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Navworx Antenna Plan

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pvalovich

Well Known Member
Thinking about buying a Navworx ADS600-exp box for my ADS-B solution (RV-8A). However, the install manual has a very stern warning about minimum 5 ft. separation between the UAT antenna and current transponder antenna.

1) What happens (operationally) if the max separation is only 4 ft.?
2) Is it possible to install 2 UAT antennas - on under each wing and connect with a splitter with a single connection to the box?

I submitted questions to Navworx yesterday - but wanted to query forum expertise before committing.

Also - nyone want to offer an opinion of Navworx vs a Garmin 345/660 ($$$) setup? I have an AFS 4500. Rob at AFS says the 4500 works with the 600-exp but they haven't tested the 345.
 
I had less than 5 ft. when I put the antenna on in my situation. Garmin said it would be fine at 4 ft. So far, it is working OK.
 
pvalovich said:
1) What happens (operationally) if the max separation is only 4 ft.?
2) Is it possible to install 2 UAT antennas - on under each wing and connect with a splitter with a single connection to the box?

.
Click to expand...

#1. Move the UAT antenna (and receiver if possible) to the bottom fuselage behind the baggage compartment.
#2. No. This is not the function or how a splitter works.

Carl
 
I asked the same question (antenna separation minimums) while visiting the RAMI (antenna) booth at Oshkosh. The response I received was 3 feet. During my visits to the various vendors, one of the ADS-B "black box" suppliers did tell me 5 feet, though.
 
Try very hard to follow manufacturer's instructions

on your installs. You will expect the manufacturer to provide you warranty and technical backup.

I installed my Navworx behind the bulkhead, and the UAT antenna on the bottom of the fuselage, near the tail. I could reach everything through the bulkhead, and by removing the fairing on the tail feathers.
 
RONSIM said:
on your installs. You will expect the manufacturer to provide you warranty and technical backup.

I installed my Navworx behind the bulkhead, and the UAT antenna on the bottom of the fuselage, near the tail. I could reach everything through the bulkhead, and by removing the fairing on the tail feathers.
Click to expand...

Ron, is your system performing ok?

I am considering same install location and wonder about the USB cable coming from the transponder antenna cable. It will have to be about 5' in length to reach the experimental box. Was that an issue?
 
Different ADS-B boxes can tolerate different distances from the transponder antenna, so just because it works OK with brand X doesn't mean that same distance is OK with brand Y, and your antenna manufacturer can't tell you what an OK distance is.

The issue is that ADS-B is on the same frequency or a very close one to the transponder. The transponder is 200+ watts only a few feet away, while the ADS-B box is trying to detect and handle nanowatts while in the presence of a pulse a billion times stronger. In some designs, getting it too close can literally overheat and destroy the receiver in the ADS-B box. So it's not even about how it performs, but in some cases if it can survive.
 
Design Factors

Just talked to Bethany at Navworx. The 5 ft. requirement is indeed dictated by the possibility (likelihood?) the UAT signal would burn out the box.

Anyone considered mounting the UAT antenna on the bottom of the wing? Wonder about signal blockage in a turn.
 
Air Tractor, for customers who want them, installs transponder antennas on the bottom of the right wing about a third of the way out and just shy of 25% chord. Seems to work fine for them.

They do that to keep the antenna out of the way of hopper and booms and any chemical spray paths.

Jim
 
David --- my installation is different in that

My transponder/encoder does not come off of the transmonde --- I have the encoder out of my D10A and the Garmin 327 transponder is my "control box"--- all are hardwired to the Navworx aft of the bulkhead.

I bought the Navworx harness, and it hooked up very well to the Stein-supplied harness for my new radio stack.

Ron
 
Some put their UAT antenna on an access panel under the wing to get the required 5 feet. I have a receive-only UAT antenna in my wing tip on the 6 and it works fine. If the metal of the plane gets in the way you will lose your line of sight to the ADSB tower but, in practice for cross country flying, that's not going to happen often.
 
RONSIM said:
My transponder/encoder does not come off of the transmonde --- I have the encoder out of my D10A and the Garmin 327 transponder is my "control box"--- all are hardwired to the Navworx aft of the bulkhead.

I bought the Navworx harness, and it hooked up very well to the Stein-supplied harness for my new radio stack.

Ron
Click to expand...
Thanks.
I considered hard wire from Becker Mode S (150 watts) but Navworx did not know if it met US standards. Although it is approved in Europe for up to 18,000' I know it is not approved here, so I opted for the transmonde device.
Placement of the UAT antenna has not been decided yet, probably as far aft as I can get it.
 
pvalovich said:
Also - nyone want to offer an opinion of Navworx vs a Garmin 345/660 ($$$) setup? I have an AFS 4500. Rob at AFS says the 4500 works with the 600-exp but they haven't tested the 345.
Click to expand...

Based on my conversations with AFS and Garmin, it is my understanding that the 345 will not provide ADS-B data to the AFS screens...there is no option for the combined GDL90 traffic/weather RS232 output format on the 345.

If anyone has heard better, I'd love to be proven wrong!
 
My UAT Antenna location

In order to get distance between the UAT Antenna and the Transponder Antenna, I placed my UAT Antenna far back on the bottom of the tail, just forward of the last bulkhead. To do this, I had to install an access panel in the tail. The access panel gives me access to both the UAT antenna as well as the aft end of the rudder cables should they need maintenance an inspection in the future. Here is a link to my installation location on my -8A. I used a Delta Poppa blade antenna for the UAT Antenna.

http://www.mykitlog.com/users/display_log.php user=jackclark&project=211&category=0&log=188956&row=3
 
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