GNC300/SL30 vs. GNS 430/SL40

While in the final stages of planning my IFR panel, I'm hoping to get some input from those who have used ALL of the radios mentioned in the thread title.
I haven't flown with any of them so I need some experience here that perhaps others could use as well before spending this kind of money.

I'll point out that cost is an object while for planning my panel, and I note that I could use either the GNC300XL/SL30 "combo", OR I could go with the GNS430/SL40 for "sort of" the same cost.

With the GNC300XL/SL30, I'd have to add an $800 annunciator, but I understand that the GNS430 has the annunciator function built into it.
Of course, a CDI would be used with both systems.
As a Nav/Comm, the SL30 is almost magic with it's capabilities and I'd hate to lose that, but the GNS430 appears to be pretty magic as well.

So what I'm looking for is input from those who've used these various radios to suggest reasons for going either way as a "package". If it makes a difference, I'm going with the GRT Sport as primary ADI and the GRT Moving Map/Engine Monitor as the basis for a glass panel.

TIA

IFR Panel

I'm planning on the GNC300/SL30. Last time I checked it was noticeably cheaper than the 480/40 - have things changed (it has been a while since I've checked prices)?
I'm also planning on a GRT Sport which has the CDI for the GPS built-in, and a separate CDI (with G/S) for the SL30, since the Sport doesn't display VOR/ILS. The Sport (I believe) displays the GPS modes, and each radio has a dedicated CDI (no switching required) - so I don't think an annunciator is needed. At least that't the plan...

Dennis Glaeser
7A Wings done - fuselage coming...

Ditto. I'd like to know the same thing, as I'm narrowing down on my avionics. Currently, I'm leaning toward the GNC-300XL plus SL-30 augmented with a 296 or 396. Here's my thinking: The cost (at least with the 296) is about the same as the GNS-430 plus SL-40. The 430 looks nice, but has fewer features and costs 3 times more than a 296. The GNS-430 doesn't appear to allow monitoring the stand-by frequency. The SL-30 is like having two radios in that respect. The 196/296/396 line continues to evolve and improve. You can get live weather, traffic info (with a GTX-330), interface to the SL-30, etc. It's like they expect you to use it in the panel. Certified GPS units evolve at a snails pace in comparison. You can also take the 296/396 with you in the car for driving directions. Also, you can upgrade much easier to future models. The GNC-300XL provides enough capability for IFR flying, but the 296 or 396 will be my primary GPS.

You can download a GNS-430 simulator from the Garmin web site. That will give you some idea of the capabilities it provides.

On a side note, the $500-800 annunciator is crazy. Is it possible to just get by with a switch and a couple of indicator lights? (I'm not planning on using the Grand Rapids--unless they improve their screen resolution.)

Dave

Annunciator

Davepar said:

On a side note, the $500-800 annunciator is crazy. Is it possible to just get by with a switch and a couple of indicator lights? (I'm not planning on using the Grand Rapids--unless they improve their screen resolution.)

Dave

Click to expand...

I believe you can roll your own for the switches & lights. However, if you are going to have only one CDI, you also need a switch (18 pole if memory serves correctly). Eric Jones (Perihelion.com) has one I think.

Dennis

What is your mission?

The real question to ask before making a decision is "What do I want to do?" Garmin has discontinued the GNC300 and, if history proves correct, will drop support for existing units within 2-3 years. OTOH, the GNS430 has become their ace moneymaker and they have just announced an upgrade that allows it to display terrain. It can also display traffic and XM weather (with additional add-ons). Either way, the question is do you invest in old technology or in a unit that will still be supported (and retain it's market value) 5-10 years from now?

The SL30 NAV/COM is a slick unit but a hefty price...If you require dual NAV/COMs, this is the way to go. If you are like most IFR flyers, you rarely, if ever, need TWO NAV radios, but DO need two COMs. Thus, the SL40 (COM only) is the ticket.

The GRT EFIS is designed to integrate quite nicely with the GNS430 and either the SL30 or SL40. No one is integrating with the GNC300 because it is going away.

The GNS430 has a built-in annunciator to select what drives the external CDI, either GPS or NAV. Or, you can use the internal CDI. Not so with the 300.

There are MANY RV builders flying the 430/SL40 with the GRT. I would suggest calling Todd at GRT and get his opinion. Heck, call Stein at Steinair.com since he has built dozens of panels and harnesses for all these avionics.

I personally think it all depends on your personal mission. Remember, a portable GPS (i.e., 296, 396) is not legal for IFR flight.

Bret

smithhb said:

The real question to ask before making a decision is "What do I want to do?" Garmin has discontinued the GNC300 and, if history proves correct, will drop support for existing units within 2-3 years. OTOH, the GNS430 has become their ace moneymaker and they have just announced an upgrade that allows it to display terrain. It can also display traffic and XM weather (with additional add-ons). Either way, the question is do you invest in old technology or in a unit that will still be supported (and retain it's market value) 5-10 years from now?

Click to expand...

Yeah, but to add XM WX to your 430 you're going to have to sell a kidney and buy a GDL 69, which MSRP's for $4995! How much is terrain going to cost you? Also, the 396 was designed from the start to support XM weather, whereas the 430 support was not..and it shows on the screen. Just look at Garmin's screenshots of WX on the 430...nothing too impressive. Also, does the GDL 69 give you all the features on the 396 such as winds aloft, local forcasts, etc?

A while back I was thinking I would put a 300-XL in my panel until I learned that Garmin discontinued it. If I had a 430 I probably would not even think about putting a GDL 69 in when I could add the 396 for half the price and get a better screen than the 430 has, plus you'll have the 396 as an internally-powered navigation backup in case you lose your 430 and/or e-buss power. The only incentive (in my opinion, of course) to the GDL 69 is it saves panel space.

Decisions, decisions....

Discontinued? So What!

I would not let the "discontinued" status be a major factor in the purchase decision. Sure, it's a factor, but not a ruling one in my mind. If I were a betting man, I'd wager a majority of light GA aircraft have "discontinued" radios in them right now.

I plan to buy the most functionality per dollar that will provide my IFR panel "mission". As previously posted, the "mission" drives the choices. At the moment, it looks like a discontinued GPS/comm (you all know the ones), SL30, and GRT sport although the research is still going on and the choices could change.

I feel that if I am "forced" to move over to a 430 at some later date, more years will have passed, some other hot holographic GPS display and cappuchino maker will be out there, and there will be more used 430's for sale at an attractive price.

Allow me to jump back in here with a couple of clarifications that some have brought up.

First, the cost between my two suggested packages really is about the same.
For the GNS430/SL40 combo, you'll pay roughly $7400.00 based on recent prices I've gotten.
Ironically, with the GNC300XL/SL30 combo, you WILL need an annunciator such as the MD-41 to be legal, so if you add up all that, it also comes to roughly $7400.

Plus, I confess ignorance about the GNC300XL being discontinued because I haven't read or heard that anywhere. I know that the GNC300 was discontinued, but that's because it was replaced by the GNC300XL with the updated display. I see, however, that I miswrote in my original title and didn't add the "XL" to the product name. I meant the GNC300XL all along. Sorry for the confusion.
Even if the GNC300XL was discontinued in the future, I have confidence that Garmin would continue to offer the updates needed to keep it "certified" for quite a while just as they do now with some units that are most definitely discontinued.

Since pricing is similar for either package, I'm sort of leaning toward using the GNC300XL/SL30 because I can see much value in having a second Nav that can be used as a radial check from nearby (off course) VOR's. Additionally, with the GNS430/SL40, you've got all your Nav eggs in one basket where with the GNC300XL/SL30, you could lose either radio and still have plenty of Nav eggs left in your basket.

So little money; so many choices. Maybe I could just get a GNS530 and an SL30 and be done with it... after the divorce, of course.

Annunciator

Highflight said:

Ironically, with the GNC300XL/SL30 combo, you WILL need an annunciator such as the MD-41 to be legal, so if you add up all that, it also comes to roughly $7400.

Click to expand...

I'm planning to have a separate CDI (with G/S) for the SL30, so no CDI switching will be required. I believe the Sport will display GPS Mode info (just sent a note to GRT to verify). If that is true, I'm not planning on a separate annunciator. Any reason that won't be legal?

Dennis Glaeser

This is some really great information and perspectives. One thing I just realized is that the SL-40 allows the same standby freq monitoring as the SL-30. It just doesn't have a VOR receiver. That's cool.

I also am not aware that the GNC-300XL is discontinued. I don't see it mentioned on Garmin's site.

I agree with Jamie that the cost of adding XM weather ($5k), ADS-B ($8k), and other doo-dads to the GNS-430 is way too expensive.

I'm not getting the same numbers on the price comparision. Using the prices from Vans for the Garmin stuff (and I know there are cheaper sources) and the most expensive annunciator at Spruce, the MD-41, I get:
GNS-430 $6750 + SL-40 $1375 = $8125
GNC-300XL $2695 + SL-30 $3275 + MD-41 $834 = $6804

Davepar said:

I'm not getting the same numbers on the price comparision. Using the prices from Vans for the Garmin stuff (and I know there are cheaper sources) and the most expensive annunciator at Spruce, the MD-41, I get:
GNS-430 $6750 + SL-40 $1375 = $8125
GNC-300XL $2695 + SL-30 $3275 + MD-41 $834 = $6804

Click to expand...

Dennis, if you hardwire your CDI to only the one radio, you don't need the annunciator so that would save those $$$ if you didn't think you wanted the functionality of the CDI with the GPS.

For pricing, check with John Stark and you'll see a difference. I figured the "new" GNC300XL rather than the "refurbished" as the price above probably indicates.

Annunciator

The GRT Sport has a CDI for the GPS (only). So I'm planning to add a separate CDI (VOR/LOC/GS) hardwired to the SL30. I want dual navs for IFR.
I'm hoping the Sport supports the switching and annunciator lights for the GPS modes. If not, I have to add switches and lights.

I plan to have a discussion with John Stark when the time gets closer (my fuselage is scheduled to ship the week after Christmas!).

Yup, that was my mistake. I forgot that Van's unit is refurbished. In fact their web site says that Garmin is no longer making the 300XL, but then Stark has them new. I just got the latest prices from Stark and the price differential is about $160 between the two setups without harnesses and about zero with.

One other thing I just thought of. The 300XL + SL-30 provides a little better back-up. If the screen went dark on the 430 for some reason, with only the SL-40 as backup you'd have no nav. The best option is to get the 430 plus the SL-30. Good thing the money tree in the back yard is about ready for harvest.

Davepar said:

Yup, that was my mistake. I forgot that Van's unit is refurbished. In fact their web site says that Garmin is no longer making the 300XL, but then Stark has them new. I just got the latest prices from Stark and the price differential is about $160 between the two setups without harnesses and about zero with.

Click to expand...

Dave, I have yet to find any direct mention of the GNC300XL being discontinued by Garmin by the Garmin company.
I'd sure like to know where that information is coming from.

It sounds more like people see that the GNC300 was discontinued (before it was redesigned to become the XL model) and then confuse the two models.

GNC300XL with GRT Sport

I emailed GRT about using the GNC300XL with the Sport and got the following info:
-------------------------------
The GNC300XL requires a manual course device. This can come from an EFIS with ARINC-429 or the OBS of a CDI. The Sport does not have these interfaces. The Horizon Series I is capable of being the CDI for the SL30 and the GNC300XL. The Sport only has cross-track deviation, it lacks the TO/FROM and other announciators. With the GNC300XL you will need to make your own or use one of the commercial units.

Regards,

Todd Stehouwer
Grand Rapids Technologies, Inc.
--------------------------------

So it looks like using the GNC300XL with the Sport will involve a bit more work than I was hoping. I'm still going to do more investigation to see what is involved. Adding annunciation lights & switches is pretty easy. The manual course device may be an issue - I thought the unit had the capability to enter the course, but need to know if that is sufficient...

Dennis Glaeser

Thanks for that piece of info Dennis. I'll sure take it into account since I had already "minimised" the cost of my panel down to a configuration that apparently will not work....

In my mind, it sure evens the playing field in a comparison of 300XL/EFIS 1 vs 430/EFIS Sport. I had ruled out the 430 as too expensive. Now I need to reevalute it.

Sport with 300XL

I sent off an email to John Stark asking what it would take to make the Sport/GNC300XL/SL30 work. I'll report what he says...

I have the user manual for the 300XL, and it says that if you don't have an external CDI you can enter the course manually on the appropriate screen. Not as convenient as twisting a knob, but I'm not sure you'd need to do it very often in all reality.

If that is the case then I think a panel is needed which has:
- TO/FROM (2 lights)
- HOLD/AUTO (GPS Sequence Mode) - 2 lights and a toggle switch
- ARM/ACTV (GPS Approach) - 2 lights and a push button switch
The only hookup which may be tricky is the TO/FROM indications.

If anyone has insights on how this would need to be wired - please let me know!

Dennis

Highflight said:

I'll point out that cost is an object while for planning my panel, and I note that I could use either the GNC300XL/SL30 "combo", OR I could go with the GNS430/SL40 for "sort of" the same cost.

Click to expand...

I don't meet your criteria, not having used any of these radios except the 430. However, I will point out that your two alternatives do not offer the same functionality. Specifically, if the 430 dies, you have no navigation receiver. In the 300/SL30 case, you can lose either box and still have nav and instrument approach capability.

Cheers,
Martin

mgomez said:

I don't meet your criteria, not having used any of these radios except the 430. However, I will point out that your two alternatives do not offer the same functionality. Specifically, if the 430 dies, you have no navigation receiver. In the 300/SL30 case, you can lose either box and still have nav and instrument approach capability.

Cheers,
Martin

Click to expand...

Right, I understood that which is why I'm leaning toward the GNC300XL/SL30 for that very reason.

Now, however, and because cost is still an issue, I'm wondering if I really "need" the certified GPS.

With the GRT dual boxes and SL30, you could save a bunch of bucks and still have a great dual nav system if one were to use the "cheap" GPS option from GRT.
No, you couldn't do GPS approaches legally, but you COULD do ILS approaches using the non-certified GPS as verification (actually, the easier way to do it would be to use the GPS as your primary and the SL30 ILS as the verifier to stay legal).

I have very specific ideas of the kind of IFR I want to fly, and that is what's usually referred to as "light" IFR where I just want to be able to get through layers and clouds in order to get off the ground and to my destination on days when VFR traffic might be kept on the ground. Heavy weather is not my kind of fun IFR.

Using the SL30 with the HSI on the GRT should fit that requirement very nicely and without the expense of certified GPS and updates all the time.
It's not likely that ILS approaches are going to go away any time soon so I'm keeping my mind open about that. Perhaps a year or two after I've been flying, I might have recovered enough from the expense of building the RV to go ahead and add the GNC300XL then.

Just thinkin'