Upgrading Terra NAV & SL-40 to SL-30

Bob Axsom · #1 06-26-2010, 10:57 AM

I just like the old ground based system that will be terminated in 2020 so don't slam the glass that will be out of date before then at me. I have been flying single nav receiver & indicator approaches with the RV-6A fo 6 years and that erratic on again off again Terra electronic indicator has made me sweat bullets and improvise with the SL-60 tied to a MAP 360 for the last time. It is not much cheaper than a 430 GPS system but I like single function dedicated instruments.

Bob Axsom

Bob Axsom · #2 06-27-2010, 09:49 PM

I went to Aircraft Spruce's website and used there online catalog to order a Garmin SL-30 and the compatible indicator with glideslope. The GI 106A listed is not the one recommended by Garmin and there is one observed incompatibility. Probably not serious but still for $5,000+ you expect the units to be completely compatible. The SL-30 has a back course annunciator output and no VLOC annunciator output. The identified indicator has a VLOC annunciator and no Back Course annunciator. All other pinouts appear compatible and I will probably end up leaving the input inactive as a work around but I have sent a message to ACS and I will work this further. There was no documentation with the indicator but I was able to get the Mid-Continent Instruments manual for the MD200-202/203/206/207 as well as the MD200-302/303/306/307 and I checked the information at the Garmin site - it appears to be a ACS error.

Bob Axsom

Bob Axsom · #3 06-28-2010, 11:26 AM

The instrument works well with the SL-30 but the back course annunciator is not included in the indicator. I does have a VLOC annunciator that is used in the GPS vertical guidance world but no straight NAV BC annunciator. We agreed to make a switch of the GI 106A (aka MD200-206) for a MD200-306 (about $100 cheaper with the BC annunciator).

Bob Axsom

Jamie · #4 06-28-2010, 12:27 PM

Quote:

Originally Posted by Bob Axsom

I just like the old ground based system that will be terminated in 2020...

Yeah, I'll believe it when all of the NDB's are decommissioned.

912ry · #5 07-01-2010, 02:07 PM

Quote:

Originally Posted by Jamie

Yeah, I'll believe it when all of the NDB's are decommissioned.

I have an SL-30 and am hooking it up to a skyview display, any body know the pin out?

Bob Axsom · #6 07-03-2010, 11:09 AM

Bob Axsom · #7 07-16-2010, 07:30 PM

Somewhat casually, I ordered a Comant CI-1125VOR/LOC Quadraplexer so that I could retain my old Terra NAV receiver and my new SL-30. As I have only three more wires to connect to aircraft power and dimmer I started thinking about the RF input to the SL-30. It has only one RF input for the NAV function so the signal processing for GS and VOR/LOC is split internally. Warnings started going off in my mind. I talked to the technical specialist at Garmin AT about the problem. He said the Quadraplexer will probably not work with the SL-30 He said what is needed is the Garmin 013-00112-00 Splitter with one output feeding the existing splitter for the Terra Nav and the other output feeding the SL-30 Nav coax connector. Garmin does not list this part on their website and Aircraft Spruce couldn't find any such number. Since it is Friday evening and I need to fly to Mitchell, South Dakota next Saturday (7-24-10) for the AirVenture Cup Race I took a shot at a Google search and found the part at Avionics Mall. Ordered with next day air shipping and hope they have one in stock.

Bob Axsom

Bob Axsom · #8 07-17-2010, 01:23 AM

The website said they do have one in stock and it also provided this information:

Garmin 013-00112-00 Nav Splitter for Garmin SL-30
$130.00
For use with one Nav antenna when feeding a SL-30 and another nav receiver. Unlike a Nav diplexer, this splitter will not degrade the Glide Slope signal needed for the SL-30.

Things look hopeful.

Bob Axsom

Bob Axsom · #9 07-19-2010, 01:37 AM

Mistake #2. Going in on this project I assumed that the SL-30 and SL 40 mounting configurations were identical and maybe two units bought today would be but mine are not. Today I completed the installation of the NAV cable and the NAV coax and started reinstalling hardware. When I got to the SL-30 it went in the tray (tube) nicely and all appeared well but it would not fully engage the tray/connectors, etc. Careful examination revealed that the latching mechanism is different. This is probably a generic design change made some time in the past decade. The SL-30 mechanism has a longer stroke and the machined part is less beefy but when the mechanism is moved to the fully inserted position the position of the fwd surface of the rear tang appears to be in the same plane as the same surface of the same element on the SL-40. There is a possibility that some careful positioning and perhaps a minor modification would make this work but my plan tomorrow is to go through the agonizing tray removal process and install the tray that came with the SL-30. By the way, the SL-40 will not latch in the SL-30 tray either. Even though the connector layouts appear identical, the full tray change out should be anticipated as a worst case situation for anyone else contemplating this change. I am planning to call Garmin AT Monday morning but I am supposed to fly to Mitchell, SD for the AirVenture Cup Race on Saturday so I'm running a little short of time.

Bob Axsom

Bob Axsom · #10 07-19-2010, 09:22 AM

Called Garmin AT and verified that the SL-30 can not use the SL-40 rack.

Bob Axsom