ADF GOAT?

Arnold

Cleared for Takeoff
Joined
Mar 8, 2005
Messages
1,480
Location
Philadelphia Area
Display Name

Display name:
Arnold
I vote Bendix T12. It was rock solid, nearly immune to atmospheric interference and reliable. Your thoughts?

Bendix T12.jpg

Looks can be deceiving, these boxes got me home innumerable times in all types of weather.
 
Our NARCO AT-150 spent most of its time in the shop, having expensive voodoo done to it. Before I sold the plane I took it out and put it on a shelf.
 
Just came across this beauty today. Have not had the opportunity to play with it yet...

20200115_174549.jpg
 
I remember flying with one of those once but I don't remember which airplane. Weird how Narco pioneered this "all in one" design but King ended up producing so many KR-86 units which were nowhere as good.
 
Are those signal strength meters on those?

If you're flying an ADF approach and the meter goes to zero, what's the move? Fly missed and get back up to an airway on the VOR?
 
Good Question. Yes they are signal strength meters. The normal procedure is to monitor the ID while navigating. If the ID goes away a missed approach is required, or if you are using it for en-route nav then you fall back to dead reckoning. Using the signal strength meter has two practical issues. First, one would need to add it to the scan. That is generally impractical unless you have an "all in one" box like that Narco above. Second you don't have anyway to tell if the meter failed or the NDB failed. Hence, listen to the ID.
 
I remember flying with one of those once but I don't remember which airplane. Weird how Narco pioneered this "all in one" design but King ended up producing so many KR-86 units which were nowhere as good.

The same airplane also has one of these. Have to admit that I had to do some research on this one. Have not seen one before. :)

20200116_090012.jpg
 
Good Question. Yes they are signal strength meters. The normal procedure is to monitor the ID while navigating. If the ID goes away a missed approach is required, or if you are using it for en-route nav then you fall back to dead reckoning. Using the signal strength meter has two practical issues. First, one would need to add it to the scan. That is generally impractical unless you have an "all in one" box like that Narco above. Second you don't have anyway to tell if the meter failed or the NDB failed. Hence, listen to the ID.

Exactly this... Have to admit that question did stump me for a moment. It has been a while since I have done an ADF approach with an actual ADF. Reason it stumped me is because I have never bothered to look at the meter. If I was still able to hear the station ID, I carried on...

Although most of the time spent listening to the ADF was with it tuned to a Rock and Roll station...

ADF... The original XM.

;)
 
It is what is made Bill Lear famous. Lear ADF.
avenger_adf14_009_variant1.jpg
 
I’m going to guess anyone posting on this thread is >60 years old, the younger crowd will start a “which iPad was the GOAT”
 
Because Loran was originally created for ships, the best and highest use for this box is ... a boat anchor.

Haha... and only for a rather small boat at that. I am surprised it is actually still installed.

We did have LORAN on my first ship but even back then (mid-80s) it was falling out of favor.
 
I have used Eskimo ADF but I ain't never heard of GOAT ADF before....
 
The Cessna 300 radios we not very good, except their ADF was really good.
 
I donated an RNAV R50 to the College Park Aviation Museum. Previously I flew a lot using the previous model, and became quite adept in combining its capabilities with the VOR system and ADF stations to make incredibly long distance transitions from an airway to an ILS. My ADF was weak, but the LORAN knew exactly where it was, so I could turn inbound for the outer marker from more than twice the distance the ADF actually detected it.

I was not happy that the government terminated the LORAN system.

I created descent profiles matching the ILS, and the desired altitude matched the actual when I was on the glide slope, with the deviation indicator matching the CDI needle.

It calculated and displayed the desired descent profile to pattern altitude with precision, and adjusted it if your ground speed changed, so you arrived at the pattern right on altitude. The same could be done to the intercept of an ILS or VOR approach.

The distance to the nav way point was continuously displayed, just like DME.

Just like using GPS today, I filed direct to airports 300 or more miles away, and flew the great circle (shortest) route there. Controllers did not have any problem with that, and off airways, there was little traffic to watch for. The distance to an airport was not important, the database had every airport, VOR, NDB, and seaplane base in North America, all instantly accessible. It also had the MEA for every part of the USA, and displayed it while the navigation was active.

All the critical data for each airport was also in the database, altitude, runways, and frequencies.

On topic, that was the longest range ADF I ever used.
 
  • Like
Reactions: smv
Good Question. Yes they are signal strength meters. The normal procedure is to monitor the ID while navigating. If the ID goes away a missed approach is required, or if you are using it for en-route nav then you fall back to dead reckoning. Using the signal strength meter has two practical issues. First, one would need to add it to the scan. That is generally impractical unless you have an "all in one" box like that Narco above. Second you don't have anyway to tell if the meter failed or the NDB failed. Hence, listen to the ID.

Thanks! Makes sense. :D
 
Are those signal strength meters on those?

If you're flying an ADF approach and the meter goes to zero, what's the move? Fly missed and get back up to an airway on the VOR?
Use the GPS on your phone, of course.
 
I did my best to keep my Collins ADF in my Lance. But during the Great Panel Upgrade of 2019, it didn't survive.

However, weeks before the Great Panel Upgrade, the Collins unit died. This saved me from having paid them to install my first piece of dead equipment. The avionics shop warned me it would die at any point, and probably sooner than later, and would be costly to repair.

My dad's Lance has an ADF, and I got to play with them beginning early in my flying. I've enjoyed ADF approaches, and find them pretty intuitive.
 
Looks can be deceiving, these boxes got me home innumerable times in all types of weather.
Would love to know how to explain "bank error", if you happen to be able to do it. I've been unable to convince pilots of the need for reading the RBI while straight and level. They argue modern avionics don't have the error, but I'm not convinced of that. I could be wrong, dunno. :dunno:
 
I've not heard of bank error with regard to ADF used for NDB approaches or NDB navigation. However, I can imagine a situation where you have a gyro stabilized compass card, sort of a poor man's RMI where the card would be subject to precession errors the way a DG is. All the RMIs I used were slaved to the same source of magnetic information that drove the HSI. Note the vast majority of my NDB approaches were shot either with a fixed compass card or one that had to be rotated by hand which I could not be bothered to do. Easier to just keep the picture in your head and not bother with twiddling knobs.
 
I've not heard of bank error with regard to ADF used for NDB approaches or NDB navigation. However, I can imagine a situation where you have a gyro stabilized compass card, sort of a poor man's RMI where the card would be subject to precession errors the way a DG is. All the RMIs I used were slaved to the same source of magnetic information that drove the HSI. Note the vast majority of my NDB approaches were shot either with a fixed compass card or one that had to be rotated by hand which I could not be bothered to do. Easier to just keep the picture in your head and not bother with twiddling knobs.
I'm referring to this error: https://www.av8n.com/fly/adf-errors.htm

I'd like to be able to explain it in a way that even I can understand it. This explanation doesn't cut the mustard.
 
I love/loved ADF.
I had a database of the location of every AM radio station in the country. Turn on ADF and follow the music.
I've wondered why such a database couldn't be used to calculate a position like GPS can. If it were possible to scan a number of stations simultaneously or in very short order an algorithm could deduce where you are within reasonable accuracy. Might not be good enough to shoot a bomb through a car window, but close enough to shoot an approach to a runway if GPS goes out.
 
I'm referring to this error: https://www.av8n.com/fly/adf-errors.htm

I'd like to be able to explain it in a way that even I can understand it. This explanation doesn't cut the mustard.

The joys of electro mechanics. Disclaimer - I'm not an engineer or physicist. This explanation is simply a way to visualize the problem and does not accurately describe or solve it. The only two times the signal is not subject to error is when it is directly in front/behind the aircraft and when it is directly abeam (I believe this is b/c of the antenna configuration). Let's call that "straight on." Any time you are not straight on there will be an error because of the physics of elctro magnetic (EM) propagation - don't ask me how that works. This is not the technical answer, but when you are banking and not straight on you are subject to an EM crosswind. Just like landing with a crosswind, or banking the aircraft, the relevant vector (wind, lift, EM) will include an direct component and a cross component, that is it will have two components perpendicular to each other. So turning reduces the direct (true) signal and this reduces the EM accuracy at the ADF and results in an error. Very small at low bank angles, and very large at large bank angles as the bank angle changes the portion of the EM making it to the box in the airplane. Either I knew this at one time and forgot, or I never learned it. In light aircraft of the time I was flying instruments for a living, all standard rate turns were all around 15 degrees of bank. Any errors were minimal. I hope this helps.
 
I've wondered why such a database couldn't be used to calculate a position like GPS can. If it were possible to scan a number of stations simultaneously or in very short order an algorithm could deduce where you are within reasonable accuracy. Might not be good enough to shoot a bomb through a car window, but close enough to shoot an approach to a runway if GPS goes out.

By the time technology reached electronic database in a box sophistication the ADF was already virtually obsolete. NDBs were primarily used for approaches to low volume airports, compass locators (very useful) and some NDB airways in Alaska, Canada and Northern Maine (I flew this one). VOR, DME, ILS for everything else. Note also that if you want to use a station for navigation you must have control over it. FAA issued NDBs were monitored and maintained and flight tested. WBZ in Boston was not. Europe used to have a fair number of NDB/DME approaches. They had straight in mins around 300/1. I shot one once and it put me where I needed to be. Then again I had an RMI so its not like I had to think or anything.
 
Shepherd said:
I love/loved ADF.
I had a database of the location of every AM radio station in the country. Turn on ADF and follow the music.

Dtuuri said:
I've wondered why such a database couldn't be used to calculate a position like GPS can. If it were possible to scan a number of stations simultaneously or in very short order an algorithm could deduce where you are within reasonable accuracy.

Before LORAN or GPS, the Coast Guard created a series of coastal low frequency transmitters, usually in groups of 6. The group would share the same frequency, and transmit for exactly one minute, with their code, then go silent for five minutes. Ships would tune to the nearest group, and record the angle and ID of each, and then do a 6 line position plot. This gave a very confident fix on their chart, and repeatable as often as desired. Many of the transmitters were co located with lighthouses, visual references in good weather, if close to shore.

Aviators along the coast could also use them. The note with the frequency and code identifier was H+5&EV 6, or similar, meaning that station broadcast 5 minutes after the hour, and repeated every 6 minutes later. Tracking to the transmitter, you only observed the ADF pointer while the correct code was being heard on the speaker or headphones. I tracked the Cape Hatteras signal to First Flight at Kitty Hawk.

In my early days, with a single VHF and ADF, I would identify Victor Airway turning points by tuning an AM radio station nearby, and determining what the angle would be when I hit the turning point. When we added another NavCom, that became unnecessary.
 
I liked ADF too...and have fond memories of a narco like in smv's picture. I think that might have been in the apache I flew for a bit, but not sure about that....
anyway, I just love the simplicity of it.

I’m going to guess anyone posting on this thread is >60 years old, the younger crowd will start a “which iPad was the GOAT”
not over 60....but North of 50..... but what do you folks mean by "GOAT"?
 
For the serious ADF flyer

upload_2020-1-19_2-14-56.jpeg
 

Attachments

  • upload_2020-1-19_2-13-41.jpeg
    upload_2020-1-19_2-13-41.jpeg
    175.1 KB · Views: 5
The Cessna 400 radios were pretty decent radios. The 300 were not. I flew my ATP multi in an aircraft with these radios and I don't remember anything wrong with them.
 
I'm assuming goat means Greatest Of All Time? Not this:

fs.jpg
 
Back
Top