Transponder replacement suggestions

On Wed, 10 May 2006 11:59:58 +0000 (UTC),
wrote:

Hey all... just got official confirmation that my KT76's power output is way
low.... classic sign of weak/dying/dead cavity tube. Just looking for suggestions on
what might be a good, cost-effective replacement. I'm tired of futzing with
transponders so I'm pretty sure I want a solid-state replacement.

I just had a thought too (for any avionics techs reading)... perhaps the lack
of DME suppression lead to the premature demise of the KT76? I was going to wire it
up when I installed the DME, but the KT76 doesn't have that capability. Maybe the DME
cooked it?

I would get another KT76. As with all avionics, install price
dominates the end cost.

Alternatively, are there any pin-compatible transponders (for KT76)?

Nathan Young wrote:
: I just had a thought too (for any avionics techs reading)... perhaps the lack
: of DME suppression lead to the premature demise of the KT76? I was going to wire it
: up when I installed the DME, but the KT76 doesn't have that capability. Maybe the DME
: cooked it?

: I would get another KT76. As with all avionics, install price
: dominates the end cost.

... except in my case.... Re-working the transponder tray is something I
can do in an afternoon and my mechanic is perfectly happy to sign it off.

: Alternatively, are there any pin-compatible transponders (for KT76)?

... but yes there are a few pin-compatible ones now that I've looked a bit.
It looks like the Narco AT165 comes in a couple of different flavors including a
replacement for KT-76, KT-76A, AT-150, or ARC. The garmin low-end ones (GTX320?) also
can come in different flavors.

Another thing I thought of as I wrote the original post was the DME
suppression. It's a wire that disables the receiver on the transponder when the DME
transmits its pulse. It prevents interference with the transponder, and allegedly can
damage the transponder. The KT76 unit does not have this capability, nor does the
connector even have and extra space for it. SO, if I get a new one that's
tray-compatible, I cannot wire that up, which isn't good.

-Cory


--

************************************************** ***********************
* Cory Papenfuss, Ph.D., PPSEL-IA *
* Electrical Engineering *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

Nathan Young wrote:

On Wed, 10 May 2006 11:59:58 +0000 (UTC),
wrote:


Hey all... just got official confirmation that my KT76's power output is way
low.... classic sign of weak/dying/dead cavity tube. Just looking for suggestions on
what might be a good, cost-effective replacement. I'm tired of futzing with
transponders so I'm pretty sure I want a solid-state replacement.

I just had a thought too (for any avionics techs reading)... perhaps the lack
of DME suppression lead to the premature demise of the KT76? I was going to wire it
up when I installed the DME, but the KT76 doesn't have that capability. Maybe the DME
cooked it?


I would get another KT76. As with all avionics, install price
dominates the end cost.

Alternatively, are there any pin-compatible transponders (for KT76)?



Yes, Narco has a slide in replacement based on their AT165. I've got an
AT165 in my airplane and am very happy with it.