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Music, ELT, ELT-GPS done.

December 22, 2011 / posted in Electrical, Fuselage, Panel / No Comments

6 hours.

I know there’s been a dearth of pictures lately, but there isn’t a whole lot to shoot.   Mostly I’ve been cleaning up wiring.   Today is a win, though.  The ELT has been a ratbastard since I first clicked ‘Add To Cart’ at ACS in March.  After the interminable wait, I was presented with the need to run a 4-pin phone cable along my central wire bundle.   A cheesy phone cable is not the first thing I’d pick to run the remote head of a potentially life-saving device, but it’s not my call, I didn’t design it.   This phone cable connects to an audio annunciator, and from that, another cable goes to the panel-mount remote control, which lets you fire off the ELT through blood-fogged vision if it hasn’t gone off from impact and you need help Right Now.   Today’s important lesson: Use the right tool for the job.  Well, no shit, but the thought of paying $40 for a tool I’d use on this project exactly once galled me, so I didn’t buy the phone line connector crimp tool.  I should have.  I spent a good while debugging why switching the ELT to ‘ARMED’ produced no beep.  First thing was that there was no battery in the audio module.  This required a CR2-type lithium battery, which the Radio Shack down the street had, thankfully.   The other thing was that without the crimp tool, the connector on the phone cable didn’t exactly work right.   No beep, no nothing.   I had already made one run to the Shack for the battery.  Now I had to make another.   But then I remembered I needed a 3.5mm mini plug extension so I could test the music input.   With products in hand, I went home and got back to it.  Sure enough, my crap connector job on the ELT cable was the problem, so with the connector installed properly and the battery in place, switching the ELT to ‘ARMED’ gave a satisfying beep.

Before I went my 10 rounds with the ELT, I’d soldered the 3.5mm snap-in CALRAD jack to the Music 1 cable, making sure to stress-relieve it with shrink tubing.   Once I had my 3.5mm cable, I was able to hear my iPod playing back Geomatic’s “Bliss” just fine.   Some adjustment may be necessary to increase the volume on the audio panel, but that shouldn’t be a big deal.   The level is also regulated properly by the audio panel.  When a radio transmission comes in, the music mutes, then comes back up after the transmission is completed.  The only thing that bums me out about the GMA340 is that I don’t have a music on/off switch, which means I’ll have to pull the plug if I want the music to just plain go away.   Fiddling with an iPod in flight is not a good idea.

So yeah, today’s a win.   Tomorrow, I need to think about mounting the comm antenna, running the comm wire, and putting my floor back together.  Then when all this avionics BS is done, I can put my flap actuation system and control arms back in.   Maybe even seats!   Then it’s on to the wonderful land of Firewall Forward, but not before a hellacious shop cleaning.

RDAC and Emergency Batt switch

December 21, 2011 / posted in Electrical, Panel / No Comments

3 hours.

Just got back from a 2-week work trip, so I needed a little downtime.   Today I got back into it and wired in the EFIS backup battery switch.  This was wired before, but it was crap, so I redid it.   I also wired the RDAC ground to the engine block, like it says to in the manual.   Apparently wiring it to the secured supply on the EFIS is not correct.   I also got started on wiring the music input.   Took me a second (and the brave sacrifice of a 1/8″ splitter) to figure out which was Tip/Ring/Sleeve, but all that remains there is to drill a hole in the panel, solder the wires on, and snap it in.

The hits just keep coming.

December 5, 2011 / posted in Panel / No Comments

4 hours.

I got the EFIS back from MGL on Saturday, with a new display board and the latest software update.   I installed it, with a few changes to the panel:  I added a power switch for the EFIS and I finally got around to wiring up an alternator warning LED.   I have no idea if it works or not, but it’s one less unterminated wire floating around.   Everything works fine, with one weird exception:   With the IOX plugged into the second LAN port, I lose sensor data after about 3 minutes of operation.   Needless to say, this is unacceptable.

First, a little background.   The IOX is the IO eXtender, a box that takes a bunch of analog and digital inputs and feeds them to the EFIS.   These are used to drive things like a CDI, or in my case, trim position indicators.   The RAC trim servo has an output wire that gives you trim position based on potential to ground.   This works OK, as long as the radio, the audio panel, and the transponder are off.   If any of those are turned on, the sensor data from the AHRS and magnetometer go away after a while.   It truly is one of the weirdest things I’ve ever seen.   The only thing I can think of is that the secured supply output on the back of the EFIS doesn’t have enough juice to run both the sensors, the RDAC (engine sensor module), and the IOX all at once.   Acccording to the docs, all those things shouldn’t add up to more than half an amp, wich is the max output of the secured supply.

When I get back from Seattle, (Redmond, actually), I’ll try connecting the IOX to bus power and see if the issue goes away.   I really hope so.   This is really driving me nuts, and I can’t have my flight data interrupted, ever.

Another issue I’ve got is that my altitude-encoding transponder seems to be reading data from the EFIS, but it’s totally wrong:  There is no way pressure altitude can be -200 after I change the pressure setting on the EFIS to show a reading of 3500ft MSL.

Another round of wiring.

November 28, 2011 / posted in Electrical, Panel / No Comments

5 hours.

In spite of the fact that the EFIS is still in the shop, I was able to produce actual panel work today.   Today was the cleanup of the rat’s nest behind the subpanel.   I bundled the wires, organized the loose ends, and finally permanently wired the pilot PTT wire.    Not only that, I ran and wired the copilot headset and mic, and connected the remote ident wire for the transponder, and it works on both stick grips.  A good day.

I picked up another LED and microswitch, with the intention of actually wiring up EFIS power to the switch so I can power cycle it in flight if necessary.   Not doing so initially was stupid on my part, but since the thing is in the shop, it’s not that big a deal.   The LED is for the alternator warning circuit.   Supposedly if the alternator goes funny, it sends 12v to something to let you know.

I didn’t get  a chance to wire the ELT GPS power, that’ll have to wait for another day, but it’s a gimme.  Should take no time at all.   I have exactly two terminals left, and they’re both spoken for, so I want to have the EFIS back in so I can get the wire length right before I crimp a terminal on there.

Of course, without the EFIS howling into the radio spectrum, I can hear SMO ATIS, which is kind of neat.   Hopefully this week I can complete the leftover tasks, because a week from today, I go up to Seattle for two weeks for work.

Really? Really?

November 25, 2011 / posted in Fuselage, Panel / No Comments

4 hours.

This is actually from last sunday, but this is the first chance I’ve had to actually write it down.    Happy Thanksgiving, everyone.    I give thanks for… The fact that MGL Avionics is being unbelievably awesome about fixing my EFIS.   Again.

I finished the connections for the SP2 and SP4, wired everything up, and started cleaning up the mess behind the EFIS.   I got everything wired in and properly arranged and the whole thing went south in a big hurry.

Over the last couple of weeks, I noticed a bit of flickering across the EFIS display, and sometimes the unit would crash, with the White Screen of Death.   This is usually solved by power-cycling the unit.   Not today.   Today the WSOD came on and stayed on.   So rather than a complete and utter freakout, I just resigned myself to sending the EFIS back to MGL for any necessary repairs.   There’s still plenty to do.

New sensor wires run

November 14, 2011 / posted in Electrical, Fuselage, Panel / No Comments

4 hours.

Ran the twisted triple up the centerline for the AHRS and compass, made a new harness to connect them, and finished the harness for the AV2 backup instrument.  The antenna inside the shop still dumps RF into the EFIS with the sensors connected, which is bad.   I think it’s largely due to bounced energy off the metal stuff in the shop.   Still, this solution is less wire, and therefore less weight.  It also combines the AV2 sensor input with the Odyssey sensor input with no need for a Y-adapter, which has no place in an aircraft.

But at the end of the day I was utterly foiled.   I don’t have a screwdriver long and thin enough to reach through the access holes to unscrew the DB9 connector on the back of the compass.   So that’s going to have to wait.

 

 

This project sucks less now.

November 10, 2011 / posted in Panel / No Comments

6 hours.

Adding this from last weekend. Got everything back in, with ferrite beads installed on everything going into and out of the EFIS and the GNS430w. There’s definitely a big difference in both the amount of noise generated by the EFIS and the amount of RF dumped into the EFIS on transmit, even in a shop full of metal things. I still have to wire in the RDAC and sensors permanently, but this time around, I actually got the EFIS audio output wired in correctly, and I can now hear Bitching Betty in my headset. The volume is a little low, and the sample rate is terrible. I’m not sure what to do about that. Maybe Matt at MGLUSA can shed some light on it.

I also mounted an avionics ground plate full of tabs right near the radio stack for shorter connections between avionics and ground. It also looks like my antenna will go under the pax floor pan to keep it as far away from the antennas, sensors, and servo in the tail or the radio stack and EFIS.

I also get to fish out the cheesy RCA cable from the main bundle and replace it with a twisted triple to carry power, ground and data to the AHRS and magnetometer. If I can get all this shite to sing in harmony, then it’s on to the baffles and other FWF fun.

The system won’t be noise-free until I no longer have unterminated wires, which means at the airport with the wings attached and all circuits complete, but I can live with that for now.

Grounded. Not.

September 26, 2011 / posted in Panel / No Comments

6 hours.

Yesterday and today was an ugly mess. I had to pull the wiring harness to try to figure out a couple of things, first and foremost, why is my radio dumping RF energy into my EFIS? I’ve checked all the grounds, twice, three times, both at radio, both ends of the antenna, and the EFIS itself. I grounded the shields of the ARINC connector as well, while I was in there. It seems to be a little better. I get no clicking of relays, but I still have the Bermuda Triangle effect whenever I key the mic. I’ve also got no mic audio. I don’t know if that’s my headset, which, at last outing, proved itself extremely unreliable in the mic department. My other headset looks like the foam muff on the mic dissolved itself into the actual microphone somehow, so I doubt that one works. This just gets weirder and weirder.

One thing I’m not too sure about: If I place one probe of my multimeter against the inner conductor on the antenna’s BNC connector and the other one on the antenna rod, I get no beep. I thought an antenna had one pole connected to the center conductor and the other pole connected to a ground plane. It may be that I have a defective antenna, which would suck, but better than a fried radio or EFIS.

Looks like I’ll be ordering yet another antenna from ACS, but until then, my old RAMI whip antenna will have to do for now.

Big day!

September 19, 2011 / posted in Panel / No Comments

6 hours.

Avionics installed! Everything powered up, no smoke! It also appears that I’ve connected everything correctly, with notable exception: One, I can’t seem to get any audio signal from the EFIS. This could be because I’ve connected the wrong wires to the RCA plug, or something is misconfigured in the EFIS software. It’s also entirely possible that the pins are in the wrong spot on the audio panel connectors. I think I used either the ADF or DME connection, but I have to check my notes to make sure. I definitely screwed up the pilot side mic connection. If you plug the mic in, it keys the mic. With nothing plugged in, the stick-grip push to talk trigger works fine. I’m going to try with my other headset, but I suspect it’ll be the same.

The GNS430W seems to be working OK. I can’t hear SMO or LAX tower, but I can hear aircraft overhead talking to them. ARINC data connection from the 430W to the EFIS seems to be working OK as well, at least there are messages being passed back and forth. I can’t pick up the SMO VOR either. It’s a weak signal, and there are a couple of hills between me and it. If I had a flatbed trailer, I’d put the fuselage on it, tow it up to the airport parking lot and to some tests there. Those devices aren’t designed to transmit to ground targets, so I’m not surprised I’m not picking it up. Had a bit of a scare though. At some point the large frequency knob stopped working. I could change the point frequencies with the small knob, but the major frequencies wouldn’t change. After going through several power cycles and various configurations, it started working. I think I had some kind of remote control enabled, but it’s working as of now.

Transponder lights up, but shows no altitude encoding from the EFIS. That’s probably a configuration issue as well, and I didn’t spend a lot of time on it.

I didn’t get all the antennas done, I just put a BNC end on the COMM antenna cable so I could test the radio without risking frying the thing by keying the mic and dumping all that RF energy right into the box itself. The location of the COMM antenna might be a problem. When I key the xmit, the EFIS shows me descending at 500fpm and a 20 degree yaw to the right. Since the plane is still in the guest house, this is clearly incorrect. I think I can swap the transponder antenna for the COMM antenna (this is why I got a new COMM antenna with a BNC connector) and get the COMM antenna the recommended 6 feet from the EFIS. The question then is, will the transmitted signal interfere with the operation of the autopilot pitch servo? I’ve still got a couple feet of antenna cable to spare on each end, so I can move that antenna all over the place and still be OK. I’m just trying to avoid punching any more holes in my airplane. Of course, in retrospect, using that cheesy audio cable to carry the AHRS data instead of a proper shielded two-conductor cable may have been a mistake. I so want to be done with this…

Before I put the EFIS back in, I made a new LED warning light for the panel. This one’s chrome and screwed in properly unlike the cheesy plastic one I had before. Much more solid. That LED is friggin’ bright, though. Apparently 800mcd is bright enough to get your attention in bright light, which is fine, since this will be primarily a daytime aircraft.

I still need to test the GPS transmit to the ELT and ground the ELT as well.

ELT wires run.

September 9, 2011 / posted in Electrical, Panel / No Comments

1.5 hours

Whoever decided that the 5-pin mini-DIN plug was a good idea for connecting the ELT to the shielded GPS cable needs to be pulled apart by 4 out-of-tune Harleys. Finicky, tiny little wires attached to miniscule pins with freaking solder. Couldn’t use a d-sub crimp-type connection, no, that would make too much sense. To add insult to injury, you need to make a pigtail off the GPS receive wire so you can check operation by, get this, making a tester out of an LED light and a 300 ohm resistor. The panel components are fastened with 4-40 screws, the only things aboard to do so.

I guess what sucked the most was after waiting 6 freaking months for the ELT itself, it has to go and be one of the most painful installs I’ve run into yet. At this point, I’m almost ready to get back into fiberglass.

But the wires are run, and I now have to join them to the big bundle going from the spar up the firewall to the panel. I also have to run the extra PTT wire at the same time, but that’s not such a big deal. The next few days will involve that, remounting the EFIS, and wiring the power and audio for the radio stack. With any luck, I should be able to hear Santa Monica ground and tower by Sunday night.

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