700 in Indiana

[BobOnTheJob]

Rare happening...listening to WLW around 1PM local time just south of Indianapolis and the carrier dropped for 10 seconds. Something was there reading an S2 on the 400' longwire...too weak for audio. I'll never know what the 1 or 2 weak signals were but speculation is always fun...

 

[Buckeyes2001]

Might have been WZOO/Asheboro, NC and WCNF/Dothan, AL or WDMV/Walkersville, MD. WZOO has a CP to operate ND days at 700 kHz 1 kW. Wonder if the winter storm is messing with their transmissions.

 

[BobOnTheJob]

Wonder if the winter storm is messing with their transmissions.

I suspect it was...probably a power outage and it took 10 seconds for the genset to come up to speed. I was listening to callers telling their storm stories. Rare day that WLW is off during the day--or anytime for that matter.

 

[rbrucecarter5]

It has been my experience that really long haul DX in the daytime, several hundred miles or more, is dominated by the more powerful stations, with lower power stations being completely absent from the mix. I think it takes a certain threshold of power, particularly at low frequencies, to make it into what little skywave is present.

I believe you might have logged KSEV, Tomball, TX, which is 15,000 watts daytime, and has a node in your general direction. It does not protect WLW in the daytime, so if WLW dipped and you had a 400 foot longwire, it would be very plausible.

 

[Schroedingers Cat]

In general, I agree that high power, including 50 kW highly directional major lobes, do the best on daytime skywave.

Skywave can be explained by statistical models, and there is probably always some very low level of skywave. I've reported before about all day skywave from WWJ 950 and WFDF 910 in the Mackinac Straits area in December. The day lobes are almost equal, and there's only a 40 kHz frequency difference and a few miles between the transmitters, so it's just about the same for both. I measured 50 uV/m groundwave when I had a field strength meter in the fall once. There are complete fades, so the skywave must also be around that level midday, and of course the resultant would be around 100 uV/m when the groundwave and skywave are in phase.

When there is a small ion cloud, you may hear lower power stations in the daytime. I have heard skywave from WFDL 1170 Waupun, WI near midday and later afternoon with no WWVA QRM near the Straits also. This was also in December.

 

[Schroedingers Cat]

If you have access to a field strength meter and know how to use it properly (older models are more difficult to use, but that is usually what is floating around outside of radio stations), you could estimate the skywave present by looking at the cyclical fluctuation of the groundwave. Say you have a 100 uV/m groundwave when no skywave is present. Say in December when other stations show daytime skywave, it goes up as high as 110 uV/m and as low as 90 uV/m in a cyclical fashion in a time when conditions are noted. The skywave would then be 10 uV/m. That won't be consistent, but it does show the existence of skywave at very low levels, all other things being equal.

I don't think there is any nonlinear diode like action from reflecting layers, though some have speculated on that. The skywave is just too weak to be detected at low powers. You might the above if you have the equipment. That may reveal a very weak skywave but I've never heard a carrier just completely and suddenly fade out completely, except on perhaps a crystal radio. It's gradual.

 

[pianoplayer88key]

If you have access to a field strength meter and know how to use it properly (older models are more difficult to use, but that is usually what is floating around outside of radio stations), you could estimate the skywave present by looking at the cyclical fluctuation of the groundwave.  Say you have a 100 uV/m groundwave when no skywave is present.  Say in December when other stations show daytime skywave, it goes up as high as 110 uV/m and as low as 90 uV/m in a cyclical fashion in a time when conditions are noted.  The skywave would then be 10 uV/m.  That won't be consistent, but it does show the existence of skywave at very low levels, all other things being equal.

I don't think there is any nonlinear diode like action from reflecting layers, though some have speculated on that.  The skywave is just too weak to be detected at low powers.  You might the above if you have the equipment.  That may reveal a very weak skywave but I've never heard a carrier just completely and suddenly fade out completely, except on perhaps a crystal radio.  It's gradual.

This FIM my dad has is currently not working properly, but if we could get it up and running, how accurate & good do you think it could be?  Or would that design be so poor that the dBµ indicators on my Tecsuns would be better even when being desensed by strong local stations?  (There's no possible way I could afford to buy an FIM - best I could possibly afford would be to fabricate necessary parts to repair/align my dad's FIM myself, which I'm not trained to do... and even then I don't know how it would handle a weak barely-detectable carrier that's 10 kHz or less than something that would overload a Tecsun radio with its internal antenna removed (or better yet an SDR like a Perseus or a high-end comm rig) this severely.)

 

[Schroedingers Cat]

With all the AM DAs around San Diego, I'd meet with the CE of one of them and bring it along. The older CEs are more into the AM DAs, but sadly, they're dying off fast. They might be able to tell if it is worth fixing up. They may have an extra old FIM of some sort that is better. I was offered an FIM with a slight meter spring linearity defect and I kick myself for not taking it. That CE has passed away though. Bringing the Stoddart along will at least give you some street cred with them. They may need somebody to help them run radials or measure monitoring points. I know a guy who did that with Glen Clark and he had virtually no real technical knowledge of DAs but helped out as an extra to change antenna switches from non-DA to DA for proofs and report readings, etc.