WODS MOVING TO PRUDENTIAL

[wcozBoston]

WODS is looking to move their transmitter to the Prudential Tower. Does anyone know if they will be using the master that WZLX, WXKSFM, WMJX and WBMX uses or will they use the Greater Media Master Antenna? If WODS is moving into town, will anyone else that is left out at FM128 make to move too?

 

[Deleted User]

I'm assuming, with nothing to back me up, that they will go on the antenna where the other CBS stations are already in place. Easier for the CE or designate to work on 3 transmitters in one place.

There may even be a spare up there already they can rework for that frequency. Plus a STL is already in place in their transmitter space from Leo Birmingham Parkway

 

[nd2023]

The loss would be 10 miles of coverage west on the Mass Pike, but they would gain listeners in downtown Boston who can't hear it due to overloading.

 

[Don Juan]

The loss would be 10 miles of coverage west on the Mass Pike, but they would gain listeners in downtown Boston who can't hear it due to overloading.

Has anyone ever complained about "overloading" from the stations on the Pru?

Unless you are using a $9 transistor radio from the 70's....

 

[necrat123]

Don, have you ever been in any of the buildings in Boston? Most offices have cheap transistor radios (clock radio types) with analog tuners, etc. With 6 stations running close to 20kW, even moderatley decent radios will have a hard time selecting away from the front end overload. Of course the newer digital radios with the DSP chips are a huge advantage, but the standard office person doesn't have these yet. It's not overload, it's just a lot of strong RF going into cheap radios.

 

[Don Juan]

Don, have you ever been in any of the buildings in Boston? Most offices have cheap transistor radios (clock radio types) with analog tuners, etc. With 6 stations running close to 20kW, even moderatley decent radios will have a hard time selecting away from the front end overload. Of course the newer digital radios with the DSP chips are a huge advantage, but the standard office person doesn't have these yet. It's not overload, it's just a lot of strong RF going into cheap radios.

Yes, I have worked in buildings in downtown. And, yes, there is a cheap clock-radio type on a lot of the desks. Most now are using ipods, etc.

I have never heard anyone complain about getting overload and most are listening to FM. AM can be a different story with noise, etc.

I had a Sanyo (quality, right?) clock-radio on my desk, and it wasn't a real problem.

The only research I have seen with people having trouble listening to their favorite station in DT office buildings, was more about picking up signals that weren't downtown.

 

[j117]

WBZ-FM, WJMN-FM, WODS-FM and WKLB-FM on 128 tower. Why are they not in the Prudential?????? If they were it would increase listeners. In New York all the station are at Empire State Building why not Boston.

 

[Eli Polonsky]

The loss would be 10 miles of coverage west on the Mass Pike, but they would gain listeners in downtown Boston who can't hear it due to overloading.

Has anyone ever complained about "overloading" from the stations on the Pru?

Unless you are using a $9 transistor radio from the 70's....

$9 transistor radios from the '70s were actually better for reception than most of today's Walkman-type radios, boom-boxes, and clock radios. Try getting anywhere within three miles of the Pru with any of those types of radios today, and getting any FM station that's not on the Pru.

 

[Eli Polonsky]

WBZ-FM, WJMN-FM, WODS-FM and WKLB-FM on 128 tower. Why are they not in the Prudential?????? If they were it would increase listeners. In New York all the station are at Empire State Building why not Boston.

There are interference issues with other stations preventing those stations from moving from 128 to the Pru. WODS recently found that they may be able to do it, but it's doubtful that the others could. I know that WKLB could not move to Boston because of IF interference with WUMB. I'm not sure what's preventing WBZ-FM and WJMN, but they probably would have done it by now if they could have.

By the way, there was already a thread on this board about this topic here. Now there are two.

 

[j117]

WBZ-FM, WJMN-FM, WODS-FM and WKLB-FM on 128 tower. Why are they not in the Prudential?????? If they were it would increase listeners. In New York all the station are at Empire State Building why not Boston.

There are interference issues with other stations preventing those stations from moving from 128 to the Pru. WODS recently found that they may be able to do it, but it's doubtful that the others could. I know that WKLB could not move to Boston because of IF interference with WUMB. I'm not sure what's preventing WBZ-FM and WJMN, but they probably would have done it by now if they could have.

By the way, there was already a thread on this board about this topic here. Now there are two.

How can WKLB-FM on 102.5 MHz Interfere with WUMB-FM on 91.9 MHz????????????????????????????????????

 

[carmen]

How can WKLB-FM on 102.5 MHz Interfere with WUMB-FM on 91.9 MHz????????????????????????????????????

91.9 + 10.7 = 102.6

 

[j117]

How can WKLB-FM on 102.5 MHz Interfere with WUMB-FM on 91.9 MHz????????????????????????????????????

91.9 + 10.7 = 102.6

very funny well WKLB-FM 102.5 can use a Band-pass filter http://en.wikipedia.org/wiki/Band-pass_filter to prevent this.

 

[Deleted User]

A band pass filter at the transmitter site does nothing to make up for a crappy RF section in a cheap radio.

IF only comes into play at the receiver

 

[j117]

A band pass filter at the transmitter site does nothing to make up for a crappy RF section in a cheap radio.

IF only comes into play at the receiver

Well 90% of people listen FM in Car Radios and most of them are good picking up the 128 and Prudential, but since more stations moved to the Prudential, and plus more power 20,000 ERP stations. Its starting to Interfere in Downtown with 94.5 98.5 102.5 103.3 but you can still pick it up. If they move all stations to the Prudential it would have a stronger signal in the Boston area.

 

[JustinT]

I'm not sure what's preventing WBZ-FM and WJMN, but they probably would have done it by now if they could have.

WJMN had a CP to move to the Pru during the 1990s, but for whatever reason, it was never built.

 

[DanStrassberg]

How can WKLB-FM on 102.5 MHz Interfere with WUMB-FM on 91.9 MHz????????????????????????????????????

It's an IF (intermediate-frequency) issue. FM receivers use an intermediate frequency of 10.7 MHz. That means that when you tune your receiver to 102.5 MHz, the local oscillator runs at 102.5 minus 10.7 MHz. (I THINK it's minus, but plus would also work, except that 102.5 + 10.7 is in a band used for aircraft communications.) 102.5-10.7 = 91.8--only 100 kHz from WUMB. Even if my reference to 102.5 minus 10.7 MHz above should read 102.5 plus 10.7 MHz, there is a potential IF interference problem between 102.5 and 91.9. The local oscillator in the radio is mixed with the desired signal (in this case, WUMB) to produce a signal at 10.7 MHz. From the point in the radio at which the mixing occurs to the point of demodulation (at which point the signal is brought down to "baseband," that is, it becomes centered around 0 Hz--DC--rather than an RF or IF frequency) everything in the radio works at 10.7 MHz. Perhaps the concern over IF interference is overblown as a consequence of improvements in receiver design and components over the last 50 or 60 years, but it is the rule and I do not believe that the FCC has ever waived it--at least not knowingly. If the signals are strong enough and there are any nonlinearities in the receiver, 91.9 MHz and 102.5 MHz can mix together to produce a signal at 10.6 MHz, which is within the receiver's IF bandwidth. The result would be pretty much unlistenable.

 

[Don Juan]

$9 transistor radios from the '70s were actually better for reception than most of today's Walkman-type radios, boom-boxes, and clock radios.

I found those old "transistors" would overload if I was anywhere near a tower...and prevent me from listening to almost any other station.

I think radios today are much better.

 

[Uncle Kaimbridge]

How can WKLB-FM on 102.5 MHz Interfere with WUMB-FM on 91.9 MHz????????????????????????????????????

It's an IF (intermediate-frequency) issue. FM receivers use an intermediate frequency of 10.7 MHz. That means that when you tune your receiver to 102.5 MHz, the local oscillator runs at 102.5 minus 10.7 MHz. (I THINK it's minus, but plus would also work, except that 102.5 + 10.7 is in a band used for aircraft communications.) 102.5-10.7 = 91.8--only 100 kHz from WUMB. Even if my reference to 102.5 minus 10.7 MHz above should read 102.5 plus 10.7 MHz, there is a potential IF interference problem between 102.5 and 91.9. The local oscillator in the radio is mixed with the desired signal (in this case, WUMB) to produce a signal at 10.7 MHz. From the point in the radio at which the mixing occurs to the point of demodulation (at which point the signal is brought down to "baseband," that is, it becomes centered around 0 Hz--DC--rather than an RF or IF frequency) everything in the radio works at 10.7 MHz.

Another byproduct of this effect is the image frequency——I think that's the right term——which is twice the IF below the apparent frequency: E.g., 107.9 - 21.4 = 86.5, which is right below the beginning of the established FM band: That is why you can hear 108 down below 88 on cheapy/junky radios (and even radio stations between and on vacant TV ch.s 4-6).
Though, in fact, I believe reality is the opposite: That is, what reads as "86.5" is really 107.9 and "107.9" is really 129.3——but all traffic on a given frequency is equally offset, so it is ultimately meaningless to all but us radio geeks! ;D ;D

 

[necrat123]

WKLB can not move downtown because the FCC has a limit on how far stations which are 10.7MHz away are spaced. (FCC 47 CFR 73.207)
For a Class B to a Class A, this is 15kM. The Distance from the PRU to WUMB is 10.9kM.

 

[j117]

WKLB can not move downtown because the FCC has a limit on how far stations which are 10.7MHz away are spaced. (FCC 47 CFR 73.207)
For a Class B to a Class A, this is 15kM. The Distance from the PRU to WUMB is 10.9kM.

And whats keeping 94.5 98.5 103.3 from moving to the PRU???????????????