Rich S. wrote:
I have a Collins VOR receiver and a connected Collins VOR/LOC display
installed in the Emeraude.

The receiver has an LED digital display for frequency or bearing. If I
select, say, "from" I will get a display of the bearing from the VOR
station. If I rotate the OBS on the panel VOR/LOC instrument until the
"from" flag appears and the needle centers, the OBS will also give me a
bearing from the station.

Problem is, these bearing don't match. I haven't done comprehensive tests to
determine the difference (it might not eve be the same depending on the
range to the VOR), but it is significant for navigation. Perhaps as much as
5+ degrees if I remember correctly.

This isn't a real problem for me as the VOR is strictly backup. (Let's think
about that, Mr. Corrigan. . .) I'm probably going to take the darn thing out
anyway and sell it before it's value goes down to that of a used SuperHomer.
When I was flying to OSH this year, my navigator (Lt. Col. USAF ret.) asked
me what I'd do if my GPS quit. I replied, "Why, land at the nearest airport
and buy a new one!".

As I write this, I'm thinking that the answer to the question is to take the
plane to an airport which has a VOR test point and check it out. Do such
things still exist? In any case, I probably won't take it to the Collins
repair station and spend a few hundred *new* dollars to get it calibrated.

Anybody else had this problem? Perhaps with two sepatate NAV-COMS giving
different headings?

Rich "A man with two clocks never knows what time it is" S.


VOR test points certainly do still exist. Check the Airport and
Facilities Directory for one near you. Keep in mind that up to a 6
degree error is permissible between units when doing an airborn check
(as it sounds like you have been doing).

Rip