Oil on transponder antenna

On Sun, 02 May 2004 17:34:05 -0400, Bob wrote:

Is it possible that some oil on the transponder antenna would cause it
to transmit intermittently?

I would have wiped it clean and tried it out but it's 5 OVC today....

Probably not. I suspect a loose signal connection or bad ground
connection in the transponder antenna. When you wipe it clean, you
are probably moving the antenna enough to make a temporary connection.
Hit enough turbulence, and the connection goes bad again.

I'd say this is especially the case if the failure mode is on/off.

-Nathan

Nathan Young wrote in
:

On Sun, 02 May 2004 17:34:05 -0400, Bob wrote:

Is it possible that some oil on the transponder antenna would cause it
to transmit intermittently?
...

Probably not...

It certainly seems to make a difference on the 172 I fly right now (a
rental). We are out in the boonies so the transponder isn't usually needed,
and the oil accumulates. When people don't clean the antenna before
venturing into civilization controllers comment that they are not getting
our altitude information. I've tried it both ways (unintentionally) and
confirmed this.

Rob

In article ,
Rob McDonald wrote:

Nathan Young wrote in
:

On Sun, 02 May 2004 17:34:05 -0400, Bob wrote:

Is it possible that some oil on the transponder antenna would cause it
to transmit intermittently?
...

Probably not...

It certainly seems to make a difference on the 172 I fly right now (a
rental). We are out in the boonies so the transponder isn't usually needed,
and the oil accumulates. When people don't clean the antenna before
venturing into civilization controllers comment that they are not getting
our altitude information. I've tried it both ways (unintentionally) and
confirmed this.

Rob

A friend had the same problem on his 182. I suggested that he switch the
Txp to the DME antenna and vice-versa, as they are identical. He
stopped having Txp problems.