Piper question

Timbeck2

Timbeck2

Final Approach
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Timbeck2
Does anyone know the year Piper started installing a rocker switch for the avionics? I've seen them on other panels but I didn't know why mine was located elsewhere. Then I found out that in planes as old as mine ('69) they didn't have a rocker dedicated to avionics or radios as it used to be called. I have a toggle pitot switch located where the pitot breaker should be and I found a rocker for that ($71, obviously made of unobtanium) that I'll install in the rocker switch panel.
 
Timbeck2 said:
Does anyone know the year Piper started installing a rocker switch for the avionics? I've seen them on other panels but I didn't know why mine was located elsewhere. Then I found out that in planes as old as mine ('69) they didn't have a rocker dedicated to avionics or radios as it used to be called. I have a toggle pitot switch located where the pitot breaker should be and I found a rocker for that ($71, obviously made of unobtanium) that I'll install in the rocker switch panel.
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Archer II information Manuals dated July 2, 1979 have it shown in the breaker panel.
 
Don't know if I was clear in my question. Not my panel but an avionics rocker like those next to the red master, fuel pump, landing light, etc. My avionics master is a push pull switch located just below the primer and my toggle pitot switch occupies the lower left breaker.

1-final-panel.jpg
 
I can’t answer the question about Piper, but there’s a break point where before that date, avionics masters in Cessnas weren’t really a thing, either. Many have them retrofitted.

My 1975 182 didn’t apparently have one from the factory by the looks of ours. The switch is installed now to the right of the normal row of switches and above the breakers on the pilot’s side. It’s nowhere near the master which is far left.

The electrical diagram I believe shows an avionics master as “optional” in mine, but I’d have to go check that. I guess if you didn’t order it, you just turned all the radios off manually before killing the engine and then the master to avoid the awful voltage spikes and junk on the bus as the engine and alternator winds down.

If ours had the option that switch has been replaced. The big old chromed thing that is really a heavy breaker switch and clicks over with “enthusiasm” and feels like it has solid contacts inside, isn’t stock, that’s for sure. The stock switches are mushy squishy plastic junk compared to that thing.
 
My '69 cherokee does not have the avionics switch either.
 
73, avionics switch not with the rockers.
 
My avionis school has a 1967 PA 28-140. That's no help for you, but I'll pass your question along to my instructor.
 
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My 79 lance did not come with one factory.....It's aftermarket.
 
That settles it then. I'm happy with the switch I have now, because I have to be. I guess I've watched too many videos on YouTube where I see the avionics rocker and it must be on newer airplanes. Appreciate everyone's input.
 
My 81 Archer does not have an avionics rocker switch. It is a toggle switch up to the right of the radio stack.
 
The one in our club is I believe a 1978 and it has the metal toggle switch not the plastic rocker with the others
 
The only factory avionics master switch in PA-28s (at least before 1986) I can recall is the little toggle switch that NRG described, and I think they first came in around 1979 or 1980. I know my '77 didn't have one.

In the photo below (from the 1980 Archer II brochure), it's the little switch between the #1 navcom and the ADF

2FC52D84-85AB-4EC1-BB8B-82BED1B05525.jpeg
 
Pilawt said:
The only factory avionics master switch in PA-28s (at least before 1986) I can recall is the little toggle switch that NRG described, and I think they first came in around 1979 or 1980. I know my '77 didn't have one.

In the photo below (from the 1980 Archer II brochure), it's the little switch between the #1 navcom and the ADF

View attachment 65944
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Yep, that's where mine is.
 
Adding a avionics master is not hard but will be a bit pricy as you will need to add the switch, rewire the breaker panel to isolate the radio bus and add a relay to handle the load. You should also add an alternate switch and relay in parrallel in case of switch failure.

Bob
 
unsafervguy said:
Adding a avionics master is not hard but will be a bit pricy as you will need to add the switch, rewire the breaker panel to isolate the radio bus and add a relay to handle the load. You should also add an alternate switch and relay in parrallel in case of switch failure.

Bob
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Is the separate relay really necessary? In most Cessna retrofits including ours, you usually see a switch/breaker rated appropriately tied to a split bus directly.

It doesn’t have the ability for a switch failure to be bypassed like your suggestion, but it’s usually a really beefy switch/breaker rated for it.

It takes a light push to flip it with a solid “snap” when it goes over center in the off direction because it’s rated for breaking contact while current is being drawn through it, and the mechanics of those are that that they break and move the contacts apart quickly under spring action. In the on direction, they move stiffly to a point about 85% of the way toward on as you preload the spring, and then snap to make contact in that direction as well. They require more force to turn on than off.
 
denverpilot said:
Is the separate relay really necessary? In most Cessna retrofits including ours, you usually see a switch/breaker rated appropriately tied to a split bus directly.

It doesn’t have the ability for a switch failure to be bypassed like your suggestion, but it’s usually a really beefy switch/breaker rated for it.

It takes a light push to flip it with a solid “snap” when it goes over center in the off direction because it’s rated for breaking contact while current is being drawn through it, and the mechanics of those are that that they break and move the contacts apart quickly under spring action. In the on direction, they move stiffly to a point about 85% of the way toward on as you preload the spring, and then snap to make contact in that direction as well. They require more force to turn on than off.
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I am assuming that Tim wants to use the rocker switches that piper uses in the switch block. I would have to look at their ratings but, I don't think they are rated for more than about 5 amps at 12v. In that case, a relay is needed to handle the load of all the avionics. In my RV I use a 30 amp switch breaker to feed the avionics buss so no relay was needed.

Bob
 
You are correct Bob and after looking at the prices of all the pieces involved just to have the switch with the rest of them, I'm happy to just keep it as it is. I'm happy just moving the pitot as that toggle really looks out of place on the breaker panel.
 
I have one ('73 -235) but it's pretty clearly an add-on; just to the right of the co-pilot side yoke.

piper.jpg
 
denverpilot said:
Is the separate relay really necessary? In most Cessna retrofits including ours, you usually see a switch/breaker rated appropriately tied to a split bus directly.

It doesn’t have the ability for a switch failure to be bypassed like your suggestion, but it’s usually a really beefy switch/breaker rated for it.

It takes a light push to flip it with a solid “snap” when it goes over center in the off direction because it’s rated for breaking contact while current is being drawn through it, and the mechanics of those are that that they break and move the contacts apart quickly under spring action. In the on direction, they move stiffly to a point about 85% of the way toward on as you preload the spring, and then snap to make contact in that direction as well. They require more force to turn on than off.
Click to expand...


A lot of cessna airplanes already have split radio bus and primary bus but the relay is not pilot controllable, its slaved to the ignition switch instead.

Every small airplane I have ever worked on was a piecemeal mess of circuit breakers of several different part number & style, not even co-located, jumpers and all that. Its pretty satisfying replacing all that crap and building a breaker panel with room to grow, tinned copper bus bars and a uniform look. I typically replace all the original breakers on the avionics bus with Klixon push/pull ones. I wouldn't mind doing the same with all the primary bus ones but that's almost twice as much money and seems overkill.
 
So you have a rock-ER switch right beside your master, beacon, fuel pump, landing light for your avionics?
 
Timbeck2 said:
So you have a rock-ER switch right beside your master, beacon, fuel pump, landing light for your avionics?
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darn auto correct, yet to install the rocket switches though …. lol

yes, apart from nav and panel lights, rest are rocker. avionics master is a diff one, flip flop metal switch next to the MFD

upload_2018-8-7_11-30-44.png
 
I think you missed the point. I was looking for a rocker switch like those we both have, to use as the avionics master. I have since learned that although possible at great expense, it isn't located on the rocker panel in anyone's plane. Its somewhere else.
 
I need me a rocket switch!

Queue the music on the"modern gear needs no avionics master" debate.
 
I got an avionics master but mines no ordinary Cherokee

22AA1B75-5F3C-4597-A392-6613ABA5366E.jpeg
 
Timbeck2 said:
I think you missed the point. I was looking for a rocker switch like those we both have, to use as the avionics master. I have since learned that although possible at great expense, it isn't located on the rocker panel in anyone's plane. Its somewhere else.
Click to expand...
ahh ok got it. yeah mine is like the switch in @CC268 's pic, located between MFD and Radio
 
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