DME without a VOR

[Guest]

HiI have been adding some navigation aids to the database with voledit and have a few questions...A number of the navaids have a type of 24 which is a combined DME and NDB according to the database tutorials. How is this possible given that a DME and an NDB use different frequencies and receivers and only one frequency is possible in the database.I solved that problem by splitting the entry into two entries, one each for the NDB (type 8) and the DME (type 16). This worked OK and allowed me to tune both frequencies and get ADF and DME information.My problem is that if I tune NAV2 for the DME frequency, the RMI NAV2 needle swings to point at the DME. As DMEs don't provide directional information how do I make the DME behave properly and just provide distance information?Rich

[RandallR 444]

Rich,The NDB/DME combination you speak of has never worked - it's one of those things that we are trying to address in one of the next beta releases. In fact, until the Build 230 release, it was not possible to have the separate entry for the DME (16) actually read the distance from its location - it kept indicating the position of the allied VOR instead, so kudos to Rich for fixing this. The trick to making it work is to be sure that the VOR's frequency is entered in the DME's record in the Frequency field - then when you tune the VOR, the DME will come alive but indicate the distance from its own location.With that in mind, I doubt that this will work yet, but you might try a slight change in the frequency setting. DMEs are usually allied (not stand-alone) with a VOR or on some rare occasions with an NDB. You would tune the VOR or NDB and get the DME with it (no separate frequency). Have you tried setting the Frequency field in your Type 16 DME to the same frequency as the allied NDB? (Maybe you've already done this.) Supposedly, this would give you DME when you tuned the NDB - and you would get the proper distance since you placed both items at the same lat/lon.There may also be no way to stop the RMI read in Fly!II right now. Since the NDB/DME is a rarety (but something we want to work properly), I'm going to ask some IFR-experienced pilots how such navaids actually indicate. I can tell you that we're attempting to resolve the Type 24 DB problem in beta - the trick will be to get it to read from the NAV 2 DME window with only the ADF needle of the RMI swinging.

[Guest]

RandallThanks for replying.NBD/DME combinations are quite common in New Zealand.Let's say that the NBD and DME in question are on frequencies of 220.0 KHz and 110.00 MHz respectively and are not colocated but are 50 meters apart.Setting the ADF receiver to 220.0 KHz results in the ADF needle indicating the correct heading.Setting NAV2 to 110.00 MHz results in the DME reading correctly but also in the RMI reading the direction which it shouldn't do.I can't set the DME to the same frequency as the NDB as they are in different bands and the NDB signal is received by the ADF and the DME signal is received by NAV1 or NAV2.I tried deleting the NDB entry from the database and just leaving the DME entry. Tuning the NAV radios to the DME still resulted in the RMI showing a direction.I wasn't aware that any development work was being done on Fly! II, so I'll look forward to a fix for this sometime in the future. It's definitely better to have too much information rather than not enough.ThanksRich

[RandallR 444]

Rich,We are aware that there are places in the world that have stand-alone NDBs, though it is rare for the most part. Our first concern will be to get co-located NDB/DME combinations functional - this combination appears to be almost nonexistent in the States. There are some in Canada and even more in Europe - I have seen a few stand-alone DMEs in Europe.I will add your info to what the beta group is working on. It could be that we may be able to kill two birds with one stone - if we are able to activate the DME with NDB (and for that matter, DME with TAC!), we may be able to kill the RMI reference when an NDB is tuned in the NAV. It is certainly Rich's intention that any fix or adjustment be as real as possible and not a compromise to reality.