pierre smith

pierre smith

Well Known Member
Mornin' guys,

We finished the 430W install and an Archer antenna in the right wingtip, away from the nav/strobe lights but today I couldn't pick up the ILS at all. The SL-30 with an outside cat's whisker worked fine.

We have a splitter in the coax from the Archer and I feel that this may weaken the signal too much to satisfy the 430W...any opinions on how much signal is lost? I'm thinking of putting a dedicated GS antenna up on the windshield by the headliner and doing away with the splitter.

Opinions/ideas?

Thanks,
 
I have a 430W and one of those aluminum strip antenna in a wingtip (Sorry...forget the name. Archer?) Seemed to do OK the last time I used it which was maybe three years ago.
 
Two-way balanced splitters cut the signal in half (-3db). So, this could be part of the problem. But, if you aren't getting a signal at all... I know from reading some of Paul's post on this that the Archer is very picky about its install. If I recall correctly, the twisted nav light wires shown on the Archer diagram have to be run exactly as shown and are necessary. I don't know why. RF stuff is voodoo magic to me.

You didn't say, but I assume the 430W VOR part is working?? If it is you'd think the GS would work at least some. If it isn't or is very weak, it might be the Archer antenna install.

FWIW, I plan on running separate antennas just to avoid the signal loss and the cost of the splitter. GS antennas are pretty easy to build. I was thinking about glassing one into the bottom cowling.
 
Pierre I am not a fan of the Archer antenna. I had problems with an Archer wingtip Nav antenna in my -8 being trashed by HID lights. That caused me to install a cat whisker antenna on the belly under the empennage. That has worked extremely well for my SL30. Others have had good luck with Archer antennas so YMMV.

I am in the process of adding a G430W to the airplane, and intend to use the cat whisker for both the SL30 and G430. For that, I'll need the following:

Mini-Circuits ZFSC-2-1B BNC (this is in the SL30 installation manual, and available on eBay for cheap)

This device splits the nav antenna signal into 2 nav signals. One output from the Mini-Circuits device will go straight to the SL30 since it has an internal VOR/GS splitter. The other output will go to a Comant Diplexer VOR/GS
(CI-507) which will split the Nav signal into VOR and GS for the 430.

FWIW, back when I had a Beech A36 I had a G430, SL30, and one nav antenna. The avionics shop did the installation as I described above and it worked great.

See this thread:

http://www.vansairforce.com/community/showthread.php?t=26063&highlight=mini-circuits+ZFSC-2-1

Here's a link for the Mini-Circuits device. Looks like the current nomenclature for the BNC version is ZSFC-2-1+

http://www.minicircuits.com/pdfs/ZFSC-2-1+.pdf
 
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I've got an Archer Nav antenna in one of my wingtips. The signal is split with a Comant CI-1125 diplexer, to feed nav and G/S inputs on my GNS-430W and a Narco 122D. The ILS reception range is not great, but I do get a usable signal within about 15 nm of the runway end. I don't know what the outer limit of the usable range is, as I haven't had a good chance to really test it out yet.
 
Try swithching the antenae around...

Pierre,

Have you tried to switch nav antennae and receivers?

I plan to use cat whisker anntenna (with a diplexer) for the 430W and an archer wingtip antenna (without splitter/diplexer) for the SL-30.

This way the signal from the stronger antenna gets split by the diplexer and the signal from the weaker archer antenna doesn't (except inside the SL-30).
 
I am using a home made aluminum strip antenna (home made) with a splitter ( I believe it is CI-507) from spruce connected to my 430W. I have never lost LOC/GS signal as I have been practicing approaches a few times a week now. The antenna is in my wing tip.
 
Hi Pierre -

First I'd do is make a list of local VOR's in order from nearest to farthest (out to 100 miles or so). Go up to 5,000' or so (I know, that's pretty dang high for a cropduster, but believe me, you can still breath there! ;)), and tune in the VOR's until you can't get them - that will give you a good sense of how well the Archer is working.

If the VOR reception is acceptable (70 mile range or so?), then try a separate GS antenna - make one out of scrap Coax.

If the VOR reception is lousy, then address the Archer installation - do it exactly as Bob Archer says. If it still doesn't work, then go with a cat whisker....

That'd be my approach (been there, done that...)

Paul
 
Believe it or not....

Ironflight said:
Hi Pierre -

.....Go up to 5,000' or so (I know, that's pretty dang high for a cropduster, but believe me, you can still breath there! Paul
Click to expand...

....but I do fly at 8500-12,500 pretty routinely:) When I first get hypoxic is after a season at 5 feet and then go to 7500 or so....hard to breathe until I re-acclimatize:)

Thanks for all the suggestions, guys....we'll solve it yet,...on to Jekyll Island....woohooooo,



Best,
 
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