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A little quiz for AM DXers

cyberdad

cyberdad

I'm currently wrapping up yet another cyberdad road trip. So yesterday (Saturday) in the car driving from Sonoma County to Salt Lake City, I was scanning the AM dial in Nevada east of Reno on I-80. About 50 miles past the Nevada-California State line. It doesn't get much more noise free than I-80 in Nevada!

Anyway, at that location in the desert, at about 10:30am local time, there were three San Francisco AM signals still present. One was a still very listenable KNBR. Another one was clearly audible, but not particularly listenable. The third was barely audible, but I was still able to ID it.

So my question for you gentlemen is, "what were those second and third San Francisco stations?"
 
cyberdad said:
So my question for you gentlemen is, "what were those second and third San Francisco stations?"
Click to expand...

I would think KCBS 740 and KGO 810, being the big 50 kW blowtorches in the Bay Area.
 
cyberdad said:
I'm currently wrapping up yet another cyberdad road trip. So yesterday (Saturday) in the car driving from Sonoma County to Salt Lake City, I was scanning the AM dial in Nevada east of Reno on I-80. About 50 miles past the Nevada-California State line. It doesn't get much more noise free than I-80 in Nevada!

Anyway, at that location in the desert, at about 10:30am local time, there were three San Francisco AM signals still present. One was a still very listenable KNBR. Another one was clearly audible, but not particularly listenable. The third was barely audible, but I was still able to ID it.

So my question for you gentlemen is, "what were those second and third San Francisco stations?"
Click to expand...

560 and 610?

740 and 810 are too directional to make it that way.

960, before its upgrade, used to make it to the East Coast, but is more limited now. 910 is just too directional. 860, on its STA, would be a longshot.

 
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Interesting topic!

My guess for the second would be KSFO. Their tower is located almost right on the Bay in San Francisco, whereas I remember seeing the old 610 KFRC's tower located near Berkeley, close to the bay, but with a much more built up land area directly to the east.

My guess for the third would be KCBS because it's not quite as directional north and south as is KGO.
 
cyberdad said:
"what were those second and third San Francisco stations?"
Click to expand...
According to Radio-Locator,
the specific signal strengths in order at Fernley, NV appear to be:
KNBR, KCBS and KSFO are nearly identical, KEAR is noticably weaker, and KGO brings up the rear.
So, assuming that these maps are accurate and all four stations are just on the edge,
I would have to go with KeithE4's KCBS and DavidEdwardo's KSFO,
maybe kEAR, but definitely not KGO.
KNBR is the best combination of a fairly low dial position and a big transmitter.
 
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KGO has an endfire array with nulls to the East. You are hearing high angle Daytime Skywave, and the skywave is less perpendicular to an endfire array.

http://fccdata.org/?facid=34471

KCBS has a broadside array, so the high angle Daytime Skywave is greater.

http://fccdata.org/?facid=9637

Look at the view towers option if it doesn't come up. So I correctly thought that it would not be KGO, since I have seen pictures of the towers for decades. Figured KCBS was one after confirming that they had a broadside array.

I would think that KSFO and KEAR would be fairly strong since they have electrically short towers and are 5000 watts nondirectional.
 
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Schroedingers Cat said:
I would think that KSFO and KEAR would be fairly strong since they...are...nondirectional.
Click to expand...
But stations at the bottom of the band would be the least effected by daytime skywave,
not that the fifty galloners are that much higher up..
 
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ai4i said:
But stations at the bottom of the band would be the least effected by daytime skywave,
not that the fifty galloners are that much higher up..
Click to expand...

5000 watters were an afterthought. Could be groundwave on 560 and 610. i find daytime skywave SR+2 hours or more down to 760 around here.
 
Congratulations to David for the first correct guess....

KSFO wasn't exactly listenable, but it was definitely clearly audible and identifiable (if that makes any sense). KEAR was indeed noticeably weaker. Barely audible, but I dide get a positive ID.

As for KCBS, I did hear something on 740. Very faint, but I couldn't make out anything, let alone ID it. KGO? No trace of anything on 810. I was impressed with KTRB's signal on 860 during the two days I spent in Napa and Sonoma (although I thought the audio was rather lousy). No trace of it in the Nevada desert, however. Same goes for 910 and 960, et al....including the skywave I was looking for on 1640.

So David, I guess I owe you a cigar or something. Would you settle for chocolate or bubble gum? Let me know and you can just stop by the house and pick it up!
 
KDIA 1640 is 10 U2. So during CH SR to SR+2, you should be able to hear it sometimes IF they are running nondirectional. I wonder though if they like running DA because it concentrates the signal in San Francisco and Oakland. In that case, the signal to the NE would be reduced.
 
How far east of Reno were you Cyberdad? A few years ago I heard KCBS & KGO during the day in the Reno area, not as strong as KNBR, but in there. Definitely groundwave as it was mid day in August.
 
cyberdad said:
So David, I guess I owe you a cigar or something. Would you settle for chocolate or bubble gum? Let me know and you can just stop by the house and pick it up!
Click to expand...

Chocolate would be this chocoholic's choice!
 
radioman148 said:
How far east of Reno were you Cyberdad?.
Click to expand...

About 50 miles. And yes, I did hear a weak KCBS and KGO just west of Reno. I'm sure what I was hearing in all instances was groundwave.

I did, however encounter daytime skywave the following day in far western Nebraska still on I-80. At about 2pm lolcal time, I was getting a solid signal from KXEL on 1540. Distance of about 600 miles. I also heard a somewhat weaker WHO, which would have been about 500 miles. After hearing these two, I tried for KFAB. That would have been 400 miles, but I didn't hear it.
 
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