Channel Width

But they now must meet the latest standards for bandwidth,
etc. Many of the old Narco, ARC and other radios cannot be
used.



"RST Engineering" wrote in message
...
| You can buy legal 1, 6, 90, and 360 channel radios.
|
| Jim
|
|
| "Roy Smith" wrote in message
| ...
| "Jim Macklin"
wrote:
| Going from 100 KHz to 25 KHz quadrupled the number of
channels. Forty
| years ago, 90 comm. channels and 50 VOR was common and
now, Comm.
| channels are in the thousands.
|
| So why are we still stuck with almost every uncontrolled
field in
| existence
| having their CTAFs crammed into just 2 or 3 freqs? How
many years is it
| since you could even buy a radio that didn't have 25 khz
spacing?
|
|

RST Engineering wrote:
You can buy legal 1, 6, 90, and 360 channel radios.

Agreed.. But who sells new ones nowadays that are ok to transmit with?
(that are only 1, 6, 90 and 360 channels, respectively)

Didn't see the "new" word in the OP. I s'pose I could round up enough parts
to make a 541 (single channel) and 542 (6 channel) and if I dug deep enough
into the obsolete parts bin I might even be able to do a 571 (360 channel).
The type certificate approval never runs out, just like a pilot certificate.

Jim



"Dave S" wrote in message
ink.net...
RST Engineering wrote:
You can buy legal 1, 6, 90, and 360 channel radios.

Agreed.. But who sells new ones nowadays that are ok to transmit with?
(that are only 1, 6, 90 and 360 channels, respectively)

thejim wrote:
This question relates to VOR.
I read that when VORs where increasing continuously in number in the
beginning of their "career" there was a lack of available frequencies.

So they increased the frequencies by increasing the number of chanels
and they did that by decreasing the chanel width e.x from 100kH width
to 50kH width.

Can you explain me please how this(meaning increase of channels by
reducing their width) will increase the number of available frequencies
for the increasing number of VOR stations.


Older radios, with older technology, were capable of transmitting on
their tuned frequency, but the signal spilled over onto neighboring
frequencies.. this dictated fairly wide channel spacing... to prevent
interference...

Newer radios with newer innards are capable of much more precise
transmission, with much less "width" to the spillover. By mandating
everyone use the newer radios to transmit, you in effect open up more
"channels" in between the existing ones that you can use.

Right now we have (on com frequencies) 25 khz spacing between designated
frequencies.. Many of the new radios being sold are already capable of
operating at the NEXT spacing designation, somewhere on the order of 8.3
khz, which will triple the existing amount of aviation band com freqs
(from 760 to over 2000).

By simply halving the nav frequency spacing, you can double the number
of nav frequencies available. Navs are currently at 50 khz spacing, if I
remember correctly.

Dave