[BC] 750-kW Class IA AMs

[Andy Green Listservers]

These sorts of power levels are far more common here in Europe, but although 
they sound dramatic, in dB terms the benefits are far less so.
For example, here in Ireland, RTE use 500 kW on 567 kHz and 300kw on 252 
kHz(it's capable of 600kW, but they don't feel the extra 3dB is worth the 
extra 1000 a day on electricity!) . Their effective range by day is a couple 
of 100 miles-ish max , and at night, the expected massive skywave is 
hammered by so much co- channel stuff from similar stations with similar 
power levels, that the net effect is no perceived benefit.

Andy Green
Total Broadcast Consultants,
Waterford,
Ireland



----- Original Message ----- 
From: "Kevin Tekel" <amstereoexp at yahoo.com>
To: <broadcast at radiolists.net>
Sent: Tuesday, July 05, 2005 1:49 AM
Subject: [BC] 750-kW Class IA AMs


> Dan Strassberg wrote:
>> Are there any superpower MW stations, in, say, the Middle East or
>> Russia that run as much as 3 million watts? If so, how do they do in,
>> say, southern Spain or Portugal during daylight hours?
>
> I have no idea if this is still in use today by what is now the Voice of
> Russia, but the 1995 World Radio/TV Handbook describes the high-power,
> highly directional "Zarya" antenna array, used by what was then Radio
> Moscow's Popovka transmitter site, 30 km southeast of St. Petersburg:
>
> "For Radio Moscow's external services to Scandinavia in the evening, the
> 1494 kHz transmitter is switched to a highly-directional antenna system
> called 'Zarya', which produces a gain of 25 dB at an azimuth of 256
> degrees.  This Beverage-type system has 26 equidistant masts on a
> straight line and a total length of about 2500 meters (1.55 miles)!"
>
> A photo caption mentions that the masts are (were?) spaced about 100 m
> (328 ft) apart and the height of each mast is just over 40 m (131 ft).
> The text also mentions that the Zarya array is fed by a 2000 kW
> transmitter which was then currently running at 1200 kW.  With 25 dB of
> gain, that's a _serious_ amount of ERP!
>
> The Popovka site is/was one of about a dozen sites which had/have a
> Zarya antenna system, which were designed in three different sizes of
> mast height and spacing.
>
> Anyway, back here in the USA, I don't think there should be any
> restriction on the power level of Class A stations.  If you can fit a
> 750,000-watt signal into the current allocation scheme, meeting all
> application protection ratios both nationally and internationally,
> then by all means, go for it!  However, in many cases, the "NIMBY"
> factor alone would be enough to effectively prevent stations from
> upgrading far beyond their current 50 kW.  Maybe 100 or 150 kW would
> be feasible (as it is in Mexico and many other countries), but once you
> start planning 500 kW or more, I doubt local residents would be happy
> when their flourescent lights stay on all the time and they start
> hearing Rush Limbaugh talking to them from their toaster oven.
>
>
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
> _______________________________________________
> This is the BROADCAST mailing list
> To send to the list, email: broadcast at radiolists.net
> For sub changes, archives and info on this other lists: 
> http://www.radiolists.net/
>