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Short spaced stations

F

ftballfan

There are a lot of short-spaced radio stations, especially in the northeast and Midwest.
Here are some examples of them:
1520 WJMP Kent, OH and 1520 WINV Canton, OH – 22 miles apart
93.3 WTPT Forest City, NC (C) and 93.7 WFBC Greenville, SC (C) – 24 miles apart
94.5 WTNR Holland, MI (B) and 94.5 WCEN Hemlock, MI (C1) - 91 miles apart
95.7 WLHT Grand Rapids, MI (B) and 96.1 WMAX Holland, MI (B) - 17 miles apart
100.3 WHTZ Newark, NJ (B) and 100.3 WRNB Philadelphia, PA (B) – 82 miles apart
101.1 WCBS New York, NY (B) and 101.1 WBEB Philadelphia, PA (B) – 82 miles apart
104.7 WNOK Columbia, SC (C1) and 104.7 WKQC Charlotte, NC (C0) – 77 miles apart
105.7 WQXA York, PA (B) and 105.7 WJZ Baltimore, MD (B) – 47 miles apart
105.9 WQXR Newark, NJ (B1) and 105.9 WHCN Hartford, CT (B) – 82 miles apart
 
In the case of AM stations, sometimes applications were filed so close to the same time that the FCC was not aware of a conflict. If the stations agreed to accept interference, they were both approved. In the case of the Ohio stations, they are also very directional.

In the case of FM short spacing, they weren't usually short spaced when they were approved. All classes A, B, and C were protected to the 1 mV/m contour, now usually designated as 60 dBu. They usually had lower ERP and lower tower heights than stations do today. In the case of noncommercials, low ERP and DAs make it possible to squeeze many stations in at short distances.

Short spaced often means "the other station is short spaced" to owners and other positions of station authority, when in fact they are MUTUALLY short spaced under CURRENT rules. The FCC itself created 90 percent or more short spaced FM stations by constantly changing the rules.

Section 73.213 created many short spaced stations at high ERP and HAAT when it allowed zones of short spacing. Some of those mentioned fall into that category, especially the second adjacents.

The FCC should copy what Canada has done with DA allotments and interference rules.
 
Another short spaced situation on 1520 was what was once WTTO Toledo, OH and WYNZ Ypsilanti, MI. WYNZ was 250 watts nondirectional daytime only, and WTTO was 1000 watts directional days with 6 towers in Temperance, MI. The night site was in Perrysburg, OH, another 6 tower array. WYNZ moved to 990 and is now WWCM. WNWTmoved to a third fulltime site with 500 watts daytime and 400 watts nighttime with 5 towers.

Old treaty restrictions required stations on 990 to protect the whole Canadian border to 5 uV/m, even though the Class A station on 990 is in Winnipeg, Manitoba. In fact, a station on 990 in Clare, Michigan aimed its signal more at Winnipeg and protected the nearby border to the east. It was not believed to be possible for both the Clare station and Ypsilanti to occupy 990, so Clare was taken off the air completely. The new rules only require 5 uV/m protection to the Canadian border where the Winnipeg station, CBW, operates and puts a 100 uV/m contour in Canada. WWCM uses 9200 watts, with a signal that goes into Ontario, in the daytime. At night, it protects the skywave of CBW in Canada, and operates with 250 watts away from Canada.
 
Schroedingers Cat said:
Old treaty restrictions required stations on 990 to protect the whole Canadian border to 5 uV/m, even though the Class A station on 990 is in Winnipeg, Manitoba. In fact, a station on 990 in Clare, Michigan aimed its signal more at Winnipeg and protected the nearby border to the east. It was not believed to be possible for both the Clare station and Ypsilanti to occupy 990, so Clare was taken off the air completely. The new rules only require 5 uV/m protection to the Canadian border where the Winnipeg station, CBW, operates and puts a 100 uV/m contour in Canada. WWCM uses 9200 watts, with a signal that goes into Ontario, in the daytime. At night, it protects the skywave of CBW in Canada, and operates with 250 watts away from Canada.
Click to expand...

CBY in Cornerbrook NFLD is also a class A at 990 khz. CKGM in Montreal used to have to protect them as well as CBW.
 
Interesting numbers. I live in the deep south so we don't really have these sort of spacing issues. It's probably why HD works on FM better here than many other parts of the country.

The stations that seem close in my market (Mobile) are because of the flat terrain and mostly tall towers tend to make FM outperform predicted coverages. The worst real world spacing here seems to between WNSP (A) 105.5 in Bay Minette and WCSN (A) 105.7 in Orange Beach. They're about 44 miles apart, so they "fit" but if you're halfway between them as I am, less selective radios have trouble with both stations interfering with the other.

WNSP (A) on 105.5 is only 22 miles from Atmore, where WBZR-FM (A) is at 105.9.
WCSN (A) on 105.7 is only 22 miles from Pensacaola, where WRRX-FM (A) is at 106.1.

There's a very rural area near the AL/FL border along the Perdido River where all four signals — 105.5, 105.7, 105.9 and 106.1 — are equally strong.

Further up the dial, some higher power stations are also wedged tightly together. Again, the spacing is all legit by FCC standards as far as I know but the flat terrain really does give these stations "extra oomph".

It starts with WHWY (C1) in Fort Walton Beach at 98.1 and WLVM (C2) in Mobile at 98.3. They're about 100 miles apart but in between them where I live, it can be pandemonium, especially when tropo kicks up.

WLVM (C2) on 98.3 is only 45 miles from rural Seminole, Alabama, where WYCT (C1) is on 98.7.

That's about as tight as it gets here, luckily. There are some close calls on AM, but ground conductivity is so bad here it doesn't hurt anything. For example, there's 9 kW WMOB in Mobile on 1360 and 5 kW WCOA in Pensacola on 1370 and they don't really overlap at all. My town has WHEP at 1310, running 2.5 kW days and there's Pensacola's WEBY at 1330 with 25 kW directional towards me, but there's very little hash between the two except on the worst of radios.
 
WFLI Lookout Mt. (Chattanooga) and WAPI Birmingham. Both 50Kw day, 143 miles apart. WAPI non directional, WFLI directional with 3 towers, nulled to the west.
 
I wonder what's the shortest spacing co-channel situation between a 50 kW clear AM station and another station?

In Cleveland, there's WCCD on 1000 kHz, only 307 air miles from 50 kW clear WMVP in Chicago.
 
Buckeyes2001 said:
I wonder what's the shortest spacing co-channel situation between a 50 kW clear AM station and another station?

In Cleveland, there's WCCD on 1000 kHz, only 307 air miles from 50 kW clear WMVP in Chicago.
Click to expand...

WCCD is a 500 watt daytimer that nulls toward Chicago. It's unlikely that WMVP makes it to Cleveland during the day.
 
Ok so these aren't as short-spaced as some mentioned so far, but...

On 1390, there's KLTX in Long Beach, CA, with 5kW DA, and XEKT in Tecate, BN, with 5kW ND.
Here's early afternoon reception in Pacific Beach on a Sony SRF-59 using only the internal ferrite.

So where else are there cases where you have comparable or more severe co-channel interference in the middle of the day? (most of the ones below may not have as severe an overlap, but I wonder if some do?)

Also there's 1030 XESDD in Puerto Nuevo, BN, which overlaps currently-silent 1040 KURS San Diego, CA.

I wonder who from southern California remembers the Tijuana stations several years ago that were briefly on 550 (overlapping KUZZ and KFYI and local 540 now-XESURF), 560 (overlapping KBLU), and 920 (overlapping El Cajon's 910 KECR)? Also I wonder how much overlap 620 XESS has vs KTAR Phoenix?

Also in SoCal there's 1310 XEC Tijuana, 1320 KKSM Oceanside and another 1320 in Hemet.
A couple others are 1220 KHTS Canyon Country and KWKU Pomona. Also 1240 KNSN San Diego & KEZY San Bernardino, and 1230 KYPA Los Angeles. Who remembers the 1240 that used to be in Pasadena? (I'm a bit young for that one.)

Speaking of short spacing.... is there *any* place where the dial is so densely packed even in the middle of the day, that your radio's scan would stop on *every* frequency from 530 to 1700 (or 531 to 1701), and none of it from a local's HD sideband? On another note, I'd like to find a pocket radio sensitive & selective enough so this would be true anywhere in USA, Mexico (even after stations move to FM per DavidEduardo) and Canada. Otherwise-blank channels might have graveyard-like co-channel interference at midday, and locals wouldn't splatter onto adjacents, even near their tower.

Since Buckeyes posted while I was writing, that reminded me. This isn't exactly close spacing, but...
I'd love to hear co-channel interference (like my XEKT vs KLTX clip above) of a Canadian *AND* Mexican at midday in June. A couple ideas I have for contenders would be 540 XEWA and CBK maybe in CO, NE or KS, or 800 CKLW and XEROK at Fairfield Park in Kansas City. :)
 
Schroedingers Cat said:
In the case of AM stations, sometimes applications were filed so close to the same time that the FCC was not aware of a conflict. If the stations agreed to accept interference, they were both approved. In the case of the Ohio stations, they are also very directional.

In the case of FM short spacing, they weren't usually short spaced when they were approved. All classes A, B, and C were protected to the 1 mV/m contour, now usually designated as 60 dBu. They usually had lower ERP and lower tower heights than stations do today. In the case of noncommercials, low ERP and DAs make it possible to squeeze many stations in at short distances.

Short spaced often means "the other station is short spaced" to owners and other positions of station authority, when in fact they are MUTUALLY short spaced under CURRENT rules. The FCC itself created 90 percent or more short spaced FM stations by constantly changing the rules.

Section 73.213 created many short spaced stations at high ERP and HAAT when it allowed zones of short spacing. Some of those mentioned fall into that category, especially the second adjacents.

The FCC should copy what Canada has done with DA allotments and interference rules.
Click to expand...
In Canada, there is at least one case of second and/or third adjacents being on the same stick!! In Michigan, there is 89.7 WLMN south of Manistee that is 15kW and 89.9 WLJN in Traverse City that has a CP for 100kW (and no, they're not co-owned, despite the very similar call signs).

Speaking of FM short spacing, there are several between Grand Rapids and Milwaukee:
94.5 (WLWK and WTNR; as mentioned above, WTNR is also short-spaced to WCEN)
95.7 (WRIT and WLHT)
102.9 (WHQG and WFUR)
106.9 (WNRG and WOOD)

A few more between Detroit and Cleveland:
92.3 (WMXD and WKRK)
93.1 (WDRQ and WZAK)
95.5 (WKQI and WFHM)
99.5 (WYCD and WGAR)

An example of second-adjacent short spacing in Cleveland:
98.1 WKDD and 98.5 WNCX are about ten miles apart
 
Buckeyes2001 said:
I wonder what's the shortest spacing co-channel situation between a 50 kW clear AM station and another station?

In Cleveland, there's WCCD on 1000 kHz, only 307 air miles from 50 kW clear WMVP in Chicago.
Click to expand...

There's much tighter than that to be found. How about WJMP 1520 in Kent, which is just 168 air miles from 50 kW clear WWKB in Buffalo?

The key here, of course, is that not all "50 kW clears" are created equal. Stations like WMVP and WWKB are former I-B clears, which operate directionally - and those directional nulls, often fairly deep ones, provide holes into which smaller stations can fit, sometimes very closely.

A more interesting question, perhaps, is what the shortest co-channel is to a former I-A non-directional 50 kW clear? You'd be looking in areas of poor ground conductivity for that answer, I suspect...
 
Originally 93.3 had WAKW Cincinnati and a Chillicothe station at about 85 miles. Both were class B's operating at reduced power. WAKW commenced directional 50KW operation decades ago and based on that, Chillicothe moved to the southern burbs of Columbus with a full 50KW non-directional. In the end, there are 2 50KW FM's on the same channel at just over 95 miles.

Another example is WFDM 95.9 Franklin,IN and WFMS 95.5 Indianapolis. Both began operation at well under maximum facilities so they "fit". At some point before I moved here in 1977, the two inked an agreement to upgrade to full 3KW/50KW facilities. It's a shame that the 6KW rules didn't exist at the time as WFDM appears to be eternally stuck at 3KW. The two stations are about 20 miles apart.
 
The ultimate case of FM short-spacing, though I don't know if it ever got on the air, was a construction permit for an FM translator in the Detroit area (proposed TL on 8 Mile Rd in Oak Park) on 93.9 - the same frequency as full-power CIDR, Windsor, ONT. The grant was made because it could be shown that the translator would not interfere with CIDR on Canadian soil, because CIDR was so strong on the Canadian side.

Such a translator would have had almost zero useful coverage. The only reasons for building it that I could think of would be either to own "a" translator license, which could be sold and/or modified for use elsewhere, or to actually JAM CIDR on the American side.
 
1L6E6VHF said:
Such a translator would have had almost zero useful coverage. The only reasons for building it that I could think of would be either to own "a" translator license, which could be sold and/or modified for use elsewhere, or to actually JAM CIDR on the American side.
Click to expand...

Or so that it could then be hopped to a more useful frequency - in this case, if memory serves, to 104.7.
 
radio-dinosaur said:
WFLI Lookout Mt. (Chattanooga) and WAPI Birmingham. Both 50Kw day, 143 miles apart. WAPI non directional, WFLI directional with 3 towers, nulled to the west.
Click to expand...

Another oddly close pairing between Birmingham and Chattanooga is on 96.5 — 100 kW WMJJ in Birmingham and 100 kW WDOD, both with 1000+' HAATs. WDOD is directional but there's still some significant overlap and interference issues on I-59 north of Gadsden.
 
Stations are not protected outside the land area of their country of origin, regardless of how strong those signals are. You could legally put translators in Windsor on Detroit cochannels as long as the 34 dBu F(50,10) contour doesn't reach US land. Countries are sovereign and can de facto legally jam signals from outside their country if they want to, and it wouldn't violate the treaty, at least from a technical standpoint, as long as the interfering contour does not reach the land area of the foreign country. With the CIDR situation, the problem was that the translator had no significant service area. It was a leapfrog situation, and it was necessitated by FCC rules.
 
Of course, this situation benefits American entrepreneurs far more than Canadian ones. A co-channel translator on the US side protects the Canadian station in such a way that only Detroit Proper is likely to receive the Canadian station well (by incident - not by design), and advertisers are not concerned about Detroit proper (except in urban-formatted stations). In contrast, the much smaller (geographically) Windsor area, with so much of its population within 2km of the US border (aka the Detroit River) can't put a translator close to Windsor without keeping that 34dB 50,10 contour in Canada. Yeah, they could licence a transmitter out by Harrow, but those in and near Windsor would have no problem hearing the US station on that frequency.
 
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