Towers & Such & Things 2018

This topic contains 172 replies, has 26 voices, and was last updated by  LinleyG 16 minutes ago.

Viewing 15 posts - 16 through 30 (of 173 total)
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  • #34134

    Andy Brown
    Participant

    Why could not 1150 diplex wth KBPS?

    At a quick glance the 1450 tower would be less then a quarter wave at 1150 even if they could use the entire length which would mean a total reconfiguration since it is now shunt fed which sacrifices some of its length (below the feed point) electrically. As Semoochie hinted at, it would be cost prohibitive not to even mention the time frame to come to agreement with PPS/Mult. County, etc. etc.

    So not a practical nor cost effective solution and it would only yield a very poorly performing result without more steel. The 1520 towers are an exact quarter wave at 1520 so they are even less as you go down in frequency to 1150 so although doable, WTFF? It probably couldn’t provide enough coverage anyway. They need to find a bigger tower or build a new site.

    #34141

    boisebill
    Participant

    110 mph wind gust @ Mt Hood Meadows.
    Not my idea of a “nice” transmitter site.
    The FMs from there still on the air tonight?

    #34143

    jr_tech
    Participant

    88.7 ok, 89.5 no modulation, 90.3 ok, with some audio drop out… signal strength on all 3 about normal.

    #34146

    boisebill
    Participant

    Date(PST)Temp(F)DewPoint(F)RelativeHumidity(%) WindChill(F)WindDirection WindSpeed(MPH)

    11 Jan 7:00 pm 27 -72 0 5 SW 66G100
    11 Jan 6:00 pm 27 -72 0 6 SSW 63G110
    11 Jan 5:00 pm 26 -73 0 14 SSW 14G67
    11 Jan 4:00 pm 26 -73 0 5 SSW 58G106
    11 Jan 3:00 pm 26 -73 0 4 SSW 65G103

    • This reply was modified 11 months, 1 week ago by  boisebill.
    #34148

    jr_tech
    Participant

    Just checked again, all 3 stations are ok now.

    #34382

    Andy Brown
    Participant

    The transfer of K264AA Salem from the KBOO Foundation to KMUZ Turner is granted. This leaves their CP upgrade in limbo from what I can gather, since it proposed fill in status for the new Dallas station. As a translator for KMUZ, it would lose fill in status. So I’m not sure what’s going on with that aspect going forward, however even at its present parameters, it has been and probably will continue to be KMUZ’s footprint in Salem now that they own it.

    #34410

    e_dawg
    Participant

    How about triple plex with kbnp / kxpd towers at oaks park. I’m not sure if they can duplex with kbms tower located next to smith lake.

    • This reply was modified 10 months, 3 weeks ago by  e_dawg.
    #34412

    Andy Brown
    Participant

    Can’t do Oaks Park since KXPD 1040 is too close in frequency to 1150 (generally speaking colocated AM’s should be >125 kHz apart).

    Smith Lake might fly but it wouldn’t work very well since the three tower 1480 array are all exactly 1/4 wavelength (~163.3 feet) and 1150 at 1/4 wave is closer to 160 feet. Another way of saying that is 1150 would be propagating off of a 1/5 wavelength tower which wouldn’t go very far. Again, you want to find a tower that is hosting (and was built for) a lower frequency then the one you want to add.

    The bigger problem at KBMS, though, isn’t technical. It’s the money thing. Chris Bennet, owner of KBMS, has had a hard time selling the 1480 license and has been trying to for quite some time. That frequency hasn’t made any money nor achieved any ratings or cross media coverage since it was KVAN 1480 The monomaniacs in the sixties and seventies. If Chris thought for a minute that the big boys wanted on one of his towers, he would probably want them to fork over a ton of money and/or buy 1480. I just don’t see a deal happening there, e dawg.

    #34413

    semoochie
    Participant

    It was a pretty good Top 40 for awhile in 1980, while they were trying to boost its coverage.

    #34414

    boisebill
    Participant

    There’s a diplexed 630 / 730 in Boise. Both are directional day, directional night different patterns. Both use all 3 towers day & night too. Wouldn’t say it works well, but they’re on the air.

    #34454

    Andy Brown
    Participant

    In yet another shoehorn in another secondary service delivery system, Bustos has applied for a translator on 101.5 which will clearly interfere with both KXYQ-LP and KDOO-LP. More info in the LPFM thread.

    #34479

    e_dawg
    Participant

    So what other tower sites would it be possible for KGDD 1150AM?

    Diplex with KPDQ 800AM tower?
    Diplex with KUFO 970AM tower?
    Triplex with KMTT 910/KFXX 1080 tower?
    Triplex with KPAM 860/KKAD 1550 tower?

    #34482

    Alfredo_T
    Participant

    The KPDQ-AM site has a single phase of 7200V power running to it, which is stepped down by a conventional (and delightfully old-looking) pole mounted transformer. (See here https://www.google.com/maps/@45.4765221,-122.7503846,3a,30y,318.6h,92.39t/data=!3m6!1e1!3m4!1s2YHsqUiJ3HHJ3fk0VhwkcA!2e0!7i13312!8i6656?hl=en ) Most 5kW transmitters require three phase power, so a site electrical upgrade would be needed here.

    I’ll let the experts chime in on the idea of diplexing with 970. For many years, I have wished that KBPS could have been broadcast from one of the 970 towers to improve its reception in the Westside. Of course, from their point of view, this would make zero sense, as they already own the land upon which their tower sits.

    Triplexing can be done, but the triplexed facilities that I can think of are all single-tower systems. Honolulu, HI has several triplexed sites, in my recollection. Opelika, AL has a triplex of 910, 1400, and 1520. Again, I’ll defer the details to the experts.

    #34494

    Andy Brown
    Participant

    910/1080 is out because 1150 is too close in frequency to 1080. Also, that site was totally rebuilt with new towers to accommodate diplexing those two frequencies, so it’s likely to be hugely expensive to engineer another channel share so it’s unlikely Salem would want to foot that bill.

    970 is most likely not tenable due to ongoing issues, the most relevant being controlling detuning/re-radiation. Read the licensee’s latest blurb at the link below, filed when they once again had to extend their Special Temporary Authority. Adding yet another frequency to the mix up there would be a major setback in their ten year effort to get the station out of their STA and back to being compliant. Of course, with endless money anything can be worked out, but I doubt 1150 is worth that much to Salem Media. Also, assuming all that was fixed, the technical fly in the ointment is skywave compliance. Those towers are huge, 170 meters (550+ feet) and at 1150 that exceeds 5/8 wave which means that the amount of skywave it would produce at night would be off the charts.

    https://licensing.fcc.gov/cdbs/CDBS_Attachment/getattachment.jsp?appn=101767449&qnum=5330&copynum=1&exhcnum=2

    860/1550 Another long history of STA’s and lots and lots of money has been spent to get the diplexed installation licensed. I think it’s safe to say that adding another frequency to any of the towers up there would be a very expensive project. Not to mention that the new owners probably would have no interest in tearing apart to whatever degree what they just bought.

    800 Alfredo’s report notwithstanding, this appears to be the only option without huge obvious flaws. Assuming a full analysis with spacing, contours, etc. was all compliant, and the fact that they own the stick already, may be their only option without buying land and building a new site. Locals have never liked that tower and adding more energy to it may be a sticky wicket to pass through.

    So e_dawg it looks like what we already knew before remains the case, they have few options when it comes to jumping on someone else’s tower.

    #34499

    cbaravelli
    Spectator

    5/8 RF wavelength Marconi antennae are an attractive choice to extend ‘ground wave’ radiation patterns. While ‘sky wave’ vertical radiation increases again above 1/2 wavelength, nulls also increase in the diagonal. Not uncommon for 4dB gain in the horizontal above a 1/4 wavelength Marconi dipole. Natural frequency vs. natural resonance. Lambda and Siemens, Andy. Lambdas and Siemens.
    If ya wanna fry migrating geese, short lambdas and low Siemens will work. KRCO-AM 690, Prineville – OR, is a prime example. Current KPDQ-AM antenna is short and suffers from sky wave component(s). Hence, half power (500 Watts), nights. Current KGDD-AM is much shorter, Hence, 100 Watts, nights
    KGDD-AM co-antenna combo with KPDQ-AM is possible. 1150 mHz is slightly longer 1/4 lambda than the existing 79.3m RF radiation structure. However, is not probable. Salem would never allow Bustos to and Bustos is cash short.

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