celesteh89
Filing Flight Plan
What are DME channels? And are they relevant for pilots or just a number at the chart? (e.g. Ch xx at the VOR/DME legend)
DME Channel
- Thread starter celesteh89
- Start date
roncachamp
Final Approach
They're irrelevant to pilots using VHF navigation receivers. DME operates on UHF, the proper DME channel is set when you select the paired VHF frequency. If you had a TACAN receiver you'd dial in the charted DME channel.
Steve has it right. DME operates on UHF and each channel is two frequencies, one that the DME transmitter in the aircraft uses and one that the DME transmitter in the ground station (TACAN, VOR/DME, LOC/DME, VORTAC) uses. Attached is a chart of the channels, the frequencies involved, and the paired VHF frequency that non-military pilots use.
http://www.e-haf.org/PublicFTP/320/UPLOAD_FOLDER/Charts/VOR Frequencies to TACAN Channel list.pdf
http://www.e-haf.org/PublicFTP/320/UPLOAD_FOLDER/Charts/VOR Frequencies to TACAN Channel list.pdf
celesteh89
Filing Flight Plan
Thanks for the repply 
dmspilot
Final Approach
- Joined
- Oct 20, 2006
- Messages
- 5,856
- Display Name
Display name:
DISPLAY NAME
The standalone DME's I've used, you tune in the associated VOR frequency.
Even standalone DMEs in nearly all civil aircraft have the channel selected by dialing in the paired VHF frequency. I've never seen otherwise in 35 years of flying.
roncachamp
Final Approach
TACAN units typically use channel numbers. THere's no "VHF" side to TACAN.
Here's a typical TACAN-only unit
You dial in the numeric part of the channel number with the two knobs and then select either X or Y with the toggle switch. The T/R position of the switch enables the DME (transmitter) portion, where RECV gives you azimuth only.
Last edited:
roncachamp
Final Approach
TACAN units typically use channel numbers. THere's no "VHF" side to TACAN.
Here's a typical TACAN-only unit
You dial in the numeric part of the channel number with the two knobs and then select either X or Y with the toggle switch. The T/R position of the switch enables the DME (transmitter) portion, where RECV gives you azimuth only.
That's all true and consistent with what I wrote.
You said "If you have a standalone DME, VOR/DME, or TACAN..."
I've never seen a TACAN unit that uses the paired frequencies. Only commercial DME.
I've never seen a TACAN unit that uses the paired frequencies. Only commercial DME.
roncachamp
Final Approach
You can see one by clicking on TACAN in post #8.
That brings up a picture of a chart not a standalone TACAN unit.
roncachamp
Final Approach
The chart shows Deering TACAN. It's not a VORTAC, it's not a VOR/DME, it's a standalone TACAN. There is nothing there that is producing a signal on 114.9 MHz, choosing that frequency actually selects the TACAN channel.
I see, you're talking about the navigation facility where Witmo and I are talking about the navigation equipment.
jonnyjetprop
Cleared for Takeoff
What's the X and Y for?
TACAN units typically use channel numbers. THere's no "VHF" side to TACAN.
Here's a typical TACAN-only unit
You dial in the numeric part of the channel number with the two knobs and then select either X or Y with the toggle switch. The T/R position of the switch enables the DME (transmitter) portion, where RECV gives you azimuth only.
BillTIZ
Final Approach
Agreed, and the civil users gets distance only when he tunes 114.9 on his civil DME box in the cockpit.
The X and Y along with the digits form the channel number. The receive frequency for the TACAN changes when you select X or Y but the transmit frequency is the same for either one.
TRANSMIT FREQ = 1024MHz + channel number.
RECEIVE FREQ FOR X CHNANELS = 961 + channel_number
RECEIVE FREQ FOR Y CHANNELS = 1087 + channel number
TRANSMIT FREQ = 1024MHz + channel number.
RECEIVE FREQ FOR X CHNANELS = 961 + channel_number
RECEIVE FREQ FOR Y CHANNELS = 1087 + channel number