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M20C Avionics Debate (failing NAV2..now what)


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I realize this topic is like asking someone about their favorite food or wine....but here goes.

My partners and I have a 1962 M20C with about 4500 hours total flight time and 900 hours on the engine.  The airplane is in overall great shape.  Probably $60K hull value.

My two partners are finishing their IFR tickets and fly for pleasure.   I have my IFR ticket and use it regularly for both pleasure and business flight for this airplane.  (would love an Ovation at some point)

We have a Garmin 430W with GPSS to a STEC 30 w/atl hold, an old NAV2 VOR and old COM2....not sure the manufactures.  We also have a new Lynx NGT9000+ transponder.  The rest of the panel is steam gauge.  Planning G5s in the next year or so.

The NAV2 VOR has very poor reception and the NAV1 VOR on the 430W is ok, but not great.  We suspect they might share the same antenna and cabling .  We are going to have our avionics guy check out the signal strength to see if this is an easy fix.  However, if it isn't, it opens a can of worms.

If the NAV2 is shot my preference would be to toss it and do one of the following:

1)  Buy a second 430W used.  Toss the old COM2 as well and this becomes the new NAV/COM2.   This is a relatively low cost option and I'm frankly not in the mindset of buying a VOR only NAV2 since I rarely use VOR navigation these days and the stations are becoming more rare.  A second 430W would give me complete redundancy (minus electrical failure).  Downside...how long with 430Ws be supported by Garmin?

2) Buy a new Garmin or Avidyne WASS NAV/COM and make it primary NAV/COM.  Keep the existing 430W as NAV/COM2.   Slightly more expensive and would require two navigation subscriptions.   

3) Keep the 430W as the only NAV/COM and keep the existing COM2...no NAV2 backup except iPad with Stratus2 (yikes).  Legal given it is WASS, but not something I am truely considering...convince me otherwise.

4) Go all in and do a big panel upgrade, but not sure it's worth it given this aircraft...and not sure my partners would do this either.

5) Pot luck....make another suggestion.

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Find in a slide in replacement for the com 2.   Put the rest in AVGAS.   If you have the V antenna on the tail more than likely the NAV1 and NAV2 are hooked up to that antenna with a splitter.behind the panel.   If you have the V antenna it might be good to pull it apart and clean the coax connections.   There is more than likely a balen that runs up the tail.  to the antenna.

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You have a fairly modern IFR panel already, and so you rarely if ever used the 2nd Nav anyway.  But I bet you use the com a lot on that same crappy old unit. Who knows when that will croak too - that's basic redundancy you really want.  The added utility of a second 430W would be nice at the same time, but the fresh install cost of one is pretty hard to justify for such an old unit, particularly if you've already got one of them. Just replace with a nice serviceable nav/com like an SL30, which will serve well for the long haul and take away the mild insecurity you feel without a backup Nav.   Save the extra cash for when you want to swap the 6 pack for glass and/or upgrade the 430W to Avidyne when it starts giving trouble.  With things like Dynon Skyview on the horizon, big panel upgrades only make sense now if money is not a major consideration and/or for someone has a much more dated panel than yours.

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3 owners soon to be all IFR "qualified and equipped(?)". Anything you spend is split 3 ways?

All of you need to take advantage of your rating without worrying about what might roll over on you while yo're IMC with your family aboard. 

Here's what you need to do:

 

IMG_20171029_131906835_HDR.jpg

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IMHP, I would not spend the cash to purchase and install a second 430W. Replace the old Nav/com with an SL30 and call it a day. If you really want another GPS then I would probably go for a 530w and let your existing 430w become the backup. The 530 is not going to be that much more than the 430 and the installation between the two is awash. At least with a 530 you will gain something


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IMHP, I would not spend the cash to purchase and install a second 430W. Replace the old Nav/com with an SL30 and call it a day. If you really want another GPS then I would probably go for a 530w and let your existing 430w become the backup. The 530 is not going to be that much more than the 430 and the installation between the two is awash. At least with a 530 you will gain something


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This, except I'd go GNC255. It's only like 1AMU more than an SL30 and will be new with a warranty. (I had the SL30 and loved it, but I'm planning a GNC255 to replace the KX155 in my current panel (display is starting to get flaky).


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This, except I'd go GNC255. It's only like 1AMU more than an SL30 and will be new with a warranty. (I had the SL30 and loved it, but I'm planning a GNC255 to replace the KX155 in my current panel (display is starting to get flaky).


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That’s what I did. I went with the 16W GNC255B for the second Nav/Com.

4a19bb8217832584f7db192cd45d2747.jpg


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I bought the SL30 as the GNC series wouldn’t fit in my left side avionics stack. Consider the size of stuff. I see a lot of engine monitors and NAV/COM 2 on the right side and their utility there is less. 

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16 minutes ago, jetdriven said:

I bought the SL30 as the GNC series wouldn’t fit in my left side avionics stack. Consider the size of stuff. I see a lot of engine monitors and NAV/COM 2 on the right side and their utility there is less. 

In my case, it's replacing a KX-155 in the left stack, so I'm betting it'll fit. The SL30 is nice and slim, though.

I'm putting in the SkyView HDX as soon as I can, with its own engine monitor, so the right panel will get the -730 as backup instrumentation (augmented with RPM/MAP and probably some other stuff, as long as the panel's getting gutted...).

COM2/NAV2 get used for intersections in the event GPS is FUBAR (once, in recent memory), and for ATIS/ground/ASRI comms, so it can really kinda live wherever. I might actually move the radio over to the right stack, since right now the controls are awkwardly interfered with by the throttle quadrant.

Edited by chrixxer
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On 7/7/2018 at 12:19 PM, Boilermonkey said:

Good advice. What's the best option that is not a VOR only replacement? I just don't see the point in spending a few thousand on legacy tech.

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We replaced the SL30 with a SL60 during our ADS-B out upgrade (GNS430W&GTX330ES). The SL60 has the same (fantastic) com as the SL30, but instead of the VOR an Enroute IFR GPS. The only time we are really using the VOR is to talk to FSS and the GPS provides for us more information than the VOR. Only downside is the missing second GS. On the upside the delta between SL30 and SL60 for radio and indicator paid for 1/2 the 430W.   

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2 hours ago, Schinderhannes said:

We replaced the SL30 with a SL60 during our ADS-B out upgrade (GNS430W&GTX330ES). The SL60 has the same (fantastic) com as the SL30, but instead of the VOR an Enroute IFR GPS. The only time we are really using the VOR is to talk to FSS and the GPS provides for us more information than the VOR. Only downside is the missing second GS. On the upside the delta between SL30 and SL60 for radio and indicator paid for 1/2 the 430W.   

All it provides is navigation to a waypoint, unless it was installed as an approach certified GPS wirh annunciators etc.  The SL30 has a real VHF Nav radio that will get you to  200’ on a ILS, which is really the point of a backup NAV radio. Backup Com nice but The NAV is what saves you. 

Edited by jetdriven
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