Replacement of DG and CDI - will these work (and cost)?

RussR

RussR

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I own a PA-28-151 with an old CDI (KI-214) that is no longer working and a DG (Sigma-Tek 4000B ) that has a leak around the knob that doesn't seem to affect much other than it seems to precess more than normal.

I fly another aircraft for a private owner that just had an Aspen put in, and therefore had the CDI (GI-106A) and DG (Mitchell 52D254) removed. They're sitting in a box and he asked if I wanted them (make an offer).

One at a time:

CDI - My KI-214 is being fed by a MX-170B, which is the slide-in replacement for a KX-170B. I think I understand that the KI-214 has an internal glideslope receiver, so I would need to also get an external GS receiver, right? Cost/recommendations? Will the MX-170 work with the GI-106A? I have already replaced the KI-214 once due to "bad resolver, not economically repairable", and it's showing the same type of symptoms and others now. Seems like I just need to get out of that spiral of old equipment. Note - my #1 NAVCOM is a Garmin GNC300XL with its own CDI (vertical needle only), so the 170 and this CDI is my only VOR/ILS source.

DG - The Mitchell 52D254 is built for driving an autopilot (which I don't have) and has a heading bug, which would be nice. Not a big capability increase here, but with my current DG having a leak (I imagine just the seal around the shaft), I don't know how much worse it will get and will eventually need repair anyway.

Both the GI-106A and the 52D254 worked when they were removed (I know this personally, as I flew with them) but do not have 8130s.

Anything else I need to consider? Any idea of what a good offer would be for either one or the other or the pair? Obviously I will have some additional installation expenses, especially for the CDI (and GS receiver), but that's my problem, not the other owner's.

Any problems with compatibility of anything I'm considering? I will talk to a local avionics shop (about the CDI anyway), but this just came up last night and thought I'd try to be prepared.
 
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Check with an avionics shop. Without the 8130s they probably need a checkout so the 8130 can be issued. The shop can give you an estimate on everything.
 
You probably already did this, take a look at a new AI and DG on eBay too, some good stuff on there, also if it doesn't work you're much more protected with eBay and paypal.
 
Yeah, considered that. I know I can get a new (exact) replacement DG from Sigma-Tek for $595, and installation is simple. So that is a data point (though no heading bug).

Don't need an AI, that one works fine.

But there's a DG and CDI sitting in a box just waiting to be installed, and we have a good working relationship already, so there's some appeal there.
 
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Yes, the GI-106A is **NOT** going to work with your radio. Your radio doesn't have the vor/loc converter that is built into the head you had. If you don't care about glide slope you can try the following KING indicators: KI-201C, KI-208, or KI-209A. If you want glide slope, you need either the KI-214 or a KI-209/KI-209A with a KN-75 glideslope receiver.



Not too long after I bought my plane the DG failed and when I pulled it out there was a piece of tape on the top of it that said $5. Another fleamarket find I guess (probably on par with what you'll find on ebay).
 
We still have the DG that came out of the Bonanza when we did our panel upgrade. It was setup to drive an STEC50 AP. To the best of my knowledge it was working fine and should have plenty of life in it.

If you wish, I can get the make/model and find out what fair price we want for it. And send pictures to you via email.
 
RussR said:
I own a PA-28-151 with an old CDI (KI-214) that is no longer working and a DG (Sigma-Tek 4000B ) that has a leak around the knob that doesn't seem to affect much other than it seems to precess more than normal.
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If you decide to replace the KI-214 please ask your avionics shop what a fair price would be for a "parts" 214. I've been patching mine together for twenty years and can always use a spare parts source.

Thanks,

Jim
 
BigBadLou said:
My 209 will soon be available if it helps.
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He still needs a KN-75 to get the glide slope. Is MX170 doesn't have a glide slope receiver. They run about three fiddy.
 
Thanks all! Some good feedback here, I appreciate it.

flyingron said:
Yes, the GI-106A is **NOT** going to work with your radio. Your radio doesn't have the vor/loc converter that is built into the head you had. If you don't care about glide slope you can try the following KING indicators: KI-201C, KI-208, or KI-209A. If you want glide slope, you need either the KI-214 or a KI-209/KI-209A with a KN-75 glideslope receiver.
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That's exactly the type of information I was wondering about, and I suppose pretty much takes me out of making an offer for his GI-106A. I DO care about the glideslope, so it looks like it's either repair/replace the 214 (again) or get a 209 and KN-75 (and connector).

Would I be right in reasoning that, any more, the newer NAV radios do all the signal processing, and essentially just tell the indicator left/right/up/down? Whereas in the past (KX-170 era) the radio just passed on the signals and the CDI had to figure out what they meant? Hence replacing the KI-214 for me (but keeping the MX-170) requires additional parts and some limitations on what indicator I can use. Sadly, all-new radios and indicators aren't in the budget right now.

weirdjim said:
If you decide to replace the KI-214 please ask your avionics shop what a fair price would be for a "parts" 214. I've been patching mine together for twenty years and can always use a spare parts source.
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I will definitely let you know. Thanks.


AggieMike88 said:
We still have the DG that came out of the Bonanza when we did our panel upgrade. It was setup to drive an STEC50 AP. To the best of my knowledge it was working fine and should have plenty of life in it.

If you wish, I can get the make/model and find out what fair price we want for it. And send pictures to you via email.
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That would be great Mike, thanks.

BigBadLou said:
My 209 will soon be available if it helps.
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Definitely let me know when it's available and how much you want for it, thanks.
 
There are at least three different interfaces between the nav radio and CDI/OBS that even King used. The KX-170's and the KX-155 (original) really are paired to matching heads. Not only do you have to move the needles back and forth you have to relay the OBS setting.
In addition somewhere the radio needs to take the VOR audio signal and compare the phase with the OBS setting to get the deviation (Or in the case of LOC and GS compare the relative strengths of the two signals).


Only when you get to the resolver style things that are designed to drive HSIs do you start to get a level of standardization. If you had a KX-165, or an KNS80 or an IFR GPS etc... you could swap in a resolver style King head or the Garmin head or drive an HSI (or one of it's electronic emulations) with a little more compatibility.
 
I thought the GNC300 was an IFR GPS. But IIRC there are only 2 indicators that will work with it.
 
It is, and I have it connected to its own indicator, a KI-202 I believe, and it works great. But since it doesn't have a NAV radio, the MX-170 is my only VOR/ILS receiver and needs a CDI with a GS needle (right now the non-functional KI-214).
 
bluerooster said:
I thought the GNC300 was an IFR GPS. But IIRC there are only 2 indicators that will work with it.
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I do not believe that is the case. If you want the required annunciators in the same unit as your CDI your choices are limited, but if you have separate annunciators you can drive an HSI or most of the resolver-style heads.
 
In case anyone is interested, Wentworth quoted me $1295!!!! for a yellow-tagged KI-214. :hairraise:
 
RussR said:
In case anyone is interested, Wentworth quoted me $1295!!!! for a yellow-tagged KI-214. :hairraise:
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They would probably quote you nearly that price for a yellow-tagged Narco Superhomer (plus $125 per channel if you wanted more than two transmit channels). THe more obsoleter stuff gets the pricier it gets. I doubt that there are a dozen Superhomers in operational condition in the world. Vibrators for those power supplies became obsolete roughly 40 years ago and a couple of the tubes are made from unobtanium.

Thanks,

Jim
 
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