WBZ-Loud and Clear plus UNID

[radioman148]

I went to college in Eastern Iowa, and two of my kids are University of Iowa graduates. 

Okay...I'll go off topic for a moment myself... Mt. Hamil Tap, Huffton, IA (not on most maps)...Late 60s-early 70s...Half a fried chicken, fries, slaw, AND a pitcher of PBR all for less than five bucks.  Plus live entertainment.  (Chix was $3.50...and always excellent.  Pitcher was $1.35)

Anyway, what I can report from all my experience there, is that Eastern Iowa is indeed in WHO's nighttime convergence zone. The result is WBZ usually had (and probably still has) a better nighttime signal.

You also previously mentioned that WLS was also getting cancelled at night in that area. I assume though that WLS came in during the day there.
Those were the days that the WLS signal really got out.

[cyberdad]

Yes, WLS was fine in Eastern Iowa during the daytime....as was WHO.  Both suffered from convergence zone issues at night.  Same goes to one degree or another for the other Chicago "1-A" blowtorches. 

WCFL was another story...  It wasn't very listenable, but it probably had almost as good of a nighttime signal as the other Chicago biggies when all was said and done.  My location was in the null, but there was no convergence, so a decent (if unsteady) signal was usually able to sneak through. Problem was that it would regularly get trashed by XEOY, CBW, and to a lesser extent KTOK.  (Daytime 'CFL got pounded by semi-local WCAZ).

[radioman148]

Yes, WLS was fine in Eastern Iowa during the daytime....as was WHO.  Both suffered from convergence zone issues at night.  Same goes to one degree or another for the other Chicago "1-A" blowtorches. 

WCFL was another story...  It wasn't very listenable, but it probably had almost as good of a nighttime signal as the other Chicago biggies when all was said and done.  My location was in the null, but there was no convergence, so a decent (if unsteady) signal was usually able to sneak through. Problem was that it would regularly get trashed by XEOY, CBW, and to a lesser extent KTOK.  (Daytime 'CFL got pounded by semi-local WCAZ).

I went to college in De Kalb and WLS had the best signal day or night of any station. OTOH, I was directly in WCFL's null. In the Day WCFL was about half as strong as WLS, at night about one tenth as strong. At night sometimes WCFL sounded like DX with a bit of an echo and I was only about 55 to 60 miles west of their transmitter.

[Schroedingers Cat]

WCFL's pattern had the nulls off the back, so at high angles, you wouldn't be in the nulls but more equivalently off the side of the pattern.  Since the heights were all near 180 degrees, there was no vertical elevation null where you describe. That's why you could hear it 50 miles away and it faded like just a skywave.  As shallow as the daytime nulls were and continue to be with the new array, I'm surprised you don't hear it better in the daytime though.

[radioman148]

WCFL's pattern had the nulls off the back, so at high angles, you wouldn't be in the nulls but more equivalently off the side of the pattern.  Since the heights were all near 180 degrees, there was no vertical elevation null where you describe. That's why you could hear it 50 miles away and it faded like just a skywave.  As shallow as the daytime nulls were and continue to be with the new array, I'm surprised you don't hear it better in the daytime though.

Well this was 40 years ago, but WCFL lost a lot of listeners at NIU in De Kalb at night. It was very difficult to hear.
I remember when I would drive west of Aurora heading towards De Kalb at night WCFL would drop off very fast west of Sugar Grove.

[cyberdad]

I'll confirm from my experience on trips to and from college in Iowa that WCFL's nighttime signal started degrading significantly once you got west of the Fox River (i.e. Aurora).  WLS, OTOH, was good all the way to the Mississippi, at which point you'd run into the convergence zone (and start looking for KOMA).

I spent two weeks of a summer job in DeKalb during 1968.  The company put me up in a motel, and with NIU on break, there wasn't a lot to do...other than fire up ye olde 4-band Radio Shack portable.  Radioman is correct.  'CFL's nighttime signal in De Kalb was horrible.  It actually was better via skywave in eastern Iowa (although it still wasn't all that good there, either).  I do remember the daytime WCFL signal in De Kalb as being almost as good as WLS.  But that was in a noise-free wood frame building on the far east side of town.

[radioman148]

Speaking of a night time convergence zone I remember driving from Chicago to St Louis at night and having a terrible time trying to listen to WLS around Rantoul, Il. The signal was unlistenable until I got closer to St Louis when it improved dramatically.

[cyberdad]

Speaking of a night time convergence zone I remember driving from Chicago to St Louis at night and having a terrible time trying to listen to WLS around Rantoul, Il. The signal was unlistenable until I got closer to St Louis when it improved dramatically.

Makes sense.  WLS was/is solid by the time you get to Des Moines.  Same goes for the drive to Minneapolis.  I've done that one dozens of times.  WLS is awful along parts of the journey north of Madison, but improves greatly by the time I-94 veers to the west near Eau Claire.

[radioman148]

Speaking of a night time convergence zone I remember driving from Chicago to St Louis at night and having a terrible time trying to listen to WLS around Rantoul, Il. The signal was unlistenable until I got closer to St Louis when it improved dramatically.

Makes sense.  WLS was/is solid by the time you get to Des Moines.  Same goes for the drive to Minneapolis.  I've done that one dozens of times.  WLS is awful along parts of the journey north of Madison, but improves greatly by the time I-94 veers to the west near Eau Claire.

I've made the same drive to Minneapolis, but during the day so I didn't get to enjoy the cancellation experience. 

[Schroedingers Cat]

WMVP Proof Of Performance Radials

https://licensing.fcc.gov/cdbs/CDBS_Attachment/getattachment.jsp?appn=101160972&qnum=5150&copynum=1&exhcnum=4

Looks like there are some radials to the west which have less than M-3 Conducitvity, which may explain the lesser observed groundwave coverage to the west, even though the old and new day pattern nulls are shallow.  New pattern daytime field ratio of second tower is 0.35.  I think the old ratio was 0.4.