KT74

[Tommy]

Hi guys!

 

Looking at replacing my very old KT78A transponder (the ident light is not blinking any more - though it's still fully functional). A recent trade-in special means that I can get KT74 for only $1500USD. Is that a good deal? 

 

Also my GPS is a very old Garmin 100 (don't laugh). Is there any WASS enabled GPS unit that can talk to KT74 to meet the ADS-B Out requirement (1019) that's also plug and play?

 

Thanks!

[carusoam]

There is a thread regarding ADSB, and the KT74.

The thread also covers installation and integration with G.

For WAAS navigation...

G GTN series...

BK KSN770 series....

Avidyne...

Nice to know...

Some BK transponders are a slide in replacement for the new KT. Obviously some ADSB related wires are extra...

Some Old G 530/430 can be slide in with Avidynes.

The choices are still coming available. G has been around for a while...

Do you have a preference G, BK or other?

The G and BK can be integrated. But G is known for making it arbitrarily difficult in other areas...

Best regards,

-a-

[ArtVandelay]

Yes, $1500 is a very good deal

[rbridges]

$1500 is a good price.  I paid $2600 for mine from Sarasota.  It can work with several Garmins, but I believe the GNS series may be the oldest. I'm sure you can look at their STC or ask the avionics shop.

 

as far as plug and play, the KT74 will do it with the KT76A and others, but only as a transponder.  The new tray has to be installed for the ADSB stuff.  The nice part is that I didn't have to modify my panel to accomodate the size of the 74.

[FBCK]

I was told by my avionics shop, and I'm not sure of its accurate it is, but some of the new transponders being produced are still using old power suppy technologies ( the KT74) included), look for one with a newer desided power supply. Its one of the reasons I purchased the new Avidyne 340, both are rebranded Trig transponders.

[ArtVandelay]

I was told by my avionics shop, and I'm not sure of its accurate it is, but some of the new transponders being produced are still using old power suppy technologies ( the KT74) included), look for one with a newer desided power supply. Its one of the reasons I purchased the new Avidyne 340, both are rebranded Trig transponders.

There is 2 considerations when selecting power supply, rf noise and efficiency.

Since transponder serves as a radio receiver and transmitter, obviously RF noise must be minimized, since they both past certification tests, we'll assume the both do that, then there is efficiency, they both have the same power draw, exactly the same; I'm willing to bet that the 340 and 74 have very similar circuitry. I think your avionics shop has a higher margins on the Avidyne which is a $1000 more expensive, hence the sales pitch.

[1964-M20E]

I am on the list for an Avidyne IFD440 WASS GPS.  I will replacing my GTX327 at that time as well for ADSB.  I have considered the 340 from Avidyne the KT74 as well at the Trig.  I would like to go with the Avidyne but it is a good $1,500 more than the Trig or the KT74.  When I get my ship date I will be trying to do some horse trading with Avidyne to at least match the competitors pricing.

[chrisk]

It's a good deal, I'd jump on it.  You can use it to fix your current problem and hook it up for ADS-B compliance later.

 

I have the trig TT31 and am quite happy with it.  For GPS sources, I believe the KT74 can use the garmin GTN and GNS series.  I believe it can use the freeflight system as well.  --For ADS-B, the source and the transponder need to be approved as a pair.  I believe the plane needs to be approved as well.  This should all be on the STC

[Tommy]

Thanks guys! Sounds like KT74 is good enough for me!

 

What about my very old GPS G100? http://www.midwestflyer.com/?p=4585

 

Is there any WASS GPS unit on the market that uses the same dimension and is able to talk to KT74 for ADS-B out?

[rbridges]

I'm not sure on this so double check. If you want weather and traffic, you may be able to use stratus and fore flight. I believe the stratus has a.built in waas. This could get you by until 2020.

[thinwing]

i am certain the old g100 was std tray size so a used 430w is your best bet and besides you get rnav/ lpv approaches ....1500 incuding tradein is better deal than any I ve heard of!!..

[Cruiser]

Please double check with your avionics installer before placing an order...........

 

To my knowledge, the Bendix King KT74 transponder is a direct replacement, (slide-in) as advertised in many of the aviation magazines and online. BUT, BUT, BUT this version of the installation is NOT ADS-B out compatible.

 

To use the King KT74 for ADS-B out and meet the 2020 Next Gen mandate, you must:

 

1. Have the transponder connected to an approved WAAS GPS 

2. Have a air switch attached to distinguish between ground and air operation.

3. Have a digital encoder source.

 

According to the Trig STC (which applies to the King KT74) ONLY the Garmin GNS 430/530W are approved for gps signal sources.

 

All the above being said, it is still the best deal available today for ADS-B out.

[ArtVandelay]

Please double check with your avionics installer before placing an order...........

To my knowledge, the Bendix King KT74 transponder is a direct replacement, (slide-in) as advertised in many of the aviation magazines and online. BUT, BUT, BUT this version of the installation is NOT ADS-B out compatible.

To use the King KT74 for ADS-B out and meet the 2020 Next Gen mandate, you must:

1. Have the transponder connected to an approved WAAS GPS

2. Have a air switch attached to distinguish between ground and air operation.

3. Have a digital encoder source.

According to the Trig STC (which applies to the King KT74) ONLY the Garmin GNS 430/530W are approved for gps signal sources.

All the above being said, it is still the best deal available today for ADS-B out.

2. I saw on another forum that A/S switch is no longer required, YMMV

3. Not true, I got the KT74 in part to be the digital encoder source

[Cruiser]

All the more reason to check with your installer. I may be wrong.............

My King KT-76C has a blind encoder for Mode C operation, the KT-74 is a direct slide in replacement so I ASSUMED it would need one also.

[ArtVandelay]

All the more reason to check with your installer. I may be wrong.............

My King KT-76C has a blind encoder for Mode C operation, the KT-74 is a direct slide in replacement so I ASSUMED it would need one also.

I had a new tray installed as well

[kshaw]

The King 74 still needs an altitude encoder.  The old Narco Mode C encoder that I was using for my KT-76C worked fine.  The STC for the Trig 31 is similar to the King 74 STC  but there are several differences as well.  There are also differences in pin outs.  The King 74 STC permits several GPS units beyond the Garmin 430w/ 530w to be used including the newer Garmin GTNs.  You only need to install the new KT-74 tray if you want to connect it to your audio panel for altitude and traffic alerts.  All other features work fine with your old tray and connector but connections have to be made to your speed sensor switch, to the GPS for ADS-B input, and another connection to your GPS unit if you want TIS displays on your GPS.