Repairing my EarthRoamer's KVH TracVision A5 (again)...

[howell_jd]

I'm putting this in the EarthRoamer section mostly because I have an EarthRoamer and the KVH TracVision A5 antenna is connected to my EarthRoamer.:elkgrin:

If it is better suited to another section I am not opposed to seeing it moved to a more appropriate section. That being said many of the EarthRoamers have either a KVH TracVision A5 or A7 antenna installed. Most of the KVH antennas I've seen are mounted at the front of the truck over the passenger side immediately adjacent to the skylight.:ylsmoke:

Oh yeah...the KVH TracVision A5 (or A7) is an on-the-move satellite antenna that allows you to watch DirecTV programming (almost) anywhere and in-motion (I think it's impossible to watch and drive at the same time as the TV is upstairs and the steering wheel is inaccessible from the bed...ha ha).:smiley_drive:

I have had to fix my KVH TracVision A5 antenna THREE times now so I figured a pictorial HOW-TO is in order just in case someone else has had a similar challenge :Wow1:

I have had the drive belt come off of the rotational gear, the inclination gear, and I had it to get JAMMED once.

This time it was the inclination gear belt. EASY!:costumed-smiley-007

DISCLAIMER
Don't attempt this repair in-motion...it's awkward enough with the truck stationary!

Seriously though, this is an electrical repair so disconnect the power to your KVH receiver so that no power goes through the coax to the antenna.

Tools you need: small flathead screwdriver, 7/16" open end wrench, 4.5mm hex head wrench, 4mm hex head wrench, torx T27 (special) bit, large phillips head screwdriver

First you have to pop the plastic cover off of the top of the corner feet.
I used a penknife screwdriver but a small flathead works too...just don't lever too much or you'll break the cover. One cover per foot.

...and disconnect the COAX (it's a powered COAX as I said above) with a 7/16" open end wrench...you might be able to get it off by hand but it's faster with the wrench.

Next loosen the 4 (or 8) hex head bolts holding the feet to the truck (4.5mm hex head wrench).

WITHOUT TIPPING THE ANTENNA OVER 45 DEGREES lift the antenna off of the 4 rubber vibration dampers. The easiest place for me is to move the antenna toward the open space at the back of the roof but for an ER with three solar panels I recommend placing a towel over one panel and gently setting the antenna on the towel.

The next part is tedious but not difficult although it is uncomfortable. You have to remove 12each 4mm hex head bolts from the bottom of the antenna (three each per side) and two of the three Torx T27 (special) bolts from each foot (you don't have to remove the middle Torx T27 bolt from each foot) WITHOUT TIPPING THE ANTENNA OVER 45 DEGREES.

Now the upper ring may be removed.

Next remove the 4 large phillips head screw securing the radome.

I don't recommend using the radome for a sled at Great Sand Dunes National Park but if you find yourself in need of a large saucer sled well...

I had to get the INCLINE gear belt back on the drive motor (I'm pretty sure this came off as a result of my FLYING :coffeedrink: at Great Sand Dunes after this year's ER rally).

The ROTATION gear belt is under everything and is a ROYAL PAIN to get at (especially as you really can't disassemble any further than what I've shown you here). When I fixed this previously, I had to use a small bladed flathead screwdriver with a LONG shaft to push the belt back onto its drive motor gear. You can't see it so it's all by feel (my grandfather would say you have to hold your mouth just right).

I recommend testing before reassembly. DON'T TIP MORE THAN 45 DEGREES WHEN MOVING THEN ANTENNA!

There are bubbles forming under my array which is glued to a mylar sheet that is glued to the antenna plate. I haven't seen any degradation of signal strength (stationary - or on the move according to my daughter). This array behaves just like the dish you may have at home for satellite delivered TV. The array amplifies some signals to provide a parabolic effect I guess. It is cool to watch this thing in action with the radome off. It spins and inclines to search for the satellite that provides DirecTV programming.

After a successful test (remember to unplug the receiver before grabbing that coax again), reassemble...

Radome back on (4 large phillips screws)
Upper ring back on (8 Torx T27 screws and 12each 4mm bolts)

Remount the dish on the rubber shock mounts and secure to the truck with 4 (or 8) 4.5mm bolts and recover the feet with their plastic covers.

Reattach the coax.:chef:

Enjoy!:victory:

Jonathan

 

[Scott Brady]

One of the funniest things I have seen regarding those antennas was the remote controls. When all of the ERs are parked around each other, the remote would turn on one, and off another, change channels, etc.

Pretty funny to watch.

Of course, I think it is nuts to install a TV in an EarthRoamer. Kind of defeats the point - don't you think

 

[howell_jd]

I remember that happening to a few others last year in Moab! I used to have DishNetwork at home so I didn't even bother turning on the receiver. Now we have DirecTV.

For a trip with the family it is "usually" off limits I AGREE.

This year's Rally, Naomi got sick (strep throat) and so the TV was a help as she was very uncomfortable. Fever of 104 from strep throat...thanks to the help of all of our friends at ER, Irina and I were able to get her seen at Children's Hospital before the Rally started. Disney Channel wound up being a secondary medication to the antibiotics.
Ordinarily she only gets a few DVDs to watch on the Interstate (not State Highways or off-road though).

I also travel quite a bit to train units on telecommunication and route reconnaissance so I try to save the government some money by not getting airfare and a hotel - so the TV is nice then too. I'll be driving to Fort Knox next week for a three day trip as an example.

I should try to find a few ranges that are open though (HIGH ADVENTURE)!

"What is that silver thing over there?" Tank 1
"I dunno. Let's shoot it!" Tank 2

Hard to be inconspicuous at times (as you know)!

Anyway you are right...it's nice to have from time to time though...mine came with a broken one so I saw it as a challenge - it's ironic that I now teach some folks how to set up satellite antennas though!

Great to hear from you Scott.

Jonathan

P.S. Nice haircut!

 

[Scott Brady]

P.S. Nice haircut!

I wish I had hair to cut

 

[Ergosol]

Hello everybody. I've just had to make some repairs to my Tracvision A5, so I thought I would share some info just in case anyone has the same problems. So at first the rotational drive belt was slipping and causing the dish to not spin. We tried (and failed) to cut nearly an inch off the belt and reconnect the ends using high strength yarn and basically tailoring the ends together. The yarn didn't last through our tests, so the belt had to be replaced entirely. This part was the least fun, since KVH is not helpful at all in regard to finding you or supplying replacement parts. Eventually we knew the only way to replace the belt was to get an exact specification match for it, so with the belt cut, it was easy to measure.

Unfortunately, the Grainger in our town closed down, so we were directed to a vendor called Kaman Industrial Technologies. We brought them the belt we had and they did all the measurements, figured out the specs, and found us a couple replacement alternatives. The original belt being 36" and slipping, we decided we had to go shorter, so they pulled up two new ones with everything matching except the length. One was 34.7" the other was 35.4". We weren't sure which would be better, so we had them order both.

In re-assembly, I first tried to get the shorter (34.7") belt in there, and it wouldnt reach the spindle on the rotational motor, with the motor bracket loosened and allowed the motor to be as close as possible to the center. Next we tried the larger (35.4") belt, and it was perfect. Belt went on and we were able to position the motor a bit further away to give us tension on the belt.

In testing before complete re-assembly, we discovered the rotational motor was failing. We spent a few hours taking it apart, examining, and testing, trying different things to no avail. The motor itself is quite simple, it's just an electromagnetic drive that takes electric current and creates a spin on the spindle, but for some reason we couldn't get it to work properly.

As of now, we are trying to find a replacement rotational motor, which may be quite a feat. The stickers on the old motor are all faded and there doesn't seem to be any sort of model or part numbers we can pull for reference. We called KVH and had to leave a message for tech support who hasn't responded yet today. I've also been warned several times by their automative operator that tech support for non-warrantied products may come with a fee. That wouldn't be a big deal if they could at least supply us with a replacement, but I seriously doubt they will be able to (never have in the past). But it looks like I will have to keep searching elsewhere.

That's all for now, when I get more info I will update this post for anyone in similar situations in the future.

Here are the part numbers for the belts we ordered from Kaman. I apologize for not keeping track of all the specs and measurements.

As they appear on the invoice:

882-3M-6_HTD Synchronous Belt $6.74 (34.7")
92930337
9003M06_Powergrip HTD Belt $6.82 (35.4")
92932085

 

[Arclight]

You might want to see if there is an electric motor shop, or an alternator/starter rebuilder in your area. The old motor might just need new brushes/bearings.

Arclight

 

[LoRoad]

Out of Curiosity

Do those things really work? I've heard that in the lower 48 pretty well, but going north (like to the arctic circle) no so much. What's been your experience with the units abilities?

 

[Arclight]

Looking at those pics more closely, I see there are 4 wires coming out. I think you've got a stepper motor there. I would call these guys and see if they can match:

http://www.anaheimautomation.com/

There are only a few different stepper frame sizes in common use. Yours looks like it could be a 23 or 34 frame:

http://www.anaheimautomation.com/products/stepper/stepper-motors.php?tID=74&pt=t&cID=19

Arclight

 

[zelatore]

Interesting. I've been into the marine Tracvision units a few times and they are radically different, as are pretty much all marine receivers. I'm guessing the biggest difference is due to greater 3-axis movement of a boat.

 

[Ergosol]

Looking at those pics more closely, I see there are 4 wires coming out. I think you've got a stepper motor there. I would call these guys and see if they can match:

http://www.anaheimautomation.com/

There are only a few different stepper frame sizes in common use. Yours looks like it could be a 23 or 34 frame:

http://www.anaheimautomation.com/products/stepper/stepper-motors.php?tID=74&pt=t&cID=19

Arclight

YES! It's definitely a stepper motor, and this site looks perfect! Thanks a ton you guys rock. I will keep updating with as much relevant information as possible. I couldn't get 100% of the specs, so finding an exact match might be troublesome unless we send them the motor we have. What I know is it's a standard (round) type motor, single shaft, 2.0" motor length, 0.25" shaft diameter. Frame size is 2.25"x2.25", but I have no idea what that equates to in their filter dropdown box. I'm also not sure of the holding torque, but I know it's impossible to turn the shaft by hand while it's holding (or just too painful to put 50+ pounds on it by hand). The power connector has 6 pins, but only 4 are in use. If 1 = connected and 0 = not connected then it would look like [101101]. For the voltages and currents, I would need my boss to return to town with all the equipment for testing, so I can't get that information at the moment. I've sent the guys at anaheimautomation all this info, so I suppose I'll just wait and see how far that gets us.

Thanks again!
J.C.

 

[Ergosol]

Hello again everyone, we are a bit stuck. The stickers on our rotational stepper motor have faded and we can't pull any model numbers from it. We were wondering if anyone on this forum with the same Tracvision A5 would have any indication or photo's of these motors with model numbers. Also, if anyone from here has had to replace on of the motors, if they can provide any information on that process that would be great. We believe both motors are identical so it shouldn't really matter which motor you get the model number from.

What we know of the motors is nearly enough to get a replacement, but we can't seem to find out certain specs like the "Current Rating". We also have to make sure the replacement motor is compatible with the driver, we know its 4 pins and is controlled by pulses and not input voltage.

Other known specs:
Standard (round) motor type
Single Shaft
Frame: Nema 23
2.00" Motor length
0.25" Shaft Diameter

Thanks for the help!
-JC, Ergonomic Solutions

 

[Ergosol]

Are bumps allowed?

 

[Arclight]

Hello again everyone, we are a bit stuck. The stickers on our rotational stepper motor have faded and we can't pull any model numbers from it. We were wondering if anyone on this forum with the same Tracvision A5 would have any indication or photo's of these motors with model numbers. Also, if anyone from here has had to replace on of the motors, if they can provide any information on that process that would be great. We believe both motors are identical so it shouldn't really matter which motor you get the model number from.

What we know of the motors is nearly enough to get a replacement, but we can't seem to find out certain specs like the "Current Rating". We also have to make sure the replacement motor is compatible with the driver, we know its 4 pins and is controlled by pulses and not input voltage.

Other known specs:
Standard (round) motor type
Single Shaft
Frame: Nema 23
2.00" Motor length
0.25" Shaft Diameter

Thanks for the help!
-JC, Ergonomic Solutions

Okay, the only things left that you need to know are the coil voltage and degrees per step.

You can figure out the coil voltage by taking a multimeter and measuring the resistance between the leads. You should see values between 2-100 ohms. The lowest value would be the coil resistance. Now compare it to this page full of various surplus steppers:

http://www.mpja.com/NEMA-23-Stepper-Motors/products/521/

You have 6 wires coming out of it, so it's unipolar. Since only 4 are being used, it's actually working as a bipolar, but that's not important here.

The coil voltage rating is fairly simple - if the input voltage is lower than it should be, it won't move as quickly and might require too much current. If it's too high, it will run hotter than it should.

The number of degrees per step is critical. Fortunately, they are generally all either 1.8 or 3.6 degrees per step. A few are .72 degrees.

Since the surplus units are so cheap, you might just want to order a couple of different NEMA 23's with the same shaft diameter and coil resistance and see what what works.

Once you get them, the wire colors may or may not be the same as the one you currently have. Fortunately, it's not that hard to sort this out as well. Check out:

http://digital.ni.com/public.nsf/allkb/0AEE7B9AD4B3E04186256ACE005D833B
http://reprap.org/wiki/Stepper_wiring


Good luck!

Arclight

 

[Ergosol]

Arclight, you rock! With that info we were able to narrow it down dramatically. The link for surplus motors also helped, I picked out the only one they had that matched most of the specs, ordered it, and we hooked it up to test and it seems to work. Today should be the day we put everything back together and maybe even put it back on the vehicle. I will post an update once it's finalized and include any and all relevant information we have to help others find a compatible replacement. Thanks again!!

 

[Arclight]

Arclight, you rock! With that info we were able to narrow it down dramatically. The link for surplus motors also helped, I picked out the only one they had that matched most of the specs, ordered it, and we hooked it up to test and it seems to work. Today should be the day we put everything back together and maybe even put it back on the vehicle. I will post an update once it's finalized and include any and all relevant information we have to help others find a compatible replacement. Thanks again!!

Nice! It sounds like you're very close.

Arclight