BeechTalk - BT - CESSNA CITATION CJ4 525C GEN. 1 TDR-94D RESTRAPPING

Username Protected · **Posted:** 11 Dec 2025, 04:45

Hi Guys,

this might sound stupid, but this is my first time restrapping a transponder for the following aicraft:

Cessna citation 525c cj4 gen. 1 equipped proline 21 avionics
transponder 1: TDR-94D PN: 622-9210-501
transponder 2/tcas: TSS-4100 PN: 822-2132-001

I do have the data for Hex/Octal/Binary and the Pins as attached.

Attachment:

BINARY CODE.jpg

I've also attached the wiring diagrams for both transponders for your reference.

I have restrapped tens if not hundreds of garmin transponders already as I am a garmin guy ever since. It's quite easy actually for garmin, you just have to boot avionics thru configuration mode and voila, you can change the parameters there.

So my question is, how do i restrap the aforesaid transponders?
1. I am not sure if i can change the parameters (hex, flight, etc...) on the cockpit by just going to the config. mode of the transponder and/or avionics? just like in garmin systems.
2. What does the transponder pins have to do with the configuration? do i need to repin them to get the correct parameters? or does it mean something else.

Hoping to get positive response from you guys.

Much love,
Ray
PH

Username Protected · **Posted:** 11 Dec 2025, 04:46

transponder 1: TDR-94D PN: 622-9210-501
WDM

Attachment:

TRANSPONDER 1A.png

Attachment:

TRANSPONDER 1B.png

Username Protected · **Posted:** 11 Dec 2025, 04:49

transponder 2/tcas: TSS-4100 PN: 822-2132-001
WDM

Attachment:

TRANSPONDER 2A.png

Attachment:

TRANSPONDER 2B.png

Username Protected · **Posted:** 11 Dec 2025, 07:44

Strapping for a TDR-94D is done by wiring, not any configuration mode.

The first drawing you posted shows the "S-Mode Relay Box". There will be jumpers or switches in that box to physically strap the pins you posted in the ICAO Calc pic to ground or to remain unconnected (open).

PS - The ICAO Calc tool is mine

Username Protected · **Posted:** 11 Dec 2025, 08:08

Username Protected wrote:

Strapping for a TDR-94D is done by wiring, not any configuration mode.

The first drawing you posted shows the "S-Mode Relay Box". There will be jumpers or switches in that box to physically strap the pins you posted in the ICAO Calc pic to ground or to remain unconnected (open).

PS - The ICAO Calc tool is mine

Hi Terry,

Its a pleasure to chat with the software creator himself!

I will fiddle with the relay box first thing in the morning tomorrow (its night time now here) and try to make sense of it. The manual for this cost around 700 usd, which is quite expensive.

I will get back to you if ever i have more questions, hope that is ok with you?

Thanks brother,
Ray
PH

Username Protected · **Posted:** 11 Dec 2025, 08:54

Username Protected wrote:

I will get back to you if ever i have more questions, hope that is ok with you?

No problem, feel free to PM me

Username Protected · **Posted:** 12 Dec 2025, 03:47

Username Protected wrote:

I will get back to you if ever i have more questions, hope that is ok with you?

No problem, feel free to PM me

Username Protected · **Posted:** 12 Dec 2025, 08:05

Username Protected wrote:

After orienting the switches, do i still need to do additional procedures? or i can go directly perform the transponder ramp test?

Right to the ramp test! Which transponder tester do you use?

Username Protected · **Posted:** 12 Dec 2025, 08:20

Username Protected wrote:

After orienting the switches, do i still need to do additional procedures? or i can go directly perform the transponder ramp test?

Right to the ramp test! Which transponder tester do you use?

Username Protected · **Posted:** 12 Dec 2025, 08:47

Username Protected wrote:

Right now I am using our new viavi solutions avx-10k which replaces our IFR600.

Also, we are looking for a comprehensive artex elt test and programmer set as our old one artex tps 8715 only supports quite a few models. We are eyeing the artex fpt 8800 series, do you have any recommendations?

The Artex reader was also my product, licensed to them. The programmer part of it I did as a contract to them, so I can't reuse it. The FPT 8800 is only a programmer, not a reader. I don't know of any other programmer. Their programming protocols are very proprietary and I don't see any other options.

On the reader side there are several options. My own CCX T-RX will read all 406 MHz ELTs, including the new Distress Tracking beacons (it will also test nav/com/transponder/ads-b, etc)

Username Protected · **Posted:** 12 Dec 2025, 09:03

Wow, i would have not guessed that you were extensively connected with artex before.
Unfortunately, we dont need a reader right now as our avx-10k also does 406 MHz elt reading, nav/com/tdr/ads-b/dme, etc...

Apologies i mispoke earlier, we need fpt 8800 "programmer only" since no other programmers avail for artex elt due to patent.

Do you mind sharing with me your company email so I can formally inquire avionics tooling should we need one in the future.

Regards,
Ray
PH

Username Protected · **Posted:** 12 Dec 2025, 10:16

Username Protected wrote:

Do you mind sharing with me your company email so I can formally inquire avionics tooling should we need one in the future.

I'll send you a PM