Here's one for all the experts.

denverpilot said:
. I’d want to get the ELT back in and properly installed before troubleshooting the Garmin. Revert all changed things first.
Click to expand...

That's kind of the plan right now. Also going to speak with the mechanic shortly about checking the GPS connections when he puts the ELT back.
 
The suggestions for cutting a bit off the ELT antenna is a very bad idea. The length is precision engineered for maximum efficiency, and any change will reduce your range and signal strength, at best, and reduce battery life at worst.

I know none of us plan to use the ELT, but if we do unexpectedly turn it on, we do hope it will broadcast a strong enough signal long enough to be rescued.

I have not set off my ELT, but have reported signals on 121.5 twice to ATC. Both had already been reported and search was under way for one, and the other was on an airport, hard landing.
 
geezer said:
The suggestions for cutting a bit off the ELT antenna is a very bad idea. The length is precision engineered for maximum efficiency, and any change will reduce your range and signal strength, at best, and reduce battery life at worst..
Click to expand...

"The length is precision engineered". No wire antenna is precision engineered. Do you know that almost all ELT manufacturers (ACK excepted) don't even have an antenna pattern range? Do you have a CLUE what the VSWR of that antenna is at the operating frequency or what VSWR even means? And if the finals couldn't load into a microscopically increased VSWR why battery life would be reduced? (I think it would be extended, but that's only after 60 years of antenna and RF circuit design.) Pray tell, geezer, what are your chops in antenna and VHF circuit design?

Jim
 
No chops at all, Jim, but the radio shop at work replaced any antenna that was damaged. They determined if the damage was significant by checking the SWR. They were the experts, but I do have a graduation certificate for radio repair, a 6 month, 8 hour a day school. Personally, I have only built one transmitter, and one receiver, both worked. I have repaired two way radios from around 2000 KH to 750 MH, and matched antenna impedance throughout all ranges. I have been amazed how much difference there is in the transmitted power if the antenna length and cable impedance are off. Design? NO, tune and repair, yes, I do know how it works. My radio operators license was issued more than 60 years ago.

I wonder about people who believe antenna length change is irrelevant to transmitter range, and manufacturers do not tune their radios for efficiency at the exact antenna wire length they fit to it..
 
In my case it was not anything that was suggested here. ELT and antenna replaced. Strobe was replaced. Moving the portable ADS-B unit helped temporarily, but it returned. Still had issues. The problem continued until I replaced the transponder. The transponder wasn't the problem either, nor was it the transponder antenna. The new transponder has ADS-B IN/OUT and the portable ADS-B IN unit hasn't been in the plane since, and have had zero issues.

No cutting of antennas, nothing like what was suggested. Just a portable device causing static on all freqs.

Experts. Ha.
 
I have some fun when I was putting my plane back together after the repairs. Nobody knows who did this but someone replaced the ELT to REMOTE wiring for the AK-450 (appears to have been just a regular phone cord). I replace the batteries in the ELT, update the sticker on the outside, do the snap test, and verify the transmission on another receiver. Great. Put it back in the plane and plug the remote in. WHOOP WHOOP WHOOP (fortunately, I still had the scanner set to 121.5). Unplug the remote. Hmm... Then I remember there's a battery in the remote. Go replace that. Still sets off the ELT. Pull the stupid remote out and look at the circuit (simple enough). Get out the ohm meter and start looking at it. Hey, this is wired up backward. Gosh darn it, I knew immediately. Phone wires by default come with the plugs installed mirror image. Cut the stupid thing off and put it back on flipped over. ARGH!

At least it wasn't as bad as finding the person who recovered the plane cut the wires off the autopilot roll servo plug right at the plug (if they'd done so a few inches back I could splice them), but off to the next airport to beg a new DB-9 plug. Don't have Radio Shack or computer stores to fall back on these days.
 
geezer said:
No chops at all, Jim, but the radio shop at work replaced any antenna that was damaged. They determined if the damage was significant by checking the SWR. They were the experts, but I do have a graduation certificate for radio repair, a 6 month, 8 hour a day school. Personally, I have only built one transmitter, and one receiver, both worked. I have repaired two way radios from around 2000 KH to 750 MH, and matched antenna impedance throughout all ranges. I have been amazed how much difference there is in the transmitted power if the antenna length and cable impedance are off. Design? NO, tune and repair, yes, I do know how it works. My radio operators license was issued more than 60 years ago.

I wonder about people who believe antenna length change is irrelevant to transmitter range, and manufacturers do not tune their radios for efficiency at the exact antenna wire length they fit to it..
Click to expand...
I refuse to have a battle of wits and experience with an unarmed man.

Jim
 
A friend asked me recently if I had any idea where the oil leak in his Jacobs radial powered Waco might be coming from...I answered ...most likely the engine :)...that is the only correct answer considering a hundred of possible places.

Lots of RF generating sources in the plane these days like cheap cigarette lighter plug usb adapters and such...good luck.
 
Was a battle about a dead technology poorly engineered 40 years ago, that’s unmonitored and dead, ever worth having?

Even the spiffy “new” stuff is outdated 90s junk that belongs in a trash can by now.

We find most people off of their cell phone tower history these days and have for a long time.

ELTs for the most part are just annoying airport ramp RF noisemakers.
 
Another RF source can be LED lights. A friend of mine purchased a new LED landing light only to find it generated so much noise the squelch had to be adjusted on his KX155.
 
Doug Reid said:
Another RF source can be LED lights. A friend of mine purchased a new LED landing light only to find it generated so much noise the squelch had to be adjusted on his KX155.
Click to expand...

Are you sure it’s the LED and not the pulse width modulation circuitry (dimmer/flashing) that’s causing it?
 
My friend recently spent a couple hundred dollars on an LED landing light...he immediately started having issues with the squelch on his com 1. We took a handheld and found the landing light would break the squelch on all channels if it was within 10 feet of the new light . No dimmer on landing light.
 
Technically nothing wrong with “the squelch” or the receiver. More noise received, squelch opens above the threshold it was set at.

Pedantic I know, but so many online discussions about squelch don’t seem to get that it’s just the setting on a signal strength gate. Signal strength below X turn off audio amplifier — is the old style stuff. A few newer ones in other radios way newer than any aviation stuff use some more advanced techniques.

And not picking on this thread, elsewhere it gets so much more messed up. “Squelch” confuses people.

“Low received signals audio output killer” just isn’t a good label. LOL
 
EdFred said:
In my case it was not anything that was suggested here. ELT and antenna replaced. Strobe was replaced. Moving the portable ADS-B unit helped temporarily, but it returned. Still had issues. The problem continued until I replaced the transponder. The transponder wasn't the problem either, nor was it the transponder antenna. The new transponder has ADS-B IN/OUT and the portable ADS-B IN unit hasn't been in the plane since, and have had zero issues.

No cutting of antennas, nothing like what was suggested. Just a portable device causing static on all freqs.

Experts. Ha.
Click to expand...

But the expert advice was to simply disconnect the ELT antenna to see if it removed the static. You didn't do that, and struck out on your own replacing parts. If you had, the expert advisor likely would have inquired if there was any other TX/RX device in the airplane, probably leading to the identification of the portable ADS-B receiver as the source of the static.
 
3393RP said:
But the expert advice was to simply disconnect the ELT antenna to see if it removed the static. You didn't do that, and struck out on your own replacing parts. If you had, the expert advisor likely would have inquired if there was any other TX/RX device in the airplane, probably leading to the identification of the portable ADS-B receiver as the source of the static.
Click to expand...

That was initially done, and it didn't solve the issue. The replacing of the parts had nothing to do with the static. The ELT was to upgrade from 121.5 only, the strobe because it crapped out, and the transponder for the ADS-B mandate.
 
You must log in or register to reply here.
Back
Top