• Get involved.
    We want your input!
    Apply for Membership and join the conversations about everything related to broadcasting.

    After we receive your registration, a moderator will review it. After your registration is approved, you will be permitted to post.
    If you use a disposable or false email address, your registration will be rejected.

    After your membership is approved, please take a minute to tell us a little bit about yourself.
    https://www.radiodiscussions.com/forums/introduce-yourself.1088/

    Thanks in advance and have fun!
    RadioDiscussions Administrators

Unconfirmed report silent WDTW (AM 1310) heard testing

Interesting thing I saw while looking through old aerial views.

A Detroit radio history fact I never knew. WJBK 1500 from Lincoln Park with eight towers in 1961:

http://claslinux.clas.wayne.edu/photos/part2/wayne/1961/fm-22-101.pdf

I had always thought that they had nine towers when they moved to LP in 1954, had to add a column of three more on the west when nine couldn't protect KSTP in the Minnesota Arrowhead, and took away three from the East to cash in on their Dixie Hwy. frontage land

Now I guess they started with two rows of four, added another row of four on the South, and then took out the Eastern column in 1989.

I also had thought they had gone to twelve towers much earlier than 1961.

I owned that station for 13 years. Ran for a few years, before that. Storer had upgraded it to 50kw/5kw (the efficiency resistors dropped the night to 2.5). We had 9 towers day and 12, night. I had all of the photos of the build. 1500 was 10w/1kw when it signed on in Lincoln Park and it was 62 or 63, something like that, when Storer signed on with the new facilities. We were able to drop three and go to 9 with separate patterns, day and night. I upgraded the night to 10kw.
 
....Back to 1310. Surprise! Their application for the six tower ungrounded array was GRANTED on May 29 by FCC, Saving Mr . Zamora the big expense of a ground system.

The CP does show that the theoretical RMS figures will be very slightly less than the licensed parameters.

I'm thinking Charlie doesn't want to be thought of as the "bad guy", denying the community a station "of their own", and this may be a silent acceptance that there is more interference on 1310 at night than official records would have it and that CIWW is the 800 pound gorilla on the channel, not WIBA or WTLC.

Funny thing is, if the array doesn't work to specs, all the better for La Trece Diez - it may be heard in SW Detroit.

I still think it would have been better off diplexed somewhere. I realized there was another array that could have been used where they "wouldn't even need to diplex". Towers 6-10 of WCHB (Radio One) are not used for the day operations of WCHB, and could have given a nice signal to 1310.

update: looking at their new authorization, I see the obvious error of a 28.98 mV/m limit at 308¤ day. Obviously 228.98 (pattern is symmetrical). Would they try to meet that errant figure?

That 23.49 limit at 310.5¤ night makes no sense. WCCW already gets plastered by WIBA at night, they don't need that much protection from WDTW.

I'd bet that the old ground system is shot. Tore up, plowed up or rotted out.
 
Chuck was manager of the station for almost a quarter century before that.

But ABC had notoriously centralized programming operations, and local managers had little input. Remember, this is the company that went Top 40" but kept some of the ultra-MOR ABC network shows on for years at WLS and WABC.

If a station's selling price is your absolute standard for the quality of radio, then radio really is in the crapper today.

Since a station's selling price is a reflection of the success of a station in its market... and pretty much always has been... the fact that Fritz increased the station's value by over 750% in a decade says that he did a lot more with it than ABC had been allowing him to do when he was manager.
 
I agree with the selling price being a reflection of success....to a point. Look at 910 in Detroit. No way did its performance justify the price that Adell paid for it. In that case, it was because it was available, had recently upgraded infrastructure and a strong signal. In the case of WXYT, I agree that Fritz did do an excellent job and at least some of the increase is attributable to his performance, but a good portion of that as well was the inflation of station values after the 1996 Telecom Act and the spending spree brought forth by consolidation. I think that, as much or more than anything, explains why WXYT sold for what it did at that time.
 
I agree with the selling price being a reflection of success....to a point. Look at 910 in Detroit. No way did its performance justify the price that Adell paid for it. In that case, it was because it was available, had recently upgraded infrastructure and a strong signal. In the case of WXYT, I agree that Fritz did do an excellent job and at least some of the increase is attributable to his performance, but a good portion of that as well was the inflation of station values after the 1996 Telecom Act and the spending spree brought forth by consolidation. I think that, as much or more than anything, explains why WXYT sold for what it did at that time.

910 was sold for what is close to stick value for a facility of its kind. Unlike ongoing enterprises, stick value pricing is employed when there is no cash flow and there may not even be a revenue stream. At any given time in any market there is a range of "prices" for non-performing or silent assets. The price for 910 of $3 million is stick value. In 2002, Disney overpaid Cumulus $3 for the same station when it was a Flint property and needed millions in development costs to move it to Framingham Hills.

The 1994 sale by Fritz to Infinity preceded the Telecom Act by two years, but was done when local ownership caps were slightly expanded. At the time, multiples had not reached the 16 to 18 times BCF of the consolidation era. From the late 80's to the early 90's, multiples had been anywhere from 12 to 14 on performing facilities. That would mean that the station only had to be producing BCF (roughly the same as EBITDA) of around $1.5 million a year on billings of over $7 million to be "worth" $23 million in the pre-consolidation era's pricing model.

I suspect that WXYT had greater BCF, but was sold for a lower multiple because it was an AM.
 
I'm with David on both of his posts. Chuck and Jock did an excellent job, building audience and wealth. Something is worth what someone will pay for it. XYT was worth quite a bit.
FDF? Take the Pop Count for the bodies within the 2 MV/M. Look at market rank and a station like FDF WILL bring appraise for what Kevie paid for it. Supply and demand is also a consideration. What else is for sale? WCAR? Right. WFDF might have even gone for a little more than this.
IF there had been cash flow, then you look at an ROI or ROE type purchase. Even in commercial real estate, guys are back the the 6-8% area. We got an offer of 2.3 Million on a property that had a net cash flow of around 200 thousand a year. The cash flow was actual cash basis dollars, not accrual. It's all slowly coming back.
 
110 kHz is kind of close for diplexing, but like you say, it's not a diplex. Two of the E-W towers might work, but the orientation and spacing might not be ideal. And you might need at least four towers in the daytime to reduce the radiation to the South toward WOBL. The advantage of the existing site and licensed parameters is that you don't have to reduce overlap or radiation toward cochannel stations at night. The day pattern nulls are the equivalent of the 1000 watt nondirectional operation when they moved from 1540 to 1310.

But E-W towers would mean a true diplex or adding new towers to the array (impossible?, the former technically and the latter politically?).

Feed towers 6 & 8 out-of-phase and you've got an N-S endfire pattern. Since those towers would be a little more than 180° apart on 1310 (they're exactly 180° on 1200), you'd get four nulls (two close together on either side of both 100° and 280° azi and slightly widened lobes at 10° and 190°). Towers 7 & 9 could be used with less field to make the 10° lobe stronger than the 190°. Using all five could make the game more interesting. It's just too bad that WCHB's towers line up along 10° and not 25°. WLQVs array is far more well-positioned for reaching the Hispanic core at night, anyway).
Since any inline array is going to be symmetrical along its line, there is no way that it would work at night (as I've said before, they need 20 watts into a Valcom at Waterman and W Vernor at night, or 10 watts of FM into a yagi beamed NE from the Jefferson and the Rouge River, but good luck finding a frequency for the latter today).
 
Last edited:
The day WCHB pattern is four towers in close to a North South line. The whole array is two rows of five towers along close to a North South line. So their would be two towers along close to an East West line that wouldn't need to be diplexed. But to reduce to the South toward WOBL, you might need a parallelogram to duplicate the footprint of the licensed WDTW day pattern.

Keep in mind that some of the towers not directly fed would be hot from the other station, even if they are detuned at their particular operating frequency. So it would be kind of a parasitic diplex anyway.
 
Last edited:
My mistake. Somehow I forgot that WCHB only uses four of their five west column towers during the day. Thanks for the info.
 
<snip>
FDF? Take the Pop Count for the bodies within the 2 MV/M. Look at market rank and a station like FDF WILL bring appraise for what Kevie paid for it. Supply and demand is also a consideration. What else is for sale? WCAR? Right. WFDF might have even gone for a little more than this.
.

I agree. I had thought that the WFDF facility would have made a good upgrade for Salem's WDTK (a class C trying to do conservative talk when only African-American listeners can hear it at night)

Or an upgrade for their WLQV.

Seeing who's buying the mice, I wonder if there is a hidden agreement that any of these stations being sold are to be non-commercial, so as to protect the value of existing AMs.
 
I agree. I had thought that the WFDF facility would have made a good upgrade for Salem's WDTK (a class C trying to do conservative talk when only African-American listeners can hear it at night)

Or an upgrade for their WLQV.

Seeing who's buying the mice, I wonder if there is a hidden agreement that any of these stations being sold are to be non-commercial, so as to protect the value of existing AMs.
Boy, i have to apologize for that post. I was doing too many things at one time. That one sentence doesn't even make sense. Yikes! Anyways. Kevin Adell runs a for profit.
The only caveat that could be used to defend future AM valuations is that 910 wasn't cash flowing. Keep in mind that if it did have good cash flow, then stick value would not be an indicator of its worth. It would have been a based on multiple of cash flow. In many markets, "stick value" for a non profitable AM can be less than 50 cents per head, way less.
 
I did hear the station (1310) a few months ago, apparently operating from a crank up tower downriver just south of I-94, west of the original 1310 site. The tower was gone soon after.
 
That was mid-November to early January. The crank-up was not sending the signal, it was holding up a wire that was. It performed very poorly.

It was AT the licensed TL.
 
I'm wondering what would happen if they couldn't get the pattern to properly operate with the 6 radials per tower. Could they increase gradually like to 12 radials and beyond until it did work properly? Has anyone done studies about this? Maybe Rich could give us some insights. I have no doubt that the day two tower pattern could work properly. The nulls are very shallow. The idea behind any directional antenna is that the individual radiators all function the same, or predictably and consistently if different designs. Usually they are the same height, but they don't have to be. One of the problems with top loading the directional antenna would be if the "umbrella" is not functioning the same electrically on all towers. You might get away with it with the less critical day pattern, but the night pattern is very tight. If you notice, cyberdad and radioman148, if you read this, is that stations like WIND (4 tower parallelogram) and WKTA (6 towers to 4 towers to now 6 towers again) did away with top loading when they rebuilt their arrays. Other stations with critical patterns are not likely to use top loading if the can get away with it.
 
Last edited:
Your mention of WKTA's array gave me the curiosity to look them up. That's an insane pattern for daytime operation! They really packed them in around Chicagoland (dare I say, more so than LA or NYC). This must be one example of a radio station that only exists because someone figured out it could be done (same goes for nearby WEEF).

Since there is no longer a 5,000 watt cap on the former regional channels, why deal with the top loading at all, when they could use simple 199' towers and run a little more than 5,000 (for the day pattern). At night, I imagine it would be hard to protect other 1310s from interference due to fact that the shorter towers will cause more RF to radiate at angles higher above the horizon. Would rebuilding the towers at licensed 220' and lighting them be that much more expensive? (I've heard installing standard lights, the electricity to light them, and the inductive couplings to transfer to the power from the ground potential to the "hot" towers is quite a pain).

Questions: Why does WDTW have to have such a deep null in the direction of WDPN at night? None of the other stations protect it well, thus, like WDTW, it gets a lot of QRM from WIBA, WTLC, CIWW, and others. I would think WDTW would be able to throw about 120 mV/m@1km in their direction, then again, I only have access to the horizon radiation from WDTW. Was their array sending a lot of power skyward in the 130° direction of WDPN?

Going back to about 1956 - could WKMH (then) have gone to 5kw with four towers, by dismantling the two towers on the south row and rebuilding them in different positions slightly to the west? Perhaps that would have theoretically allowed just a little less than 5,000 watts, which, under the rules then, meant still only 1,000 watts.

Could a new WDTW array improve performance by using towers of dissimilar height? I've finally found an array that is stranger than WXYT's! WNIO, Youngstown, OH. Like WXYT, the towers are in a pseudo-random array, as if someone just threw the towers on a table. While WNIO has six towers vs. WXYT's nine, WXYT's are all the same height, while WNIO's six towers are five different heights!

Update: I found another reason WNIO's array is unusual - they have a seventh tower, as their daytime operation is a relatively short stick several miles away from their nighttime array. The shorter stick lets them brag they have 9.5 kW in the day while their six tower array was built only for the night, and to cover Youngstown as well as one can on 1390.
 
Last edited:
I'm thinking WGH's NIF can't be all that low, as WEMG in Camden (NJ) throws 155mV/m@1km in all directions. For what it's worth, WEMG is older than dirt (1925), yet suffers a 9 mV/m NIF itself.

Nice resource for NIFs on 1310: WRSB upgraded their signal awhile back, and their app (including their engineering exhibits) is still on the FCC database.
 
The WCCW Class B application has those also. You're right, the WGH NIF is not that low, around 10.5 mV/m. Usually if there is a station with a 3 letter callsign or one of the oldest stations with a 4 letter callsign, you're looking at an NIF in the neighborhood of 2-4 mV/m for the old III-As and 4-7 mV/m for the old III-Bs. But there might be the answer also. I think you could only put a 125 uV/m for a III-A and a 200 uV/m for a III-B interfering signal. We could look in David's archives to see if it was a III-A. Keep in mind that III-Bs could have been 5 kW night, and III-As could be 1 kW night, contrary to DXer beliefs. In later years, the Broadcasting Yearbook stopped putting the III-A and III-B designations in the AM Stations by Frequency List, probably because of the confusion.

Two other possibilities for the deeper null could be that one null was designed in a compromise direction between two pattern considerations with closely spaced azimuths. Also, as there is a degree of symmetry to the array and pattern, though not symmetrical, it may be that the null on the other side of the axis of the array has to be deep. That is where your idea for doglegging the array might be beneficial. You might have been able to go to more than 1 kW with four towers, but back when it went to fulltime, Class III-B, there were no power levels in between 1000 watts and 5000 watts. Only around the late 1970s did 2500 watts even become an option. Like WJBK, there were plenty of stations operating with series limiting resistors. There were, and still are, MANY stations still licensed as 5000 watts with around 3800 watts input to the antenna. That is why you see a lot of stations in that range if they had to relocate the TL or wanted to change licensed patterns.

When I first visited the WCAR 1130 (now WDFN) array back in the 1970s, the Chief Engineer there had never heard of reduced input power being licensed as the nominal power. We even talked about WJBK/WDEE (now WLQV), which with 132 degree towers and the endfire (the three tower in line component) efficiency gain, was able to get 5000 watt efficiency with a 2500 watt input power. With nondirectional, you could get the same efficiency gain with a high enough tower (an inverse field around 400 mV/m @ 1 km @ 1 kW). That corresponds to a tower in that magical 195 degree range typical of many Class A (I-A) AM stations.
 
Last edited:
I just looked it up on americanradiohistory.com (Thank you, David, for your fine reference site) in the 1970 Broadcasting Yearbook. WKNR Keener 13 is listed as a Class III-B. WGH is listed as as a Class III-A. I think that you had to restrict your interfering signal to 125 uV/m even if the NIF was higher than the 2.5 mV/m normally protected Class III-A contour. Possibly you could base your interfering signal on the actual NIF (<50% of the RSS with <50% of the consecutively recalculated RSS interfering 10% skywave signals excluded), but I think the stations interfered with would challenge it and hold up the application, and possibly they would look for some way to dismiss it.

A 500 watt night station could not be Class III-A. The best it could be would be Class III-B. If you read the rules in the NAB Engineering Handbook, you'll see this spelled out in the wording of the section about Station Classes. If the interfering signals were above 200 uV/m, they were considered just as Class III. As the years went on, the list became less accurate. When they changed the skywave curves and NIF calculation, many stations increased in NIF, partly due to inclusion of first adjacent channel interference. Even stations like WWJ have NIFs exceeding 2.5 mV/m. I think the idea with the 125 and 200 uV/m restrictions was that it would be unlikely that more than one or two stations would be interfering at any particular time. So if there were two 125 uV/m signals, the NIF would be about 3.5 mV/m, and if there were two 200 uV/m signals, the NIF would be about 5.6 mV/m, or 20 times the RSS of the two interfering signals. If you look at the NIFs of former Class III-As and Class III-Bs, you'll see that this is a reasonable first approximation of the current NIF contour for those stations. Except for WGH and possibly others.
 
Last edited:
Status
This thread has been closed due to inactivity. You can create a new thread to discuss this topic.


Back
Top Bottom