New Avidyne problems, pirep

[LANCECASPER]

5 hours ago, chriscalandro said:

Looks like you missed the part where mine was a COMBINATION of the radio not liking the old wire AND the original radio having a fault on the com card...

 

I still don't think that a quality radio should have that much degraded quality from RG58 to RG400.

"Not liking the old wiring" must be a nice way of saying "I didn't follow the installation instructions".  

[MikeOH]

Just now, LANCECASPER said:

"Not liking the old wiring" must be a nice way of saying "I didn't follow the installation instructions".  

@LANCECASPER

LOL!  You wrote what I was thinking!

[chriscalandro]

12 hours ago, LANCECASPER said:

"Not liking the old wiring" must be a nice way of saying "I didn't follow the installation instructions".  

It’s not a slide on replacement when you have to replace wiring to make it functional. 

[LANCECASPER]

14 minutes ago, chriscalandro said:

It’s not a slide on replacement when you have to replace wiring to make it functional. 

Of course that has absolutely nothing to do with your installation, which was not a slide-in replacement, but a new installation with re-used coaxial, which was later replaced with rg-400.

No company is perfect, including Avidyne or Garmin. They stepped up and did their part. We all make mistakes, it's all part of learning. Not being able to admit that part of it was your fault is what everyone else sees except you.

 

[dzeleski]

22 minutes ago, chriscalandro said:

It’s not a slide on replacement when you have to replace wiring to make it functional. 

The instructions say what is required for it to be a slide in replacement, otherwise its not. Its pretty clear. Mine required a new antenna for WAAS, thankfully the previous 430 installer used RG400 everywhere otherwise that would have been needed as well.

[LANCECASPER]

1 hour ago, chriscalandro said:

Again, the original radio WAS bad. 
 

I didn’t say I had a problem changing the cable. I believe at the time Avidyne didn’t believe the cable was creating that big of an issue either. 
 

what I AM saying as that with a good quality transmit driver, a 12ft rg58 run shouldn’t not have created that much of a problem. 
 

Because again, the original radio had a fault on the com board. 
 

Where did you get your electrical engineering degree from that you feel it’s appropriate to make such a dick comment? As this thread shows, I’m clearly not the only one to come across this, and my experience helped someone else experiencing exactly the same thing. 
 

People wonder why generally I stopped offering public advice. It’s people like you. Now go fuck off and let this thread sit, Because the next person to install an IFD4x/5x in their plane as a retrofit or slide in may very well have the same issue as the 2 of us already had in the time period of the last couple of months. 
 

@GeeGeeBee I’m glad this thread helped solve your problem. I’m an experienced electrical engineer with some experience in transmitters. If you have any questions please reach out privately. 

This reply sums you up perfectly.

[Marauder]

Just a little color commentary (and BTW,  I work around some serious electrical engineers  ). I have no experience with the Avidyne products but did have start up issues with a Garmin 650. The Garmin replaced a MX-170B slide in replacement. My Garmin had a series of firmware updates in the first couple of years to do deal with open squelch issues. I also noted than the range of the Garmin was less than than both the MX-170B it replaced and even the Narco 12D+ that was in the panel. I suspect some of the range issues had to do with them jacking up the squelch starting point. I am not sure if there are manufacturing changes (ex. surface mount versus through hole components, quality of components, etc.) to the modern avionics that make them more suspect to interference issues, but it sure looked that way. I can personally acknowledge that my Garmin 650 certainly didn't like the JPI 900's remote indicator. Nor did my Vertex handheld.  

As for the installation of these units. Most shops will not replace the RG58 unless you specifically tell them to. RG400 is expensive and it is a pain to run new wiring. I found replacing all of my RG58 came with some benefits, the most notable was that it replaced damaged wiring! When I found the damage wire, I personally ran all new RG400 for both radios. I am not an expert on making the BNC connectors, so I let the avionics shop make them. After the new wire had their connectors added, the plane was returned to me. Guess what, I had an issue with one of the VORs not receiving at distance. Found a bad connector. When I did an SWR on the rest of them, I found one of the Com runs also had a bad connector. So, installation quality can certainly play a role, if not be the main culprit. 

I have learned that any avionic installation can and most likely will cause me angst.

Something you think shouldn't happen when 5 digit checks are involved.  

Edited March 25, 2021 by Marauder

[chriscalandro]

Anybody else with this issue, when you find this thread, PM me.  I'll be happy to help privately.

[GeeGeeBee]

Just my 1/50th of a dollar's worth - while mistakes and miscommunication (and assumptions) were made by several parties on my installation, I mostly blame the shop that upgraded the Garmin 430 to 430W (well before I owned this aircraft).  During that upgrade, Garmin required the installer to change the antenna (which was done) and the coax to a low-loss type like RG400 or RG142B (those are specifically mentioned in the Garmin install manual), which they failed to do.  Now, should my avionics shop that installed the IFD440 have noted that it was the wrong cable?  Yes.  We all know the old saying about "assume"...

In the end, Avidyne came through with flying colors and I am happy to recommend them.

[N201MKTurbo]

After dealing with these issues, The Avidyne works adequately with the finest coax and perfect antennas. The KX-155 works better with old RG-58 and rusty antennas than the Avidyne with perfect parts. With the RG-400 and perfect antennas, the Kx-155 will far out perform the Avidyne. 

[carusoam]

Great follow-up GGB!

Thanks for sharing it...

Best regards,

-a-

[LANCECASPER]

18 hours ago, N201MKTurbo said:

The Avidyne works adequately with the finest coax and perfect antennas. 

Which would be the coax and antennas that they specify in their installation manual. This thread dealt with two complaints where these weren't used. 

In the 90's an older pilot was flying with me in a new Mooney with King Silver Crown radios, which I thought were the best thing since sliced bread. He made the comment that they didn't sound nearly as good as the old Narco radios in his 182. Time marches on and the tendency is to remember the good ol' days and to compare apples to oranges. Avionics have changed a lot and I agree that on the newer generation of radios (Garmin, Avidyne) the sound isn't as rich, but try putting in a 10 leg flight plan on a Narco Mark 12 or a King 170B or even a Garmin 530, although the latter is possible, with enough patience. The newer equipment is a lot more intuitive but it is engineered to a certain spec that must be followed. Whether it's better or worse is in the eyes of the beholder.  @Marauder's post of the wiring paints a picture showing that the old poorly shielded wiring does not mix well with the new generation, whether it's Avidyne or Garmin. We all want the best installation for the least money. Usually the lowest quote isn't going to include running new everything, unless it specifies that. 

[N201MKTurbo]

1 hour ago, LANCECASPER said:

Which would be the coax and antennas that they specify in their installation manual. This thread dealt with two complaints where these weren't used. 

In the 90's an older pilot was flying with me in a new Mooney with King Silver Crown radios, which I thought were the best thing since sliced bread. He made the comment that they didn't sound nearly as good as the old Narco radios in his 182. Time marches on and the tendency is to remember the good ol' days and to compare apples to oranges. Avionics have changed a lot and I agree that on the newer generation of radios (Garmin, Avidyne) the sound isn't as rich, but try putting in a 10 leg flight plan on a Narco Mark 12 or a King 170B or even a Garmin 530, although the latter is possible, with enough patience. The newer equipment is a lot more intuitive but it is engineered to a certain spec that must be followed. Whether it's better or worse is in the eyes of the beholder.  @Marauder's post of the wiring paints a picture showing that the old poorly shielded wiring does not mix well with the new generation, whether it's Avidyne or Garmin. We all want the best installation for the least money. Usually the lowest quote isn't going to include running new everything, unless it specifies that. 

I’m talking about the radio, not the navigator. It is the difference between a real radio and a SDR. One is is a high quality communications device and the other is a piece of software.

They use an SDR, not because it is better, but because it is cheaper.

https://en.wikipedia.org/wiki/Software-defined_radio

Edited April 1, 2021 by N201MKTurbo

[EricJ]

5 hours ago, N201MKTurbo said:

I’m talking about the radio, not the navigator. It is the difference between a real radio and a SDR. One is is a high quality communications device and the other is a piece of software.

They use an SDR, not because it is better, but because it is cheaper.

https://en.wikipedia.org/wiki/Software-defined_radio

SDRs can, and usually do, improve performance substantially over analog processing.   Potentially only an LNA, filter, and data converter (ADC) are needed in the receiver, which minimizes distortion compared to a tuner or full rf receiver chain, etc.    Regardless, there's a reason the RF chain gets smaller and smaller and does less and less as time goes on and the processes move to the digital domain, for pretty much any radio comm system.

IMHO the only SDR or digital receiver that's not better than analog is one that is either poorly designed or poorly implemented.

The Avidynes appear to be somewhat sensitive to installation.    My airplane still has the original 7 comm antennas and the original coax, and my IFD540 comm works way better than the KX-170Bs that were in there before, or the MX170C next to it.  So it's not a universal problem with old cables or antennas, just some particular installations.  I wish it was better known what the exact issues are, but it appears to me that the Avidyne radios are very good, especially compared to older stuff, just with some installation sensitivities that aren't yet fully understood.

 

[N201MKTurbo]

32 minutes ago, EricJ said:

SDRs can, and usually do, improve performance substantially over analog processing.   Potentially only an LNA, filter, and data converter (ADC) are needed in the receiver, which minimizes distortion compared to a tuner or full rf receiver chain, etc.    Regardless, there's a reason the RF chain gets smaller and smaller and does less and less as time goes on and the processes move to the digital domain, for pretty much any radio comm system.

IMHO the only SDR or digital receiver that's not better than analog is one that is either poorly designed or poorly implemented.

The Avidynes appear to be somewhat sensitive to installation.    My airplane still has the original 7 comm antennas and the original coax, and my IFD540 comm works way better than the KX-170Bs that were in there before, or the MX170C next to it.  So it's not a universal problem with old cables or antennas, just some particular installations.  I wish it was better known what the exact issues are, but it appears to me that the Avidyne radios are very good, especially compared to older stuff, just with some installation sensitivities that aren't yet fully understood.

 

So, the LNA is critical to getting a usable signal to the A/D. But The LNA is an analog circuit. Limiting the bandwidth within the LNA can go a long way to improving the noise figure of the signal and down converting it can go a long way to reducing the computing power needed for the DSP and ADC. Or course, this is all moot, we don’t know exactly what Avidyne did.

[EricJ]

1 hour ago, N201MKTurbo said:

So, the LNA is critical to getting a usable signal to the A/D. But The LNA is an analog circuit. Limiting the bandwidth within the LNA can go a long way to improving the noise figure of the signal and down converting it can go a long way to reducing the computing power needed for the DSP and ADC. Or course, this is all moot, we don’t know exactly what Avidyne did.

All of that is true on any radio, regardless of SDR/digital/or analog.   The LNA is the thing you can't avoid having on nearly any receiver.   Analog downconversion is only necessary/useful if the ADC or band filtering are limiting performance, or if you are limited in how much digital processing you can do.   For VHF systems these days those limitations are pretty easy to overcome.   We were doing 70MHz sampled IF systems thirty years ago and getting performance within 0.3 dB of theoretical limits, and it's much, much easier these days than it was then.   I've done SDR digital satellite receivers with very simple hardware in L-band (1.5GHz), also with very high performance.   Making an SDR VHF AM voice radio ranks among the easier things to do well in an SDR, and likely improve performance significantly along the way.   I don't think that's where the problems lie that people are having with the Avidynes.   I wish we all knew where the actual issues are, but I think it unlikely that it has to do with the SDR.   I'd be surprised if the Garmin receivers aren't SDR also, and if they're not they should be. 

 

[chriscalandro]

19 hours ago, EricJ said:

 My airplane still has the original 7 comm antennas and the original coax, and my IFD540 comm works way better than the KX-170Bs that were in there before, or the MX170C next to it.  So it's not a universal problem with old cables or antennas, just some particular installations. 

YoU dIDnT FoLlOw ThE iNsTaLl MaNuAl

[LANCECASPER]

23 hours ago, EricJ said:

The Avidynes appear to be somewhat sensitive to installation.    My airplane still has the original 7 comm antennas and the original coax, and my IFD540 comm works way better than the KX-170Bs that were in there before, or the MX170C next to it.  So it's not a universal problem with old cables or antennas, just some particular installations.  I wish it was better known what the exact issues are, but it appears to me that the Avidyne radios are very good, especially compared to older stuff, just with some installation sensitivities that aren't yet fully understood.

 

Having everything work out using the old cables, coax and antennas reminds me of this story from Japan:

 

A 22-year-old man “plagued by a compulsion to wash hundreds of times a day” accidentally “performed successful neurosurgery on himself” while attempting suicide, reports the New York Daily News. Distressed over his obsessive-compulsive behavior, he “put a .22-caliber rifle in his mouth and fired a shot that hit the left front lobe of his brain,” explains the News. Instead of killing himself, the young man actually removed the portion of the brain that is believed to control obsessive behavior, reported Dr. Leslie Solyom in the British Journal of Psychiatry. Freed from his compulsive behavior, the individual has a new job and currently attends college.

 

The point of the story is  . . . . even though it worked out very well for him, most people wouldn't recommend that option.

 

[EricJ]

4 hours ago, LANCECASPER said:

Having everything work out using the old cables, coax and antennas reminds me of this story from Japan:

Since the IFDs are slide-in replacements for GNS 430/530s, I suspect that many if not most installations use existing cables and antennas.   Since people don't complain about it when it works, and there are quite a few installations out there, I suspect that the number that have trouble are small compared to total installations.   It does suck for the people who have trouble, just like with anything, but it doesn't seem to be a universal problem.

The install manual mostly just says the cable needs to be 50 Ohms and the VSWR not worse than 2:1 (which is fairly generous in my experience).   I do suspect that some aged installations may not meet those, but I don't know whether that correlates with the problem installations.

 

Edited April 2, 2021 by EricJ

[LANCECASPER]

I agree.

I did slide-in replacements on a 2000 Mooney Ovation 2 - first with a IFD540 in 2014 and then a IFD440 in 2015, both with zero problems. The original wiring was put in at the factory, so a better chance it was done right. The slide-in ones where the 530 or 430 was  installed replacing an old radio from the 70's  would be more suspect.