Re: Is this group about amateur radio in the UK?

In article <cf7455ti8po1t5cm1ult9r8ana7jdnnhna@4ax.com>, Walt Davidson
<g3nyy@invalid.invalid> writes

>>*The important part to grasp is that the linkage of NDB to DME is as a
>>*PROCEDURE ONLY*  there is no technical linkage of equipment.*
>
>I don't believe I ever said there was any technical linkage of
>equipment.  I was at great pains to emphasise that I was describing a
>procedure.
Fairy Nuff :)

>However, many thanks for your detailed reply ... very interesting and
>instructive!  By coincidence, I just returned home from EGBJ ten minutes
>ago.
Welcome :)

Spot my deliberate mistake, whoops, sorry :P   Range, in the USA, as
well as being d/f'd was also directionally beamed for fairly long
distances.  In the beam were transmissions coded as A or N to one side
or the other - DIH DAH blending though a steady tone to DAH DIT on the
other side.  It was a fairly short lifed system.  I had forgotten :)

And I have used Consol (not just listened to it) too :D

As a bye the bye, GPS is a funny one for aviation.  All aviation Nav
aids are designed for use as such, but GPS is not.  When GPS is good it
is very, very good, but when it is bad it is a horror.

When an aviation navigation system goes phut, inbuilt automatic
monitoring systems either on the ground or in the aircraft detect that
fault and instantly remove the gear from service.  That is, the nav
beacon is strangled, a flag drops over the dial, a nav fault flag
lights, a warning tone sounds and bells ring or whatever - you are not
able to use the stuff!  Instant suitable recovery action is then taken,
if at a critical stage!  NDB's however are caveat emptor...  the
protection is solely the monitoring of the coding and the ADF dial
moving as expected against the compass checks.

GPS does not have that fault monitoring and it may be up to 24 hours
before a warning is issued.  In a nav suite, a GPS fault will show as a
discrepancy against the other aids and be flagged up in due course, no
problems.  However, GPS is *NEVER* to be used as the sole aid when
making an instrument approach of some kind!  It could, if a fault
happens at that moment, happily fly you into the ground :(


John
--
JC Morrice
john@pentode.demon.co.uk
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