Remove Brittain heading coupler

[TheTurtle]

I took the cover off the front.  The whole thing slides forward an 1/8th inch or so but doesn't want to come out.

Anybody know if there's a trick?

I haven't opened. The instrument inspection panel yet to see if there's something back there holding it.

Got the pc system working so figured I'd get started on the nav coupler.  Brittain says there's test Jacks on the side I need to put a voltmeter on to test it.

[carusoam]

Did you try the hex tool that removes the king radio below it?  Left turning (to loosen) screw with a cam on it?

I am not familiar with the Britain devices, but all the other radios tend to come out in a similar fashion.

I see what looks like a hole like your KY197 has...  made me ask the question...

PP guessing only, not any knowledge behind this statement...  

Best regards,

-a-

[Hank]

Turtle, I posted all of the Brittain docs that I have in the Downloads section. Happy hunting! I love my heading bug . . . .

[TheTurtle]

2 hours ago, carusoam said:

Did you try the hex tool that removes the king radio below it?  Left turning (to loosen) screw with a cam on it?

I am not familiar with the Britain devices, but all the other radios tend to come out in a similar fashion.

I see what looks like a hole like your KY197 has...  made me ask the question...

PP guessing only, not any knowledge behind this statement...  

Best regards,

-a-

i looked at removing the com below.  of course it doesnt want to come out either.  Seems all my instruments are welded in from years of being there.  Ill beat it on it some more tomorrow.

1 hour ago, Hank said:

Turtle, I posted all of the Brittain docs that I have in the Downloads section. Happy hunting! I love my heading bug . . . .

I have them all.  Nothing says anything about how to take it out.  Ill call them tomorrow and see if they have any hints. 

I'll take off the inspection panels tomorrow.  Being lazy today, Ive had the cowl on and off so many times in the last few weeks....

Edited March 9, 2017 by TheTurtle

[Hank]

Talk to your mechanic. King & Garmin require a long, tiny Allen wrench, something like 7/64, through the little hole on the front that Anthony mentioned. You'll need one very long, ~6" length; without it, it won't matter how much you beat on the radio, it ain't gonna come out.

[Yetti]

As a recall the other brittian Accutrac used a slotted screw in the front.  The screw to the lower left of the heading dial looks like a good suspect.  Proceed with caution.  Maybe back it off a bit and see if the unit is loosened in the rack.

 

[TheTurtle]

5 hours ago, Yetti said:

As a recall the other brittian Accutrac used a slotted screw in the front.  The screw to the lower left of the heading dial looks like a good suspect.  Proceed with caution.  Maybe back it off a bit and see if the unit is loosened in the rack.

 

the manual says that screw removes the dust cover (whatever that it).  I got the front plate off which I assume is the dust cover but that screw didnt affect it.  tugging on the unit while spinning that screw didnt seem to do anything either.  Ill see what brittain has to say today.

[TheTurtle]

took some wrangling but I got it out enough to get to the jacks.  unfortunately its still going to have to go to brittain as it isnt working right.

first you dont need to take off the front plate.  Just spin this screw and it will slide out.  My issue was twofold.  1 The wires on the back were really tight and weirdly angled so pulling on the unit was pulling against the wires so I had to push on the wires from the IP access panel to get them to move.  2 the tang that moves when you spin that screw was hanging and took some jiggling to get it up over the groove it was in so the screw could be spun.

 

Heres what the tang looks like.

 

Heres what the test jacks on the side look like

 

Heres what it looks like out of the panel.  I dont think that PCB was made by robots in a factory!!  Single layer.

 

[Hank]

Yeah, that circuit board probably predates wave solder tanks, or at least small, inexpensive wave tanks for little companies . . .

But the doggone things work! Love, love, love my AccuFlite II!

[TheTurtle]

Just now, Hank said:

Yeah, that circuit board probably predates wave solder tanks, or at least small, inexpensive wave tanks for little companies . . .

But the doggone things work! Love, love, love my AccuFlite II!

does yours have the altitude hold?  Anybody know how that works?  theres no servos on the elevator and the trim is manual. I dont have it on mine but was just wondering.

Edited March 10, 2017 by TheTurtle

[Hank]

Alt hold is a completely separate module, the B6 I think. 

[TheTurtle]

1 minute ago, Hank said:

Alt hold is a completely separate module, the B6 I think. 

I have cutouts in the front of mine for pitch trim and alt hold.  Im just wondering what actually moves the elevator.

Edited March 10, 2017 by TheTurtle

[Hank]

Just now, TheTurtle said:

I have cutouts in the front of mine for pitch trim and alt hold.  Im just wondering what actually moves the elevator.

I dunno, I've never seen one live in the flesh. I've got the AccuFlite (tied to the heading bug) and AccuTrak, with a switch to follow the 430W or VOR #2, but that's all. Love the AccuFlite!

[TheTurtle]

then i guess i have accuflite and accutrak as well.  I have a switch on the panel to switch between nav #1 and Nav #2.  Does your accutrak work?  Talking with brittain yesterday they mentioned the "loc" setting on the dial will track a localizer.  Still trying to wrap my head around the difference between the Trk and Cap settings.

[EricJ]

1 hour ago, TheTurtle said:

Heres what it looks like out of the panel.  I dont think that PCB was made by robots in a factory!!  Single layer.

 

I think I see some electrolytic caps on there.   Those are usually what fails due to aging in electronics like this, or a cracked solder joint from many years of vibration.

56 minutes ago, TheTurtle said:

then i guess i have accuflite and accutrak as well.  I have a switch on the panel to switch between nav #1 and Nav #2.  Does your accutrak work?  Talking with brittain yesterday they mentioned the "loc" setting on the dial will track a localizer.  Still trying to wrap my head around the difference between the Trk and Cap settings.

I'm guessing "track" and "capture"?   Usually the control loop for "capture" is more aggressive than "track", which should be much tighter so that it doesn't wander around.  i.e., set it to Cap to home in on (capture) an omni radial, and Trk once you are on heading on the radial and the needle is centered.   That's totally just speculation on my part, so take it with a grain of salt.   Are there no manuals left around for these?

 

[TheTurtle]

Just now, EricJ said:

I think I see some electrolytic caps on there.   Those are usually what fails due to aging in electronics like this, or a cracked solder joint from many years of vibration.

I'm guessing "track" and "capture"?   Usually the control loop for "capture" is more aggressive than "track", which should be much tighter so that it doesn't wander around.  i.e., set it to Cap to home in on (capture) an omni radial, and Trk once you are on heading on the radial and the needle is centered.   That's totally just speculation on my part, so take it with a grain of salt.   Are there no manuals left around for these?

 

i have the manual and it said basically what you did.  makes more sense in a single sentence like you gave it though.  Im guessing then that "LOC" is even tighter on the tracking?

[Vance Harral]

You understand the manual correctly, assuming it works like our B5.  The CAPTURE setting sets up a 45 degree intercept to a radial you're not yet on.  When the VOR or localizer needle comes alive, the unit will turn on to the radial as the needle centers up.  Once that's complete, you switch from CAPTURE to TRACK (for enroute navigation) or APP (for an approach).  The difference between CAPTURE and APP is different multipliers in the controller circuit.  "Aggressiveness", if you will.  I expect the APP setting on our B5 and the LOC setting on your unit behave the same way.

Regarding altitude hold, what moves the elevator is a pair of vacuum servos attached to the elevator push rod.  The "pitch trim" indicator that goes in the cutout indicates how much vacuum is being pulled in one direction or the other.  The idea is that if the indicator is consistently on one side or the other of center, you can roll in/out a little elevator trim to help the autopilot.  Attached is a picture of our B5, with the pitch trim indicator.

[Yetti]

suddenly I feel the need to obtain a B5....   

[Browncbr1]

I finally got my B-11 in and flew yesterday. (Added accutrak to my accuflite b-12). Awesome.  They work together to do what capture mode does on the b-6.  Approach mode on the b-6 is just simply higher sensitivity.   On my b-11 accutrak, there is a high or low sensitivity switch that accomplishes this.  Best $600 you can spend!

i also have alt/pitch hold and it works pretty well.