How much longer will WBZ stay at 1170 SFR?

[Dan.Strassberg]

Would take about as long as a pattern change. In modern antenna
systems, usually less than 1 second. WXKS (AM) and WRCA are the best
examples around here. As long as you are in an area where the signal
strength doesn't change much, you have to be listening very carefully
or you will miss the pattern change; it's not as long as a syllable. I
don't listen to WEEI that much, but they used to have the longest
pattern changes (the time varied from day to day but they sometimes
took close to 10 seconds). I don't know whether Entercom has recently
updated the antenna system and really sped up the pattern change, but
I caught one within the last couple of weeks that must have taken no
more than 1 second.

But I have to ask this question: WBZ's towers are only about 1/4
wavelength apart. Assuming the phasor were set up to ground either
tower and send substantial power (say 25 kW) into the other tower,
wouldn't someone working on the grounded tower--say, at a height at
which the active tower's RF current were maximum--be exposed to a
hazardous RF magnetic field? (If I'm not mistaken, doesn't the current
maximum occur half way up a half-wave tower?) 1 MHz may not be
considered ionizing radiation. If that's the case, maybe there would
be no problem, but does anybody know for sure? Dale?

-----
Dan Strassberg (dan.strassberg@att.net)
eFax 1-707-215-6367

----- Original Message ----- 
From: "A Joseph Ross" <joe@attorneyross.com>
To: <boston-radio-interest@lists.BostonRadio.org>
Sent: Monday, June 13, 2011 4:46 PM
Subject: Re: How much longer will WBZ stay at 1170 SFR?


> On 6/13/2011 3:43 PM, Scott Fybush wrote:
>
>
>> There are very, very, VERY few AMs with completely separate aux
>> sites. Beyond WBZ and WCCO, I'm hard-pressed to think of any. The
>> more common arrangement for AMs with any aux at all is to erect a
>> separate shorter tower at the main site, as most of the I-A AMs
>> have done. In the case of a directional, like WBZ, a fairly simple
>> modification of the phasor would allow them to run ND into one
>> tower while working on the other.
>
> But how long would they have to shut down completely to do that?
>
> -- 
>
> A. Joseph Ross, J.D.                     617.367.0468
> 92 State Street, Suite 700          Fax: 617.507.7856
> Boston, MA 02109-2004     http://www.attorneyross.com
>