Another dumb question?

I've read in a couple of places that I should use insulating washers when installing mic and phone jacks to keep things from grounding to the panel, but doesn't the threaded portion pass right through the panel and thus come in contact with the hole itself?

Steve Zicree
RV4 with lots of dangling wires

Insulated washers

Nope, the insulated washers I'm thinking of sit in a larger hole than the threaded part of your jack. One half of the washer set has a protruding chunk which fits into the larger hole, and the other half is just a flat washer. The jack itself is totally isolated.

B&C sells these washers. http://www.bandc.biz

)_( Dan
RV-7 N714D
http://www.rvproject.com

Thanks a bunch Dan. I thought it might be something like that. Watch for more novice electrical questions real soon

Steve Zicree

another dumb question #2

btw, just put my phone jacks in, hopefully I got it right.

hey, it's Sunday, I can't find an alternator belt, can I still go ahead and mount my prop?

prop off, belt on

mark manda said:

I can't find an alternator belt, can I still go ahead and mount my prop?

Click to expand...

Yes you can. Assuming you don't mind removing it again later to put the alternator belt on.

)_( Dan
RV-7 N714D
http://www.rvproject.com

wait on mounting prop

Mark,
If you mount the prop, you will then have to remove it in order to get the alternator belt on.

More Electrical Confusion

I'm trying to decifer all the various installation guides for my panel and came across this one for the intercom

http://www.ps-engineering.com/docs/PM501_wiring_diagram.pdf

If I'm reading it correctly it calls for multi-connector wire with an outer shield. The diagram seems to show the shields for each jack all being connected to each other at the Sub-D plug. I'm hoping somebody with more experience than me (that would be any at all) can tell me exactly how all those shields are actually connected together. Thanks folks.

sTeveZicree
RV4 that you can sit in, but not much else

too many grounds too few ground pins

szicree said:

If I'm reading it correctly it calls for multi-connector wire with an outer shield. The diagram seems to show the shields for each jack all being connected to each other at the Sub-D plug.

SteveZicree
RV4 that you can sit in, but not much else

Click to expand...

I feel your pain, here you go with a few pictures.

http://www.aeroelectric.com/articles/dsubs/d_solder.html
http://www.aeroelectric.com/articles/pigtail/pigtail.html

(SEE STEP 7: daisy-chaining of shield grounds)

G

G,

Dang, a picture really is worth... well, you know. Thanks so much. I've read Bob's book, but didn't realize there was so much great reference stuff on his website.

Hey, as long as I've got everybody looking at my intercoms's diagram

http://www.ps-engineering.com/docs/PM501_wiring_diagram.pdf

can somebody tell me why it seems to show the shields connected only at the intercom end. In my limited experience I've always used the outer shield as a conductor but here it doesn't appear to be the case. Am I making any sense?

Steve Zicree

szicree said:

can somebody tell me why it seems to show the shields connected only at the intercom end. In my limited experience I've always used the outer shield as a conductor but here it doesn't appear to be the case. Am I making any sense?

Click to expand...

You can use the shield in shielded wire as a conductor, but then it is no longer functioning as a shield. If the installation calls for shielded wire, then connect the shield to either ground, or to the unit, or both. The rule of thumb is that it's only connected at one end, but different devices call for the shield to be connected differently, and I'd follow the manual for the device.

Jeff Point
RV-6
Milwaukee

Common practice

szicree said:

can somebody tell me why it seems to show the shields connected only at the intercom end. In my limited experience I've always used the outer shield as a conductor but here it doesn't appear to be the case. Am I making any sense? Steve Zicree

Click to expand...

Yes, I know exactly what you mean. It is common to used the shield as a conductor, but it is also common to use the shield as a......well..., a shield. The latter is a true shield and best for protecting the wires from noise (EMF).

When shielding it is common to ground only one end. It is all good and the PS engineering guys know there stuff, just follow the directions and ground the shield at the unit only per note 4. If you make it this way and isolate the jacks from aircraft ground (per note 3) you will have a noise free system. Multi point grounds is the curse of a noise free system. That is why the sheild and jacks all ground to the unit, not the airframe.

The harness is a pain, but it will be worth it. My DRE 244e for my RV-7 came with a harness, thank goodness. I wired a PS Engineering in my RV4. Making the harness was a little pain, but it is not as bad as it looks. PS Engineering is Good equipment and loved min for the +600 hours I flew it. You will like it. G