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KSON AM 1240

N

najemarg

Guest
Is AM 1240 still broadcasting on that chopped up
stick, or are they temporarily transmitting off another
tower.
The same question for KURS AM 1040 and KBNT LP-17.
 
KSON-AM and KURS-AM are at the "chopped up stick." KBNT-LP (Officially: KBNT-CA) had to move. However, I will have to ask some in the know where the stick is now. CA in the call letters is for 'class A'


For TV 17:
Map Here<P ID="signature">______________
+--
Chris
SDRadio.net</P>
 
> Is AM 1240 still broadcasting on that chopped up
> stick, or are they temporarily transmitting off another
> tower.
> The same question for KURS AM 1040 and KBNT LP-17.

The tower is still a quarter wave, and works for both 1040 and 1240. I don't think there is going to be a change of towers, even if the radiator is shorter.
 
> > Is AM 1240 still broadcasting on that chopped up
> > stick, or are they temporarily transmitting off another
> > tower.
> > The same question for KURS AM 1040 and KBNT LP-17.
>
> The tower is still a quarter wave, and works for both 1040
> and 1240. I don't think there is going to be a change of
> towers, even if the radiator is shorter.
>
David it's slightly less than a quarter wave for KSON and even a little less for KURS. The old structure was way too tall and presented matching problems for both stations. That's why it used to be shunt fed. It's now series fed for both stations and works much better, even though it looks funny.
 
> > > Is AM 1240 still broadcasting on that chopped up
> > > stick, or are they temporarily transmitting off another
> > > tower.
> > > The same question for KURS AM 1040 and KBNT LP-17.
> >
> > The tower is still a quarter wave, and works for both 1040
>
> > and 1240. I don't think there is going to be a change of
> > towers, even if the radiator is shorter.
> >
> David it's slightly less than a quarter wave for KSON and
> even a little less for KURS. The old structure was way too
> tall and presented matching problems for both stations.
> That's why it used to be shunt fed. It's now series fed for
> both stations and works much better, even though it looks
> funny.

Thanks for updateing me. I had heard that they were going to replace the topmost surviving section with another, slidghtly larger, one, and it would be just over 1/4 wave on 1240 and just a tad under for 1040. Did they not do this?

I did not know it was shunt fed... I have never seen a low power shunt fed tower! Was it noticably directional due to the shunt?
 
> KSON-AM and KURS-AM are at the "chopped up stick." KBNT-LP
> (Officially: KBNT-CA) had to move. However, I will have to
> ask some in the know where the stick is now. CA in the call
> letters is for 'class A'
>
>
> For TV 17:
> Map Here
>

KBNT is now on the KGB/KHTS/KLSD tower on 52nd street.
 
Glad you asked. As radioengineer replied below is the way things are now. But, the tower will be re-built to its original height in the months to come, and return to a shunt fed affair. KBNT-CA has crews on the tower today installing a new antenna at the 186' height. This will be a back-up site for them as they have their main on the KLSD/KGB tower.
 
> Thanks for updateing me. I had heard that they were going to
> replace the topmost surviving section with another,
> slidghtly larger, one, and it would be just over 1/4 wave on
> 1240 and just a tad under for 1040. Did they not do this?
>
> I did not know it was shunt fed... I have never seen a low
> power shunt fed tower! Was it noticably directional due to
> the shunt?
>
Well first off I'm astounded at the comment above from wattsup. I can't imagine rebuilding that structure to 442' unless they're just looking for vertical real estate. If that is being done, I hope they have the sense to isolate the structure above 230' or so.

It was not directional at all with the shunt feed. The FCC wouldn't have approved it if it was. Measurements taken several years ago before the KURS diplexing indicated basic non-D operation. There were several factors in play. Readings toward the west tended to be a little higher, but you're dealing with a difference in ground conductivity as you get closer to the ocean. The ground system was also an interesting find. None of the radials extended beyond the outer perimeter fence. I some cases these radials were in the mid 80's feet long, in others they were out to the mid 260's. Consultants questioned on this suggested it should not be a problem as to directionality.

The feed system consisted of a matching network at the center base of the structure, with four feed lines extending out to the outside of each leg. The feed lines then went up each tower leg, on insulated stand offs of course, to about the 250 foot level. They were then each tapped at somewhere around 226' to get the best resistive match. When KURS was diplexed on, new matching and filtering networks were installed and an additional four feedlines added with a different tap point for their resistive match.

The down side to all of this was that it caused the bandwidth of both stations to be very high Q with the Smith charts resembling more of a pig tail than a bow tie.

Joel Saxberg did the work of converting from a shunt to series feed because KURS just wouldn't play shunted, although KSON had a beautiful match.
 
> > Thanks for updateing me. I had heard that they were going
> to
> > replace the topmost surviving section with another,
> > slidghtly larger, one, and it would be just over 1/4 wave
> on
> > 1240 and just a tad under for 1040. Did they not do this?
>
> >
> > I did not know it was shunt fed... I have never seen a low
>
> > power shunt fed tower! Was it noticably directional due
> to
> > the shunt?
> >
> Well first off I'm astounded at the comment above from
> wattsup. I can't imagine rebuilding that structure to 442'
> unless they're just looking for vertical real estate. If
> that is being done, I hope they have the sense to isolate
> the structure above 230' or so.
>
> It was not directional at all with the shunt feed. The FCC
> wouldn't have approved it if it was. Measurements taken
> several years ago before the KURS diplexing indicated basic
> non-D operation. There were several factors in play.
> Readings toward the west tended to be a little higher, but
> you're dealing with a difference in ground conductivity as
> you get closer to the ocean. The ground system was also an
> interesting find. None of the radials extended beyond the
> outer perimeter fence. I some cases these radials were in
> the mid 80's feet long, in others they were out to the mid
> 260's. Consultants questioned on this suggested it should
> not be a problem as to directionality.
>
> The feed system consisted of a matching network at the
> center base of the structure, with four feed lines extending
> out to the outside of each leg. The feed lines then went up
> each tower leg, on insulated stand offs of course, to about
> the 250 foot level. They were then each tapped at somewhere
> around 226' to get the best resistive match. When KURS was
> diplexed on, new matching and filtering networks were
> installed and an additional four feedlines added with a
> different tap point for their resistive match.

Oh, so it was really a folded unipole. I have trouble thinking these are the same as "real" shunt fed towers with the nice open line and the ATU spaced as much as 1/8 wave from the base. If I am not mistaken, WWL and WBZ use or used a shunt to directionalize away from the ocean.
 
> Oh, so it was really a folded unipole. I have trouble
> thinking these are the same as "real" shunt fed towers with
> the nice open line and the ATU spaced as much as 1/8 wave
> from the base. If I am not mistaken, WWL and WBZ use or used
> a shunt to directionalize away from the ocean.
>
I don't know the answer to that one. Open line in my experience is usually 220 ohms, and I'm not sure how a shunt feed could be used to directionalize. The nice thing about the KSON shunt feed was that you could touch the tower at the base and not become bacon. I'll check with the WWL folks to see about using a shunt feed for directionalizing.
 
> > Oh, so it was really a folded unipole. I have trouble
> > thinking these are the same as "real" shunt fed towers
> with
> > the nice open line and the ATU spaced as much as 1/8 wave
> > from the base. If I am not mistaken, WWL and WBZ use or
> used
> > a shunt to directionalize away from the ocean.
> >
> I don't know the answer to that one. Open line in my
> experience is usually 220 ohms, and I'm not sure how a shunt
> feed could be used to directionalize. The nice thing about
> the KSON shunt feed was that you could touch the tower at
> the base and not become bacon. I'll check with the WWL
> folks to see about using a shunt feed for directionalizing.
>

Check out about 9 or 10 photos down on this link...

http://www.davidgleason.com/Mexico-Photos-E.htm

This is the same "touchable base" as you describe, and the next picture shows the shunt leaving the ATU, and you can see inside the transmitter. All the high power Mexico City stations like this one, XEB at 100 kw, had shunt feeds, including 250,000 watt XEW.

The engineers at these stations, XEX-730, XEQ-940, XEW-900 and XEB-1220 said that the shunt created a slight directional effect, so they purposely aimed them at the center of the valley of Mexico.

I have put Unipoles on a bunch of Class IV stations, and the results, especially in places where there can not be a big ground system, are good. Only thing better would be a true Franklin, but those suckers are expensive.
 
> The engineers at these stations, XEX-730, XEQ-940, XEW-900
> and XEB-1220 said that the shunt created a slight
> directional effect, so they purposely aimed them at the
> center of the valley of Mexico.
>
> I have put Unipoles on a bunch of Class IV stations, and the
> results, especially in places where there can not be a big
> ground system, are good. Only thing better would be a true
> Franklin, but those suckers are expensive.
>
I'm guessing here, but it would seem reasonable that if the shunt feed only ran up one side of the tower you would get some minor pattern distortion from the structure radiating toward the feed line. I don't think it would amount to much though.
 
> KSON-AM and KURS-AM are at the "chopped up stick." KBNT-LP
> (Officially: KBNT-CA) had to move. However, I will have to
> ask some in the know where the stick is now. CA in the call
> letters is for 'class A'
>
>
> For TV 17:
> Map Here
> Chris do you know if, when they rebuild that tower will
they put up the KSON 1240 call letters back on, or is there
a possibility that multicultural radio broadcasting will
apply to the FCC for new call letters, thus not to confuse
arbitration ratings and for the generall public.
 
> > KSON-AM and KURS-AM are at the "chopped up stick."
> KBNT-LP
> > (Officially: KBNT-CA) had to move. However, I will have to
>
> > ask some in the know where the stick is now. CA in the
> call
> > letters is for 'class A'
> >
> >
> > For TV 17:
> > Map Here
> > Chris do you know if, when they rebuild that tower will
> they put up the KSON 1240 call letters back on, or is there
> a possibility that multicultural radio broadcasting will
> apply to the FCC for new call letters, thus not to confuse
> arbitration ratings and for the generall public.
>
Man it hurt when they cut those letters off the stick. My guess is that the expense of putting the letters back up will be too great. If I was Jeff Pilot, I would want Multicultural to change the calls. That might be part of the deal.
 
> > > KSON-AM and KURS-AM are at the "chopped up stick."
> > KBNT-LP
> > > (Officially: KBNT-CA) had to move. However, I will have
> to
> >
> > > ask some in the know where the stick is now. CA in the
> > call
> > > letters is for 'class A'
> > >
> > >
> > > For TV 17:
> > > Map Here
> > > Chris do you know if, when they rebuild that tower will
> > they put up the KSON 1240 call letters back on, or is
> there
> > a possibility that multicultural radio broadcasting will
> > apply to the FCC for new call letters, thus not to confuse
>
> > arbitration ratings and for the generall public.
> >
> Man it hurt when they cut those letters off the stick. My
> guess is that the expense of putting the letters back up
> will be too great. If I was Jeff Pilot, I would want
> Multicultural to change the calls. That might be part of
> the deal.
> If they put the letters up do you think they will have room
to add KURS 1040, just a thought.
 
> > If they put the letters up do you think they will have
> room
> to add KURS 1040, just a thought.
>
It goes beyond the cost of such a project, you have to also consider weight amd wind load. While the remaining structure is pretty stout, there will be issues if they try to restore the original height.
 
> > > If they put the letters up do you think they will have
> > room
> > to add KURS 1040, just a thought.
> >
> It goes beyond the cost of such a project, you have to also
> consider weight amd wind load. While the remaining
> structure is pretty stout, there will be issues if they try
> to restore the original height.
> Do you think that was the reason,when that storm hit
the letters put on a little to much weight.
 
> > > > If they put the letters up do you think they will have
>
> > > room
> > > to add KURS 1040, just a thought.
> > >
> > It goes beyond the cost of such a project, you have to
> also
> > consider weight amd wind load. While the remaining
> > structure is pretty stout, there will be issues if they
> try
> > to restore the original height.
> > Do you think that was the reason,when that storm hit
> the letters put on a little to much weight.
>
No. The structure broke initially about 50 feet down from the top, then pulled the rest down with it.
 
> > > > > If they put the letters up do you think they will
> have
> >
> > > > room
> > > > to add KURS 1040, just a thought.
> > > >
> > > It goes beyond the cost of such a project, you have to
> > also
> > > consider weight amd wind load. While the remaining
> > > structure is pretty stout, there will be issues if they
> > try
> > > to restore the original height.
> > > Do you think that was the reason,when that storm hit
> > the letters put on a little to much weight.
> >
> No. The structure broke initially about 50 feet down from
> the top, then pulled the rest down with it.
> Oh thats right I remember it was above the letter K, that
the tower broke off dangaling off the top.
And one more thing which is the website that gives you
pictures of radio towers in San Diego, also in Tijuana.
 
> And one more thing which is the website that gives you
> pictures of radio towers in San Diego, also in Tijuana.

If you're not going to give the URL for the website, why did you post?
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