And before ADF there was MDF

https://upload.wikimedia.org/wikiped...io_compass.jpg

I guess that's a US/not-US thing. In the US it is a problem, or at least soon will be, because all the NDB and VOR approaches are disappearing. Very soon there will only be GPS (RNAV) and ILS, so if you don't have GPS you're going to be pretty limited where you go. For training purposes there's nothing to stop you flying an old, decommissioned VOR approach under the hood in VFR (for as long as the VOR is there, which may not be very long). But if you actually want to fly around on an IFR flight plan, you need GPS.

Quote from India Four Two:
"MW AM radio - that takes me back. Who says nostalgia ain't what it used to be!
Radio Luxemburg 208
Radio Caroline 199
Radio London 266"

You had me foxed on those BS numbers for a moment - then I realised they were not frequencies, but wave-lengths in metres! Don't think you'll find wave-lengths on the dial or frequency-selector of any airborne ADF receiver, but I stand to be corrected.

In case it hasn't been mentioned earlier, the landlubber's MW (medium-wave) and LW (long-wave) are aviators' MF (medium frequency, i.e., 301 kHz - 3000 kHz) and LF (low-frequency, i.e., 31 kHz - 300 kHz) respectively.

Your quoted Radio Luxembourg wave-length of 208 metres MW would equate to a frequency of about 1442 kHz (300,000 divided by 208). However, all MW frequencies now have to be divisible by 9, so it was on 1440 kHz, I believe.**

Don't forget Droitwich, which has its big, powerful long-wave antenna-array (for BBC Radio 4 LW) broadcasting on 198 kHz (used to be 200 kHz in the days when I was using it for navigation). You can receive it well down into France. I believe France itself, sadly, is shutting down its LW broadcasts.

**(EDIT) I now see this (Radio Luxembourg) transmission shut down at the end of 1991...

Chris, it was a test to see if anyone was paying attention! ;)

No, I could never forget Droitwich which of course was 1500 m on the valve radios I grew up with.

Here in North America, all AM radio stations use kHz, which makes it much easier to tune them on an ADF. :)

The T-12C was a sought-after unit for flying around the Australian bush. Generally, it locked on to the NDB at greater range than many other (even newer) units. When I bought my first aircraft, a C150F, I was delighted to find a T-12C, even though it was an antique by the time I acquired the aircraft in the 1980s. With only standard tanks on the very modestly equipped C150, a sensitive and reliable ADF able to tune both AM broadcast stations and NDBs gave me a tiny bit of redundancy in the often challenging bush VFR navigation task.

In answer to an earlier question, the 'CW' setting on the Bendix is essentially the same as the 'BFO' setting on some other units. Both permit the accurate tuning of the AM carrier, or the reception of keyed CW (morse) transmissions. There's a bit more to it than that in terms of the history of direction finding, but for most pilots that's close enough.

The aircraft in which I did my initial training also had a T-12C (it having been retrofitted to replace a hopeless Cessna ADF). In that situation its main use was to allow the CFI to listen to the cricket whilst inflicting navigational pain on the student.

Crab -
Bendix T-12-C User Manual here - Bendix ADF-T-12C Auto. Direct. Finder Pilot's Manual ...... Download ten bucks.
(PS Maintenance manual available elsewhere for $160) ........ LFH

.........

Quote from India Four Two:
"No, I could never forget Droitwich which of course was 1500 m on the valve radios I grew up with."

Yep, 200 kHz until new rules insisted on LW BS frequencies being divisible by 3 - hence the 198 kHz today.

I see on line that the RTE LW BS on 252 kHz from the Clarkson transmitter in County Meath, Ireland was due to close down this month. Just tried to tune it without success, so perhaps that's already happened. (Used to be Atlantic 252: see ETOPS post #10.)