at less than $50, a good basis for the proof of concept (POC) system shown below.

The POC system is simply the development board with a shaft encoder and LEDs mounted on a daughter board. The daughter board connects to the peripheral connectors on the Futurelec board. This enabled me to start developing the software to handle the shaft encoder and the USB port to connect the board to the PC.

The development of the USB software was greatly accelerated by using Ian Harris' PIC PACK library – I covered this in a previous post which you can find here. I quickly got the development board connected to the PC via USB and began implementing the CAT-like control protocol to talk to DDUTIL.

In short order Steve had the basic support for the knob integrated into DDUTIL and had the POC system working as an active tuning knob with DDUTIL. With a little bit of tweaking in DDUTIL we realized we were pretty close to that "silky smooth tuning" effect we were looking for but if you really spun the knob quickly, there was still a lag.

Kevin suggested I implement acceleration detection – change the tuning rate generated by the knob when it was turned quickly. Some thought and basic calculus later, I had this figured out and suggested to Steve that we modify the CAT stream so that the knob could signal that a faster tuning rate was required.

As we were getting this done, Kevin sent the hardware design to the PCB manufacturer and we built up a handful of tuning knobs. You can see this rev A version of the knob below – you can get an idea of scale as the physical knob itself is a little over 2 inches in diameter.

Acceleration detection got us a long way to eliminating the CAT queue but the lag still showed up with aggressive tuning. The challenge was the chain of commands sent to PowerSDR to change the tuning rate – multiple CAT commands to effect a single tuning step – regardless of the size.

Steve had worked closely in the development of DDUITL with Bob Tracy K5KDN who developed the CAT support in PowerSDR. With Bob's help and support from FlexRadio, we were able to get a couple of new CAT commands implemented in the next development build of PowerSDR. This reduced the number of commands needed to tune a step to one. This nailed the CAT queue problem and we got the coveted "silky smooth tuning" we were looking for!

Feedback on the rev A board was positive – we had used the switch incorporated into the shaft encoder to implement a number of different features. We used switch clicks much like mouse commands – single, double and long click. Clicks are detected by the knob and signaled up to DDUTIL so that it can change different controls on PowerSDR.

At the time, Steve was also working with Lee Crocker W9OY to get DDUTIL as the control center for SO2R operation. Lee really liked the idea of the Tuning Knob but said he wanted some additional control switches that could be used with DDUTIL to automate other aspects of station control.

We had decided to spin the PC board to make some manufacturing changes and so it was a logical decision to add three simple push button switches to the hardware. Kevin re-laid the PCB and sent out for board manufacture. The boards came back and we built the rev B version of new tuning knob.

Between us, we built a fair number of rev B units and got them to folks for "real world" testing. This time the feedback was very strong and very positive – we knew we were getting very close to the final solution!

We started the process of getting the tuning knob turned into a product - more on this in the next post…

Adding the auxiliary switches was easy for both hardware and software but I'd made a decision to detect just a simple on/off operation – allowing another three actions to be automated. By now Lee W9OY had his hands on a rev B unit and just like Oliver Twist wanted "More!" – Lee asked for the same kind of click detection on the auxiliary switches as I'd implemented on the shaft encoder switch.

I groaned when I heard this request… since the auxiliary switches had been an afterthought, I'd grafted support for them into the code rather than taking an integrated approach. Supporting multiple click detection on the auxiliary switches required a fair amount of code re-factoring to avoid an even worse "graft" – ok, kludge!

Over Christmas 2010 I finally found time to re-factor the code, document the changes to the CAT stream to allow for signaling auxiliary clicks to DDUTIL and get new code off to Steve.

By late January 2011, we were DONE! Steve added a whole new tab for configuring the knob into DDUTIL and Lee was happy! One of our knob users in Europe took a high place in a major contest and gave the knob the credit for his success.

The journey from concept to product has been very interesting. We started with a distributed development team of three – unique because we've all never met in person. The final version required the collaboration of two more people in different parts of the country… and we've all never met in person or even had a joint conference call together. Email was our primary communication tool and it worked because of a shared vision and mutual respect.

Finally, I'd like to recognize…

  • Kevin K6TD and Steve K5FR – they shared the vision and gave their full support to this project. Without them, the tuning knob would likely never have seen the light of day!
  • Team FlexRadio Systems for their willingness to incorporate changes into PowerSDR that we requested – there aren't many companies that will take this kind of feedback so willingly to heart from their customers!

In the next post, I'll talk about the final steps of the journey…