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

In message , Stubby
writes
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.

I can't, sorry. I've long forgotten it. Even though I was supposed to
write the Vol 1 for the RAF. After a fortnight they posted me!

Mike
--
M.J.Powell

"Stubby" wrote in message
. ..
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.

There's a nice writeup at

http://www.radarpages.co.uk/mob/nava...can/tacan1.htm

Keith

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?"

Keith W wrote:
"Stubby" wrote in message
. ..

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.


There's a nice writeup at

http://www.radarpages.co.uk/mob/nava...can/tacan1.htm

Keith


That's a fine reference. I saved a bookmark there. It looks as if the
UK TACAN is the same as the USAF TACAN, but I'm still not clear as to
the differences from a VOR. Maybe it's just the frequencies. Or, I
believe all TACANs are supposed to have DME built in.

Stubby wrote:

Keith W wrote:

There's a nice writeup at

http://www.radarpages.co.uk/mob/nava...can/tacan1.htm

That's a fine reference. I saved a bookmark there. It looks as if the
UK TACAN is the same as the USAF TACAN, but I'm still not clear as to
the differences from a VOR. Maybe it's just the frequencies. Or, I
believe all TACANs are supposed to have DME built in.

There's a VOR reference at
http://www.navfltsm.addr.com/vor-nav.htm.

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

"Keith W" wrote in message
...

"Stubby" wrote in message
. ..
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.

There's a nice writeup at

http://www.radarpages.co.uk/mob/nava...can/tacan1.htm


Here is another description that explains how the VOR ground station signals
are used to determine the radial.

http://www.answers.com/main/ntquery;...a&linktext=VOR

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

Hilton wrote:
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?


An advantage of VORs over TACANs is the VOR antenna does not physically
more, whereas it does in a TACAN. Electronic "rotation" of the antenna
intuitively makes shipboard use easier, but I might not understand ships
enough!