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KCOH & its current experimental synchronous operation

P

purpledevil

Guest
Can someone educate me on what exactly it is? 1230 is running a 410 watt "experimental synchronous operation" off site from the licensed Ennis site. What is its purpose, and how does it benefit Liberman or Ben Hall to operate it at even less power than the regularly licensed 1kW facility?

Coordinates for the KCOH synchronous operation is 29°51'34"N, 95°33'32"W, if you're interested in taking a look.
 
purpledevil said:
Can someone educate me on what exactly it is? 1230 is running a 410 watt "experimental synchronous operation" off site from the licensed Ennis site. What is its purpose, and how does it benefit Liberman or Ben Hall to operate it at even less power than the regularly licensed 1kW facility?

Coordinates for the KCOH synchronous operation is 29°51'34"N, 95°33'32"W, if you're interested in taking a look.
Click to expand...

Synchronous transmitters have been used for many decades to expand or fill in the coverage of licensed stations.

Take 1230: the 1 kw transmitter could be located in a wide area of Harris County without interfering with other 1230's or adjacent channels. But the single 1 kw maximum-power-for-the-class does not cover all the area they want to serve. So they add one or more synchronous transmitters to expand the coverage. No further interference to other licensed stations, and greater total 1230 coverage in total.


Another use: KKOB in Albuquerque is 50 kw on 770, and daytime serves the entire ABQ-Santa Fé market. But at night, KKOB goes directional to protect WABC. So they run a synchronous transmitter in Santa Fe to fill in the coverage lost by going directional.

Still another: Puerto Rico has very low ground conductivity in most areas, and is very mountainous. No AM even covers half the Island well, and most only cover a smaller part of it. Several stations employ synchronous transmitters to cover additional areas on the Island that they could not cover even with 50 kw, and they do it with much lower power.

The grand-daddy of synchronous operations was WBZ-WBZA Boston and Springfield. WBZ's 50 kw on 1030 did not quite cover Springfield daytime, and, I am told, was in the cancellation zone at night. Westinghouse had a 1 kw synchronous repeater to cover the western market of MA.

The Lowell-Lawrence twins on 1400 also were early synchronous operations, as was WBT-WBTA CHarlotte-Shelby, NC on 1110.
 
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Thank you Brad & David, I very much appreciate the responses. So, this is basically along the same lines as an FM booster, only for AM. I understand the idea now.

Given the coordinates listed for the synchronous operation, it appears KCOH's 410 watt signal is next to Kyle Field in College Station. I understand the concept of a fill-in, or an extension of licensed service area, but that is quite a stretch. There's over 100 miles between east downtown Houston, where KCOH/KLTN originate, and Texas A&M. What has changed that allows for KCOH to place a "booster" so far out of its originally intended coverage area? If this option has been available for sometime, as it appears is the case from the above cited instances from David, why don't more AMs with limited power(like KCOH) make an effort to do this?
 
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purpledevil said:
Thank you Brad & David, I very much appreciate the responses. So, this is basically along the same lines as an FM booster, only for AM. I understand the idea now.

Given the coordinates listed for the synchronous operation, it appears KCOH's 410 watt signal is next to Kyle Field in College Station. I understand the concept of a fill-in, or an extension of licensed service area, but that is quite a stretch. There's over 100 miles between east downtown Houston, where KCOH/KLTN originate, and Texas A&M. What has changed that allows for KCOH to place a "booster" so far out of its originally intended coverage area? If this option has been available for sometime, as it appears is the case from the above cited instances from David, why don't more AMs with limited power(like KCOH) make an effort to do this?
Click to expand...

AM synchronous stations generally are not inside the normal coverage area but, rather, adjacent to it.
 
This is very old information.

The then KNUZ 1230 had a synchronous transmitter just east of the West Sam Houston Parkway central toll plaza back in the 1990's. The coordinates given in the OP map to there, but the tower apparently was taken down a few years ago...IIRC it was a rather short (perhaps 45 degree?) stick. I don't think it had been on the air anytime after 2000. Sure put in a solid signal into Cy-Fair when it was on.

The current KCOH signal is quite poor from the downtown site. Either major antenna issues or they are running less than the authorized 1kw.
 
I remember when KNUZ turned it on in the early 1980s. Both transmitters were operating at 1KW. What a mess. They finally got it to work by taking the synchronous transmitter to 50 watts during the day and 410 watts at night. That seemed to work pretty well for them. However, Houston was already an FM town and it was not going to be competitive. The bad signal? Well, many many, years ago, Dave Morris, the owner of Texas Coast Broadcasters, leased out part of the transmitter site as an old battery dump. That acid ate up part of the groundwave. When he sold the station to SFX, they found out about it and he had to pay for the clean-up. However, I do not know what has happened since that time.
 
To my knowledge not a whole lot, they had to put a clay cap over the site to protect the ground watter. That prohibits the possibility of digging to repair the grounding system with out a LARGE cost.
 
Mediafrog+ said:
This is very old information.

The then KNUZ 1230 had a synchronous transmitter just east of the West Sam Houston Parkway central toll plaza back in the 1990's. The coordinates given in the OP map to there, but the tower apparently was taken down a few years ago...IIRC it was a rather short (perhaps 45 degree?) stick. I don't think it had been on the air anytime after 2000. Sure put in a solid signal into Cy-Fair when it was on.

The current KCOH signal is quite poor from the downtown site. Either major antenna issues or they are running less than the authorized 1kw.
Click to expand...

The sync site was a 90 degree stick...fed by microwave....IS (or was) at the SW corner of Beltway and 290 (it WAS still there in 2002-04 when I was at LBI)...but I heard its gone now....too much fade in the overlap areas...........1230 has two issues besides being on a Class C graveyard near downtown Houston:

1) the ground at the site has short radials.....the ditch to the NE cut the radial length in half from the original 1230 install....and Chuck is right about the battery acid, etc...they never cleaned the site up (was supposed to be as a Superfund site...someone took the money and ran)...

2) The folded monopole....when Dave Morris extended the tower for 102.9 (and had to drop its ERP from Superpower level), the AM was never redone right.....the guys have insulators, etc but the mutual coupling is probably screwing the take off angle......another detuning skirt SHOULD BE around the upper part of the tower...and is not....so the MW RF sees that...and couples into it and thus creates an awful signal......The station should have been moved to a 1/4wave site years ago..
 
And LBI never ran the sync site...in fact, iirc, the license for the sync site and tower ASR was under Capstar's name (Steve Hicks before he and brother Tom combined to form AMFM)....and MAY have transferred to CC before it was deleted....shame, that tower would have made a nice 160m contest site with the ground system ;)
 
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