Sunday, November 29, 2009
November 25, 2009
WWL-870, New Orleans, LA (50KW) appeared this morning at 0455L (1155 UTC). The signal was weak with much phase distortion, however, it is now finally and positively logged! Received both on the Tecsun PL-600 barefoot and with the 24-inch loop.
Last week I completed construction of the 24-inch box loop. As previously described, the frame is composed of 1 x 2 inch furring strips, notched at their centers, and screwed together to form a cross. Length of each member is 33.9 inches (24 x 1.414). A 36 inch piece of 3/4 x 3/4 inch wood is screwed to one of the cross members to form a pivot, which will rest on the ground, elevating the loop to chair height.
Using a wood file, a wide, flat notch was cut at the end of each member to keep the coil turns in place. Sixteen turns (128 feet) of 20 gauge insulated wire was then close-wound on the frame, secured by small nails at each end.
Earlier this summer I rescued a small AM-band variable tuning capacitor from a very old transistor radio. It will serve as our tuning device. Using vinyl electrical tape, I taped this to the end of one of the cross members. These capacitors are actually two capacitors in one. In a superhet radio, one section tunes the signal and the other section tunes the superhet oscillator at 455 KHz higher than the signal, therefore this second section's capacitance is less, and not usually usable for tuning a wide range. We will use the section with the greater capacitance (the first section mentioned) to tune the loop.
Tuning range of the loop was found to be 530 KHz to about 1400 KHz. A short clip lead is used to short about five turns of the coil to allow tuning to the top (1710 KHz) of the band.
Turning the loop, signal peaking and nulling is fairly sharp. Signal strength increase over a barefoot radio is excellent and better than a 7-inch inductively coupled, tuned loopstick. Local electrical noise pickup is low, but the loop will transfer noise if pointed towards close noise sources. Atmospheric noise pickup is very low, and the signal-to-noise ratio seems markedly better than the tuned ferrite loopstick.
Performance. Inductively coupled to the Tecsun PL-600, signal strengths off the loop are equal to or greater than the 240 foot longwire attached to the Eton E1 last winter here at this location. 500+ mile mid-day DX is routine. KGO-810, San Francisco, CA, and KALL-700, N. Salt Lake City, UT are exceptional during the day using the loop, and are not receivable using the barefoot PL-600.
The 24-inch loop is a good compromise between a small loop and a large one. It is easily transportable. Try building one for yourself.
Friday, November 20, 2009
Nice signals out of Japan this morning at 0710L (1410 UTC). Caught both JOUB-774, Akita, and JOAK-594, NHK-Tokyo. Audio fair to good on JOUB, and fair to poor on JOAK. This is the first time I have heard readable audio out of JOAK. Both stations received with the Tecsun PL-600 barefoot. Tried to enhance the signals with the tunable loopstick, but no luck, the background noise came up right along with the signals.
Thursday, November 19, 2009
Started building a 24 inch box loop Monday. It is made from 1 x 2 inch furring strip, the cross notched at the center and screwed together. Left is to wind the wire and install the variable capacitor. Am planning to use a small transistor-radio variable cap, due to not having a standard sized one at the moment, though not sure if it will work yet.
Checked for JOUB-774, Akita, Japan three times this week. It has not been in at a strength where audio is recoverable, just a carrier present. Carrier is present on 594 KHz, presumably another Japanese station. The Tecsun PL-600 makes tuning for carriers very easy in SSB mode with the nice BFO knob.
Just at sunrise this morning I caught both KKOH-780, Reno, NV (50KW) and KAZM-780, Sedona, AZ, playing tag with each other for superiority. Not sure of KAZM's power at that time as it was just minutes before sunrise. It runs 250W nighttime and 5KW daytime. WBBM-780, Chicago, IL, was long gone by that time of course.
Strung 180 feet of wire across the property early in the week. Unfortunately, I am right near a power line and the noise on the BCB band is rather objectionable. I think I'll give up on the long wire this winter since I'm in town and go strictly with the loops and tunable loopsticks.
Monday, November 16, 2009
I am in Arizona again, at the little desert town of Quartzsite.
THE TRIP REPORT
Just as the landscape changes incrementally as you cross the country, so does the radio reception. From Rochester, NY, WSM-650 out of Nashville, TN is not receivable during daytime hours. Cross over into Ohio and then head southwest out of Cleveland, and it suddenly appears, weakly at first, then getting stronger as you approach the I-70 cross-country corridor. Astonishingly, it remains readable all the way to St. Louis and into Missouri during daytime hours, where it finally fades to nil.
Spending night one near Spiceland, Indiana, near Indianapolis, the next morning before sunrise the Cuban radio time ticks are quite strong. I tune down to 530 KHz, and there is Radio Enciclopedia, weak, but copyable. Now why do I have so much trouble with this station in Rochester? KOA-850 Denver, CO is also in there, as is WBAP-820 in Dallas, TX. Both are tough catches at home. We proceed west.
Night two is spent in Joplin, Missouri, the extreme southwestern corner of Missouri, just 7 miles from the Oklahoma border. Leaving at 6AM, hopping on the Will Rogers Turnpike after crossing into Oklahoma, I tune to 530 KHz. There, and beaming in like a local this morning, is Radio Enciclopedia again. We are at mid-country now, and I wonder if the west coast is in. Tuning up to 640 KHz, there is KFI, Los Angeles, weak but readable. Nice!
As you pass Oklahoma City and get onto I-40, heading west, long distance daytime DX starts to show. KGNC-710, Amarillo, TX is readable from 40 miles west of Oklahoma City. The land becomes flat as a pancake, and mostly treeless. Passing Amarillo, from the panhandle of Texas, the "Talk Monster", KKOB-770, Albuquerque, NM (50KW) appears, very weak, at a distance of several hundred miles.
At night three I arrived in Tucumcari, NM, and the remainder of the trip was spent camping in the wilds of New Mexico and Arizona. But from this point on, little DXing was done, except to see how far west WWL-870, New Orleans, LA could be heard. Benson, Arizona, 40 miles southeast of Tucson, seemed to be the practical limit, where is was very weak at sunset, while camped on a mountain top about 10 miles north of town. I am going to make a concerted effort this winter to see if it is receivable in Quartzsite (extreme western) Arizona, near the California state line.
November already. On the Yahoo Ultralight group, I've been reading recently that JOUB, 774 KHz, Akita, Japan has been receivable all the way into Oklahoma for most of October. Last week I decided to have a check of this frequency at sunrise. It was receivable for three of the five days I checked, Nov 8-10, on the Tecsun PL-600. On Nov 10, the signal was strong enough to copy the audio on the Sangean DT-400W barefoot! A nice catch.
WWL-870, New Orleans, LA, is still elusive. One October evening just at sunset I caught WBBM-780, Chicago, IL underneath another station. Chicago is a long way from here, well outside the usual 1200 mile nighttime DX bubble.
Finally, long distance daytime DX is a daily thing. With the tunable loopstick, KKOB-770, Albuquerque, KALL-700, North Las Vegas, NV, and the San Francisco stations KNBR-680, KCBS-740, and KGO-810 are copyable on both the Tecsun PL-600 and Sangean DT-400W. All are in excess of 500 miles except for KKOB.
A day off today, and I might spend it building a box loop! Hope to have more reports soon.