If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Garmin 430 VOR reception
Hi!
I have a SL30 and a GNS 430 in my plane. They use the same antenna via a splitter. When I dial in the same VOR in both units the SL30 catches up the radials always between 20 and 50 nautical miles earlier than the GNS 430! (Altitude about 3000 ft, flat area) Is this normal? What is your experience? How far away do you have a reception of a VOR with your GNS 430? Fly safe! Maik |
#2
|
|||
|
|||
I can't speak for the GNS 430, but the SL30 has UNBELIEVEABLE signal
processing capability. I can track a good VOR well over 100 miles, and I've got a mediocre cats whisker antenna mounted on my tail. I'm told the SL30 uses digital signal processing; I don't know what the GNS 430 uses. In short, I'm not at all surprised by your experience. Rich Maik wrote: Hi! I have a SL30 and a GNS 430 in my plane. They use the same antenna via a splitter. When I dial in the same VOR in both units the SL30 catches up the radials always between 20 and 50 nautical miles earlier than the GNS 430! (Altitude about 3000 ft, flat area) Is this normal? What is your experience? How far away do you have a reception of a VOR with your GNS 430? Fly safe! Maik |
#3
|
|||
|
|||
It would seem that UPS-AT technology is significantly better than Garmin's.
Rich wrote: I can't speak for the GNS 430, but the SL30 has UNBELIEVEABLE signal processing capability. I can track a good VOR well over 100 miles, and I've got a mediocre cats whisker antenna mounted on my tail. I'm told the SL30 uses digital signal processing; I don't know what the GNS 430 uses. In short, I'm not at all surprised by your experience. Rich Maik wrote: Hi! I have a SL30 and a GNS 430 in my plane. They use the same antenna via a splitter. When I dial in the same VOR in both units the SL30 catches up the radials always between 20 and 50 nautical miles earlier than the GNS 430! (Altitude about 3000 ft, flat area) Is this normal? What is your experience? How far away do you have a reception of a VOR with your GNS 430? Fly safe! Maik |
#4
|
|||
|
|||
On 29-Sep-2004, Rich wrote: I can't speak for the GNS 430, but the SL30 has UNBELIEVEABLE signal processing capability. I can track a good VOR well over 100 miles, and I've got a mediocre cats whisker antenna mounted on my tail. I'm told the SL30 uses digital signal processing; I don't know what the GNS 430 uses. In short, I'm not at all surprised by your experience. VOR reception range is dominantly determined by line-of-sight. However, in marginal situations (i.e. the station is just over the horizon) receiver quality and/or antenna cable loss can make a significant difference. I do not know if he VOR processing system in the GNS 430 is similar to the one used in the SL30, however a simpler explanation for the difference could be different RF losses in the cables from the splitter to the receiver. By the way, a VOR test system could quantify the sensitivity difference very quickly with a simple over-the-air test. -- -Elliott Drucker |
#5
|
|||
|
|||
The VOR signal out of the receiver is a 9960Hz sine wave that is AM
modulated at 30Hz and FM modulated at 30Hz. The phase difference between the AM and FM signals is the bearing to the station. Outside of the standard service volume of a VOR, this signal starts to get quite noisy. This makes domodulating the AM and FM components more difficult as the signal to noise ratio degrades. The quality of the filtering of the 30Hz and 9960Hz bandpass filters (or equivalent digital bandpass filters in a DSP) determines how far out you can accurately receive the station. Apparently the SL30 does a better job of filtering out the noise than the GNS430. Dean Maik wrote in message ... Hi! I have a SL30 and a GNS 430 in my plane. They use the same antenna via a splitter. When I dial in the same VOR in both units the SL30 catches up the radials always between 20 and 50 nautical miles earlier than the GNS 430! (Altitude about 3000 ft, flat area) Is this normal? What is your experience? How far away do you have a reception of a VOR with your GNS 430? Fly safe! Maik |
#6
|
|||
|
|||
I wouldn't be satisfied with the answer that one unit is more sensitive or
has better demod until I knew that the splitter, connectors, and coax were all in good shape. Then I'd wonder if the Garmin was detuned somehow instead of jumping right on poor or lesser design. Dan |
#7
|
|||
|
|||
All he has to due is swap coax cables between the units to find out...
"DP" wrote in message news:kuK6d.69$lf2.60@trnddc09... I wouldn't be satisfied with the answer that one unit is more sensitive or has better demod until I knew that the splitter, connectors, and coax were all in good shape. Then I'd wonder if the Garmin was detuned somehow instead of jumping right on poor or lesser design. Dan |
#8
|
|||
|
|||
Maik wrote in message ...
Hi! I have a SL30 and a GNS 430 in my plane. They use the same antenna via a splitter. When I dial in the same VOR in both units the SL30 catches up the radials always between 20 and 50 nautical miles earlier than the GNS 430! (Altitude about 3000 ft, flat area) Is this normal? What is your experience? How far away do you have a reception of a VOR with your GNS 430? Fly safe! Maik You may want to try swapping the coax leads at the splitter. That would quickly tell you if you had any splitter / connection / coax issues. Jack |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Garmin 296 worth the money? | Terry | Owning | 15 | June 22nd 04 09:03 AM |
Garmin Specials ADV | Michael Coates | Home Built | 0 | March 18th 04 12:24 AM |
Garmin DME arc weidnress | Dave Touretzky | Instrument Flight Rules | 5 | October 2nd 03 02:04 AM |
"Stand Alone" Boxes (Garmin 430) - Sole means of navigation - legal? | Richard | Instrument Flight Rules | 20 | September 30th 03 02:13 PM |
Garmin 430/530 Questions | Steve Coleman | Instrument Flight Rules | 16 | August 28th 03 09:04 PM |