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GNS530 exchange to Avidyne IFD540?

Hi, is there any experience to replace an GNS 530. Is the avidyne IFD 540 a good choice? Obviously it is pin-compatible.
Welcome to get more information.

Berlin, Germany

I have an IFD540 and can recommend it. Mine was a new installation rather than a swap in to replace a GNS530. There are lots of nice bits such as the BT keyboard that can be mounted on the yoke.

If want to do a straight swap, then there is a checklist you need to review to ensure there are no surprises. Do you have a GNS 530 or 530W? Clearly, the IFD 540 straight swap won’t give you WAAS if the existing GNS 530 installation isn’t WAAS/SBAS capable or configured. Just one example is the antenna difference, incl cable.

If you are interested in the IFD, then the Avidynelive forum has lots of information. Also, there is an iOS sim (called IFD Trainer, not to be confused with the IFD100 app which is meant to sync with the in-panel unit) if you want to play a bit and get familiar. The pilot manual is on the Avidyne web site.

Any specific questions, feel free to ask further.

LSZK, Switzerland

I did the swap myself. It really is plug and play. Just make sure you write down all the settings of the GNS530, which must be replicated on the IFD540.

A GA35 antenna install and a RG 400 cable replacement to enable WAAS should be a trivial job for any maintenance facility/avionics guy.

I highly recommend the IFD540. Avionics Source should be able to give you a good trade in price (around $7,000).

LRIA, Romania

paging @By9468840

GA PRO, IFR Instructor, Safety Pilot,...
LOWG | Worldwide

Yes I exactly did that and swapped my non waas gns530 with IFD540. Installation was 2 minutes. :) we spend an hour or two on a new waas antenna and by far the longest work was doing the paperwork. Everything worked with ifd540 right from the start.

If you have a gns530 switching to IFD540 is no brainer in my opinion. Trading it in is a good option but you get a good deal only when trading in a waas 530. I sold mine my non waas 530 privately for $5000 after installing the IFD.

By the way I bought avionics from Avionics Source before. Great guys and I highly recommend them.

Last Edited by By9468840 at 27 Apr 21:47

There is a debate about whether the WAAS antenna is actually needed because it isn’t any different from the non WAAS one for practical purposes. See e.g. here.

Shoreham EGKA, United Kingdom

whether needed or not, the STC requires a WAAS antenna and a doubler plate under the antenna . Without one you couldn’t use it for IFR operations.


Garmin recommends a 11db GPS attenuator to be inserted in case you use a WAAS antenna with a non WAAS unit.

I ordered one for my old GNS430 that will be replaced next year, as I’ve already changed all the GPS antennas.

Don’t tell me I’ve just spent $300 for no reason. Surely the old GNS530 non WAAS would have ended up in flames without the pricey attenuator…

LRIA, Romania

Garmin recommends a 11db GPS attenuator to be inserted in case you use a WAAS antenna with a non WAAS unit.

Where is this specified? 11db is quite a lot.

would have ended up in flames

No; the signals are miniscule.

But this doesn’t make sense – see here. The two antenna types have almost the same spec. In fact they are so close they could be the same one, with different labelling to support the very different price tags.

Shoreham EGKA, United Kingdom


TSO-C144 antennas can also meet requirements for the 400 Series (non-WAAS) units if their gain is offset by added attenuation in-line with the 400 Series (non-WAAS) unit. A Garmin TSO-C129 (GA 56) antenna has a nominal 16dB gain at 1.5 GHz. Therefore, if using a TSO-C144 (GA 35) antenna with a nominal 27dB gain, an 11dB attenuator should be used. If an in-line attenuator is used, it must pass DC current (40 mA max at 4.6 VDC) which is provided from the GPS receiver to the antenna pre-amplifier.

LRIA, Romania
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