Avonics Testing

ghatch · #1 07-16-2009, 07:50 PM

I'm getting close to riveting the top front fuselage skin (RV7) and was wondering what Y'all might suggest for testing that I can do on the ground inside the hanger. Dual GRT HX w/GPS, GRT EIS, Ryan TCAD 9900B, TT VSGV, 495, PS 800B Audio, (2) SL-40's GTX-327 TX.

As always, thanks for your input,
Gerry

L.Adamson · #2 07-16-2009, 08:53 PM

A few items I can think of..

Use a auto or airplane battery. A charger will create a hum.

Don't get in a hurry and reverse the positive and negative leads. I'm not the only dummy that's done that.

Open the hangar doors, and you might get a GPS signal.

Use a handheld comm to check your SL-40's.

And... did you see the SL-40 recall, mentioned on this list last week? A dealer has to send them in, but it took less than a week to get back.

See how your transponder altitude compares with 29.92 on the altimeter. My transponder/encoder was about 200' off. I had to have a avionics tech come to the hangar. Wasn't a Garmin though.

L.Adamson --- RV6A

ghatch · #3 07-17-2009, 05:26 AM

Thanks for your reply. I did not see the recall for SL-40s. Do you have a link?

Gerry

L.Adamson · #4 07-17-2009, 06:14 AM

Quote:

Originally Posted by ghatch

Thanks for your reply. I did not see the recall for SL-40s. Do you have a link?

http://www.secure4host.net/upload/fi...rminSB0921.pdf

Look on the bottom for Mod AE. That's the one required.

flion · #5 07-17-2009, 07:42 AM

I agree with Larry, use a battery. I hooked up a charger to my battery to keep it fresh. You can't do all the operational tests but you can at least check that each item is connected and powering up correctly and many items you can at least see are working in static configuration. I dunno about the GRT, but if sensors were not connected to the Engine Pod on my plane, there would be no reading as opposed to a static reading when connected. Tach, for instance, read "--" without the sensor and "0" with the sensor connected. Before I permanently installed the GPS antennae, I ran them outside the hangar and was able to test the database and flight director functions. And, of course, I was able to do things like calibrate the fuel senders. You can actually do quite a lot before you ever start the engine.

PS: One of the cool things was to be working in the cockpit with headphones on instead of hearing protectors and listening to the airport traffic over the intercom (as well as plugging in an MP3 player). You might say my audio system had extensive testing before the first flight; good way to get used to radio traffic again, too, if you haven't been flying while building.

LarryT · #6 07-17-2009, 09:49 AM

At the recommendation of Bob Nuckoll's @ Aero-Electric connection, I purchased a small bench power supply unit from Marlin (sp) P Jones Company. Cost was $60 on sale.

This type of device can be set for both voltage and to limit current. While it is my hope when I get that far that my wiring will survive the "smoke" test, it is also my hope that if I do something wrong, having a limited amount of current might save something (expensive?) that might otherwise get fried.

However, since I am just a dumb mechanical engineer and not a brilliant electrical engineer, I could be all wet!

LarryT

Jim P · #7 07-17-2009, 10:55 AM

As much as I hate going to Fry's Electronics, they also have some decent bench power supplies. I ended up using a 20A supply that put out about 13V. Works great for driving the electrical system, especially when you have all your avvionics turned on for configuration and test.

Jim

Noah · #8 07-17-2009, 11:11 AM

Question: Why is a bench power supply any better than a still-pretty-good-but-won't-quite-crank-in-the-winter car battery for bench testing? If you're worried about limiting current, just stick a fuse or CB in line with the battery, no?

erich weaver · #9 07-17-2009, 11:19 AM

Quote:

Originally Posted by L.Adamson

And... did you see the SL-40 recall, mentioned on this list last week? A dealer has to send them in, but it took less than a week to get back.

This is not an issue. I spoke with the Garmin rep that answered the phone at the number listed on the recall notice before I sent mine in. I specifically told them I was not a dealer and that I had installed it myself in my experimental aircraft. They issued the return number number immediately and I got the unit sent back to my home address in a week.

erich