Re: Turn AM DA's into tourist attractions

[dan.strassberg@att.net]

Thanks, Rob. I found the Web page at
http://www.valcom-guelph.com/lowfreq/v33070.html
There's also a second page that describes a 49' version. 
Both pages contain a lot of specifications, but an 
important spec that I could not find is the efficiency. 
I suspect that, at least at the low-frequency end of the 
AM band, the efficiency does not meet the FCC minimum 
requirements for standard broadcast stations.

However, there is a type of antenna that is almost as 
short as the Valcom unit and does meet the efficiency 
requirements, even at the low end of the AM band. It's 
called a Paran antenna, and there are two or three in 
use by US stations. One is at a station in, I believe, 
Blaine, WA, near Bellingham, close to Puget Sound and 
the Canadian border. The station operates at 650, if 
memory serves, with 10 kW-D/1 kW-N ND-U. Another Paran 
is in use in Hawaii at one of the synchronous TXs of a 
station on 620 licensed to Hilo. That TX runs 10 kW-U ND-
U.

A Paran consists of four short, closely spaced towers 
(the WA station's towers are 100' high and are spaced 
60' apart, I believe). A wire runs from the top of each 
tower to the tops of the other three, forming a massive 
top load, which significantly increases the electrical 
length. Unfortunately, the FCC does not consider the 
four towers to constitute a single radiator, though that 
is, in fact, the case. So the FCC does not allow the use 
of Parans in directional arrays. I understand that the 
concept originated in the middle east--perhaps in Egypt. 
I do not know whether there are any directional 
installations in foreign countries that use these 
antennas.

I have seen some really outrageous claims made for 
Parans. My favorite is the assertion that they 
completely eliminate skywave radiation.

BTW, the AM you referred to in CA was on 1540 with 10 kW-
D DA-D. It was licensed to Aptos-Capitola (adjoining 
communities) and has been dark for a number of years. It 
was already dark when Infinity purchased and turned in 
the license to permit increasing the D power of what is 
now KYCY in San Francisco (now 50 kW-D/10 kW-N DA-2). 
KYCY's day site is now in Milpitas, at the south end of 
SF Bay but the night site remains along the Bayshore 
freeway south of SF.
 
> AM however offers a number of possibilities. For instance, there's an
> outfit in Ontario called Valcom which makes helically wound antennas for
> the AM broadcast band. They are only 74 feet tall, and WSHP (1450 kHz, 222
> watts) in Shippensburg, PA, uses one.