Crystal Radios Of The 2009 Contest Entrants
Ron Everingham, Open Class Entry
This double tuned radio is really my first attempt for DX listening by virtue of using two vernier dials, variable coupling and audio matching.
L1 is wound on a piece of ferrite rod connected to a swinging arm to obtain variable coupling for L2. The S meter is a surplus 30uA movement which gives a good indication for setting the tuning capacitors to a particular frequency when a signal generator is loosely coupled to the aerial.
The aerial used is about 20 feet high and 80 feet long bent to fit into my small lot.
Dave Schmarder, Loop Class Entry
Jack Hennon, Open Class Entry
Jack used the venerable Miller 565 with an external audio matching unit. Notice the very rare 10 ua meter
in his audio unit!
Evan Haydon, Open Class Entry
I spent a lot of time preparing for the 2009 contest. I spent many hours most evenings for the last three months listening to the broadcast band. From both notes made then and from memory, I am very familiar with what stations appear at what time of the day at this location. I watch band conditions carefully and fairly accurately know which stations it is even possible to hear at any time on any frequency.
My crystal radio will at night hear any signal that my spotter radio will hear except for weak signals 10kc either side of my 3 local stations. My crystal radio will hear 95% of the daytime signals that my spotter radio will hear. On a good cold winter day, I have received 57 stations. My radio, traps, and antenna system are exactly the same as used in the 2008 contest. I could not find any way to improve the system.
This year’s contest had unusual conditions here. The first day had very good receiving conditions. The second day had good conditions. The band then stagnated. It did not change for the rest if the contest. The stagnant condition was not what I would call a normal winter condition either. There was no flux or change (due to weather conditions) to cause stations to appear and disappear. For day after day it was the same old stations all up and down the band.
The contest was fun to work as always. My list of all time stations identified on the broadcast band now numbers 505 stations. I identified 66 stations this year that I did not hear in the 2008 contest. That means that I identified 36 stations in the 2008 contest that I did not hear this year. In the 2009 contest, I logged 4 stations from New York state, 1 from Boston, 3 from California, 2 from Philadelphia, and 25 stations from Canada. I identified stations from 31 different states, Canada, Mexico, and Cuba. IBOC probably cost me 3 or 4 stations to not be logged this year
Below is a summary of my activities during the 2009 crystal radio contest.
Stations Day Logged Time spent 1-16 197 15 Hr 35 Min 1-17 32 12 Hr 20 Min 1-18 27 11 Hr 20 Min 1-19 21 11 Hr 10 Min 1-20 11 8 Hr 0 Min 1-21 9 7 Hr 20 Min 1-22 8 6 Hr 50 Min 1-23 8 8 Hr 15 Min 1-24 7 7 Hr 35 Min 1-25 8 10 Hr 20 Min Total time spent - 98 hours 45 minutes Total stations heard - 328 Total stations identified - 312 Total points - 583,312
Michael Bartolone, Open Class Entry
My current contest rig has contra wound solenoid coil 5.25 in diameter, each section 29 turns of "indoor antenna wire", 2.15in length per section, single gang 400pf air variable cap, unknown diode scavenged from a clock radio picked up at Goodwill (the diode has two red bands on one end and no other markings), Clevite brush phones.
Coils suspended in a slide cradle 20 inches above the desk. The tank is loose coupled to an ATU with contra wound solenoid coil 5.25in diameter, each section 26 turns switchable so I can use either single section, or both in series, or in parallel, with a 5 gang 380pf per gang cap switchable to put various gangs in series or parallel with the various coil configs.
One tunable trap with a single 5.25 in diameter coil, 43 turns, 3 in long with 440pf cap for tuning.
Note the 'indoor antenna wire" is like very cheap litz…35 strands individually insulated but only twisted, not braided like true litz. However, the price was too good to pass up ($0.02 per foot when I bought it).
My antenna is a 75+ foot long wire (16ga speaker wire) average about 12 feet above ground, run from the eaves at one corner of the house to a tower about 35 feet from the house and then back to the other corner. The ground is a single copper clad rod about 3 feet long about 2 feet into the ground with two 3 meter long radials.