How far away from a VOR can you pick up its signal.
I am planning a cross country flight in a Cessna 172 with DME. This xc is suppose to make good use of VOR navigation, but one leg consists of a 75 mile leg. Will I be able to pick up the VOR at 75 miles away?

75 miles would be pushing it at lower altitudes. It would depend on the type of VOR, your altitude, and any terrain anomalies in the area. The AIM has a chapter on NAVAIDS which describes the exact service volume of each type at various altitudes.

Basically you would need oxygen or pressurization to get high enough to get reception at that range.

Also check your charts and notams for anomolies particular to that VOR.

Cessna 172 - plan on 40 NM unless it's a terminal VOR. Keep in mind that's a guarantee...you COULD pick it up farther away (75 NM is pushing it though). DME could be received farther away, but again, in your case...figure 40. You might get intermittent numbers between 60-40. You can find the above information in the very first chapter of the AIM.

Lastly - aren't you posting as an ERJ pilot???

I agree with rickair. According to the AIM (1-1-8), or page 687:

High altitude VOR
If u are below 14,500, you should receive a signal atleast 40nm away. Again, depends on terrain and such like rickair said.

Low altitude VOR
40nm

Terminal VOR
25nm

Again, these are absolute minimums. You will often get them at larger distances, but a good plan would be to plan 40-50nm.

As for DME, it works depending on signal strength. Generally, airliners have stronger signals than Cessna's, and they get first priority at the greatest distance. At night, or when there is little traffic, you can usually pick up DME at a further distance.
A friend of mine who was flying Angel Flight on 9/11 told me a story about how erie it was to be flying with hardly anyone in the sky. He said he was downright surprised when he picked up a DME station in a cessna 182 at over 120nm. No airplanes = no signal competition = DME at a great distance.

I hope this clears this up for u.

I am not an ERJ pilot. ERJ is an abbreviation. It was suppose to be a joke, but I don't think anyone has caught on yet.

I am not an ERJ pilot, and I do not pretend to be one.

Care to explain? I know I still don't get it.

I'm confused too...just goin' on what was written underneath your picture...

Max range on DME is usually 199 NM. This is NOT based on signal strength like almost all other NAV systems. Since the DME receiver times the pulses to determine range, it is programmed to disregard return pulses that take too long to come back...that "time out" is usually set to a time-interval corresponding to 199NM distance (in most common GA recievers). Some DME receivers were built with time-out's at 100, 300, and maybe other ranges too.

There are several reasons for this, one of which it to keep high-altitude airplanes from getting conflicting data from every DME ground station sharing a certain frequency in say, western north america. Presumable not too many pilots need to reference a navaid that far away, there should be plenty that are closer.

However, for lower altitude pilots the line-of-sight problem and signal strength are likely to reduce the actual effective range of DME below 199NM. You would have no problem getting DME at 199NM in a cessna if you are at a reasonable altitude and the the VOR was on a mountain (JLI for example).

What's a VOR?

Get GPS.

Rickair- Do you fly in or around SoCal?