05/08-09 Tropo OK>IL

[KA9UVY]

Very short opening came here just before midnight into the Oklahoma City area last night. It lasted only about 30 minutes at the 500 mile distance of OKC then shortened up to the Tulsa area for another 45 minutes before shut down.
The opening though short gave me 6 new OK DTV's:

KOCB-33
KAUT-40
KTBO-15
KJRH-56
KGEB-49
KQCW-20

DTV count now stands at 241 stations here.

[NN2E]

Hi Bob,
I hope you missed all of the bad WX on Friday.
I knew I'd be missing some good openings while the big antennas are down. I'm working on the P-7...new hardware, bending & straightening (the ice storm didn't help it any), modifying the feed assembly, might even chicken wire the dish to try for better front to back ratio.
My indoor DTV Dxing set up hasn't found anything new lately. Lots of signal indications (Louisville? Little Rock? Evansville? Nashville? St. Louis?) but not quite enough signal to latch on to any new ones.
Now, if it'll just stop storming for a while I'll get the antennas back up. Looks like we're stuck in the second of our three seasons...Winter, Thunderstorms and Drought.
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

[KA9UVY]

Hi Ed, I wondered if you had the antennas back up yet. I talked to Vern N3VL last night and He said that He had taken a replacement antenna down your way. Vern was on battery power along with many others South of me due to the big storm event. We did fine here and mostly got the flooding and lightening, no wind this time.
The band opened last night also into AL,GA but only gave up one new DTV here WELF-16 Dalton GA.
I hope you get your P-7 back in good shape, mine also has issues but I am unable to climb right now due to back trouble so it will have to hang in there for a while.
This WX has to break sometime so get those antennas back up and help me keep an eye on the band.

DTV Total now 242 here and still looking for that first E-skip DTV!

[NN2E]

The new VHF (Antennacraft CS-1100, Thanks Vern) is assembled and parked in the garage. I'm gonna reinforce a few things on it before it goes up.
I'm thinking of replacing the folded dipole feed on the P-7 with a 1 wavelength, circular loop, made out of 3/4 inch aluminum tubing. This should give a broader frequency response and have a feedpoint impedance that is closer to 75 ohms. I plan using RG-11 co-ax between the feedpoint and the pre-amp. A choke (W2DU type) will be placed on the co-ax at the feedpoint. I'm hoping to pick up some gain, ahead of the pre-amp, by the use of the loop feed (1 or 2 db?) and the elimination of the 4:1 transformer (several db?). I'm gonna try to do some testing, to see if this actually works, before I put the antenna back up. It's supposed to storm all week so who knows when I'll get this done.
Been sitting on channel 8, looking for WSIU, since I went on the indoor antenna but it still hasn't locked in yet. It almost made it, on Friday, just before the storm hit Carbondale.
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

[KA9UVY]

Ed, The mods to the P-7 feed sound great and I hope it works out OK. I always wanted to do a little something to mine but I do like the P-7 feed as it is.
I haven't seen mine in a few years but if I recall it is a DC grounded system unlike the 4251. I saw one of them take a lightening strike right on the bowtie and vaporize the balun hooked to it.
The P-7 is lightweight and flexible (good) but not a great frame to try screening or other common improvements. I think the best thing a guy might do for one is attach a 7 foot aluminum ring of tubing on the outside of the antenna keeping all of the elements in more of a true parabolic without loading things so much.
I hope to also get another corner reflector yagi up to use in those mean F/B situations where the P-7 comes up short.
One situation like that is KSPR 19 in Springfield MO that I cannot get WUSI off of. In fact I also have never been able to get WBKI out of KY over WUSI. Maybe a phase box for killing WUSI might be the only thing to work.

[NN2E]

I'm gonna go out on a limb and "chicken wire" the dish. It survived the ice storm, with the reflective surface completely iced over, so it's stronger than it looks. The only problem was the mast, it was mounted on, couldn't handle the load. When it goes back up it'll be on a "heavy duty" mast.
I've read that the reflection surface should not have openings larger than 1/10 wavelength at the highest operating frequency. At 698 MHZ (the top of channel 51) 1/10 wavelength is about 1.7 inches so, the chicken wire, with it's 1 inch holes, should work. I hope this improves the lousy front to back ratio of the stock P-7.
FWIW...The replacement feed element is also designed to operate in the "new" band (470 to 698 MHz, Channels 14 through 51)
Much like you problems with WUSI I've had problems with stations in opposite directions. If I'm beaming at Memphis I still get Evansville. Beam at Evansville, I get Memphis. Beam at Nashville, I get St. Louis. Beam at St. Louis, I get Nashville and so on.
I've not been able to get WBKI-DT because WAZE is in the way. Shouldn't be a problem as soon as the analogs shut down.
I hope I can grab WDKY on channel 4 before they make the switch to 31. I've almost gotten them before. Maybe the new VHF will do the trick.
I'm headed out to the shop to work on the P-7......
73, Ed NN2E
Owner / Operator - Murphy's Law Test Site & Thunderstorm Proving Grounds

[KA9UVY]

Ed, I hope that things go as planned with the P-7 mods. Be sure and make detailed notes so that others can follow suit down the road.
I am surprised that WBKI has not been recd there but I guess WAZE might be more of a problem than I thought...for the both of us.
I have noticed that when an analog is on the same channel as a digital it seems easier to pull the digital through than if both are digital channels. At least that has been my experience here.
I still have yet to log anything on Low band digital but I did have a slight signal detect on channel 4 one evening last summer. Not sure if it was E-skip or Danville, KY but the heading was SE.
St. Louis has always made DXing VHF a pain here so honestly I can't wait til they shut off all of the analogs over there.
I would say the first week of digital only will be very busy with all of the shuffle and if your on your toes the log should get a nice boost.