[ARC5] [Bulk] Re: R23 repair, dynamotor mounts, questions...AN/ARN-9

[Jack Antonio]

On 12/23/2015 12:22 PM, DSP3 wrote:
> These posts beg a question, or two.  I understand the 90/150 Hz VHF and
> UHF LOC and G/S but how did this VHF-only system (ARN-9) work?  Or, was
> is horizontal guidance only??

Hi Jeep

It wasn't VHF-only.

In the ZA and ARN-9, the localizer function was done on LF or MF.
Hence the use of a low frequency receiver. My ZA manual references
the RU and RAX.

The glide slope was on approximately 90 Mc. It used a single beam,
not a comparison of two signals.

It apparently wasn't too successful. I have read that the localizer
was bothered by propagation effects, and the glide slope angle was
highly dependent on ground conditions, like dew.

 From my reading of the manual, it was a tricky thing to use, requiring
quite a bit of work from the pilot prior to making the landing.

No wonder it was quietly forgotten.

Jack Antonio WA7DIA/4