Friday, January 25, 2008

Antennas Work Best if You Bleed on Them

Yesterday I was feeling a little "under the weather." I had a sinus headache for most of the day but it did not stop me from working CT3/OM3GI in Madeira Islands for Country No. 99 on 160-M. However, I did go to bed a bit early to try and shake the headache and general bad feeling.

About 11:00 a.m. today, Tim, KC8UHE, called and said he was not working and was coming over to help me find why the Famous W8TN 160-M Inverted-L antenna was not performing as well as it had at first. Tim knew the CQ 160-M CW Contest started tonight and he wanted to help me get up to speed with the antenna. I tried to beg off, telling him I'd just work on it later, but he would have nothing of that. When I told him it was just too cold to work on the antenna he said the cold didn't bother him and I could just stay inside and he would go over the hill and see what had happened to the antenna. Since I was not able to dissuade him from coming over, I agreed and struggled out of bed to take some more Tylenol.

By the time he showed up I had most of my gear together. Tim brought his spin-casting rod and some new 20 pound test line. He strung the new line on the Zebco reel and we were ready to go. Down over the hill we slid (lots of snow still there) but no one fell. At the antenna I could see that the top-hat portion of the antenna had pulled back out of the trees and the antenna was "drooping" in the vertical section as well. I had known something was wrong since the SWR had creeped up to where it was 1.43 : 1 at resonance and that resonant point had crept up to 1.850 MHz. At 1.830 and below it was well over 2 : 1 which is bad for working DX!

The tree I needed to put the line over was about 90 feet tall and we did not think we could cast the line from the ground. So, up the tower I went (boy that steel was cold!) At about the 65-foot level I belted on and got ready to cast. However, the line was fouled in the reel! So, for about 40 minutes I hung off the side of the tower, disassembled the Zebco spinning reel, and removed the tangled line. I had to cut off the tangled part then re-string the pole and re-tie the lead weight.

Finally, I was ready to make the cast. The line sang out and the yellow lead weight sailed right over the spot I wanted. Then, it suddenly stopped! I had run out of line! Rats! So, I thought I would just cut off the line and tie it to the end of the support line for the top-hat portion of the antenna and hope the weight would pull the line down to the ground (about 85 feet worth!) But, I could not pull the top of the antenna out of the trees. It had gotten fouled in there and no matter how hard I pulled, the tree just bent and the line stayed tight.

Now I had to think quick and formulate a Plan B. I decided that since the line was tight in the tree, I would just climb further up the tower and tie off the vertical portion of the Inverted-L a little higher up. That's what I did and it worked! The vertical portion was now about 15 feet higher and there was a little more of an angle for the top-hat but the antenna was firm. When we finally made it back to the house (only 1 fall - me!), the SWR was now 1.25 : 1 at resonance and the resonant point was at 1.838 MHz. much nicer! The Alpha was very happy and would put out 1,500 watts with only about 20 watts reflected.

I'm sure most seasoned DX'ers are familiar with the old saw that an antenna does not work well unless you leave some blood or skin on them. Well, that's what I did. In cutting the excess line I managed to cut myself twice! Once on my thumb and once on my ring finger.

I can now attest that the old saw about bleeding on your antenna is TRUE! With the new antenna I managed to work SIX New Ones on 160-M in just my first 1-1/2 hours of the contest. Yee, Haw! And, those were worked with an A-Index of 11 and a K-Index of 2 which is not all that great.

I worked EI-Ireland, V3-Belize, YU-Serbia, UA2-Kalingrad, VP9-Bermuda and CT-Portugal. This brings me to 105 Countries Worked on Top Band. That's about 83 New Ones in the last 9 weeks since I put up the Famous W8TN 160-M Inverted-L. I think I'll hit the sack now and see if I can snag a ZL or a VK6 early Saturday morning.

Sunday, January 20, 2008

Received EME Signals on 7 MHz.

The High Frequency Auroral Research Program (HAARP) ran some tests on the 40-M band this weekend. They transmitted a 2 second carrier from their station in Gakona, Alaska, then were silent for three seconds. Hams and SWL's were asked to see if they could hear the resultant echoes from the moon. It takes 2.7 seconds for a signal to reach the moon and return to the Earth. So, a little over 1/2 second after the HAARP transmitter went silent (if you could hear it directly), the echo from the moon would appear.

I did not try to hear the test on Friday night since I felt I had no chance with only an 80-M Inverted-V and the Famous 160-M Inverted-L for antennas. But based on the fact that many hams did hear the signal (see this YouTube video), I decided to give it a try on Saturday night. Last night Garie, K8KFJ, heard it on his Icom 706-MkIIG with a vertical and Don, W8DL, heard it using an Icom IC-746 and a 270-ft. longwire.

The first hour of the test was on 6.7925 MHz and I heard NOTHING. I was drowsy and about gave it up but decided to at least spend a few minutes on the second hour of the test on 7.4075 MHz just to see if it was any different. I peaked up the Yaesu FT-1000MP MkV for the weakest signal I could detect. The AGC was OFF, no attenuation, RF Gain at maximum, the VRF was ON and peaked and the 125 Hz crystal filter was switched in to give the maximum signal to noise ratio.

About 9 minutes into the test I began to hear a signal. So, I began recording the audio out of the radio on my computer. I noticed I was only hearing one signal. Was it the HAARP transmitter directly via the ionosphere or was it the signal reflected from the moon? I didn't know. However, I had very carefully adjusted my station clock to WWV just before the test. My digital seconds would click over to the next second exactly as WWV "clicked." Also, I began the audio recording as close to 0839 and 00 seconds GMT as possible.

After about 13 minutes of recording the signal was getting fairly strong. I carefully watched the digital clock and the signal began at 2-1/2 seconds, 7-1/2 seconds, 12-1/2 seconds, 17-1/2 seconds and so on. I was receiving the signal from the MOON!

Of course, this conclusion was based on the assumption that the HAARP signal was begun exactly on the minute and every 5 seconds thereafter. Later on in the test, after a period when I could hear no signal, I began to hear a signal again and this time I noticed that it began exactly at 00, 05, 10, 15 seconds. So, I was now hearing the HAARP transmitter. (There was a short period where I "think" I could hear both signals but the EME signal was so weak I could not be sure. I'll check the audio file later to see if both signals can be pulled out.)

Here is a spectrogram that was recorded in real-time as I was receiving the signal. The width of the graph is just about 15 seconds and you can see three of the 2-second long transmissions.

When I played back that portion of the audio I had recorded on the computer, I found that section 13 minutes and 17 seconds into the file. If you look closely at the timeline from the audio program below, you can see that each signal starts at 17-1/2 seconds, 22-1/2 seconds and 27-1/2 seconds. This shows it is the signal reflected from the moon!

You can listen to the 14-second MP3 file of this signal HERE. The file size is 227 K. The audio tone is at about 580 Hz.

This signal is a good deal stronger than a lot of EME signals I had QSO's with on 432 MHz. from Ravenswood. It was definitely good enough to make a contact, IF the HAARP station could have heard my 1,500 watts (unlikely since they were transmitting in the range of 3.2 MEGA WATTS!)

All in all, I had hoped to do a little better. But, conditions tonight may not have been as good as last night. The A-Index was 9 and the K-Index was 3. But, it was still a hoot to have heard an EME signal on 40-M. Not something you run across just any day.

Friday, January 18, 2008

New W8TN QSLs Going Out

I recently received my QSL's from the printer and I am starting to send them out. It has been a long time since I had nice QSL's and these are FINE. I had them printed by UX5UO in the Ukraine and they were delivered to my door just TWENTY-TWO DAYS after I approved the proof he emailed me. That's just astounding! It normally takes three times that long for me to get them from a U.S. printer. And, the cost was just $65 per thousand - DELIVERED - for 4-color PHOTO cards! Un-real!

You can see my new QSL on CLICK HERE.

The cards I've started sending out are already yielding a result! I have now received a QSL from a Top of the Honor Roll DX'er for an 80-M QSO I had with him earlier this week.

Thanks, Bob. I'll be putting this QSL in a place of honor in my shack.

Saturday, January 12, 2008

Learning to Use the FT-1000MP MkV

Click HERE to listen to a brief MP3 audio file I recorded tonight. It will give you some idea of what my radio is able to hear. I picked a weak signal on 160-M to better demonstrate the dramatic ability to improve on what might be considered a very difficult signal to copy.

I have recorded a CQ being sent by SM5EDX at about 0550 GMT. This is 1 hour and 45 minutes before his sunrise.

The first 7 seconds of the CQ are with my 400 Hz filter in line. Then, I switch in the 125 Hz filter. I think you will hear a marked decrease in the QRN and a resultant improvement in the signal-to-noise of the received signal. Then, at 12 seconds into the file I switch on the VRF (Variable RF Front-end Filter). This is a narrow band-pass "preselector" filter in the RF circuit path. As you can see, it turns the signal into nearly arm-chair copy when it would have been very difficult (if not impossible) to copy it otherwise.

Below is a graphic showing the resultant waveform of this audio file. The improvement in noise reduction added by the 125 Hz. filter is obvious. And, you can see a further noise reduction when the VRF is engaged.

I am still learning about all the controls on this radio but the more I use it, the better I like it. I expect the receiver (and the filters) are part of why I am able to hear so much on the Inverted-L, don't you think?

Wednesday, January 9, 2008

KC8UHE's Inverted "L" for Top Band

Today, Steve, KC8FVE, and I helped Tim, KC8UHE, erect a clone of my 160-M Inverted "L" antenna. Shortly after I left he worked a station on SSB in Iowa and later he was in the pile-up for NP4A but was beaten out by Phil, W8UV, with his new "Killer" antenna. Of course, we don't know how much power Phil was running (Tim was running 200 watts.) And, after Phil completed his QSO, Tim broke the pileup next. Not bad I'd say.

Here are a couple of photos of the antenna. The first shows the feedpoint. The unmarked lines are just support ropes. The second photo shows the elevated radial being supported by 5-foot lengths of PVC.

Tim used a 30-year old Zebco Model 33 spinning reel (with rotten line!) to cast a lead weight over two of his neighbor's trees. (The neighbor is very friendly in letting Tim use her trees as antenna supports.) A support rope over the first tree held a pulley that the center of the Inverted-L was threaded through and pulled horizontal by a rope that was cast over the other tree. The first iteration had the antenna about 6-feet too long. So, we let down the end of the center conductor, cut off 6-feet and pulled it back up. The process could not have been simpler. The new length had the SWR 1.0:1 at 1.840 MHz. The photo below shows the tree which supports the end of the "hot" side of the antenna after it transitions from vertical through the pulley on a similar tree.

Now that Tim has joined the ranks of those using the infamous "W8TN - Inverted-L" 160-M antenna. We will both be in competition with Phil in the pileups. It will be interesting to see which antenna wins out.

Saturday, January 5, 2008

I Posted these two photos without commenting on them so here is what you are seeing. This is the back and then the front of a sweatshirt I saw at the Charleston Department Store. This, of course, relates to the win by the WVU football team over Oklahoma in the 2008 Fiesta Bowl. Since WVU's coach bolted and went to Michigan, WVU was given "No Chance" to win this game. Oklahoma even petitioned the BCS committee for a "more worthy" opponent. I guess WVU pushed those words right down their throats!