TACAN

Bob Moore wrote:
"M. J. Powell" wrote


Except ICs instead of valves?


It wasn't the size of the electronics, but rather the
large antenna array required of the VOR system. A VOR
antenna must be permanently aligned to the earth,
something not possible with such a large array onboard
a ship. The TACAN system operating on a different
principle than VOR solved the size and alignment problems.


Bob Moore
Can you either explain how a TACAN works or provide a reference? Thanks.

In message , Bob Moore
writes
"M. J. Powell" wrote

Except ICs instead of valves?

It wasn't the size of the electronics, but rather the
large antenna array required of the VOR system. A VOR
antenna must be permanently aligned to the earth,
something not possible with such a large array onboard
a ship. The TACAN system operating on a different
principle than VOR solved the size and alignment problems.

Right. Thank you, again.

Mike
--
M.J.Powell

Bob Moore wrote:

"M. J. Powell" wrote

Except ICs instead of valves?

It wasn't the size of the electronics, but rather the
large antenna array required of the VOR system. A VOR
antenna must be permanently aligned to the earth,
something not possible with such a large array onboard
a ship. The TACAN system operating on a different
principle than VOR solved the size and alignment problems.

The writeup at
http://www.radarpages.co.uk/mob/nava...can/tacan1.htm
has already been mentioned.

Aside from size and earth orientation, TACAN has two advantages
over VOR for shipboard use.

1. TACAN uses a bearing reference direction of due east. For a
shipboard installation, that means a properly corrected compass
reference and a means of correcting the antenna orientation.

2. TACAN incorporates a ranging transponder (DME) in the
transmitter site. The aircraft interrogates the system, and the
site's transponder responds after a fixed 50 microsecond delay.
The site's azimuth and range are typically displayed on a
combined bearing/distance/heading indicator. The combination of
bearing and range display clears up any of the to/from confusion
possible with VOR sites.

| George Ruch
| "Is there life in Clovis after Clovis Man?"

Bob Moore wrote:
A VOR
antenna must be permanently aligned to the earth,

Why? Why not have a heading indicator (or DG) to drive the 'angles' (i.e.
phase) it sends out?

Hilton

M. J. Powell wrote:
Is TACAN still in use? I worked on it briefly in 1956 when I was in the
RAF.


I remember from a recent history or discovery channel program that
air-to-air tacan is still used for aerial refueling operations.

Here's a page about it from Rockwell:
http://www.rockwellcollins.com/ecat/gs/TCN-550_Tacan.html

- Ray

Ray wrote:

M. J. Powell wrote:
Is TACAN still in use? I worked on it briefly in 1956 when I was in the
RAF.

I remember from a recent history or discovery channel program that
air-to-air tacan is still used for aerial refueling operations.

Here's a page about it from Rockwell:
http://www.rockwellcollins.com/ecat/gs/TCN-550_Tacan.html

When I was stationed in Thailand, I also heard about A-A mode
being used in a two-ship formation when a major system (attack
radar or INS) failed. The aircraft with working systems would
lead, and the aircraft with the failed system would follow the
leader. As I understand it, buddy bombing was possible, but may
not have been all that accurate.

| George Ruch
| "Is there life in Clovis after Clovis Man?"