Dirt Is Good (Friday Ride)

The hum of the knobby tires on the hardpacked earth.  The heightened sense of awareness brought on by endorphins released during intense exersion.  The rush of the descent. Satisfaction of cleanly navigating a tricky section of trail.  The churning crank and the searing burn on a long climb.  Being in nature, no concrete no cars no buildings no phones.  All the trappings of modern civilization gone except for one machine of steel and aluminum and rubber. 

PSK-31 Operations at KD8JHJ

Here is a shot of my computer screen while receiving the ARRL (American Radio Relay League) Propogation Forecast Bulletin which is broadcast from the ARRL station W1AW in Newington CT.  Recently the ARRL has started transmitting the bulletins using the digital mode PSK-31.  W1AW is a state of the art amateur station with an excellent antenna farm.  Geographically W1AW is only a couple states away from my location so the signal is always loud and clear.  These informational transmissions are also sent using other modes such as CW and RTTY.  For many years hams have sharpened their CW copy skills by listening to the ARRL bulletins broadcast in Morse Code. 

Think of PSK-31 as instant messaging by wireless without an internet connection, phone lines, 3G networks and associated baggage that we pay money for every month.  PSK-31 was developed by Peter Martinez, G3PLX and introduced into the amateur community in December of 1998 as a way for hams to communicate in a live chat keyboard to keyboard fashion.  Note the deep blue area at the bottom of the screen.  This is called the waterfall.  It is basically a graphical representation of a 3 KHz slice of radio spectrum.  When a digital signal appears in this piece of bandwidth it is shown as a yellow stripe that starts at the top of the waterfall and slowly decends. When the transmission ends so does the stripe, the tail end dropping down and finally out of sight off the waterfall.  This visual display lets the operator tune in on the narrow signal and allows the software to begin decoding the digital signal into readable text that appears in the larger receive window above.   The incoming text prints in real time one character at a time as the sending operator types.

The integration of computers into ham radio is an amazing and ever changing facet of this great hobby.  Most of this is very technical and flies way over my head but I am learning and having fun at the same time.    One purpose of this blog is an explanation of my hobbies and activities for friends and family.  For that reason I try to keep things from turning into a dry technical report.  Writing about the digital modes is a real challenge.  I barely understand how much of this stuff works myself, let alone try to explain it in layman's terms.

When I am ready to transmit I begin typing into the orange window and the information from my keyboard is encoded into audio tones by the software and a dedicated sound card.  Shown below is the Signalink USB interface.  This piece of equipment is the link between my laptop and the transmitter.  The Signalink has a high quality soundcard that is dedicated to ham radio duty so the laptop's inferior soundcard can be left to do it's thing for the computer.  I'm a knob guy so I like the Signalink for the manual controls on it's front instead of accessing windows on the laptop to manipulate sliders controlling the soundcard functions.  

Basically the Signalink and it's soundcard are like a modem.  The information encoded into audio tones is fed to the transmitter by this device and ultimately radiated out into the ether. The shielded USB connection cable is not visible but it's there plugged into the back of the unit and drops down behind the table top.  Here is where things get interesting and more confusing.  The TX knob on the Signalink controls the amout of audio "drive" to the radio.  To provide the most efficient and "clean" signal this drive has to be carfully controlled.  The TX knob on the Signalink works in conjuction with the radio's ALC or Automatic Limiting Control.  ALC limits the RF drive level to the power amplifier during transmit to prevent distortion.  To adjust for proper operation I switch my rigs output coax to a dummy load.  This is just a giant resistor that absorbs the RF signal and bleeds it off as heat instead of sending it on to an antenna.  While transmitting a PSK signal I watch the ALC meter on the rig.  If the TX knob on the Signalink is turned up too high one or more bars will show on the meter.  Backing off the TX knob until no indication of ALC is evident on the meter lands you in the sweet spot and the ideal balance of drive power is met.  This is why I like the Signalink USB.  My laptop's operating system is quirky enough and I think it would be a real pain to minimize fldigi (digital mode software) and go to the control panel window and jump through those hoops just to make a small adjustment to the soundcard drive. 

That's it! Once the ALC conditions are met and the output is switched back to an antenna all systems are go for digital radio fun. 

Click on the picture for a close up view and look at the yellow signal on the waterfall display.  You will notice two fine red lines that straddle the yellow strip.  This is the tuning indicator and is movable by using the mouse.  If you see a signal and click on it the two red lines will jump to that spot and the software will begin decoding.  The same applies when transmitting.  Find a clear space on the waterfall, click on it and where the red indicator rests shows the exact frequency of the transmitted PSK signal.

Last night I spotted a bright PSK signal on 30 meters.  I copied the callsign that belonged to the trace and when the QSO was over I gave Jean VE2GHI in St Georges, Quebec a call.  He responded and we had a pleasant textbook PSK-31 QSO.  I am very proud of the unsolicited comment that Jean made concerning my signal.  The tricky part with the digital modes is that you cannot see your own signal on the waterfall so you can't tell if it is overdriven.  This is why monitoring the ALC is so important.  With the system properly adjusted 15 watts is more than adequate to send a good clean signal just about anywhere.  

Note that there is no yellow stripe under the red indicator on the waterfall.  I took the photograph after our QSO ended.  The indicator shows where Jean's signal was.  To the right are two bright signals and a very faint one just visible.

PSK Facts

PSK stands for Phase Shift Keying.

A PSK-31 signal bandwidth is 31.25 Hz wide. Hence the name PSK-31.

Because of the very efficient and narrow bandwidth PSK-31 is well suited for low power operation and less than ideal antenna systems.

PSK-31 contacts can be conducted with about 100 Hz separation between signals without interference.  This means that twenty hams can carry on PSK-31 contacts in the same amount of bandwidth required for one sideband voice contact.

PSK-31 is probably the most widely used and popular of the digital modes in amateur radio.

Commute!

Here we are saddled up heading off to work and school.  The weather has been picture perfect this week and we actually got two commutes by bike in this week.  Wyatt said "I like riding to school.  It's a nice way to get a ride in."  Some words any cycling dad is happy to hear.

On the way I passed this church bulletin board.  The message has some significance if you have been following pro cycling at all this past week or two.  I think the Pastor at this church might be a cyclist.  Last summer they hosted a stop on the GOBA tour (Great Ohio Bicycle Adventure).  GOBA is a three day fully supported tour that has a different route each year.  They load your camping gear on box trucks and you ride your bike all over the state without panniers and racks and 70 pounds of gear on board.

Recumbent Goal Achieved!

This morning after coffee and breakfast the conditions were ideal for a bike ride.  Clear sunny blue skies and not a breath of wind.  The temperature was a pleasant 75 degrees.  I wanted to go mountain biking to try out the new tires but the past week was very rainy.  Rather than face the possibility of encountering mud I settled for the old standby recumbent ride on the B & O Trail.

I got warmed up and was feeling pretty good cruising along at a nice clip.   At one hour elapsed ride time I noticed I had traveled 15.99 miles.  This meant that I had a whole hour to finish 14 more miles and put myself safely into record breaking range of a sub two hour 30 miler.  The ride was mostly uneventful except at some point I got stung by a bee in the side of the face.  I think he got caught under my helmet strap.  Not a big deal really, it's spring and everything is blooming so bees will do what they do and stay busy.  On this ride I encountered the most recumbent riders that I have ever seen on one ride.  I lost count around ten or so.  Mostly older folks on long wheel base bikes however I did see a lone rider who might have been younger than me.  On a high note I must comment that not just one but two serious looking roadies actually waved to me in passing.  This more than makes up for the bee sting!  I think everybody was pumped because of the great riding conditions. 

When the odometer turned over to 30.00 I stopped to take a picture.  I actually smashed my old record of 2:09 by nearly 20 minutes.  Soldiering on I rode well until around 35 miles where my output usually begins to diminish.  I still managed to keep above 15 or 16 mph for  the rest of the ride.

Here's the stats for the complete ride which itself is another record broken.  (New course record for the HP Velotechnik. Old record was 2:29 set June 2008.)

Ride time:  2:17

Distance: 37.5 miles

Average speed:  16.3 mph

It is important to keep in mind when looking at this data that my recumbent bike weighs about 34 pounds.  That's like riding one Trek Madone and carrying a second one on your back.  Now six months short of my 40th birthday I am pleased with my fitness and the fact that I am still able to raise my performance bar by such a big chunk.  

Saturday Afternoon Homebrew

I love Morse Code keys.  I have a small collection of keys that represent the different designs that have appeared throughout the history of telegraphy.  Because of this I am not an operator who is happy pounding away on the same old brass.  I am always changing out keys, using different ones on the air at my amateur radio station.  Reaching around to the back of the transceiver amid the jungle of wires to connect and reconnect key cables is a drag.  This project is something I have wanted to do ever since I got my second key.

The key junction box lets me connect four different keys to my radio at one time and use any of the four without interruption.  Luckily I have access to some light fabrication equipment at my screen printing shop.

 

I used 1/16" aluminum to make my juction box.  It's really not a box, more like a bracket to hold the four 1/4" mono jacks.  Using a manual punch press I accurately made holes in the aluminum panel spaced and sized just right to accept the jacks.  I changed out the punch and die to a smaller size to make holes for the mounting screws and the cable clamp at the bottom of the bracket.

The next step was on to the bending brake to bend the bracket to 90 degrees.

Here is the junction box with the four jacks installed.  I used solid copper hook up wire and soldered each of the jacks to the main cable.  Heat shrink tubing finished off the connections.

The opening picture shows the junction box in its final position at the back of the operating desk just behind the transceiver.  It is easily accessible from the left end of the desk yet out of sight from the front.

An Interesting Amateur Radio QSO

USS Douglas H. Fox DD779 

Image contributed by Howard Longstreth to the archive at http://www.navsource.org/ 

On May 14th I met Andy KB3IFK on 40 meters CW.  Andy is retired and lives in Baltimore, Maryland.  I was excited to learn as I decoded the beeps in my headphones that Andy was once a Radioman in the US Navy.  I am always amazed and honored at the chance to work these professional radio operators on the amateur bands.   

Andy enlisted in the Navy in 1961 and spent six months in "Radioman A" school where he learned Morse Code and RTTY (radio teletype).  With training complete he began his career aboard the Destroyer USS Douglas H. Fox.  The Fox had recently been outfitted with the days latest anti-submarine warfare equipment.  After an honorable discharge in 1965 Andy settled into civillian life and never gave ham radio a thought as he had morse code ringing in his ears for years after leaving the service.  He became a licensed radio amateur in 2002.

Being the ever curious history buff I looked up Andy's ship online and discovered some very interesting history.  The Fox was already 15 years old when Andy went aboard.  Commissioned in 1944 the Douglas H. Fox first saw action in May 1945 during the final campaign of the Pacific war.  During the Battle of Okinawa she successfully thwarted a number of kamikaze attacks but not without extensive damage and the loss of ten brave crewmen. 

During 29 years of dutiful service The Fox saw action in three wars, WW2, Korea and Viet Nam.  The Douglas H. Fox was decommissioned in 1973.

It was a unique and rewarding experience to use ham radio to communicate with someone who served as a radio operator aboard this destroyer.  Particularly cool to use Morse Code I might add.

Thanks Andy.

Tire Test

Over the past couple seasons I have been running less and less air in my off road bike tires.  Back in my racing days (1994-96) I would use narrower tires 1.75" wide and 45 psi or more of air pressure.   For a long time I needlessly punished myself with a harsh ride and less than optimum traction all for the sake of less rolling resistance.  These days I look to optimize comfort and I have realized that less pressure lets the tires grip the trail much better and a softer ride results.  I believe this line of thinking pays off on long 3 hours trail rides.  Rolling resistance is an important factor for road bikes but not such a big deal on the trail.

Last season I ran Hutchison Airlight Pythons 2.00" wide folding beads.  The Pythons are a great tire but the knobs were starting to round off and tiny dry rot cracks were setting in on the sidewalls.  From one of the big mail orders I found a pair of Michelin Dry2  2.3" inch folders for $9.99 a tire.  They are fat!

I mounted them up and took the bike out for a test ride.  The air pressure was 30 psi.  I don't have any trails near the house but nearby is an upground reservoir which has a few bare patches that simulate a "trail".  The ride is very plush and I am liking these tires already.  They feel heavier but I cannot really comment until I can ride on some real dirt. 

No fancy tubeless rims or anything just good old 26" MTB wheels with presta innertubes.  My weight is 160 pounds so I don't suffer from pinch flats like the bigger guys.  I am also reluctant to make the move to 29er wheels.  I am 5'8" tall and a frame my size with 29" wheels would have to be pretty compact.  I know there are small rigs out there but I still worry about my toes hitting the front tire.  And besides the Yeti is still a sweet single speed conversion even with its old timey "V" brakes.

Happy Trails

Antenna work at KD8JHJ

On Sunday I managed to get my support lines for the EFHW antenna wires much higher into the tree out back.   The tree is a silver maple whose trunk splits into 3 smaller trunks about four feet above ground.  After closely looking at the tree for a month or so I settled on a target support branch about 25 feet up in the only area of the canopy that was in the clear and free of smaller branches and foliage.  I know it probably would not matter at my low power levels and the fact that the wire is insulated but it would bug me if the 40 meter wire was in contact with the foliage.  I was going to climb the tree and attach a pulley system but it was a bit windy and I don't enjoy climbing trees quite as much as I did when I was 13. 

One day at the local hardware I spotted a roll of very bright pink string.  I also picked up a 7/8" nut that weighs an ounce or two to tie onto the pink string.  I explained to my son how I would twirl the string with the nut and fling it up into the tree David and Goliath style and hopefully over the branch.  I could tell by his expression he thought I was crazy.   After ten or fifteen throws I got the string right where I wanted it and pulled up the black Dacron antenna cord.  Wyatt was impressed.  Showing tricks like this to my son is one of the little joys of parenthood that I really get a kick out of.

Searching in my scrap wood box I found some pieces of 1/4" X 12" mahogany to wrap the cordage on to keep tangle free for future use.

I had doubled the height at the far end of the antennas.  Back in the shack I noticed right away that the noise floor was lower and signals seemed louder.  I believe I was picking up lots of electrical noise from the house.  Incoming signals are not any stronger now, there is just less static in the background.  As for any improvement in my transmitted signals I can't really say.  I have made 7 contacts since the modification and the stations I am reaching are not reporting any difficulty hearing me.  One ham I worked last night on 40 meters, Bob W0CAB (Been a ham for 60 years!) near Kansas City said the rig sounded great for only 40 watts.   

Friday Ride

Fridays after work I like to go for a bike ride.  Last Friday, I celebrated Arbor Day with a mountain bike ride among the trees at Clear Fork.  I rode about 5 miles with lots of short climbs on the blue trail.  This Friday I was feeling like a bent ride.  I started a few miles from the northern end of the B & O trail and planned on riding 15 miles south and turning back.  Once I got going I noticed I might just luck out and get a tailwind push on the way back so I decided to run for time.  A few miles into the ride a gentleman caught up with me riding a P38 Lightning.  He was retired from commercial printing after 42 years in that industry.  He has been riding recumbents for 9 years he said.  I hit 15 miles at about an hour and 10 minutes and did indeed have a nice tailwind to help me home.  The weather was beautiful and sunny but clouds moved in along with tornado watches for all the surrounding counties.  I made it home long before the rain.

 I have been trying to crack 2 hours for 30 miles on the recumbent.  I have done 1:45 on my Lemond road bike and just under 2 hours riding the Ti general purpose bike when it was a single speed.  I think this season I will reach my goal.

                                            

Bike: Recumbent

Ride Time:  2:09

Distance:  30 Miles

Average Speed:  13.9 MPH

Max Speed:  23.9 MPH 

HP Velotechnik  Street Machine GTE

American Morse Equipment - Bushwhacker Paddle

A new key at KD8JHJ

This year I was lucky enough to receive a tax refund.  After some careful consideration I decided to treat the station to some new Morse Code equipment being that most of my keys are of 19th century design.  The latest key in my lineup is actually called a paddle.  A single lever paddle to be specific. 

The paddle came as a kit well packaged as shown to protect the finely machined parts until final assembly.  The various parts are tiny but when put together result in a compact and precise feeling switch.  I mounted the paddle to the optional desk base and it is solid.  Never moves even when I am on the air.

It took me about an hour to put the kit together.  A well written and thorough assembly manual can be found online.  Operation is EASY- push right for dots and left for dashes.  Spring tension and leverage of the mechanism are fully adjustable.  Doug Hauff, W6AME and his shop American Morse Equipment is a FB operation that specializes in QRP stuff like paddles and machined enclosures for electronic projects.  They are located in San Luis Obispo, California.

The paddle's cord plugs into a Logikey K-5 Keyer. This device is a microprocessor that makes the string of dots or dashes.  The K-5 is the gray box in the picture with 6 buttons and a single knob on the front beside the insulators.  With the large knob the character speed of the morse code can be increased or decreased.  Other functions such as memory are controlled with the 6 buttons. The keyer in turn is connected to the key jack on the back of the Transceiver.  These two great American made components represent one of the latest designs in the 170 year history of telegraphic equipment.  

Yesterday on 40 meters I called CQ and made contact with Tom, W8JI near Macon, Georgia.  Tom is a great op who was keying with a vintage Vibroplex Lightning Bug. We had a pleasant QSO and I got to report back to Tom the difference in his signal strength as he rotated his Yagi antenna from the west to the north focusing his signal in my direction.  

The paddle and keyer let me concentrate on what I am trying to say while the equipment works out the length of each character element and the spacing of the dashes and dots.  Much easier than sending with a straight key or manipulating the bug which still requires you to regulate the start and stop and length of each dash.  At slower speeds around 15 words per minute or slower straight keys are fine but as my copying speed has slowly increased I now enjoy sending with the paddle.  

("FB" is an old land line Morse Code signal that means excellent or great. Fine Business.)

Insulator Post

Here is a cool insulator from my collection.  It is a power piece made back in the 1930's or 40's.  This color is called amber.  I like to call it "Beer Bottle Brown"  Below is an excerpt from some Hemingray literature that I found on the web. 

Hemingray D-510

For Primary Power Distribution Circuits 2300 Volts. Also for 4600 and 4000-volt Y circuits.

An insulator of high dielectric and mechanical strength. Ideal for primary distribution circuits. Extra heavy constructions -- rugged and everlasting. New in design and material. Carefully annealed by special Hemingray process.


Voltage Rating _ _ _ _ _ _ 6,600 Volts
Dry Flash-over _ _ _ _ _40,000 Volts
Wet Flash-over _ _ _ _ _22,000 Volts
Leakage Distance _ _ _ _ _ _ 4 3/8 in.
Wet Arcing Distance _ _ _ _ _ _ 1 in.
Diameter of Groove _ _ _ _ _ _ 7/8 in.
Weight per Piece _ _ _ _ _ _ _ 20 oz.
Quantity per Carton _ _ _ _ _ _ _ 50
Weight per Carton _ _ _ _ _ _ 68 lbs.
Weight per 100, packed _ _ _ 136 lbs.

The new Hemingray Glass possesses extra mechanical strength and high dielectric qualities. These insulators are unaffected by rapid temperature changes. They are thoroughly tested for heat shock.

-From: Hemingray Bulletin D-1 page 4