Harrisburg PA Area Non Directional Beacons (NDBs)
On Friday March 18th 2022, my good friend Glenn K3SWZ and I went on an NDB photo-safari in the Harrisburg PA area. I wanted to photograph the CX 219 and MD 204 beacons. A fine day it was, and both specimens availed themselves to some photographs. Click on the images to enlarge.
CX 219 KHz - 'Latle'
CX Is currently on the air and is used for general air navigation in the Harrisburg area. It is located adjacent to Friendship Park and employs a typical 3 wire T antenna being fed in the middle of the center element.
Audio Clip Received at K3MSB 17-Oct-2021 1810Z
Note the concrete base near the structure. Glenn and I suspected it was once used for the 70 MHz Marker Beacon antenna. I pulled out my old flight bag which contained my old Instrument Approach plates from 1997. Comparing the 1997 plate to the current 2022 plate shows two interesting things:
First, CX is no longer used as the LOM/IAF for the Runway 8 ILS approach into Harrisburg's Capital City airport.
Second, since CX was an LOM, there was indeed a Marker Beacon associated with CX in 1997.
Not being a component of the ILS approach increases the possibility of the NDB being decommissioned sooner.
MD 204 KHz - 'Enola'
The Enola NDB is the LOM/IAF for the ILS Runway 13 approach into Harrisburg International airport.
The beacon is located in Lemoyne PA and is surrounded by small businesses and residential homes. The large building across the street from the beacon is an old school that is being converted
MD Was last logged in September 2019. Successive NOTAMS have extended it's date for return to service and it is currently scheduled to return in June 2022. The NDB Listening Community is cautiously optimistic, but successive extensions usually do not bode well for a beacon.
The NDB utilizes the typical 3 wire T antenna and this one is fed off center. The Marker Beacon antennas (dual Yagis) are displayed nicely.
Regarding the parabolic antenna: Dave, an ex-FAA navaid/radar technician, recently posted on the NDB reflector: "Those are 'permanent echoes', used by Air Traffic and FAA technical personnel to confirm that the airport radar is working correctly. They receive the radar signal, delay it by a predetermined amount of time (microseconds), then transmit back to the radar. It then shows up as a 'target', in one specific location always. That way the radar can be confirmed as working even if there are no aircraft in the area. This is a general explanation, but that's the gist of it."
Alex VE3GOP, who works on NDBs in Canada said "We call them PARROTs up here. The only difference is ours are protected inside heated radomes and they're mounted much higher to ensure the SSR gets a good hit on it."
Here's are the approach plates from 1997 and 2022:
Copyright (c) Mark S. Bell 2022