RadioBanter - View Single Post - Shunt feed tower for Aircraft NDB beacon Help

[email protected] · July 5th 07, 01:45 AM posted to rec.radio.amateur.antenna

wrote:
I have installed a FAA approved NDB beacon here at our private
airport located in Manchester,TN .

The Beacon is transmitting on 529 KHZ Carrier power is 50 watts the
facility Id is : LYQ

I have shunt feed a 120 foot high Rhon 25G tower. The tap wire (3/8
dia aluminum 'power line' cable) is at the 90 foot level runs down
the face of the tower with 24 inch spacing to the matching network.

I am using the 'Gamma' match network : the SWR is down to 1.2 or so.

The top of the tower has 4 ten foot radials

The base of the tower has 8 200 foot 3/ 8 inch aluminum cable
radials we plan to add more.

The tower has a 3/8 'power line' type cable from the top to the base
to ensure bonding of each section.

When I fly the Company's Jetstar from 1000 to 41,000 feet, I get
solid points on the RMI indicator:

when I pass right over the beacon tower the RMI needle swings to the
tail indicating positive station passage.

The problem is the range of the LYQ beacon it seems to work 10 miles
or less??? The airplane has dual ADF systems that work perfect.

As an aside, 10 miles away, is another ADF beacon on 332 KHZ 25
watts! using the traditional three strand 'flat top' suspended
between two telephone poles. The vertical radiator for this beacon is
less than 60 feet high : I can track the beacon out to 70 miles or so!

Is a shunt feed tower lossy??? poor radiator??? comments???

I am a Ham op WA4SZE : by the way, we will QSL the beacon when we
get it commissioned.

Thanks!!

More radials certainly won't hurt, especially since at this freq 200
feet is short.

What's the ground around it like?

--
Jim Pennino

Remove .spam.sux to reply.