SPARC members showed up at Hamcation and for the 12 Noon annual member’s picture.
Click here for the slide-show clip: February 10, 2018
SPARC
This serving of Lagniappe features some poetry of Olde.
Silent Key
By Howard O. McCall
From The Sparks Journal, Vol. 3 #2
A shaft of sunlight,
Pierces the gloom,
Of the shadowy quiet,
In the radio room,
The equipment sits idle,
Because, you see,
The one who used them,
Joined SILENT KEY.
The once shiny microphone,
Now dusty and dull,
A coaxial switch,
Angles off from the wall,
The chrome plated bug,
A beauty to see,
The one who made use of these,
Joined SILENT KEY.
Gone is the good cheer,
When talking to a friend,
The signal is stilled,
SK, or the end,
No more will the call sign,
Used, ever be,
The one who signed them,
Joined SILENT KEY.
Some time as your listening,
And tuning around,
Do not be startled,
If you hear a strange sound,
Like a quavering, ghostly,
S e v e n t y – T h r e e,
From the departed friend
Who Joined SILENT KEY.
Power Supply
by Eileen V. Corridan
Published in September, 1942 QST
The how and why of a power supply
Is something very quaint.
It takes the a.c. current
And makes it what it ain’t.
You start with good ole a.c.
But you need some pure d.c.
How the PS finally makes it
Is now quite clear to me.
First, gimme a primary winding;
A secondary, too.
Now I’ve got a transformer
Let’s see what it will do.
The primary takes the line juice;
Inductance does the rest.
But you gotta split the secondary
To do its job the best.
“Less turns in the coil for the heater,
More turns for the plate supply.”
We’ve still got only a.c.
Which the tube will rectify.
Now we come to the moment
When tube and a.c. meet.
Just keep in mind a rectifier
Acts like a one-way street.
A.c. travels in wave form
From plus to minus, and then
It simply changes direction
And does it over again.
But the tube says, “Nothing doing
This is no swinging door.
I’ll take one-half of your wavelengths,
One-half – and nothing more!”
At least a half-wave rectifier
Would act about that way.
We’ll use another plate in there
And thus save wave and day.
So now one plate says, “Come ahead.”
It takes its half-waves through
The other plate is minus, then;
It has no job to do.
Then comes along the other half.
The second plate starts working.
So half and half are now a whole
While number one plate’s shirking.
From filament to filtering
The current that is flowing
Is now d.c. – pulsating kind
That toward the filter’s going.
It isn’t pure by any means.
Its ripples need some smoothing.
Chokes and condensers serve for this;
The waves find these quite soothing.
The filter circuit works like this:
In a condenser-input filter,
Inductance and capacitance
Keep pure d.c. in kilter.
Pulsating d.c. also has
Some a.c. current flowing.
Condensers short the a.c. out,
And chokes keep d.c. going.
And so at last like Ivory Soap
Our current’s pure d.c.
I must confess this whole darn thing
Has made a wreck of me, see?
*Lagniappe: (LAN-yap) “A little something extra.”
Related Images:
Home Brew Night was a big hit with the near 50 SPARC members who turned out. An informative evening with 7 presenters and 8 projects shown/explained to those present.
See the video clip of the presentations at:
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One of the first Field Days I ever attended (back in 1982) was at the Fairgrounds in Largo (home of the Renaissance festivals). At that event, the Clearwater Amateur Radio Society (CARS), the Metro Repeater Association (Metro) and the St. Petersburg Amateur Radio Club (SPARC) came together in the spirit of inter-club cooperation to put on a huge ARRL Field Day effort. This was complete with a great location, good equipment, operators to man the stations, great food and loads of fun.
An additional vertical was setup as were three separate HF station locations and supporting computers.
At 2:00 PM, the HF stations leap into gear making contacts with stations all around the country. Very poor HF propagation made it slow going limiting most contacts to 20m and 40m with mostly East coast and Mid-west stations responding.
Around 6:00 PM, it was time for dinner of pulled pork, side dishes brought for the potluck and desserts.
Several times during the day, a satellite contact was attempted using an Arrow antenna, a Yaesu FT-817 radio and a satellite tracking program on an iPhone.
Having our 1500 satellite bonus points in the bag, we settled into finish up making more contacts followed by a lunch of leftovers (pulled pork gets better with time). It looked like a storm was moving in around Noon so the decision was made to start taking down some antennas that were not used. The final station stopped at 12:30 PM and the antennas high on the fire towers were removed. The team proceeded to start dismantling the equipment, antennas, computers and other items. As usual, the site came down much faster than it went up. At the end, while waiting to help load some items, a bunch of us hung around just chatting and enjoying the camaraderie of the day. It was an incredibly fun time all weekend and if you missed it, I do hope you plan on attending next year.
Below is an image browser of all the pictures I have been sent. Please feel free to browse. If you have any pictures I am missing, please send them to webmaster@sparc-club.org.
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Another interesting email arrived at SPARC this week. A lady had “received” a message in Morse code she couldn’t decode. Strange you ask? True. She asked us for help in decoding the message. Forwarding the request to a few SPARK members, Ed NZ1Q, stepped up to the challenge.
Ed was given a phone number that connected him to the recorded CW message. Thirty seconds later, the message was decoded. It turns out that sender of the email was involved in a “learning challenge that involves solving [a series of] ciphers.” The result of solving the previous clues hidden in a series of movie clips, was the phone number given to Ed. Dialing the number, Ed heard a CW recording which contained the next clue. Ed decoded the message and relayed the clue (contents of the message) back to the originator. We received a quick thank you email for our timely response, and was off to solve the next cipher.
It was fun adding a link to the message chain. Where will the chain will lead? We may never know, but we may have found another way to promote ham radio to the public.
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Every night on the net members and non-SPARC members check-in to just chat about their day after handling any NTS traffic. We also have a multiple choice question each night from the license pool. On your check-in you can give your best answer or just take a guess. We do it just for fun and to help those that are thinking of taking an exam.
We just completed the General class questions and are now starting the Extra Class questions. Even if you are studying for the General Class, many of the question are similar and one can get a lot out of the discussions that follow.
All ham operators in the Tamp Bay area are welcome on the SPARC 2m repeater. The antenna is high up on a bank building just north of downtown St Pete and has great coverage of Pinellas and the surrounding counties.
Stop by the frequency anytime – 147.060, transmit offset +600 kHz and no tone (no PL) required.
Join us on “SPARC Net” every evening at 6:30 PM on the 2m machine.