WDOD Gone -- Why No Apps to Up Power on 1310?

[smedge2006]

WDOD, Chattanooga TN, was an old station that had a low nighttime-interference level. A lot of stations had to protect it. You'd think some of them would have appled for upgrades by now.

 

[davideduardo]

WDOD, Chattanooga TN, was an old station that had a low nighttime-interference level. A lot of stations had to protect it. You'd think some of them would have appled for upgrades by now.

I'm guessing that in today's declining AM world, the costs of engineering, a new phasor, real estate, etc. are more than a high-band AM station can justify. In addition, the new protection requirements as well as other crowding of the band makes improvements nearly impossible.

If a half-decent Chattanooga station on AM can't make it, I doubt there is much "in it" for smaller market AMs that might consider a night pattern adjustment or power increase.

 

[smedge2006]

Which doesn't necessarily explain why KTCK in Dallas would pass on the opportunity to lose that null toward Plano and Greenville.

I'm guessing that in today's declining AM world, the costs of engineering, a new phasor, real estate, etc. are more than a high-band AM station can justify. In addition, the new protection requirements as well as other crowding of the band makes improvements nearly impossible.

If a half-decent Chattanooga station on AM can't make it, I doubt there is much "in it" for smaller market AMs that might consider a night pattern adjustment or power increase.

 

[davideduardo]

Which doesn't necessarily explain why KTCK in Dallas would pass on the opportunity to lose that null toward Plano and Greenville.

I thought they protected Newport News and Madison, not Chattanooga. And with changes on 1320 and 1300 over the decades, I think they would lose coverage if they tried to make a change now.

 

[Steve Green NEPA]

Side note ......

Apart from the higher-powered stations in that region, WDOD always put a pretty solid signal into Florida at night. It was one of the more faithful regionals over numerous visits.

Shame to see such a monument dismantled.

All the others -- Indianapolis, Durham, etc -- seem to have those Euclidean 3-tower patterns. Would it be correct to say that to loosen their nulls and send more power in the direction of Chattanooga (while still keeping things proper in the other directions) many of those upgrading stations would have to put up a fourth tower?

 

[N4GBK]

Most AM stations are in a survival mode. Suppose a 1310 could increase coverage without having to do equipment upgrades. The engineering expenses to change DA psrameters probably would not increase listeners or revenue. What does a full night time DA proof cost today?

 

[K4WRF]

I can imagine there would be little or nothing to be gained in another station upgrading as a result of the WDOD cancellation. The night interference is a Root-Sum-Square (RSS) of the interfering signals and in short, you could not increase anyone else s NIF limit also if the FCC is still using the "Ratchet" clause even less.

Best regards,
w/

 

[Schroedingers Cat]

I can imagine there would be little or nothing to be gained in another station upgrading as a result of the WDOD cancellation. The night interference is a Root-Sum-Square (RSS) of the interfering signals and in short, you could not increase anyone else s NIF limit also if the FCC is still using the "Ratchet" clause even less.

Best regards,
w/

In some cases, you can upgrade with just one less restriction, but it is hit and miss. You just about have to do the what ifs before they happen and be right on top of them before somebody else does. CFCO was such a situation. When the legacy KDWB 630 went to Class D and the 630 in Winnipeg went silent under Domestic Canadian rules, CFCO upgraded. It's good if the chief engineer knows what the situations at his particular stations are, and keeps a watch on these things. But most station engineers these days aren't that well informed about AM allotment rules. In CFCO's case, they used their existing towers. They probably could have applied for more power if they started from scratch with a new array.

 

[pianoplayer88key]

Which doesn't necessarily explain why KTCK in Dallas would pass on the opportunity to lose that null toward Plano and Greenville.

I thought they protected Newport News and Madison, not Chattanooga. And with changes on 1320 and 1300 over the decades, I think they would lose coverage if they tried to make a change now.

Something I was thinking about related to adjacent protections...

If I understand correctly, ±10kHz is normally protected by 6dB at the 0.5 mV/m contour (another station's 0.25 mV/m cannot overlap), and ±20 kHz is protected at 5 mV/m (two signals shouldn't have those contours overlap). I'm guessing these protections are designed to reduce interference, BUT... there are a few things I don't quite understand...
BTW I'm near El Cajon, CA - east of San Diego. Among other radios, I have a Panasonic RQ-SW20, Coby CX-70, Coby CX-83 and a yellow Ultronic sports radio. (I have better ones, but those are the ones I'm referring to below.) Also all situations referenced below are for daytime groundwave scenarios.

There are two close spaced stations near me - 1030 XESDD (35mi, 180°, 5kW) and 1040 KURS (11 mi, 246°, 360 watts), both of which have fairly strong signals here. The radios mentioned above have little trouble separating those signals. (The CX-70 and Ultronic do lack a little on sensitivity, though. One of these days I hope to go some place near south San Diego (maybe Chula Vista, San Ysidro or Imperial Beach) and test those signals, along with 1620 WNSB415 San Ysidro vs 1630 XEUT Tijuana, but it'll have to wait as I'm recovering from a cold.)

However... none of those radios can dig 1110 KDIS (111mi, 147°, 80kW ERP, just in Radio-Locator's 0.5 mV/m) out from under 1130 KSDO (6 mi, 350°, 13.75kW ERP). The Panasonic can hear a weak KDIS when KSDO is unmodulated or off the air, though. Also, the Panasonic has an even tougher time with 1190 KGBN (97 mi, 147°, 4.3kW ERP, on R-L 0.15 mV/m) vs. 1170 KCBQ (9 mi, 7°, 112 kW ERP, indicates ~80/25 on Tecsun PL-606). (It's not quite as bad as about 10 years ago or so when 1170 KCBQ was only 6 miles away with something like a 300 kW or so lobe blasting right at me.) Also impossible to dig out from under KSDO and KCBQ is 1150 KTLK (106 mi, 145°, 1.35 kW ERP, right on R-L 0.15 mV/m).

When 1170 KCBQ has been occasionally off the air, though, I've been able to hear faint signals, at least with the PL-606, from 1160 XEQIN (163 mi, 158°, est. 2-2.5x past R-L 0.15 mV/m) and 1180 KERN (237 mi, 326°, 64.5kW ERP, est. 2x past R-L 0.15 mV/m). When KCBQ is on, though, there's not a trace.

I thought the protections were supposed to reduce interference. How is it, then, that on a not-very-selective portable (ones that at best would get a "D-" on selectivity in Gary DeBock's Ultralight shootouts), two strong first-adjacents are fairly cleanly separated, but a weak signal 2nd-adjacent to a strong one is buried? I know the signals (as well as the first-adjacents to KCBQ mentioned above) are there, as I've heard them when the local blowtorches were off the air.